The document summarizes 15 clinical trials comparing the Diaton transpalpebral tonometer to other tonometers. Key findings include:
1) A study of LASIK patients found the Diaton tonometer was not influenced by corneal thickness changes after surgery, unlike Goldmann and air pulse tonometers.
2) A study of Boston Type 1 keratoprosthesis patients found transpalpebral and transcleral Diaton measurements agreed closely with tactile estimates, unlike air pulse tonometry readings.
3) A study of keratoconus patients found Diaton readings were less influenced by thinning corneas and yielded pressures closer to actual values compared to Goldmann and air pulse tonometry.
The age, creatinine, and ejection fraction score to riskVishwanath Hesarur
CTOs are the most challenging coronary lesions for PCI, with a success rate ranging from 55% to 100%.
Successful PCI of CTOs is associated with improved long-term clinical outcomes compared with conservative management.
Nevertheless, the clinical outcome even after successful recanalization remains worse compared with patients with non-CTO stenoses who underwent PCI.
The document describes a study comparing instantaneous wave-free ratio (iFR) to fractional flow reserve (FFR) for assessing coronary stenosis.
The study involved 2492 patients with intermediate coronary lesions randomized 1:1 to iFR-guided or FFR-guided percutaneous coronary intervention (PCI). The primary endpoint was a composite of death, myocardial infarction, or urgent revascularization at 30 days, 1 year, and 5 years.
Results showed non-inferiority of iFR-guided PCI compared to FFR-guided PCI for the primary endpoint. An iFR cutoff of 0.89 provided comparable classification of lesions to an FFR cutoff of 0.80. iFR assessment does not require induction
Este documento describe las funciones del sistema operativo, los insumos y el equipo de cómputo. Explica los tipos de sistemas operativos, sus funciones y componentes. También describe los recursos que administra el sistema operativo como la memoria, CPU, entrada y salida de dispositivos, interfaz de usuario, y control de procesos. Por último, detalla los servicios que ofrece el sistema operativo Windows y cómo acceder a ellos.
Ansell Hyd-Tuf 52-502 Gloves Description
The Ansell Hyd-Tuf 52-502 glove has a high performance impregnated coating on a jersey lining and supersedes the classic leather general purpose glove in medium-duty applications. The Hyd-Tuf 52-502 gloves have more flexibility, comfort and far more hard-wearing. Ansell 52-502 glove offers superior resistance to abrasion and good protection against snags, cuts and puncture whilst also effectively repelling grease, oil and dirt.
Ansell Hyd-Tuf 52-502 Gloves fit comfortably and safely cushions the hands. Hyd-Tuf gloves keeps hands dry by absorbing perspiration and gives excellent dry grip.
Ansell Gloves Hand Protection for Oil & Gas
Ansell Hyd-Tuf gloves are antistatic according to EN1149 and are fit for special purpose.
Ansell Hyd-Tuf 52-502 Gloves Specifications
Construction: Cut & Sewn
Ansell Hyd-Tuf 52-502 Hand Protection GlovesLiner Material: Cotton Jersey
Coating Material: Nitrile
Finishing: Fully Impregnated
Cuff Style: Knitwrist
Hyd-Tuf 52-502 Colour: Brown
EN Size: 9 & 10
Length (mm): 290
Packaging: 12 Pairs in a bag; 12 Bags in a carton
Ansell Hyd-Tuf 52-502 Gloves Applications
Assembling metal parts and components
Assembly and finishing
Gas and electricity supply
General purpose - offshore
Handling light castings and metal parts
Injection moulding, handling cold components
Maintenance
Mining
Operating machinery
Warehouse work
Ansell Hyd-Tuf 52-502 Gloves EN Test Data
Abrasion resistance: Performance level 3
Blade cut resistance: Performance level 1
Tear resistance: Performance level 1
Puncture resistance: Performance level 1
CRISIL is a global analytical company that provides ratings, research, and risk advisory services. The letter acknowledges Saquib Mohammad's participation in CRISIL's 13th annual Young Thought Leader competition, which promotes excellence in thought leadership among business schools. The competition received fresh insights from young individuals like Saquib, making it a unique competition.
Este documento presenta un problema matemático sobre el cálculo de superficies encerradas por curvas y el eje x usando integrales definidas. El problema propone construir figuras geométricas como una elipse y una circunferencia y calcular aproximadamente las superficies encerradas. El documento también describe la distribución de la clase, posibles estrategias de los estudiantes, y momentos de la clase para abordar el problema colaborativamente usando software geométrico.
The age, creatinine, and ejection fraction score to riskVishwanath Hesarur
CTOs are the most challenging coronary lesions for PCI, with a success rate ranging from 55% to 100%.
Successful PCI of CTOs is associated with improved long-term clinical outcomes compared with conservative management.
Nevertheless, the clinical outcome even after successful recanalization remains worse compared with patients with non-CTO stenoses who underwent PCI.
The document describes a study comparing instantaneous wave-free ratio (iFR) to fractional flow reserve (FFR) for assessing coronary stenosis.
The study involved 2492 patients with intermediate coronary lesions randomized 1:1 to iFR-guided or FFR-guided percutaneous coronary intervention (PCI). The primary endpoint was a composite of death, myocardial infarction, or urgent revascularization at 30 days, 1 year, and 5 years.
Results showed non-inferiority of iFR-guided PCI compared to FFR-guided PCI for the primary endpoint. An iFR cutoff of 0.89 provided comparable classification of lesions to an FFR cutoff of 0.80. iFR assessment does not require induction
Este documento describe las funciones del sistema operativo, los insumos y el equipo de cómputo. Explica los tipos de sistemas operativos, sus funciones y componentes. También describe los recursos que administra el sistema operativo como la memoria, CPU, entrada y salida de dispositivos, interfaz de usuario, y control de procesos. Por último, detalla los servicios que ofrece el sistema operativo Windows y cómo acceder a ellos.
Ansell Hyd-Tuf 52-502 Gloves Description
The Ansell Hyd-Tuf 52-502 glove has a high performance impregnated coating on a jersey lining and supersedes the classic leather general purpose glove in medium-duty applications. The Hyd-Tuf 52-502 gloves have more flexibility, comfort and far more hard-wearing. Ansell 52-502 glove offers superior resistance to abrasion and good protection against snags, cuts and puncture whilst also effectively repelling grease, oil and dirt.
Ansell Hyd-Tuf 52-502 Gloves fit comfortably and safely cushions the hands. Hyd-Tuf gloves keeps hands dry by absorbing perspiration and gives excellent dry grip.
Ansell Gloves Hand Protection for Oil & Gas
Ansell Hyd-Tuf gloves are antistatic according to EN1149 and are fit for special purpose.
Ansell Hyd-Tuf 52-502 Gloves Specifications
Construction: Cut & Sewn
Ansell Hyd-Tuf 52-502 Hand Protection GlovesLiner Material: Cotton Jersey
Coating Material: Nitrile
Finishing: Fully Impregnated
Cuff Style: Knitwrist
Hyd-Tuf 52-502 Colour: Brown
EN Size: 9 & 10
Length (mm): 290
Packaging: 12 Pairs in a bag; 12 Bags in a carton
Ansell Hyd-Tuf 52-502 Gloves Applications
Assembling metal parts and components
Assembly and finishing
Gas and electricity supply
General purpose - offshore
Handling light castings and metal parts
Injection moulding, handling cold components
Maintenance
Mining
Operating machinery
Warehouse work
Ansell Hyd-Tuf 52-502 Gloves EN Test Data
Abrasion resistance: Performance level 3
Blade cut resistance: Performance level 1
Tear resistance: Performance level 1
Puncture resistance: Performance level 1
CRISIL is a global analytical company that provides ratings, research, and risk advisory services. The letter acknowledges Saquib Mohammad's participation in CRISIL's 13th annual Young Thought Leader competition, which promotes excellence in thought leadership among business schools. The competition received fresh insights from young individuals like Saquib, making it a unique competition.
Este documento presenta un problema matemático sobre el cálculo de superficies encerradas por curvas y el eje x usando integrales definidas. El problema propone construir figuras geométricas como una elipse y una circunferencia y calcular aproximadamente las superficies encerradas. El documento también describe la distribución de la clase, posibles estrategias de los estudiantes, y momentos de la clase para abordar el problema colaborativamente usando software geométrico.
The document discusses the use of Pinterest to raise awareness about children's obesity. It describes Pinterest as a social media site where users can pin pictures, videos, and articles to boards on various topics. The author created an account with 11 boards on topics like healthy foods, activities, and weight loss tips. The boards contain over 300 pins aimed at providing parents with ideas to help their kids eat healthy and be more active to fight obesity.
ENFOQUE COMUNICATIVO TEXTUAL III CICLO 2015Mariluz Tacora
El documento describe el enfoque comunicativo textual, explicando que (1) se enfoca en el uso del lenguaje en situaciones comunicativas reales para cumplir propósitos, (2) considera al texto como la unidad fundamental de comunicación, y (3) abarca tanto la perspectiva cognitiva como la sociocultural al desarrollar competencias comunicativas en los estudiantes.
Este documento describe las funciones HOY(), DÍA(), MES(), AÑO() y FECHANUMERO() en Excel para trabajar con fechas. HOY() devuelve el número de serie de la fecha actual. DÍA(), MES() y AÑO() extraen diferentes partes de una fecha dada su número de serie. FECHANUMERO() convierte una fecha de texto a número de serie. También incluye ejemplos de una tabla con datos de ventas deportivas con fechas.
Speciale Capodanno a Malta! Tutto Incluso!!!Viaggiovunque
Manca pochissimo alla festa più attesa dell'anno!
Cogli al volo i nostri ultimi posti a prezzi mai visti per festeggiare in vacanza il tuo Capodanno 2014!
Capodanno a Malta a 279,00€!!!!
Quanzhou Teamup Electronics Co., Ltd is a professional handheld Two-way Radio (Walkie Talkie) Manufacturer in China. Any interested in, please feel free to contact us to get more information.
