This document discusses several studies that have investigated the relationship between intraocular pressure (IOP) and intracranial pressure (ICP). The studies have shown mixed results, with some finding a correlation between IOP and ICP, and others finding no correlation. The current study aims to further explore this relationship by experimentally reducing IOP in dogs through medication or surgery and measuring the impact on ICP over time. Fifteen healthy dogs were divided into groups that received eye drops, eye surgery, or no treatment to the right eye. IOP and ICP were measured at baseline and 2 and 4 weeks later to analyze any changes and potential correlation between the pressures.
This study investigated the effects of acupuncture on brain damage caused by ischemia-reperfusion in rats. Rats were divided into two groups - one that underwent ischemia-reperfusion only, and one that received acupuncture after ischemia-reperfusion. The group that received acupuncture showed significantly less brain damage than the group that did not receive acupuncture. The findings suggest that acupuncture may help reduce brain damage caused by ischemia-reperfusion, though more research is needed to understand the mechanisms involved.
Decompressive Craniectomy: A Review of the Adequacy of the Bony Decompression...CrimsonPublishersTNN
Decompressive Craniectomy: A Review of the Adequacy of the Bony Decompression in a Single Institution by Haitham Ben Ali in Techniques in Neurosurgery & Neurology
1. The document discusses various neurosurgical emergencies including brain trauma, subarachnoid hemorrhage, and intracerebral hematomas.
2. It outlines key factors that influence prognosis in brain trauma such as age, Glasgow Coma Scale score, pupillary reactivity, and CT scan findings. Secondary factors like hypotension can also worsen outcomes.
3. Management principles for neurosurgical emergencies focus on maintaining cerebral oxygenation and perfusion while controlling factors like intracranial pressure, temperature, blood pressure, and glucose.
Therapeutic hypothermia is effective at reducing intracranial hypertension according to this review of clinical trials. The review identified 11 randomized controlled trials and 6 cohort studies that showed hypothermia reduced ICP by an average of 10 mm Hg compared to normothermia. Hypothermia works by reducing cerebral metabolism and blood flow, which decreases brain swelling. While hypothermia is as effective or more effective than other ICP therapies like mannitol and barbiturates, some therapies like hypertonic saline and CSF drainage may be more effective. However, hypothermia appears to have a favorable risk-benefit profile. The main risk is rebound ICP increases when rewarming, so slower rewarming
The document summarizes research on stress-induced hypertensive responses during exercise and pharmacological stress tests. It finds that while some studies show exercise hypertension predicts worse outcomes, others show it predicts better outcomes or is a neutral factor. The document also discusses how stress-induced hypertensive responses are associated with subtle systolic dysfunction, diastolic dysfunction, hyperdynamic myocardial function, increased regional contractility, and potential nonischemic cardiomyopathy. It concludes that stress-induced hypertensive responses may have more clinical importance than previously recognized and warrant further evaluation.
Whole body retention of I-131 at 24hr vs 48hr as a predictor of maximum tole...Michael
This study evaluated using the 24-hour whole body retention (WBR) of I-131 as a predictor of the maximum tolerated activity (MTA) for radioactive iodine treatment, as an alternative to the standard 48-hour time point. For 99 thyroid cancer patients, the 24-hour and 48-hour WBR were highly correlated. A model using 24-hour WBR predicted MTA well when retention was <35%, which applied to about half of patients prepared with recombinant human thyroid stimulating hormone. For other patients, the 48-hour measurement was still needed. Using the 24-hour time point could simplify dosimetry for some patients but not replace the 48-hour measurement entirely.
This document discusses constructivist learning theory. It outlines key aspects of constructivism such as collaborative learning, knowledge construction through experience, and learning as an active process. The document also presents contemporary contributors to constructivism like Dewey, Vygotsky, and Piaget. Additionally, it provides examples of applying constructivist principles through a 5 stage model of engaging, exploring, explaining, elaborating and evaluating learning. Both benefits like developing lifelong learning skills and challenges like needing extensive training are acknowledged.
TeezCorrelation Between Intraocular pressure(IOP)and Intracranial pressure(IC...Alireza Sheikhi
This document discusses several studies that have investigated the relationship between intraocular pressure (IOP) and intracranial pressure (ICP). Some studies found a significant correlation between IOP and ICP, while others did not find a clear relationship. The current study aims to help address limitations of prior studies by experimentally reducing IOP in animal models to observe the effects on ICP.
This study investigated the effects of acupuncture on brain damage caused by ischemia-reperfusion in rats. Rats were divided into two groups - one that underwent ischemia-reperfusion only, and one that received acupuncture after ischemia-reperfusion. The group that received acupuncture showed significantly less brain damage than the group that did not receive acupuncture. The findings suggest that acupuncture may help reduce brain damage caused by ischemia-reperfusion, though more research is needed to understand the mechanisms involved.
Decompressive Craniectomy: A Review of the Adequacy of the Bony Decompression...CrimsonPublishersTNN
Decompressive Craniectomy: A Review of the Adequacy of the Bony Decompression in a Single Institution by Haitham Ben Ali in Techniques in Neurosurgery & Neurology
1. The document discusses various neurosurgical emergencies including brain trauma, subarachnoid hemorrhage, and intracerebral hematomas.
2. It outlines key factors that influence prognosis in brain trauma such as age, Glasgow Coma Scale score, pupillary reactivity, and CT scan findings. Secondary factors like hypotension can also worsen outcomes.