This document appears to contain a version number with no other context provided. It consists of the string "1.0.231.0" which seems to indicate a primary version of 1, secondary version of 0, tertiary version of 231 and quaternary version of 0, suggesting it relates to the versioning of some system, product or component. However, without more context around what is being described, the purpose and meaning of this version number cannot be determined from the limited information provided.
La corteza terrestre está dividida en 30 placas tectónicas que se empujan y mueven entre sí, causando la deriva continental y fenómenos como terremotos y erupciones volcánicas, ya que la mayoría de los volcanes se encuentran donde las placas se mueven o chocan.
Eye Pressure After Lasik Surgery - Study, BiCOM Inc.DevelopAll
The document discusses a study that evaluated the use of transpalpebral scleral tonometry for measuring intraocular pressure (IOP) in patients with refractive errors both before and after keratophotorefractive surgery. The study found that transpalpebral tonometry provided IOP measurements that more closely approximated modified applanation tonometry readings which accounted for corneal thickness, as compared to standard applanation tonometry. Transpalpebral tonometry also showed smaller differences in pre-operative and post-operative IOP measurements compared to standard applanation tonometry, demonstrating its advantage in avoiding the effects of corneal changes from refractive surgery on IOP readings.
This study compared intraocular pressure (IOP) measurements from the Diaton transpalpebral tonometer to the TonoPen applanation tonometer in 74 eyes of 38 patients. The average IOP was 16.24 mmHg with the Diaton and 16.37 mmHg with the TonoPen. 81% of measurements were within 2 mmHg of each other. There was no statistically significant difference in IOP values between the two devices. The Diaton measurements correlated well with TonoPen measurements and did not require anesthetic drops or contact with the cornea.
Tonometry, or the measurement of intraocular pressure (IOP), has evolved significantly over time. The Goldmann applanation tonometer, introduced in the 1950s, was long considered the gold standard but does not account for factors like corneal thickness and stiffness. Newer devices use air puffs, indentation, or advanced cameras to record the cornea's response and provide a more accurate IOP reading. Specifically, the Corvis ST uses a high-speed camera to measure hysteresis and account for biomechanical properties, allowing for a truly personalized IOP assessment. As technology advances, tonometry continues to improve our understanding and treatment of glaucoma.
This study compared intraocular pressure (IOP) measurements from the Diaton transpalpebral tonometer to the TonoPen applanation tonometer in 74 eyes of 38 patients. The mean IOP was similar between the two devices. 81% of measurements were within 2 mmHg of each other. There was no statistically significant difference in IOP values between the Diaton and TonoPen. The Diaton provides a clinically useful alternative to applanation tonometry as it does not require corneal contact or anesthesia.
Comparison Of Diaton Tonometry And Non Contact TonometryDevelopAll
The purpose of this study was to compare
Intraocular Pressure (IOP) measurements
obtained with the Diaton Tonometer (DT) and
Non Contact Pneumotonometer (PT) in
normal eyes. The effect of central corneal
thickness (CCT) on IOP measurement using
both the tonometers was also evaluated.
This study compared measurements of intraocular pressure (IOP) obtained using the Diaton transpalpebral tonometer versus the gold standard Goldmann applanation tonometer. The study retrospectively reviewed IOP measurements in 64 eyes of 32 patients, finding a mean IOP of 15.09 mm Hg with Goldmann and 15.70 mm Hg with Diaton, with no statistically significant difference. The mean variation in IOP between the two methods was 1.74 mm Hg, and 83% of measurements were within 2 mm Hg of each other. The study concluded that IOP measurements with the Diaton tonometer correlate well with those from Goldmann applanation tonometry.
Diaton tonometer vs. Goldmann applanation clinical comparisonDevelopAll
The document compares measurements of intraocular pressure (IOP) taken with the Diaton transpalpebral tonometer versus the gold standard Goldmann applanation tonometer. A retrospective chart review found the mean IOP was similar between the two methods and 83% of measurements were within 2 mm Hg of each other. The Diaton tonometer showed good agreement with Goldmann applanation and may be a clinically useful alternative for measuring IOP in routine eye exams as it is non-contact and requires no anesthesia or sterilization.
The document discusses various techniques used to measure intraocular pressure (IOP), including:
1) Digital tonometry which involves applying gentle pressure to the eyeball with a finger, though it is subjective.
2) Indentation tonometry like the Schiotz tonometer which measures corneal indentation from a known weight on a plunger, though readings require correction for ocular rigidity.
3) Applanation tonometry like the Goldmann tonometer which flattens a small corneal area to balance internal and external pressure, providing a more accurate IOP reading less influenced by ocular rigidity factors.
This document summarizes the history and principles of tonometry. It discusses how William Bowman first used digital tonometry in 1826 to estimate eye tension. It then describes the development of early indentation and applanation tonometers from the 1860s onwards, culminating in Goldmann's constant-pressure applanation tonometer from 1954. The principles of indentation, applanation, and modified Imbert-Fick's law are explained. Common tonometry devices like Schiotz, Perkins, and Goldmann are characterized along with their procedures. Potential sources of error are also outlined.
Intraocular pressure
Intraocular pressure (IOP) is the fluid pressure inside the eye. . IOP is an important aspect in the evaluation of patients at risk of glaucoma.
Tonometry is the method eye care professionals use to determine this. Most tonometers are calibrated to measure pressure in millimeters of mercury (mmHg).
Physiology
• Intraocular pressure is determined by the production and drainage of aqueous humour by the ciliary body and its drainage via the trabecular meshwork and uveoscleral outflow. The reason for this is because the vitreous humour in the posterior segment has a relatively fixed volume and thus does not affect intraocular pressure regulation.
• The intraocular pressure (IOP) of the eye is determined by the balance between the amount of aqueous humor - that the eye makes and the ease with which it leaves the eye.
The Goldmann equation states:
Po = (F/C) + Pv
Po is the IOP in millimeters of mercury (mmHg),
F is the rate of aqueous formation,
C is the facility of outflow,
Pv is the episcleral venous pressure.
Measurements
Intraocular pressure is measured with a tonometer as part of a comprehensive eye examination.
Types of Tonometry
1. Applanation tonometry
Applanation tonometry is based on the Imbert-Fick principle, which states that;
‘’The pressure inside an ideal dry, thin-walled sphere equals the force necessary to flatten its surface divided by the area of flattening’’
P = F/A
where P = pressure, F = force and A = area
In applanation tonometry, the cornea is flattened and the IOP is determined by varying the applanating force or the area flattened.
Goldmann and Perkins applanation tonometry
Equipment
• Tonometer, either Goldmann (used on slit lamps) or Perkins (hand-held)
• Applanation prism
• Local anaesthetic drops
• Fluorescein strips
• Clean cotton wool or gauze swabs.
Method
• The Goldmann applanation tonometer measures the force necessary to flatten an area of the cornea of 3.06mm diameter. At this diameter, the resistance of the cornea to flattening is counterbalanced by the capillary attraction of the tear film meniscus for the tonometer head.
• The IOP (in mm Hg) equals the flattening force (in grams) multiplied by 10. Fluorescein dye is placed in the patient’s eye to highlight the tear film. A split-image prism is used such that the image of the tear meniscus is divided into a superior and inferior arc. The intraocular pressure is taken when these arcs are aligned such that their inner margins just touch.
• Applanation tonometry measurements are affected by the central corneal thickness (CCT). When Goldmann designed his tonometer, he estimated an average corneal thickness of 520 microns to cancel the opposing forces of surface tension and corneal rigidity to allow indentation. It is now known that a wide variation exists in corneal thickness among individuals. Thicker CCT may give an artificially high IOP measurement, whereas thinner CCT can give an arti
This document discusses various methods of measuring intraocular pressure (IOP), including direct cannulation and indirect tonometry techniques. It provides details on Schiotz indentation tonometry, Goldmann applanation tonometry, pneumatic applanation tonometry, and tonography. It also mentions factors that can affect IOP measurements such as ocular anomalies, patient behavior, instrumentation errors, and operation errors.
This randomized crossover study compared end-tidal oxygen (ETo2) levels during preoxygenation with a bag valve mask (BVM) alone and with supplemental nasal cannula (NC) oxygen at different flow rates. Healthy volunteers underwent 3 minutes of preoxygenation with a BVM alone or a BVM with NC at 0, 5, 10, or 15 liters per minute. The primary outcome was ETo2 after 3 minutes of preoxygenation. NC flows of 0 and 5 L/min resulted in significantly lower ETo2 levels compared to the other groups. There were no differences in ETo2 between the BVM alone, NC 10 L/min, and NC 15 L/
This document provides definitions and information about various types of tonometry. It begins by defining intraocular pressure, normal IOP, and factors that influence IOP. It then discusses the history of tonometry and ideal characteristics of a tonometer. The document outlines different types of tonometry including indentation, applanation, and non-contact tonometry. It provides details on Goldmann applanation tonometry, including the principle behind it and how to perform the procedure. In closing, it discusses calibration, sterilization, and accuracy considerations for tonometry.
The document discusses the use of Pinterest to raise awareness about children's obesity. It describes Pinterest as a social media site where users can pin pictures, videos, and articles to boards on various topics. The author created an account with 11 boards on topics like healthy foods, activities, and weight loss tips. The boards contain over 300 pins aimed at providing parents with ideas to help their kids eat healthy and be more active to fight obesity.
ENFOQUE COMUNICATIVO TEXTUAL III CICLO 2015Mariluz Tacora
El documento describe el enfoque comunicativo textual, explicando que (1) se enfoca en el uso del lenguaje en situaciones comunicativas reales para cumplir propósitos, (2) considera al texto como la unidad fundamental de comunicación, y (3) abarca tanto la perspectiva cognitiva como la sociocultural al desarrollar competencias comunicativas en los estudiantes.
Este documento describe las funciones HOY(), DÍA(), MES(), AÑO() y FECHANUMERO() en Excel para trabajar con fechas. HOY() devuelve el número de serie de la fecha actual. DÍA(), MES() y AÑO() extraen diferentes partes de una fecha dada su número de serie. FECHANUMERO() convierte una fecha de texto a número de serie. También incluye ejemplos de una tabla con datos de ventas deportivas con fechas.
Speciale Capodanno a Malta! Tutto Incluso!!!Viaggiovunque
Manca pochissimo alla festa più attesa dell'anno!
Cogli al volo i nostri ultimi posti a prezzi mai visti per festeggiare in vacanza il tuo Capodanno 2014!
Capodanno a Malta a 279,00€!!!!
Quanzhou Teamup Electronics Co., Ltd is a professional handheld Two-way Radio (Walkie Talkie) Manufacturer in China. Any interested in, please feel free to contact us to get more information.
This document appears to contain a version number with no other context provided. It consists of the string "1.0.231.0" which seems to indicate a primary version of 1, secondary version of 0, tertiary version of 231 and quaternary version of 0, suggesting it relates to the versioning of some system, product or component. However, without more context around what is being described, the purpose and meaning of this version number cannot be determined from the limited information provided.
La corteza terrestre está dividida en 30 placas tectónicas que se empujan y mueven entre sí, causando la deriva continental y fenómenos como terremotos y erupciones volcánicas, ya que la mayoría de los volcanes se encuentran donde las placas se mueven o chocan.
Eye Pressure After Lasik Surgery - Study, BiCOM Inc.DevelopAll
The document discusses a study that evaluated the use of transpalpebral scleral tonometry for measuring intraocular pressure (IOP) in patients with refractive errors both before and after keratophotorefractive surgery. The study found that transpalpebral tonometry provided IOP measurements that more closely approximated modified applanation tonometry readings which accounted for corneal thickness, as compared to standard applanation tonometry. Transpalpebral tonometry also showed smaller differences in pre-operative and post-operative IOP measurements compared to standard applanation tonometry, demonstrating its advantage in avoiding the effects of corneal changes from refractive surgery on IOP readings.
This study compared intraocular pressure (IOP) measurements from the Diaton transpalpebral tonometer to the TonoPen applanation tonometer in 74 eyes of 38 patients. The average IOP was 16.24 mmHg with the Diaton and 16.37 mmHg with the TonoPen. 81% of measurements were within 2 mmHg of each other. There was no statistically significant difference in IOP values between the two devices. The Diaton measurements correlated well with TonoPen measurements and did not require anesthetic drops or contact with the cornea.
Tonometry, or the measurement of intraocular pressure (IOP), has evolved significantly over time. The Goldmann applanation tonometer, introduced in the 1950s, was long considered the gold standard but does not account for factors like corneal thickness and stiffness. Newer devices use air puffs, indentation, or advanced cameras to record the cornea's response and provide a more accurate IOP reading. Specifically, the Corvis ST uses a high-speed camera to measure hysteresis and account for biomechanical properties, allowing for a truly personalized IOP assessment. As technology advances, tonometry continues to improve our understanding and treatment of glaucoma.
This study compared intraocular pressure (IOP) measurements from the Diaton transpalpebral tonometer to the TonoPen applanation tonometer in 74 eyes of 38 patients. The mean IOP was similar between the two devices. 81% of measurements were within 2 mmHg of each other. There was no statistically significant difference in IOP values between the Diaton and TonoPen. The Diaton provides a clinically useful alternative to applanation tonometry as it does not require corneal contact or anesthesia.
Comparison Of Diaton Tonometry And Non Contact TonometryDevelopAll
The purpose of this study was to compare
Intraocular Pressure (IOP) measurements
obtained with the Diaton Tonometer (DT) and
Non Contact Pneumotonometer (PT) in
normal eyes. The effect of central corneal
thickness (CCT) on IOP measurement using
both the tonometers was also evaluated.
This study compared measurements of intraocular pressure (IOP) obtained using the Diaton transpalpebral tonometer versus the gold standard Goldmann applanation tonometer. The study retrospectively reviewed IOP measurements in 64 eyes of 32 patients, finding a mean IOP of 15.09 mm Hg with Goldmann and 15.70 mm Hg with Diaton, with no statistically significant difference. The mean variation in IOP between the two methods was 1.74 mm Hg, and 83% of measurements were within 2 mm Hg of each other. The study concluded that IOP measurements with the Diaton tonometer correlate well with those from Goldmann applanation tonometry.
Diaton tonometer vs. Goldmann applanation clinical comparisonDevelopAll
The document compares measurements of intraocular pressure (IOP) taken with the Diaton transpalpebral tonometer versus the gold standard Goldmann applanation tonometer. A retrospective chart review found the mean IOP was similar between the two methods and 83% of measurements were within 2 mm Hg of each other. The Diaton tonometer showed good agreement with Goldmann applanation and may be a clinically useful alternative for measuring IOP in routine eye exams as it is non-contact and requires no anesthesia or sterilization.
The document discusses various techniques used to measure intraocular pressure (IOP), including:
1) Digital tonometry which involves applying gentle pressure to the eyeball with a finger, though it is subjective.
2) Indentation tonometry like the Schiotz tonometer which measures corneal indentation from a known weight on a plunger, though readings require correction for ocular rigidity.
3) Applanation tonometry like the Goldmann tonometer which flattens a small corneal area to balance internal and external pressure, providing a more accurate IOP reading less influenced by ocular rigidity factors.
This document summarizes the history and principles of tonometry. It discusses how William Bowman first used digital tonometry in 1826 to estimate eye tension. It then describes the development of early indentation and applanation tonometers from the 1860s onwards, culminating in Goldmann's constant-pressure applanation tonometer from 1954. The principles of indentation, applanation, and modified Imbert-Fick's law are explained. Common tonometry devices like Schiotz, Perkins, and Goldmann are characterized along with their procedures. Potential sources of error are also outlined.
Intraocular pressure
Intraocular pressure (IOP) is the fluid pressure inside the eye. . IOP is an important aspect in the evaluation of patients at risk of glaucoma.
Tonometry is the method eye care professionals use to determine this. Most tonometers are calibrated to measure pressure in millimeters of mercury (mmHg).
Physiology
• Intraocular pressure is determined by the production and drainage of aqueous humour by the ciliary body and its drainage via the trabecular meshwork and uveoscleral outflow. The reason for this is because the vitreous humour in the posterior segment has a relatively fixed volume and thus does not affect intraocular pressure regulation.
• The intraocular pressure (IOP) of the eye is determined by the balance between the amount of aqueous humor - that the eye makes and the ease with which it leaves the eye.
The Goldmann equation states:
Po = (F/C) + Pv
Po is the IOP in millimeters of mercury (mmHg),
F is the rate of aqueous formation,
C is the facility of outflow,
Pv is the episcleral venous pressure.
Measurements
Intraocular pressure is measured with a tonometer as part of a comprehensive eye examination.
Types of Tonometry
1. Applanation tonometry
Applanation tonometry is based on the Imbert-Fick principle, which states that;
‘’The pressure inside an ideal dry, thin-walled sphere equals the force necessary to flatten its surface divided by the area of flattening’’
P = F/A
where P = pressure, F = force and A = area
In applanation tonometry, the cornea is flattened and the IOP is determined by varying the applanating force or the area flattened.
Goldmann and Perkins applanation tonometry
Equipment
• Tonometer, either Goldmann (used on slit lamps) or Perkins (hand-held)
• Applanation prism
• Local anaesthetic drops
• Fluorescein strips
• Clean cotton wool or gauze swabs.
Method
• The Goldmann applanation tonometer measures the force necessary to flatten an area of the cornea of 3.06mm diameter. At this diameter, the resistance of the cornea to flattening is counterbalanced by the capillary attraction of the tear film meniscus for the tonometer head.
• The IOP (in mm Hg) equals the flattening force (in grams) multiplied by 10. Fluorescein dye is placed in the patient’s eye to highlight the tear film. A split-image prism is used such that the image of the tear meniscus is divided into a superior and inferior arc. The intraocular pressure is taken when these arcs are aligned such that their inner margins just touch.
• Applanation tonometry measurements are affected by the central corneal thickness (CCT). When Goldmann designed his tonometer, he estimated an average corneal thickness of 520 microns to cancel the opposing forces of surface tension and corneal rigidity to allow indentation. It is now known that a wide variation exists in corneal thickness among individuals. Thicker CCT may give an artificially high IOP measurement, whereas thinner CCT can give an arti
This document discusses various methods of measuring intraocular pressure (IOP), including direct cannulation and indirect tonometry techniques. It provides details on Schiotz indentation tonometry, Goldmann applanation tonometry, pneumatic applanation tonometry, and tonography. It also mentions factors that can affect IOP measurements such as ocular anomalies, patient behavior, instrumentation errors, and operation errors.
This randomized crossover study compared end-tidal oxygen (ETo2) levels during preoxygenation with a bag valve mask (BVM) alone and with supplemental nasal cannula (NC) oxygen at different flow rates. Healthy volunteers underwent 3 minutes of preoxygenation with a BVM alone or a BVM with NC at 0, 5, 10, or 15 liters per minute. The primary outcome was ETo2 after 3 minutes of preoxygenation. NC flows of 0 and 5 L/min resulted in significantly lower ETo2 levels compared to the other groups. There were no differences in ETo2 between the BVM alone, NC 10 L/min, and NC 15 L/
This document provides definitions and information about various types of tonometry. It begins by defining intraocular pressure, normal IOP, and factors that influence IOP. It then discusses the history of tonometry and ideal characteristics of a tonometer. The document outlines different types of tonometry including indentation, applanation, and non-contact tonometry. It provides details on Goldmann applanation tonometry, including the principle behind it and how to perform the procedure. In closing, it discusses calibration, sterilization, and accuracy considerations for tonometry.