3. Management principles for neurosurgical emergencies focus on maintaining cerebral oxygenation and perfusion while controlling factors like intracranial pressure, temperature, blood pressure, and glucose.
Therapeutic hypothermia is effective at reducing intracranial hypertension according to this review of clinical trials. The review identified 11 randomized controlled trials and 6 cohort studies that showed hypothermia reduced ICP by an average of 10 mm Hg compared to normothermia. Hypothermia works by reducing cerebral metabolism and blood flow, which decreases brain swelling. While hypothermia is as effective or more effective than other ICP therapies like mannitol and barbiturates, some therapies like hypertonic saline and CSF drainage may be more effective. However, hypothermia appears to have a favorable risk-benefit profile. The main risk is rebound ICP increases when rewarming, so slower rewarming
The document summarizes research on stress-induced hypertensive responses during exercise and pharmacological stress tests. It finds that while some studies show exercise hypertension predicts worse outcomes, others show it predicts better outcomes or is a neutral factor. The document also discusses how stress-induced hypertensive responses are associated with subtle systolic dysfunction, diastolic dysfunction, hyperdynamic myocardial function, increased regional contractility, and potential nonischemic cardiomyopathy. It concludes that stress-induced hypertensive responses may have more clinical importance than previously recognized and warrant further evaluation.
Whole body retention of I-131 at 24hr vs 48hr as a predictor of maximum tole...Michael
This study evaluated using the 24-hour whole body retention (WBR) of I-131 as a predictor of the maximum tolerated activity (MTA) for radioactive iodine treatment, as an alternative to the standard 48-hour time point. For 99 thyroid cancer patients, the 24-hour and 48-hour WBR were highly correlated. A model using 24-hour WBR predicted MTA well when retention was <35%, which applied to about half of patients prepared with recombinant human thyroid stimulating hormone. For other patients, the 48-hour measurement was still needed. Using the 24-hour time point could simplify dosimetry for some patients but not replace the 48-hour measurement entirely.
This document discusses constructivist learning theory. It outlines key aspects of constructivism such as collaborative learning, knowledge construction through experience, and learning as an active process. The document also presents contemporary contributors to constructivism like Dewey, Vygotsky, and Piaget. Additionally, it provides examples of applying constructivist principles through a 5 stage model of engaging, exploring, explaining, elaborating and evaluating learning. Both benefits like developing lifelong learning skills and challenges like needing extensive training are acknowledged.
TeezCorrelation Between Intraocular pressure(IOP)and Intracranial pressure(IC...Alireza Sheikhi
This document discusses several studies that have investigated the relationship between intraocular pressure (IOP) and intracranial pressure (ICP). Some studies found a significant correlation between IOP and ICP, while others did not find a clear relationship. The current study aims to help address limitations of prior studies by experimentally reducing IOP in animal models to observe the effects on ICP.
Guidelines for the indications for 131I remnant ablation on differentiated t...Michael
This document compares guidelines from seven organizations - ATA, ESMO, BTA, NCCN, SNM, EANM, CSE/CSS/CACA/CSNM - for 131I remnant ablation in patients with differentiated thyroid cancer. While all organizations define ablation as eliminating the thyroid remnant, some guidelines incorporate additional treatment of microscopic tumors and metastases. Indications vary between guidelines and there is controversy around management of low risk patients. More evidence is needed to standardize risk stratification and guidelines. The NCCN emphasizes diagnostic imaging prior to 131I administration to target uptake in the thyroid bed. Overall guidelines are becoming more standardized with improved terminology and evidence.
This document discusses constructivist learning theory. It outlines key features of constructivism such as collaborative learning, knowledge construction through experience, and student-directed learning goals. The document also presents the 5 E model for lesson planning (engage, explore, explain, elaborate, evaluate) and provides examples of how this could be applied to teaching osteopathic students. Both benefits, such as developing lifelong learning skills, and challenges, such as the need for training and lack of structure, of using constructivist teaching approaches are mentioned.
Dokumen tersebut membahas tentang korupsi dan upaya pemberantasannya di Indonesia. Korupsi didefinisikan sebagai tindakan yang dilakukan oleh seseorang untuk merugikan keuangan negara atau ekonomi negara dengan menggunakan kewenangan jabatannya. UU No. 30/2002 membentuk Komisi Pemberantasan Korupsi dan lembaga swadaya masyarakat ikut serta dalam pemberantasan korupsi di Indonesia.
This document discusses the impact of mobile culture on young people. It begins by outlining how mobile culture has accelerated communication but also crime and violations of norms. It then provides historical background on the development of mobile phones from the first call in 1946 to modern smartphones. The document also covers the features of modern phones and SIM cards as well as the utility of mobile phones for communication, entertainment and staying connected with others. Both positive impacts like strengthened relationships and negative impacts like distracted driving are discussed. The conclusion is that while mobiles have changed many aspects of life, their impact can be made positive.
This document provides a summary of a report on the fashion accessories industry in Nepal. It includes profiles of 29 verified Nepalese suppliers of fashion accessories, with details on their location, employees, and export capabilities. The report also gives an overview of the industry in Nepal, key findings on production, exports, challenges, and trends. Product galleries with images and specifications are provided for different categories of fashion accessories.