Presentation Summary
Unique Diaton Tonometer
Awards, New Technology Recognition
Typical uses of the Diaton Tonometer
Benefits / Necessity of Diaton
Advantages of the Diaton Tonometer
Results of comparative analysis
Clinical Study 1: accuracy correlating with GAT; safety and operating speed of NCT
Clinical Study 2: Primary Care Physician and Patient Experience With Non-corneal Tonometer Glaucoma Screening
Publications (articles from Ophthalmology and Optometry Times)
Diaton Posters / Clinical Studies
Brochures / Catalogue
Diaton is delivered with: appearance of the tonometer / case
Contact information
SUMMARY
www.TonometerDiaton.com
This document discusses various methods for measuring intraocular pressure (IOP), including direct and indirect techniques. It describes manometry and tonometry in detail. For tonometry, it covers indentation tonometry using the Schiotz tonometer, various types of applanation tonometry including Goldmann, Perkins, pneumatic, and non-contact tonometers. It discusses the principles, techniques, advantages, limitations and sources of error for different tonometry methods. Newer tonometers like dynamic contour and ocular response analyzer are also summarized.
This study evaluated changes in aqueous humor dynamics (AHD) after selective laser trabeculoplasty (SLT) treatment for glaucoma. 31 patients underwent baseline AHD measurements including IOP, aqueous flow, outflow facility, and other parameters before and 3 months after SLT. SLT significantly lowered IOP at 9 AM and noon through an increase in outflow facility as measured by fluorophotometry and tonography. No changes in aqueous flow or other AHD parameters were observed. Higher baseline aqueous flow and lower baseline outflow facility were associated with greater IOP lowering from SLT.
Iris Publishers - journal of ophthalmology | Demystifying Role of Ultrasound ...IrisPublishers
Objectives: The aim of this study was to compare sonoelastographic findings in the retina– choroid–sclera (RCS) complex and vitreous in glaucomatous and healthy eyes.Methods: For this cross-sectional comparative study, 20 patients with primary open-angle glaucoma (POAG) and 20 healthy volunteers were recruited. Ultrasound elastography measurements were taken with a sonographic scanner of the RCS complex, anterior vitreous (AV), posterior vitreous (PV), retrobulbar fat tissue (RFT), optic disc, and optic nerve in each eye.Results: The elasticity index of the RCS complex, RFT, optic disc, optic nerve, AV, and PV were similar in both groups (p > 0.05), though the AV/PV strain ratio in the group of patients with glaucoma was significantly higher (p = 0.04).Conclusion: Glaucoma increases the AV/PV strain ratio. In providing reproducible and consistent values, the real-time elastography technique may be helpful in elucidating the mechanisms of glaucoma in some aspects.
This document discusses various techniques for measuring intraocular pressure (IOP), including manometry, digital tonometry, Schiotz tonometry, Goldmann applanation tonometry, non-contact tonometry, and Pascal's dynamic contour tonometry. It provides details on the principles, procedures, advantages, and limitations of each technique. Goldmann applanation tonometry remains the gold standard method, though newer techniques like Pascal's dynamic contour tonometry may provide a more accurate measurement by reducing the influence of corneal biomechanical properties. An ideal tonometer would accurately measure IOP, be convenient and easy to use, and not be affected by factors like corneal thickness.
Comparison of iop measurements between goldmann applanation tonometry and bal...DevelopAll
1) The document compares measurements of intraocular pressure (IOP) using Goldmann applanation tonometry and Ballistic Principle Diaton tonometry in different patient groups.
2) There was found to be a statistically significant correlation between the two tonometry methods. 83.11% of measurements had an absolute difference of 2mmHg or less between the two methods.
3) The Ballistic Principle Diaton tonometry can be used as an alternative to measure IOP above the eyelids for patients who have had recent eye surgeries or have conditions affecting the cornea.
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Diaton Tonometer Clinical Trials Guide
1. Diaton Tonometer Clinical Trials Guide:
A summary of 15 Clinical Comparison Trials Related to Diaton Transpalpebral
& Transscleral Tonometer vs Goldmann, Tonopen, Non-contact, Ocular
Response Analyzer, Perkins and Pascal Dynamic Contour Tonometers in
Normal, Glaucoma, Keratoconus, post LASIK and post KPro Type 1 subjects +
Reviews, Testimonials, Manuals & User Guides, Videos:
• Comparison of Intraocular Pressure before and after Laser In Situ Keratomileusis
Refractive Surgery Measured with Perkins Tonometry, Noncontact Tonometry, and
Transpalpebral Tonometry. J Ophthalmol. 2015;2015:683895. doi: 10.1155/2015/683895.
Epub 2015 Jun 8.
http://www.ncbi.nlm.nih.gov/pubmed/26167293
• Diaton Tonometer use in Boston KPro Type 1. Clinical Study from University of Illinois
at Chicago: Agreement among Transpalpebral,Transcleral and Tactile Intraocular
Pressure Measurements in Eyes with Type 1 Boston Keratoprosthesis
• Diaton tonometer in Keratoconus study: Tonometric Values of Intraocular Pressure,
Using the Goldmann Tonometer, Tonopen and Diaton Transpalpebral Tonometer in
Keratoconus
• Clinical Comparison of 3 tonometers: Comparative Agreement Among Three Methods of
Tonometry: Goldmann Applanation, Transpalpebral and Dynamic Contour
• Diaton tonometer use post LASIK: Diaton tonometer for intraocular pressure
measurements after laser in situ keratomileusis
• Additional trials/articles can be found here:
http://www.tonometerdiaton.com/index.php?do=home.Comparison_clinical_trials_Diato
n_Tonometer_Goldmann_Tonopen_Applanation_Tonometers
• Instructions Videos and step-by-step Easy to follow picture guides + Quick User Guide+
Training videos can be found here: https://tonometry.wordpress.com/2015/05/19/diaton-
2. tonometer-manual-quick-user-guide-how-to-use-diaton-tonometer-user-videos-helpful-
tips/
• The following video would give you a great overview to see how quick and easy the test
really is: https://www.youtube.com/watch?v=Mfu2leF4UYw
• Testimonial: Review of Advantages and Benefits of DIATON Tonometer by Dr
Mark Latina and Dr Emil Chynn
http://www.tonometerdiaton.com/index.php?do=home.viewNews&item=Review_Diaton
_Tonometer_by_Dr_Mark_Latina_Dr_Emil_Chynn_Advantages_Benefits
Comparison of Intraocular Pressure before and after Laser In Situ
Keratomileusis Refractive Surgery Measured with Perkins Tonometry,
3. Noncontact Tonometry, and Transpalpebral Tonometry.
http://www.ncbi.nlm.nih.gov/pubmed/26167293
Cacho I1
, Sanchez-Naves J1
, Batres L2
, Pintor J3
, Carracedo G4
.
Purpose. To compare the intraocular pressure (IOP) before and after Laser In Situ
Keratomileusis (LASIK), measured by Diaton, Perkins, and noncontact air pulse
tonometers. Methods. Fifty-seven patients with a mean age of 34.88 were scheduled for
myopia LASIK treatment. Spherical equivalent refraction (SER), corneal curvature (K),
and central corneal thickness (CCT) and superior corneal thickness (SCT) were obtained
before and after LASIK surgery. IOP values before and after surgery were measured
using Diaton, Perkins, and noncontact air pulse tonometers.
• Results. The IOP values before and after LASIK surgery using Perkins tonometer and air
tonometers were statistically significant (p < 0.05). However, no significant differences
were found (p > 0.05) for IOP values measured with Diaton tonometer. CCT decreases
significantly after surgery (p < 0.05) but no statistical differences were found in SCT (p =
0.08). Correlations between pre- and postsurgery were found for all tonometers used,
with p = 0.001 and r = 0.434 for the air pulse tonometer, p = 0.008 and r = 0.355 for
Perkins, and p < 0.001 and r = 0.637 for Diaton.
Conclusion. Transpalpebral tonometry may be useful for measuring postsurgery IOP
after myopic LASIK ablation because this technique is not influenced by the treatment.
PMID: 26167293 [PubMed] PMCID: PMC4475733
Agreement among Transpalpebral,Transcleral and Tactile Intraocular
Pressure Measurements in Eyes with Type 1 Boston Keratoprosthesis
Jessica L.Liu,Thasarat S.Vajaranant,Maria S.Cortina,Jacob T.Wilensky. Glaucoma,
University of Illinois at Chicago, Chicago, IL
Purpose: The use of keratoprostheses (KPro) to restore vision in eyes with corneal
opacities has become increasingly popular in the last five years. Intraocular pressure
(IOP) is a cardinal measurement employed in glaucoma management. This presents a
major problem since glaucoma remains a major visual limiting factor in eyes with KPro
and most forms of tonometry require an intact cornea. The purpose of this study is to
determine if transpalpebral IOP measurement can be an alternative method of measuring
IOP and yield valuable data in eyes with KPro.
Methods: We retrospectively reviewed IOP measurements in patients who had received
Type 1 Boston KPro, and their IOP were estimated by three different methods during
routine visits to their cornea! surgeon. The surgeon estimated the IOP range tactilely by
palpation of the globe. A pneumatonometer (Model 30 Classic; Mentor, BioRad, Santa
Ana, California, USA) was used to measure IOP by placing the tonometer tip on the
sclera peripherally to the contact lens in the inferotemporal quadrant. The Diaton
tonometer (BiCOM, Inc., Long Beach, NY, USA) was used to obtain values through the
upper lid in accordance with the instructions by the manufacturer. An average of two
Diaton IOP measurements was used in the analysis. Since the tactile IOP were recorded
as a range rather than a definite number, we computed the percent agreement, the
percentage of eyes in which pneumatometer or Diaton lOPs were within 2 mmHg of the
tactile IOP range. Two-tailed t-test was used to compare the mean of pneumatonometer
and Diaton IOP measurements.
Results: The analysis included 23 eyes of 20 patients. The percentage agreement was
85% between tactile range and pnematonometer lOPs, and 95% between tactile range and
Diaton lOPs. Pneumatonometer consistently yielded higher IOP values, compared to
4. Diaton (p=0.04). The overall IOP mean ± SD was 17.2 ± 6 mmHg for pneumatonometer
and 13.8± 5 mmHg for Diaton tonometer.