The document discusses the recommendations of the Narsimham Committee I, which was formed in 1991 to recommend reforms for improving the efficiency and effectiveness of India's financial system and banking sector. The committee recommended several reforms, including reducing statutory pre-emptions like SLR and CRR, introducing interest payments on CRR balances, phasing out directed lending programs, increasing transparency, improving loan recovery processes, deregulating interest rates, restructuring banks, introducing standardized asset classification and provisioning norms, allowing entry of private banks, abolishing branch licensing controls, implementing capital adequacy requirements, standardizing income recognition practices, and having RBI solely regulate the banking system instead of joint control with the Ministry of Finance. Many of the recommendations were
This document discusses ocular blood flow in glaucoma. It provides details on the arterial blood supply and venous drainage of the eye. It describes how glaucoma may be related to low ocular perfusion pressure and abnormalities in ocular blood flow autoregulation. Several studies linking low ocular perfusion pressure to glaucoma risk are summarized. Possible mechanisms like atherosclerosis, vasospasm and endothelial dysfunction that could contribute to impaired ocular blood flow in glaucoma are also outlined.
Cerebral perfusion pressure among acute traumatic brain injury patients at su...Alexander Decker
1. This study assessed the effects of supine and semi-fowler positions on cerebral perfusion pressure (CPP) and other physiological parameters among 39 patients with acute traumatic brain injuries.
2. In the semi-fowler position, patients experienced a significant increase in CPP, oxygen levels, blood pressure, and decrease in carbon dioxide levels compared to supine. The semi-fowler position was found to positively impact blood gas values, blood pressure, respiration, and oxygen saturation.
3. The supine position was associated with a significant decrease in pulse rate but no other significant changes. The study recommends further research on additional positions like side-lying and prone to establish optimal positioning guidelines for traumatic brain injury patients
Association between Blood Pressure and Intraocular Pressure in Relation to Gl...AI Publications
High blood pressure is not only associated with systemic cardiovascular complications, but also, ocular complications such as glaucoma. This study sought to determine the association between blood pressure, intraocular pressure and glaucoma. In this cross-sectional study, 162 hypertensive patients (with mean age of 57 (±14.26) years) visiting the St. Dominic’s hospital, in Ghana were purposively sampled to participate in the study. Data on patient’s history, blood pressure, intraocular pressure and cup-to-disc ratio were collected and analysed using Statistical Package for Social Sciences (SPSS) version 20. Descriptive statistics was computed and thestatistical significance of associations was assessed at a significance level of 0.01. The outcome of the study revealed a positive correlation of 0.364 and 0.309 between systolic blood pressure and the intraocular pressure of the right and left eye respectively.The correlation between diastolic blood pressure and intraocular pressure of the right and left eyes were 0.334 and 0.239 respectively. Out of the 104 patients with systolic blood pressure exceeding 139mmHg, 54 of them (51.9%) had intraocular pressures greater than 21mmHg and 58 of them (55.8%) had cup-to-disc ratio in the range of 0.7–1.0. A weak but positive correlation between systolic blood pressure and cup-to-disc was also established.Last but not least,a correlation of 0.441 between intraocular pressure and cup-to-disc ratio of the right eye of participants as against a correlation 0.256 for the left eye was reported.The susceptibility to glaucomawas thus, relatively high in patients withuncontrolled hypertension and higher intraocular pressure.Hence, pragmatic measures should be takenby all stakeholders towards managing hypertension and intraocular pressurein order to safeguard the health and sight of all.
1) Intracerebral hemorrhage is now understood as a dynamic process that evolves over days rather than a single event. Recent studies have provided insights into hematoma expansion, edema formation, and optimal blood pressure control.
2) Ongoing clinical trials are exploring intensive blood pressure control, induced hypothermia, hypertonic saline use, and other therapies to reduce hematoma growth and edema, with the goal of improving outcomes.
3) For anticoagulant-related hemorrhages, rapidly reversing coagulopathy through agents like prothrombin complex concentrates or recombinant factor VIIa may help limit expansion and improve prognosis over traditional fresh frozen plasma therapy alone.
This document summarizes evaluation and management of elevated intracranial pressure in adults. It discusses causes of increased intracranial pressure including brain masses, edema, hydrocephalus, and venous obstruction. It covers monitoring of intracranial pressure, indications for monitoring, and types of monitors. It also provides an overview of general management strategies and specific therapies to lower intracranial pressure such as osmotic therapy, glucocorticoids, hyperventilation, barbiturates, and decompressive craniectomy.
This document provides an overview of pediatric idiopathic intracranial hypertension (IIH). It discusses the epidemiology, pathophysiology, clinical presentation, diagnosis, and management of pediatric IIH. Some key points include:
- The demographics of pediatric IIH differ from adults, with equal gender distribution and no association with obesity in pre-pubertal children.
- Diagnosis involves MRI/MRV of the brain and lumbar puncture to measure intracranial pressure and check CSF.
- Treatment aims to alleviate symptoms and prevent vision loss, beginning with weight loss and acetazolamide before considering lumbar puncture or shunt placement for severe cases.
This document provides an overview of pediatric idiopathic intracranial hypertension (IIH). It discusses the epidemiology, pathophysiology, clinical presentation, diagnosis, and management of pediatric IIH. Some key points include:
- The demographics of pediatric IIH differ from adults, with equal gender distribution and no association with obesity in pre-pubertal children.
- Diagnosis involves MRI/MRV of the brain and lumbar puncture to measure intracranial pressure and examine CSF.
- Treatment aims to alleviate symptoms and prevent vision loss, and may include weight loss, acetazolamide, or CSF diversion procedures for severe cases.