Conclusions: The presence of KPro did not appear to interfere with IOP with Diaton
tonometer, and Diaton tonometer yielded IOP readings that were similar to those
obtained by palpation. Scleral pneumotonometry yielded values that were consistently
higher than tactile estimates and Diaton IOP. In addition to routine IOP estimates by
palpation, transcleral and transpalpebral IOP measurements can be considered to monitor
patients with KPro.
Influence of Corneal Thickness on Tonometrical Values of Intraocular
Pressure,using the Goldmann tonometer and transpalpebral Diaton
tonometer
Federal University of São Paulo – Paulista School of Medicine Department of
Ophthalmology and Visual Sciences, Felipe Taveira Daher, MD, Augusto Paranhos
Junior,MD, PhD
Introduction:
The corneal thickness is one of the factors having influence on the tonometrical values.
Keratoconus usually evolutes with decrease of corneal thickness and, as a consequence,
the tonometrical values may underestimate the real intraocular pressure.
The transpalpebral tonometer diaton surges as an equipment that may not be influenced
by the corneal thickness and obtain tonometrical values closer to the real intraocular
pressure.
Purpose:
Compare intraocular pressure values acquired by three different tonometers
(Goldmann,Tonopen and transpalpebral diaton tonometer) in patients in two groups:
control group and keratoconus patients. And evaluate the influence of corneal thickness
on each tonometer.
Material and methods:
Patients were divided into two groups: the control group, with patients without
keratoconus or corneal thinning, and the keratoconus group, with patient with
keratoconus or corneal thinning.
Patients were than submitted to an OCT pachymetry and the intraocular pressure were
measured by three tonometers under the study (one measure with Goldmann tonometer
and Tonopen, three measures with transpalpebral tonometer). After that, ophthalmic
glycerol was applied on the corneal surface and the OCT pachymetry were repeated after
five minutes. Finally, the intraocular pressure values were measured again, with the
Tonopen and transpalpebral tonometer, one and three retrospectively. There were
fourteen volunteers on the control group and twelve volunteers on the keratoconus group.
The concordance evaluation between the two groups was made using the Blant-Altman
graphic and the interclass correlation coefficient evaluation between three different
tonometers independently of the group was made.
Results:
5. The interclass correlation coefficient was satisfactory for the three measures with the
transpalpebral tonometer (0.88- CI: 0.80 to 0.92), but not satisfactory among the three
tonometers (0.60 – CI: 0.35 to 0.76).
The regression analysis of the differences shows a trend of the discordance on the
extreme values of the Tonopen and the transpalpebral tonometer comparing to the
Goldmann tonometer. For the lowest intraocular pressures the transpalpebral tonometer
trends to measure the pressure higher and, for the highest pressures, the transpalpebral
tonometer trends to measure lower, which is the same for Tonopen, independently of the
group, however the lower intraocular pressure were of the keratoconus group.
Conclusion:
The measures of the transpalpebral tonometer show satisfactory reproducibility and their
concordance with the Goldmann, mainly in the patients with keratoconus on which the
pressure values were higher than the Goldmann, may trend to measure a value closer to
the real intraocular pressure, as the Goldmann tonometer underestimates the intraocular
pressure on patients with keratoconus.
Tonometric Values of Intraocular Pressure, Using the Goldmann Tonometer, Tonopen
and Diaton Transpalpebral Tonometer in Keratoconus
Comparison of Accuracy of diaton Transpalpebral Tonometer Versus
Goldmann Applanation Tonometer,Dynamic Contour Tonometer and
Ocular Response Analyzer
Henry D Perry,MD,Valeriy Erichev,MD PhD; E.S. Avetisov MD;Alla Illarionova,MD,
Alexey Antonov MD
PURPOSE: To compare intraocular pressure measurements obtained with the diaton
transpalpebral tonometer with those from ocular response analyzer (ORA), dynamic
(should be in same order as title)contour tonometry (DCT) and Goldmann applanation
tonometry (GAT) in patients diagnosed with primary open-angle glaucoma (POAG) and
glaucoma suspects, and to determine the effects of central corneal thickness (CCT) and
corneal hysteresis (CH) on intraocular pressure (IOP) measurements with these devices.
METHODS: 40 patients (80 eyes) age 42-83 years with POAG and glaucoma suspects
were included in the study. The average of ORA (corneal compensated IOP [IOP-
ORAcc] and Goldmann-correlated IOP [IOP-ORAg]), DCT, GAT, and Diaton tonometer
levels were compared and the devices were examined with respect to CCT and CH.
Spearman's correlation tests were used for statistical analysis.
RESULTS: Mean CCT was 561,2±32,4mum and mean CH was 10.6+/-2.0 mmHg.
Mean IOP obtained using DCT was 18,9±4,1 mmHg, whereas those provided by ORA
were 18,2±3,4 mmHg for IOP-ORAcc and 18,4±3,5 mmHg for IOP-ORAg. The mean
IOP obtained using GAT and Diaton were 18,4±4,1 mmHg and 17,0±3,0 mmHg
respectively.The performed analysis of correlation between IOP meanings shows high
conformity of results of Diaton with IOP-ORAcc and DCT. The differences between the
measurements of DCT, ORA and Diaton were statistically significant. Correlated rates
relations: between IOP-ORAcc and DCT 0,89; between IOP-ORAcc and Diaton 0,96;
IOP-ORAcc and GAT 0,56; between GAT and Diaton 0,61; GAT and DCT 0,73; DCT
and Diaton 0,87.
6. CONCLUSIONS: Transpalpebral Tonometry is an accurate method of IOP
measurement that is also independent from the biomechanical characteristics of cornea. It
can be recommended for IOP measurements of patients diagnosed with glaucoma
including those cases where cornea pathology or cornea characteristics have been altered.
COMPARATIVE AGREEMENT AMONG THREE METHODS OF
TONOMETRY: GOLDMANN APPLANATION, TRANSPALPEBRAL
AND DYNAMIC CONTOUR
LUIS A. ZARATE,Magdalena García-Huerta,Rafael Castañeda Diez,Mauricio
Turati,Felix Gil Carrasco,Jesus Jimenez-Roman,Jose A.
Paczka.1GLAUCOMA,ASOCIACION PARA EVITAR LA CEGUERA EN
MEXICO,Mexico;2.Glaucoma;3.Asistencia e Investigacion en Glaucoma
Purpose: To investigate agreement of intraocular pressure (IOP) as measured by the
Goldmann applanation tonometer (GAT), the Pascal dynamic contour tonometer (DCT),
and Diaton transpalpebral tonometer (DTT).
Methods: Device agreement was calculated by Bland-Altman analysis in 77 eyes of 40
individuals (mean age 58.9 ± 13 years) with a mixed diagnosis of glaucoma suspicion
and primary open-angle glaucoma. All measurements were performed in a random order
by the same clinician according to standard procedures.
Results: Mean IOPs ± S.D. were 14.4 ± 2.9 mm Hg (GAT), 18.8 ± 3.2 mm Hg (DCT; P
= 0.005, ANOVA), and 15.1 ± 3.1 mm Hg (DTT). Bland-Altman analysis demonstrated
that, on average, DCT IOP measurements overestimated in approximately 3 mm Hg,
values derived from GAT and DTT, although agreement was fairly good.
Conclusions: All methods of tonometry were adequate to measure IOP in our sample.
Agreement among devices was considered good;nevertheless, DCT values of IOP were
significantly higher as compared to the other two assessed methods.
Clinical study of the influence of the anti-hypertensive drugs on the
intraocular pressure level with Non-Corneal Through-The-Eyelid
Diaton Tonometer
Illarionova A, Ivanov S, Savenkov M
Aim: To analyze the influence of the anti-hypertensive medicines on the intraocular
pressure (IOP) level in patients. Material and methods: 82 patients with arterial
hypertension of the 1-st and 2-nd degree with high cardiovascular risk, 10 patients
from this group had the Primary open-angle glaucoma. We used diuretics
(Hydrochlorothiazide 12,5-25 mg/day), calcium channel-blocking agents (Amlodipine
2,5-5 mg/day), beta-adrenergic blocking agents (Bisoprolol 2,5-5 mg/day), inhibitors of
angiotensin converting enzyme (iACE) (Enalaprilum 5-10 mg/day), nitrates (Isosorbide
mononitrate 40-50 mg/day and Isosorbide dinitrate (1,25 mg/day). All the patients were
measured IOP with transpalpebral Diaton tonometer before taking the medications, 3 and
24 h after taking the drugs and after 7-14 days. The IOP was measured initially during the
use of Isosorbide dinitrate as the spray (ISOKET) 30, 60 and 90 min after taking it.
Results:
The reliable change of IOP wasn’t detected in patients who were taking
diuretics, calcium channel inhibitors, iACE and B1-adrenergic blocking agents
neither during the acute pharmacological testing, nor during the intake of the anti-
hypertensive drugs. The IOP reduction was found during the intake of the B2-adrenergic
blocking agents (mean initial IOP 19,2±1,3 mmHg, mean IOP after 7-14 days 16,3±1,4
7. mmHg). The increase of IOP was observed during the intake of the nitrates (mean initial
IOP 18,8±1,2 mmHg, mean IOP after 7-14 days 23,8±1,3 mmHg). According to the
results of the acute pharmacological testing the IOP increase was observed 40 min after
the intake of one dose (1,25 mg) of Isosorbide dinitrate and remained increased up to
1,5 hours on patients with POAG (mean initial IOP 22,7±1,8 mmHg, IOP after 40 min
26,1±1,9 mmHg, IOP after 90 min 25,8±1,9 mmHg).
Conclusions:
Portable, ergonomic ophthalmo-tonometer diaton suits perfectly in general medical
practice for IOP monitoring to make anti-hypertensive drugs treatment safe.