This study investigated the effect of under-correcting myopia on myopic progression by analyzing clinical refraction data from 275 visits of 76 myopic patients. The results showed a significant positive correlation between the degree of under-correction and myopic progression, with greater under-correction associated with greater progression. Myopic progression also correlated positively with the degree of myopia. However, progression did not correlate with age or gender. The findings suggest that under-correcting myopia may induce small increases in myopic progression compared to full correction.
1) The study examined clinical measurements and neural changes associated with vision therapy in adults with convergence insufficiency.
2) Four subjects with convergence insufficiency underwent 18 hours of vision therapy. Clinical measurements improved and neural activity increased in areas related to vergence eye movements.
3) Convergence peak velocity was slower in subjects with convergence insufficiency compared to controls, but increased after vision therapy, suggesting therapy can improve underlying neurophysiology.
1) The study examined clinical measurements and neural changes associated with vision therapy in adults with convergence insufficiency.
2) At baseline, adults with convergence insufficiency had slower convergence eye movements compared to controls.
3) After 18 hours of vision therapy, the adults with convergence insufficiency showed improvements in clinical measurements of nearpoint of convergence and fusional vergence, as well as increased cortical activity and faster convergence eye movements.
Guidelines for the indications for 131I remnant ablation on differentiated t...Michael
This document compares guidelines from seven organizations - ATA, ESMO, BTA, NCCN, SNM, EANM, CSE/CSS/CACA/CSNM - for 131I remnant ablation in patients with differentiated thyroid cancer. While all organizations define ablation as eliminating the thyroid remnant, some guidelines incorporate additional treatment of microscopic tumors and metastases. Indications vary between guidelines and there is controversy around management of low risk patients. More evidence is needed to standardize risk stratification and guidelines. The NCCN emphasizes diagnostic imaging prior to 131I administration to target uptake in the thyroid bed. Overall guidelines are becoming more standardized with improved terminology and evidence.
This document discusses constructivist learning theory. It outlines key features of constructivism such as collaborative learning, knowledge construction through experience, and student-directed learning goals. The document also presents the 5 E model for lesson planning (engage, explore, explain, elaborate, evaluate) and provides examples of how this could be applied to teaching osteopathic students. Both benefits, such as developing lifelong learning skills, and challenges, such as the need for training and lack of structure, of using constructivist teaching approaches are mentioned.
Dokumen tersebut membahas tentang korupsi dan upaya pemberantasannya di Indonesia. Korupsi didefinisikan sebagai tindakan yang dilakukan oleh seseorang untuk merugikan keuangan negara atau ekonomi negara dengan menggunakan kewenangan jabatannya. UU No. 30/2002 membentuk Komisi Pemberantasan Korupsi dan lembaga swadaya masyarakat ikut serta dalam pemberantasan korupsi di Indonesia.
This document discusses the impact of mobile culture on young people. It begins by outlining how mobile culture has accelerated communication but also crime and violations of norms. It then provides historical background on the development of mobile phones from the first call in 1946 to modern smartphones. The document also covers the features of modern phones and SIM cards as well as the utility of mobile phones for communication, entertainment and staying connected with others. Both positive impacts like strengthened relationships and negative impacts like distracted driving are discussed. The conclusion is that while mobiles have changed many aspects of life, their impact can be made positive.
This document provides a summary of a report on the fashion accessories industry in Nepal. It includes profiles of 29 verified Nepalese suppliers of fashion accessories, with details on their location, employees, and export capabilities. The report also gives an overview of the industry in Nepal, key findings on production, exports, challenges, and trends. Product galleries with images and specifications are provided for different categories of fashion accessories.
The document discusses the recommendations of the Narsimham Committee I, which was formed in 1991 to recommend reforms for improving the efficiency and effectiveness of India's financial system and banking sector. The committee recommended several reforms, including reducing statutory pre-emptions like SLR and CRR, introducing interest payments on CRR balances, phasing out directed lending programs, increasing transparency, improving loan recovery processes, deregulating interest rates, restructuring banks, introducing standardized asset classification and provisioning norms, allowing entry of private banks, abolishing branch licensing controls, implementing capital adequacy requirements, standardizing income recognition practices, and having RBI solely regulate the banking system instead of joint control with the Ministry of Finance. Many of the recommendations were
This document discusses ocular blood flow in glaucoma. It provides details on the arterial blood supply and venous drainage of the eye. It describes how glaucoma may be related to low ocular perfusion pressure and abnormalities in ocular blood flow autoregulation. Several studies linking low ocular perfusion pressure to glaucoma risk are summarized. Possible mechanisms like atherosclerosis, vasospasm and endothelial dysfunction that could contribute to impaired ocular blood flow in glaucoma are also outlined.
Cerebral perfusion pressure among acute traumatic brain injury patients at su...Alexander Decker
1. This study assessed the effects of supine and semi-fowler positions on cerebral perfusion pressure (CPP) and other physiological parameters among 39 patients with acute traumatic brain injuries.
2. In the semi-fowler position, patients experienced a significant increase in CPP, oxygen levels, blood pressure, and decrease in carbon dioxide levels compared to supine. The semi-fowler position was found to positively impact blood gas values, blood pressure, respiration, and oxygen saturation.