Transpalpebral tonometer application during intraocular pressure evaluation
in the patients with refraction anomaly before and after keratophotorefractive
surgery
by Prof. A.P. Nesterov, MD., T.B. Dzhafarli, MD., A.R.Illarionova, MD. Russian State Medical
University, Moscow.
Great success of the modern keratorefractive surgery, especially excimerlaser cornea
microsurgery (FRК, LASIK, LASEK, Epi-LASIK) and its wide spread require high attention to
the eye morphophysiological rates in pre- and postoperational period. The most important rates
are still the characteristics of the cornea, such as thickness and its changes, regenerative response
of corneal tissue and its regulation, as well as the data of intraocular pressure (IOP) and their
correlation with cornea metrical rates.
According to the data of numerous investigations, underestimation of IOP level during
applanation tonometry in patients, which were subject to keratophotorefractive surgeries, is of
great importance in glaucoma diagnostic search. Hence, the advantages of scleral tonometry
application in this category of patients for ophthalmotone appropriate evaluation and timely
ophthalmohypertension detection are clear.
Purpose
The purpose of the study is to evaluate the clinical use of transpalpebral scleral tonometry,
reliability of its application in the patients with refraction anomaly in pre- and postoperational
period, dynamics of eye morphometric rates (pachymetry of the central corneal zone, IOP) and
their correlative bond before and after photorefractive surgeries.
Methods
We have analyzed the results of prospective comparative case series clinical study in 98 patients
(194 eyes) with ametropia of various degrees, among which 59 persons (118 eyes) form the
group of patients, who have no keratophotorefractive surgeries in past history, and 39 patients
(76 eyes), which were the subject to excimerlaser vision correction (Epi-LASIK, LASIK, FRK)
with various length of postoperational period from 7 days to 4 years.
The patients age distribution was from 18 to 53 years, the women make 61%, the men - 39%.
The following factors were exclusion criteria from the study:
Cornea pathology, influencing prognosticly the applanation tonometry results;
Upper eyelid and sclera pathology, which are the contraindications for transpalpebral diaton-
tonometry.
8. Before and after the surgery all patients were subject to the complete refractive examination,
including keratotopography and wavefront-aberrometry (AMO, USA). In a number of patients
for cornea state morphologic evaluation we conducted US-biomicroscopy of the corneal optical
zone before and in two months after laser correction (Picture 1).
Before and after surgery we trice measured pachymetry corneal thickness in central (4 points)
zone - central corneal thickness (CCT) in each patient. We realized the study using two devices:
US-pachymeter UP 1000 by NIDEK (Japan) and А-scan-pachymeter P55 by Paradigm (USA).
IOP was measured with Goldmann applanation tonometer (Rodenstok, Germany),
pneumotonometer (NIDEK, Japan) and transpalpebral scleral diaton tonometer (RSIME, Russia,
picture 2) using traditional methodology (picture 3), all ophthalmotone measurements were
realized the patients being in the sitting position with time interval being 2-3 minutes between
two investigators.
The surgeries were carried out using excimer laser VISX Star S4 IR (AMO, USA),
microkeratome LSK Evolution II (Moria, France) and epikeratome Centurion SES (Norwood,
Australia)
Statistical treatment of the received results was realized using common methods of medical
mathematical statistics. Statistic calculations were carried out using "Analysis Tools Pack".
Determination of differences reliability between the groups being compared in the presence of
normal distribution in sampling of one-type factors was realized using two-sample t-tests.
Correlation analysis by Pearson allowed detecting the character of correlations between
showings. Correlation with Р<0,05 was considered to be reliable.
Results and discussion
In 93,6% cases visual acuity without correction after surgery was 0,6 - 1,0 (Table 1) in the early
postoperative period.
Results of the study are shown in Tables 2 and 3.
While analyzing morphometric parameters in the group of patients which were not the subject to
photorefractive surgeries the mean PCT value was 554,5±32,4 m, and the mean value of
applanational IOP - 16,1±2,6 mm Hg, the fluctuation being from 10 to 21 mm Hg; mean
ophthalmotone level evaluated with diaton tonometer - 14,7±2,5 mmHg, the fluctuation being
from 9 to 20 mmHg. At that correlation between values of the applanation tonometer and
transpalpebral scleral diaton tonometer was highly reliable (r = 0,73, р±0,005). To define the
advantages of scleral tonometry in comparison with the traditional keratoapplanational method
we made calculations of real ophthalmotone in the patients of this group taking into account
pachymetry (PCT), ophthalmometry and applanation tonometry data. Mean value of the real IOP
after applanation value converting was 15,4±2,4 mmHg. Pearson correlation coefficient between
real IOP (modified result, received with applanation tonometry) and the value, determined with
diaton tonometer was 0,89, р<0,005, which shows high reliability of transpalpebral scleral
tonometry.
In the groups of patients, underwent photorefractive vision correction, mean PCT was
499,8±50,9 m (fluctuations from 407 to 513 m), mean applanation value of IOP - 12,4±2,91
mmHg (fluctuations from 7 to 20 mm Hg), modified taking into account keratometry IOP rates -
13,9±3,0 mm Hg, mean diaton-tonometry result - 15,1±2,75 mm Hg. At that we notice
approximation of diaton-tonometry figures to the modified applanation IOP value taking into
consideration keratometric rates - increase of correlation coefficient from 0,51 to 0,81 (table 4).
9. Correlation analysis of PCT and IOP results in the group of patients, examined both in
preoperational period and after photorefractive vision correction showed reliability of this
correlation, p<0,005, reduction of IOP for 1 mm Hg is registered PCT being decreased for 29,7
m. At that difference between pre- and postoperational IOP during applanation tonometry was
3,5 mm Hg, and during diaton-tonometry - 1,8 mm Hg, that is statistically dissimilar (t>2,
p<0,005), which shows significant advantage of ophthalmotone evaluation if we omit cornea.
Conclusion. Thus, cornea thickness is the important factor of IOP evaluation and monitoring and
requires the necessity of including corneal pachymetry in the program of examination the
patients with suspicion of glaucoma and hypertension, especially after various keratorefractive
surgeries while using the traditional corneal methods of ophthalmotonometry. At the same time
clinical application of transpalpebral scleral diaton tonometer makes it possible to evaluate IOP
using only one device, the procedure being efficient, economical, simple in performance and
requiring no additional instrumental examination.
Literature
Nesterov A.P. Transpalpebral tonometer for intraocular pressure measuring.// Ophthalmology
Bulletin - 2003. - Vol. 119. - №1. - P. 3 - 5.
Blaker JW, Hersh PS. Theoretical and clinical effect of preoperative corneal curvature on
excimer laser photorefractive keratectomy for myopia.//Refract. Corneal Surg. - 1994;-Vol.10:P.
571-574.
Buratto L, Ferrari M, Genisi C. Myopic keratomileuesis with the excimer laser: one-year follow-
up.//Refract. Corneal Surg. - 1993;-Vol.9:P.12-19.
Cennamo G, Rosa N, La Rana A, et al. Non-contact tonometry in patients that underwent
photorefractive keratectomy.//Ophthalmologica.- 1997;-Vol. 211:P.341-343
Duch S, Serra A, Castanera J. Tonometriy after laser in Situ keratomileusis treatment. //J
Glaucoma. - 2001. - Vol.10. - P. 261 - 265.
Emara B.et al. Correlation of intraocular pressure and corneal thickness in normal myopic eyes
and after laser in situ keratomileusis.//J. Cataract. Refract. Surg. - 1998;-Vol.24(10):P. 1320-
1325
Mardelli PG, Piebenga LW, Whitacre MM. The effect of excimer laser photorefractive
keratectomy on intraocular pressure measurements using the Goldmann applanation tonometer
//Ophthalmol. - 1997. - Vol.104. - P. 945-948.
Pandav SS, Ashok Sharma, Amit Gupta. Reliability of Proton and Goldmann applanation
tonometers in normal and postkeratoplasty eyes. //Ophthalmol. - 2002. - Vol. 109. - P. 979-984.
Simon G, Small RH, Ren Q, et al. Effect of corneal hydration on Goldmann applanation
tonometry and corneal topography.//Refract. Corneal Surg.- 1993;-Vol. 9:P.110-117
Vakili R, Choudhri SA, Tauber S, Shields MB. Effect of mild to moderate myopic correction by
laser-assisted in situ keratomileusis on intraocular pressure measurements with goldmann
applanation tonometer, tono-pen, and pneumatonometer. //J Glaucoma. - 2002. - Vol.11. - N6. -
P. 493-496.
Whitacre MM, Stein R. Sources of error with use of Goldmann-type tonometers. //Surv
Ophthalmol. - 1993. - Vol. 38. - P.1 - 30.
Wu X, Liu S, Huang P, Wang P. Analysis of intraocular pressure after myopic photorefractive
keratectomy. //Chung Hua Yen Ko Tsa Chih. - 2002. - Vol.38. - N10. - P.603-605.
Zadok D, Raifkup F, Landao D. Intraocular pressure after LASIK for hyperopia. //Ophthalmol. -
2002. - Vol. 109. - P.1659-1661.
Picture 1 Topographic ultrasonic biomicroscopy of the cornea in optical zone of normal myopia
eye (А), after PRK (B) and after LASIK (C)
10. Cornea, as the
basic optical lens of the eye, is the main element to be influenced during various, and first of all
laser, surgeries with refractive, reconstructive, optical and other purposes. Picture 2
Transpalpebral scleral diaton tonometer
Comparison of the Diaton Transpalpebral Tonometer Versus
Goldmann Applanation
R. S. Davidson 1; N. Faberowski2 ; R. J. Noecker3 ; M. Y. Kahook1
1. Ophthalmology, Rocky Mountain Lions Eye Institute, Aurora, CO, USA.
2. Ophthalmology, Denver Health Medical Center, Denver, CO, USA.
3. Ophthalmology, UPMC, Pittsburgh, PA, USA.
Financial Disclosure
The authors have no financial interest in the subject matter being presented
Background
Diaton tonometry is a unique approach to measuring intraocular pressure (IOP) through
the Eyelid. It is a non-contact (no contact with cornea), pen like, hand-held, portable
tonometer. It requires no anesthesia or sterilization.