3. The supine position was associated with a significant decrease in pulse rate but no other significant changes. The study recommends further research on additional positions like side-lying and prone to establish optimal positioning guidelines for traumatic brain injury patients
Association between Blood Pressure and Intraocular Pressure in Relation to Gl...AI Publications
High blood pressure is not only associated with systemic cardiovascular complications, but also, ocular complications such as glaucoma. This study sought to determine the association between blood pressure, intraocular pressure and glaucoma. In this cross-sectional study, 162 hypertensive patients (with mean age of 57 (±14.26) years) visiting the St. Dominic’s hospital, in Ghana were purposively sampled to participate in the study. Data on patient’s history, blood pressure, intraocular pressure and cup-to-disc ratio were collected and analysed using Statistical Package for Social Sciences (SPSS) version 20. Descriptive statistics was computed and thestatistical significance of associations was assessed at a significance level of 0.01. The outcome of the study revealed a positive correlation of 0.364 and 0.309 between systolic blood pressure and the intraocular pressure of the right and left eye respectively.The correlation between diastolic blood pressure and intraocular pressure of the right and left eyes were 0.334 and 0.239 respectively. Out of the 104 patients with systolic blood pressure exceeding 139mmHg, 54 of them (51.9%) had intraocular pressures greater than 21mmHg and 58 of them (55.8%) had cup-to-disc ratio in the range of 0.7–1.0. A weak but positive correlation between systolic blood pressure and cup-to-disc was also established.Last but not least,a correlation of 0.441 between intraocular pressure and cup-to-disc ratio of the right eye of participants as against a correlation 0.256 for the left eye was reported.The susceptibility to glaucomawas thus, relatively high in patients withuncontrolled hypertension and higher intraocular pressure.Hence, pragmatic measures should be takenby all stakeholders towards managing hypertension and intraocular pressurein order to safeguard the health and sight of all.
1) Intracerebral hemorrhage is now understood as a dynamic process that evolves over days rather than a single event. Recent studies have provided insights into hematoma expansion, edema formation, and optimal blood pressure control.
2) Ongoing clinical trials are exploring intensive blood pressure control, induced hypothermia, hypertonic saline use, and other therapies to reduce hematoma growth and edema, with the goal of improving outcomes.
3) For anticoagulant-related hemorrhages, rapidly reversing coagulopathy through agents like prothrombin complex concentrates or recombinant factor VIIa may help limit expansion and improve prognosis over traditional fresh frozen plasma therapy alone.
This document summarizes evaluation and management of elevated intracranial pressure in adults. It discusses causes of increased intracranial pressure including brain masses, edema, hydrocephalus, and venous obstruction. It covers monitoring of intracranial pressure, indications for monitoring, and types of monitors. It also provides an overview of general management strategies and specific therapies to lower intracranial pressure such as osmotic therapy, glucocorticoids, hyperventilation, barbiturates, and decompressive craniectomy.
This document provides an overview of pediatric idiopathic intracranial hypertension (IIH). It discusses the epidemiology, pathophysiology, clinical presentation, diagnosis, and management of pediatric IIH. Some key points include:
- The demographics of pediatric IIH differ from adults, with equal gender distribution and no association with obesity in pre-pubertal children.
- Diagnosis involves MRI/MRV of the brain and lumbar puncture to measure intracranial pressure and check CSF.
- Treatment aims to alleviate symptoms and prevent vision loss, beginning with weight loss and acetazolamide before considering lumbar puncture or shunt placement for severe cases.
This document provides an overview of pediatric idiopathic intracranial hypertension (IIH). It discusses the epidemiology, pathophysiology, clinical presentation, diagnosis, and management of pediatric IIH. Some key points include:
- The demographics of pediatric IIH differ from adults, with equal gender distribution and no association with obesity in pre-pubertal children.
- Diagnosis involves MRI/MRV of the brain and lumbar puncture to measure intracranial pressure and examine CSF.
- Treatment aims to alleviate symptoms and prevent vision loss, and may include weight loss, acetazolamide, or CSF diversion procedures for severe cases.
This study investigated the effect of under-correcting myopia on myopic progression by analyzing clinical refraction data from 275 visits of 76 myopic patients. The results showed a significant positive correlation between the degree of under-correction and myopic progression, with greater under-correction associated with greater progression. Myopic progression also correlated positively with the degree of myopia. However, progression did not correlate with age or gender. The findings suggest that under-correcting myopia may induce small increases in myopic progression compared to full correction.
1) The study examined clinical measurements and neural changes associated with vision therapy in adults with convergence insufficiency.
2) Four subjects with convergence insufficiency underwent 18 hours of vision therapy. Clinical measurements improved and neural activity increased in areas related to vergence eye movements.
3) Convergence peak velocity was slower in subjects with convergence insufficiency compared to controls, but increased after vision therapy, suggesting therapy can improve underlying neurophysiology.
1) The study examined clinical measurements and neural changes associated with vision therapy in adults with convergence insufficiency.
2) At baseline, adults with convergence insufficiency had slower convergence eye movements compared to controls.
3) After 18 hours of vision therapy, the adults with convergence insufficiency showed improvements in clinical measurements of nearpoint of convergence and fusional vergence, as well as increased cortical activity and faster convergence eye movements.
1) The study examined clinical measurements and neural changes associated with vision therapy in adults with convergence insufficiency.
2) Convergence peak velocities were slower in subjects with convergence insufficiency compared to controls, which may contribute to asthenopic complaints.
3) Subjects underwent 18 hours of vision therapy. Several clinical measurements, including nearpoint of convergence and positive fusional vergence, improved significantly after therapy. Neural activity in frontal and cerebellar regions also increased significantly.