Purpose
To investigate the agreement in the measurement of intraocular pressure (IOP) obtained
by transpalpebral tonometry using the Diaton tonometer versus Goldmann applanation in
adult patients presenting for routine eye exams.
11. Methods
Retrospective chart review of consecutive IOP measurements performed on 64 eyes of 32
patients age 34-91 years with both the Diaton tonometer and Goldmann applanation.
Results between groups were examined using analysis of variance (ANOVA) where
appropriate.
Results
Mean IOP was 15.09 +/-4.31 mm Hg in the Goldmann group and 15.70 +/-4.33 mm Hg
in the Diaton group (p=0.43).
Mean IOP variation between groups was 1.74 +/-1.42 mm Hg (range 0-8). 83% of all
measurements were within 2 mm Hg of each other.
Conclusions
The transpalpebral method of measuring IOP with the Diaton tonometer correlates well
with Goldmann applanation. Diaton applanation may be a clinically useful device for
measuring IOP in routine eye exams.
http://tonometerdiaton.com/index.php?do=home.Comparison_Study_Diaton_Tonometer_
Goldmann
Comparison of the Diaton Transpalpebral Tonometer Versus Tono-Pen
Applanation
Theodore H. Curtis, M.D.1
, Douglas L Mackenzie, M.D.1
, Robert J. Noecker M.D.2
, and
Malik Y. Kahook M.D.1
1
The Rocky Mountain Lions Eye Institute, University of Colorado Health Sciences
Center, Aurora, CO
2
Eye and Ear Institute, University of Pittsburgh Medical Center, Pittsburgh, PA
Financial Disclosures
· None of the authors have financial interests relevant to the supject discussed.
Purpose
· To compare intraocular pressure (IOP) measurements obtained with Diaton trans-
palpebral tonometry versus Tonopen applanation tonometry in children and adults.
Introduction
· Goldmann applanation is the gold standard for IOP measurement
· It has been supplanted by TonoPen applanation in many settings because of it's ease of
use, portability, convenience, and minimal training requirements.
· The TonoPen requires contact with the corneal surface, and has the risks of iatrogenic
corneal injury, spread of pathogens, and requires topical anesthetics.
Introduction
· The newly-developed Diaton tonometer is a handheld device that measures pressure
through the tarsal plate (Figures 1 & 2).
· It avoids contact with the cornea and the need for topical anesthesia.
Figure 1: The Diaton Transpalpebral Tonometer
Figure 2: Using the Diaton Tonometer
Methods
12. · We looked at 74 eyes of 38 consecutive patients who received both Tonopen and Diaton
tonometry
· TonoPen measurements were taken in the sitting position following topical anesthesia
with proparicaine.
· Diaton measurements were performed in the sitting position with the patient gazing at a
45o
angle, placing the eyelid margin at the superior limbus. If necessary, gentle traction
was placed on the brow to align the lid with the limbus. The device was activated when
the signaling mechanism indicated the device was vertical.
Results
· Age range 3-91 years of age (mean 47.5 years).
· The average IOP with the Diaton was 16.24 (+/-5.11 mm Hg; range = 7-32 mmHg).
· The average IOP with the TonoPen was 16.37 (+/-4.90 mm Hg; range = 8-33 mmHg).
· The mean variation between the two modalities was 1.59 mmHg (+/-1.31 mm Hg; range
= 0-6 mmHg).
· Eighty-one percent of all measurements were within 2 mmHg of each other (Table 1).
· There was no statistically significant difference in mean IOP values obtained with the
two devices (p=0.87). Table
Conclusions
· The Diaton tonometer pressure measurements correlated well with TonoPen
measurements in this retrospective review.
· We did not find problems performing the exam in children, and many were reassured by
the fact that no drops were needed.
· There may be a notable benefit in patients after refractive surgery or with corneal
pathology since the Diaton does not applanate the cornea.
· The Diaton tonometer appears to be a clinically useful device in the IOP measurement
of both children and adults.
References
· Li J, Herndon LW, Asrani SG, Stinnett S, Allingham RR. Clinical comparison of the
Proview eye pressure monitor with the goldmann applanation tonometer and the
TonoPen. Arch Opthalmol 2004;122:1117-21.
· Eisenberg DL, Sherman BG, McKeown CA, Schuman JS. Tonometry in adults and
children: a manometric evaluation of pneumotonometry, applanation, and TonoPen in
vitro and in vivo. Ophthalmology 1998;105:1173-81.
· Diaton: digital portable tonometer of intraocular pressure through the eyelid. Operation
Manual. Ryazan State Instrument Making Enterprise. Ryazan, Russia.
· Garcia Resua C, Giraldez Fernandez MJ, Cervino Exposito A, Gonzalez Perez J, Yebra-
Pimentel E. Clinical evaluation of the new TGDc-01 "PRA" palpebral tonometer:
comparison with contact and non-contact tonometry. Optom Vis Sci 2005;82:143-50.
· Troost A, Yun SH, Specht K, Krummenauer F, Schwenn. Transpalpebral tonometry:
reliability and comparison with Goldmann applanation tonometry and palpation in
healthy volunteers. Br J Ophthalmol 2005;89:280-3.
· Losch A, Scheuerle A, Rupp V, Auffarth G, Becker M. Transpalpebral measurement of
intraocular pressure using the TGDc-01 tonometer versus standard Goldmann
applanation tonometry. Graefes Arch Clin Exp Opthhalmol. 2005;243:313-6.
Test report and a comparison of the pressure measurements of the digital portable
tonometer DIATON for the measurement of the intraocular pressure through the
eyelid
13. Ina Conrad-Hegegerer MD., Mr. Fritz Hengerer MD.
Eichenstrasse 3, 65468 Trebur, Germany
The measurements have been conducted in Germany, in our private doctor's office by
Mrs. Ina Conrad-Hegegerer MD. and Mr. Fritz Hengerer MD.
The results have been obtained with the following methods:
1.Applanation tonometry by Goldmann(Splitlamp Haag Streit 900)
2.Digital portable Tonometer Diaton
3.Non-Contact tonometry with Niedek Tonometer 1000
The purpose of the measurements is to evaluate the reliability of Diaton in the direct
comparison with the already established processes.
There were 2 groups of test persons: Healthy subjects and glaucoma patients. Exclusion
criteria were: Previous glaucoma patients, eyelid operations or inflammatory states of the
front eye section. Furthermore, patients were excluded where a Goldmann tonometry
could not be performed (Keratokonus, Epitheledema).
The static analysis contains:
a) Mean
b) Standard deviation
c) Median error
d) Correlation coefficient (Pearson)
Table 1. shows the measurements on healthy patients, Table 2. on those with glaucoma.
The results of the statistical analysis are summarized in Table 3. and 4.
Summary:
The analysis of the measurements confirms the validity of the measurements of the
digital portable Tonometer Diaton.
TRANSPALPEBRAL TONOMETER FOR INTRAOCULAR PRESSURE MEASURING
Eye diseases department of the Russian State Medical University medical faculty, Moscow,
Eye tonometry is one of the leading methods used in the patient with ophthalmopathology
checkup. The first tonometer acceptable for clinical practice was designed and described in 1884
by A.N.Maklakov [2]. The tonometers introduced earlier had serious drawbacks and were not
used in clinical practice. Before this the intraocular pressure (IOP) was evaluated only
approximately with the help of eye palpation through the upper eyelid. At present palpation
method is still widely used in clinical practice. Using it a skilled ophthalmologist can evaluate
approximately whether ophthalmotone is normal (Tn), increased (T+1, T+2) or decreased (T-1, T-
2), distinguish normotension from hyper- or hypotension. The palpation method suffers from
subjectivism, uncertainty of results at ophthalmotone moderate change but at the same time it
shows the principle possibility of transpalpebral tonometry.
Intraocular pressure
14. The eyeball is a reservoir of the spherical form, filled with fluid, incompressible contents. IOP is
caused by the influence of the elastic forces, arising in eye coverings while they are being
stretching.
IOP level is determined by watery moisture (WM) circulation in an eye and by pressure in
episclera veins [3]:
PO=F/C+Pv,
where PO – IOP; F – WM minute volume; C – coefficient of easiness of WM flow-out from an
eye, Pv – pressure in episclera veins.
IOP increases while moving from vertical to horizontal position and especially in Trendelenburg
position and while squeezing the neck’s veins because of the pressure increasing in episclera
veins (Pv) [4].
IOP is a dynamic, continuously changing value. They distinguish its system, rhythmic fluctuations
around relatively constant level and momentary changes of casual character. IOP fluctuations
around the level depend on changes in bloodfilling of intraocular vessels and on outer pressure
on the eyeball.
There are 3 types of rhythmic IOP fluctuations around the level [3]:
1.eye pulse (from 0,5 to 2,5 mm Hg),
2.respiratory waves ( from 0 to 1 mm Hg),
3.Hering-Traube waves (from 0 to 2,5 mm Hg).
The successive measurings of IOP in the same eye with a tonometer vary
from each other mainly due to the ophthalmotone rhythmic fluctuations.
Winking, pressing of the eye with orbicular muscle or external muscles of the eyeball
momentary increase IOP, provide eye massage and decrease venous congestion. At the same
time changes of orbicular and transpalpebral muscles tone during tonometry are often the
cause of error while measuring IOP level.
Statistically normal IOP varies from 9 to 21 mm Hg (on average 15-16 mm Hg). It has daily and
seasonal fluctuations. The IOP distribution in the normal population is asymmetrical (splayed to
the right). In middle age the distribution asymmetry increased. More than 3% of healthy persons
have IOP above 21 mm Hg [4]. The ophthalmotone measuring accuracy in the area of the normal
and reasonably increased (up to 30 mm Hg) IOP is especially important for a practical doctor.
Intraocular pressure regulation
Each eye is adjusted to a certain IOP level (balance pressure) which is supported by passive and
active mechanisms. IOP being increased pressure of moisture flow-out and filtration from an eye
increased, WM production being decreased its flow-out decreased and the balance pressure
restores.
Active mechanisms of IOP regulation have been not enough studied. Collaboration of
hypothalamus, adrenal glands, vegetative nervous system and local autoregulatory mechanisms
is possible.
Opthalmotonometry
The IOP measuring is based on the eyeball deformation under the influence of an outer effect.
At that the values of deformation (S), the force (W) influencing the eye and IOP (Pt) as a first
approximation are connected with each other with the following dependence [5]: Pt = f(W/ S).
All tonometers fall into devices: 1) with constant and variable pressure force on the eye, 2) with
constant and variable value of eye deformation, 3) corneal, scleral and transpalpebral, (4)
applanation, impression and ballistic.
Ophthalmotonometers used in the Russian Federation
1.Maklakov tonometer and Filatov-Kalve elastotonometer.
2.Goldmann applanation tonometer (reference)
15. 3.Perkins and Dregger applanation tonometers
4.Grolman non-contact applanation tonometer, 1972
5.Schiotz impression tonometer
6.diaton transpalpebral tonometer
All the tonometers mentioned above (besides diaton) measure IOP through cornea.
Advantages and disadvantages of corneal tonometry
It is possible to note the following advantages of corneal tonometry: 1) it is more accessible for
tonometry on an open eye then sclera; 2) between tonometer and eye cavity there’s no other
structures interposition (conjunctiva, eyelid, ciliar body), but cornea; 3) cornea’s individual size,
thickness and crookedness are less different in comparison to other parts of eye fibrous
membrane.
At the same time corneal tonometry has serious drawbacks:
1.Cornea has high pain sensitivity and the tonometry is impossible without prior anesthesia,
which in some patients causes conjunctiva irritation, hypostasis of cornea epithelium, short-
term IOP increasing, and allergic conjunctivitis.
2.Cornea has regular spherical shape only in the central zone and flattens towards periphery; its
thickness increases from 0,5-0,6 mm in the center to 0,8 in the periphery. Besides, the existent
individual peculiarities both in cornea’s crookedness and thickness influence significantly on the
tonometry results [6, 12].
3.During the corneal tonometry it is very difficult to prevent the increasing of orbicular and
palpebral muscles tone, that leads to IOP increasing. The ophthalmotone increasing may be also
connected with the blood pressure increasing during the tonometer’s bringing near the open
eye [3].
4.It is known that a tear may contain bacteria and dangerous viruses (hepatitis B virus, herpes,
adenoviruses, AIDS). But the problem of tonometers sterilization is far from perfection [11].
5.The corneal tonometry is contraindicative in eyelids and cornea edema, nystagmus,
conjunctivitis, corneal erosions, keratitis, hypostasis and sores.
Diaton tonometer – basic principles
Transpalpebral ophthalmic tonometer (diaton) was designed by a group of ophthalmologists
and engineers. There was the task to design portable and simple in use device, which could
provide IOP measuring through the eyelid not only in ophthalmology studies but at home as
well. It should possess enough accuracy, quick operation and provide the possibility to carry out
ophthalmotone monitoring that is very important both for glaucoma diagnostics and for
controlling the effectiveness of treatment. “Digital Portable Tonometer of Ocular Pressure”
(diaton) designed by us fulfills all these tasks (fig.1).
Fig.1
The peculiarities of the new tonometer are that IOP measuring is realized through the eyelid
that excludes contact with conjuctiva and cornea and does not require anesthetics application.
At that the mechanical influence on the eye is realized through the eyelid on sclera. The
tonometere’s position while measuring IOP is shown on fig.2.
16. Fig.2
The measuring principal of the new tonometer is based on processing the rod movement
resulting from its free fall and interaction with the elastic surface of the eye to be measured.
The main problem was how to exclude the influence of an eyelid individual peculiarities on the
tonometry results. This was solved by pressing the eyelid on the area with the diameter of 1,5
mm to such extent that the pressed area of the lead acts like a rigid transfer link while the rod
interacts with the eye at the same time excluding the painful sensation. This method of
compensating the eyelid influence led to the choose of dynamic (ballistic) way of dosated
mechanical influence on the eye for evaluating its elastic peculiarities.
To determine the position in the process of its free fall from the constant height and the
interaction with eye through the eyelid the device has position sensor. Value of the points of the
rod movement function in time is remembered by the built-in processor. In diagram form the
function of the rod movement in time is shown in fig.3.
Fig.3 Function of the rod movement in time:
H – change in the rod position during the free fall, t – time after the fall starting, B – minimum
point of the rod movement function.
For point B the following equation is true: P=F/S, where P – IOP, F – eye elasticity force,
influencing the rod, S – the area of eye and rod interaction (area of its square). According to
Newton’s second law: F=m*a, where m – the rod’s weight, a – the rod’s acceleration while
interacting with the eye elastic surface. Then P=m*a/S. The rod’s weight and the interacting
17. area - S are constants So to evaluate P it is enough to measure the rod movement acceleration
(a) in point B.
Errors of IOP measuring
In clinical practice it is customary to evaluate errors of IOP measuring with the new tonometers
in comparison with the results received in the same eyes with Goldman tonometer (Reference
tonometer) and taking into consideration scatter of data received during repeated measurings
with the same tonometer [8].
Numerous studies carried out in hundreds of patients during several years show high reliability
of IOP measurings with diaton tonometer. Scatter of results received using the new tonometer
and Goldman tonometer had no systematic character and did not exceed 4 mm Hg. In repeated
IOP measurings in healthy eyes the displays fluctuations were in the range 2-4 mm Hg [1].
According to the literature data the scatter of results while carrying out the repeated
measurings using Goldman tonometer is 2-3 mm Hg in healthy eyes [10]. While checking various
samples of Goldman tonometers produced in lots it is found the systematic difference of the
displays of 2-3 mm Hg depending on the variant of each device’s double prism and spring
calibration. Eye refraction, astigmatism, cornea’s crookedness and thickness, width of the
moisture ring around the flattening area, hyper- or hypofluorescence of the ring [6, 7, 9]. As it
was mentioned above, the error of IOP level measuring depends on the character and value of
ophthalmotone rhythmic and casual fluctuations as well as on the tonometrist’s skill.
The experience of operating diaton and Goldman tonometers shows that their displays have
good correlation.
Diaton tonometer has accuracy enough for clinical purposes, requires no anesthetics and
sterilization. Besides, they are safe (can not damage the cornea), comfortable for the patients
and easy in use. They can be used not only in ophthalmology studies but at home as well.
LITERATURE
1.Илларионова А.Р., Пилецкий Н.Г.//Клин.офтальмол.-2001-№2.-С.55-56
2.Маклаков А.Н.//Мед.обозр.-1884.-Т.22-С.1092-1095
3.Нестеров А.П., Бунин А.Я., Кацельсон Л.А. Внутриглазное давление: физиология и
паталогия.-М.,1974
4.Нестеров А.П. Глаукома.-М.,1995
5.Goldmann H., Schmidt T.//Opthalmologica.-1957-Bd 136.-S.221-231.
6.Mark H.H.//Am.J.Ophthalmol.-1973.-Vol.76-P.223-227
7..//Ibid.-1960.-Vol.49.-P.1149
8.Moses R.A., Liu C.H.// Ibid.-1968.-Vol.66.-P.89-94
9.Motolko M.A.//Can/J/Ophthalmol.-1982.-Vol.17.-P.93-97.
10.Phelps C.D.,Phelps G.K.//Graefes.Arch.Clin.Exp.Ophthalmol.-1976.-Vol.198.-P.39-44
11.Schottenstein M.H.//The Glaucomes/Eds R.Ritch et al.-St.Louis, 1996.-Vol.1.-P.407-428.
12.Whitacre M.M., Stein R.A., Hassanein K.//Am.J.Ophthalmol.-1993.-Vol.115.-P.592-597.
Donated DIATON Tonometer was used at Mother Theresa’s orphanage to
screen for Glaucoma in Tanzania – a Thank You Letter +Photos are
Very Touching
A Very Touching “Thank You Letter & Photos from a orphanage in Tanzania which received
Diaton tonometer as donation to screen people at Risk for Glaucoma to prevent Blindness:
18. photo: Donated Diaton tonometer Saves Sight at Mother Theresa’s orphanage
Subject: Donation Of Diaton Tonometer
Dear Sir/Madam,
Attached please find pictures of recent activity at Mother Theresa’s orphanage and old age home
were 200 needy people underwent eye exam and glaucoma screening. Fifteen people were
glaucoma suspects and 3 with advanced glaucoma.
This screening would have not been possible without your generous donation of Diaton
tonometer, a wonderful marvel of technology, that made this massive screening for glaucoma an
easy one and with perfect accuracy.
Old age people normally have dry eyes,poor tear film quality, where there is a risk of corneal
damage with schiotz tonometry and applanation tonometry needs use of lots of fluoroscein dye
because it dries up fast. With Diaton tonometer this was not a problem ! Diaton tonometer is the
best and only device suitable for use with aged patients and those with dry eyes.
Thank you Diaton for wonderful device thats going to help save sights of thousands of people.
God bless.
Please go through attached pictures.
Kind regards,Dr. Shabbir Kapasi Ph.D(MA)
ELITE OPTICIANS
Jamhuri/India street, Opp. Ministry of Science & Technology Bldg., P.O. Box
1737, Dar Es Salaam, Tanzania.
19. Thank you for your review of Diaton tonometer
clinical trials, reviews and testimonials.
For any additional information about Diaton
tonometer please visit :
http://www.TonometerDiaton.com
Or contact BiCOM Inc at
Phone: 1-877-DIATONS (877-342-8667)
Email: contact@tonometerdiaton.com
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