1) The study examined clinical measurements and neural changes associated with vision therapy in adults with convergence insufficiency.
2) At baseline, adults with convergence insufficiency had slower convergence eye movements compared to controls.
3) After 18 hours of vision therapy, the adults with convergence insufficiency showed improvements in clinical measurements of nearpoint of convergence and fusional vergence, as well as increased cortical activity and faster convergence eye movements.
Nursing Case Study of a Patient with Severe Traumatic Brain Injuryrubielis
This details the critical care nurse's role in caring for a patient with severe traumatic brain injury, managing ICP and brain oxygenation. Ties in closely with Orem's self-care deficit theory for nursing.
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.
Neurocritical Care Triad - Focused Neurological Examination, Brain Multimodal...Apollo Hospitals
Intensive care is rightly described as “an art of managing intense intricacy” and this situation is further complicated in the care of patients with critical neurological illness. Brain
damage directly related to an insult is primary brain injury (PBI). The cascade of pathobiological events following PBI is known as secondary brain injury (SBI). PBI is most often
irreversible so, the focus of neurocritical care is to prevent, detect and manage SBI.
The document summarizes guidelines from the Brain Trauma Foundation (BTF) for the management of severe traumatic brain injury (TBI). The BTF released the 4th edition of these guidelines in 2016 to provide evidence-based recommendations for treating severe TBIs. The guidelines provide recommendations on various treatment strategies, such as decompressive craniectomy, hypothermia, hyperosmolar therapy, cerebrospinal fluid drainage, ventilation, anesthetics/sedatives, and monitoring thresholds. Each recommendation is assigned a level depending on the quality of evidence.
To study the variations of autonomic nervous system in hypertensive patients using a set of autonomic function tests
and to correlate cardiac autonomic function with Heart rate variability in hypertensives. Background: The pathophysiological mechanism for the development of hypertension is the lack of balance between sympathetic and parasympathetic nervous system. Both Heart rate variability (HRV) and Autonomic function tests provide a tool to know the concept of autonomic modulation of heart. They also forms an index of cardiac autonomic regulation. Methods: The study included 50 hypertensive patients and 50 normotensive
subjects. All the subjects underwent for the analysis of heart rate variability in time domain (TD) and frequency domain and a set of autonomic function tests were done to assess the autonomic functions. These results were compared with age and sex matched controls (normotensives). The subjects were selected based on exclusion-inclusion criteria. Results: Results showed that S: L ratio, Valsalva ratio & Heart rate response to deep breathing test values were decreased in Hypertensives as compared to Normotensives (p<0.05).><0.05). Both the time domain and frequency domain values of HRV reduced significantly in hypertensives indicated that there is increased sympathetic activity and decreased parasympathetic activity. Conclusion: From this study, it is evident that Hypertension can alter the normal autonomic functions of the body and predisposes to autonomic neuropathy. Early and regular screening of these individuals is necessary to prevent any future complications.
- Studies show that lowering IOP reduces risk of glaucoma progression and maintaining a steady IOP level over time is important. IOP fluctuation is associated with progressive visual field loss and is a stronger predictor of progression than mean IOP. Higher IOP fluctuation during office hours and over 24 hours is seen in glaucoma patients compared to normal subjects.
- Educating patients about their condition and treatment through tools like perimetry, OCT/GDx imaging can help improve compliance which is important for minimizing IOP fluctuations and risk of further optic nerve damage. Compliance is better with once or twice daily dosing compared to multiple medications or more frequent dosing.
Anaesthesia for elective neurosurgery journal (zuhura)AnaestHSNZ
This document summarizes key aspects of anaesthesia for elective neurosurgery. It discusses the importance of maintaining optimal cerebral perfusion pressure and oxygenation. While volatile agents remain popular, studies have found propofol and sevoflurane to be suitable options. Propofol may help reduce intracranial pressure and cerebral blood volume compared to other agents. Awake craniotomy techniques are gaining popularity for removal of brain lesions near eloquent areas to allow for neurological monitoring during the procedure. Advances in minimally invasive techniques continue to offer benefits like reduced trauma and faster recovery times.
Similar to Correlation Between Intraocular pressure(IOP)and Intracranial pressure(ICP) inDog (20)
These lecture slides, by Dr Sidra Arshad, offer a simplified look into the mechanisms involved in the regulation of respiration:
Learning objectives:
1. Describe the organisation of respiratory center
2. Describe the nervous control of inspiration and respiratory rhythm
3. Describe the functions of the dorsal and respiratory groups of neurons
4. Describe the influences of the Pneumotaxic and Apneustic centers
5. Explain the role of Hering-Breur inflation reflex in regulation of inspiration
6. Explain the role of central chemoreceptors in regulation of respiration
7. Explain the role of peripheral chemoreceptors in regulation of respiration
8. Explain the regulation of respiration during exercise
9. Integrate the respiratory regulatory mechanisms
10. Describe the Cheyne-Stokes breathing
Study Resources:
1. Chapter 42, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 36, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 13, Human Physiology by Lauralee Sherwood, 9th edition
Muktapishti is a traditional Ayurvedic preparation made from Shoditha Mukta (Purified Pearl), is believed to help regulate thyroid function and reduce symptoms of hyperthyroidism due to its cooling and balancing properties. Clinical evidence on its efficacy remains limited, necessitating further research to validate its therapeutic benefits.
Histololgy of Female Reproductive System.pptxAyeshaZaid1
Dive into an in-depth exploration of the histological structure of female reproductive system with this comprehensive lecture. Presented by Dr. Ayesha Irfan, Assistant Professor of Anatomy, this presentation covers the Gross anatomy and functional histology of the female reproductive organs. Ideal for students, educators, and anyone interested in medical science, this lecture provides clear explanations, detailed diagrams, and valuable insights into female reproductive system. Enhance your knowledge and understanding of this essential aspect of human biology.
- Video recording of this lecture in English language: https://youtu.be/kqbnxVAZs-0
- Video recording of this lecture in Arabic language: https://youtu.be/SINlygW1Mpc
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Adhd Medication Shortage Uk - trinexpharmacy.comreignlana06
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These lecture slides, by Dr Sidra Arshad, offer a quick overview of the physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar lead (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
6. Describe the flow of current around the heart during the cardiac cycle
7. Discuss the placement and polarity of the leads of electrocardiograph
8. Describe the normal electrocardiograms recorded from the limb leads and explain the physiological basis of the different records that are obtained
9. Define mean electrical vector (axis) of the heart and give the normal range
10. Define the mean QRS vector
11. Describe the axes of leads (hexagonal reference system)
12. Comprehend the vectorial analysis of the normal ECG
13. Determine the mean electrical axis of the ventricular QRS and appreciate the mean axis deviation
14. Explain the concepts of current of injury, J point, and their significance
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. Chapter 3, Cardiology Explained, https://www.ncbi.nlm.nih.gov/books/NBK2214/
7. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Correlation Between Intraocular pressure(IOP)and Intracranial pressure(ICP) inDog
1. Alireza Sheikhi M.D
Under super vision of
EhsanAli Aliby M.D and
M.Mehdizadeh,M.D
Neuroscience Research Center
Department of Neurosurgery
Poostchi Eye Research Center
Department of Ophthalmology
Shiraz university of medical sciences
2.
3. 1-1: optic nerve
Optic nerve is the second pair of the cranial nerves in
the human and overall it is considered as the parts of
central nervous system.
It is surrounded by all three meningial layers. In the
other word , optic nerve is a part of brain which is
extending into the periphery and it covers as it in the
brain tissue. (1, 2)
Overall the optic nerve has four anatomical parts: the
intraocular, intra orbital, intra canalicular, and intra
cranial sections. (2)
4.
5. 1-2: Intra ocular pressure
Intra ocular pressure (IOP) is the pressure of fluid inside the
eyes. (3, 4) the fluid is produced by aqueous humor and
drainage from trabeclar meshwork which is located in the
anterior chamber angle. The pressure is also influenced by
thickness and rigidity of corneal.
Tonometer is an acceptable method for measurement of IOP.
Normal IOP is defined between 10 mmHg up to 20 mmHg.
(Average of 15.5) (3, 4)
With considering of direct connection of optic nerve and brain
tissue, it is acceptable to think about the possible correlation
between intraocular pressures in the globe and intra cranial
pressure in the brain.
6. 1-3: Intra Cranial Pressure
Intracranial pressure (ICP) is the fluid pressure
inside the skull and on the brain tissue. The
pressure is mainly controlled by balance in the
production and absorption of fluid. CSF produced
by choroid plexus and the brain float in it.
(5) ICP is normally varied between 7-20 mmHg in
the supine position and became negative in the
vertical position. (6,7)
7. There is several mechanism of increasing in ICP,
mass effects of tumors or abscess can directly
cause increasing in ICP. Increase in CSF production
in meningitis, idiopathic intracranial hypertension
is the other cause. (6)
Headache, nausea and vomiting are most important
symptoms in increasing in ICP. Altered level of
consciousness and papilledema are the signs that
detected in physical examination. An edemas optic
nerve is a helpful sign that shows the ICP elevation.
(7, 8)
8. 1-4: Lamina cribrosa
Lamina cribrosa works as a junction between intra
cranial and intra ocular compartments. It is a Mesh-
like structure. This structure formed by several layers
which is containing of collagen fibers.
The optic nerve fibers exit the eye ball through this
sclera hole in the posterior part of the globe. It is
helps to maintain the pressure gradient among the
eye tissues and surrounding parts. By increase in the
intraocular pressure this component bulges outward,
this bulging and pressure effect on the optic nerve is
considered as an important pathology in glaucoma
and other disease with increasing IOP. (9)
9.
10.
11. 1_5:CSF pressure may be equivalent to IOP in
its influence on laminar pressure gradient
and optic disk surface movement.
The correlation of IOP and ICP was based
partly to both anatomical and physiological
connection between intracranial fossa in one
hand and orbit in the other hand, considering
with the compression of posterior globe by
neuro imaging in some patients with
increased ICP.
12. 1_6:The direct connection of optic nerve and the
brain tissue suggests that there should be a possible
correlation between IOP in the globe and ICP in the
brain, lamina cribrosa works as a junction between
these two compartments and it may play an unknown
role in this relation.
In the other word, both CSF pressure and IOP
influence the laminar pressure gradient in and
consequently on the optic disk surface movement.
The influence of CSF pressure affects the axonal
transport, which is known to be important in
glaucoma process.
13. 1_7:Based on the detection of posterior
compression of the globe in some patients with
increased ICP in neuro imaging studies, the
balance between the CSF pressure around the
optic nerve and the IOP in the globe may change
the position of the lamina cribrosa.
So papilledema may be the results of imbalance
between ICP and IOP that leads to bowing of the
lamina cribrosa toward the less pressured
chamber, i.e. the vitreous cavity. (10)
14. 1_8:Posterior bowing of the lamina cribrosa known as
cupping in the glaucoma patients may be another
presentation of this imbalance.
Accordingly, it was supposed that this compression of
posterior of glob may lead to a transient event that may
resemble as a temporary increase in IOP. The increase of
IOP would accordingly return to base line by any means
since IOP was controlled by numerous factors.
The correlation between IOP and ICP still remains un-
clarified and there are controversies of presence of any
correlation between IOP and ICP. In this study we try to
investigate the effect of iatrogenic reduction of Intraocular
Pressure on Intracranial Pressure in dogs as animal
models.
17. 1_1)Berdahl JP et al study in 2008
Berdahl JP et al in 2008 via a case control study
tried to compare cerebrospinal fluid (CSF)
pressure in patients with primary open-angle
glaucoma (POAG) and with that in
nonglaucomatous patients.
In this study between 1996 to 2007 Thirty-one
thousand, seven hundred and eighty-six subjects
were underwent lumbar puncture (LP)..
18. The mean CSF pressure was 13.0+/-4.2 mmHg
in nonglaucomatc patients and 9.2+/-2.9 mmHg
in POAG patients (P<0.00005). The CSF pressure
was lower in POAG patients.
Linear regression analysis showed that cup-to-
disc ratio was correlated independently with IOP
(P<0.001), CSF pressure (P<0.001), and the
Trans laminar pressure difference (P<0.001).
On the other hand Multivariate analysis showed
that larger cup-to-disc ratio (P<0.001) was
associated with lower CSF pressure.
19. Accordingly in his study the researchers
demonstrated that CSF pressure is
significantly lower in POAG patients in
compare with that in nonglaucomatous
controls.
Their results support the notion that CSF
pressure may play an important contributory
role in the pathogenesis of POAG. (11)
20. 2_1)Dickerman RD et al study in 1998
In the study of Dickerman RD et al in 1998 the
researchers tried to investigated that does Intra-
ocular pressure changes during maximal isometric
contraction reflect intra-cranial pressure or retinal
venous pressure or not.
This study was started with review of the articles
which was evaluated the recent publications. The
researchers mentioned that the recent studies have
suggested IOP may be an indirect assessment of ICP.
21. Both IOP and ICP have similar physiologic pressure
ranges and both have similar responses to changes in
intra-abdominal, intra-thoracic and aortic pressure.
The researchers said that there are many reports that
showed the intracranial hemorrhage, subarachnoid
hemorrhage, retinal hemorrhage and retinal
detachment are associated with weight lifting but
there are no human study which examined the IOP
changes during heavy exercises and weight lifting.
So they tried to investigate the IOP changes during
maximal isometric contraction.
22. In this study Intra-ocular pressure was measured
by noncontact tonometry at rest and during
maximal isometric contraction.
All subjects IOP were within normal ranges
(mean 13 +/- 2.8 mmHg) at rest but it was
significantly (p < 0.0001) elevated in each
subject during maximal contraction (mean 28
+/- 9.3 mmHg).
Linear regression analysis showed a significant
linear relationship (r = 0.62, p < 0.0001) in the
net change of IOP from rest to maximal
contraction for each subject.
23. Their study demonstrates that IOP elevates to
pathophysiologic levels during resistance
exercise. The increased pressures generated
by power athletes during weightlifting may
leads to elevations in ICP which obstruct
venous outflow leading to hemorrhage and
elevations in IOP. (12).
24. Sajjadi SA et al study in 2006
In the study which was done on 2006 in Tehran
university sajjadi et al evaluated the correlation
between ICP and IOP. Their study was performed on
77 patients. The patients who had any history of
glaucoma, using drugs which affected IOP and
abnormal ocular finding were excluded from the
study.
ICP of the other patients was measured by LP and
IOP was measured by two scales of Schiotz tonometer
in both eyes and the mean was calculated. Finally
they found a significant correlation between IOP and
ICP. (13)
25. Sheeran P et al study in 2000
In the study which was performed at 2000 by
Sheeran P et al they demonstrated that
although there is a significant correlation
between intraocular pressure and intracranial
pressure in neurosurgical patients, change in
intraocular pressure is a poor predictor of
change in intracranial pressure. (14)
26. Han Y, et al study in 2008
On the other hand Han Y, et al in 2008 showed there
isn’t any correlation between intraocular pressure and
intracranial pressure.
They reviewed the medical records of all patients
who underwent lumbar puncture between 1991 and
2007 in the neuro-ophthalmology clinic of the
University of California San Francisco. Data for IOP
and ICP were available for 55 patients. But they didn’t
find any correlation between IOP and ICP (Pearson
correlation coefficient, r = 0.07; p = 0.59) and
accordingly mentioned that IOP measurement is not a
useful substitute for ICP measurement. (15)
27. 1_The mentioned studies had several
limitations for example some of these studies
was performed only patients with both
glaucoma and neurological problem
necessitate lumber puncture that may affect
the results of study by some unexpected
biases.
28. 2_Nowadays, the subject of any correlation
between IOP and ICP remains as a
sophisticated puzzle to be resolved.
Since there is no animal model study in the
literature, as a first experience in the world,
the present study was designed to evaluate
any relation of IOP and ICP under controlled
experimental condition by inducing iatrogenic
reduction of IOP in normal eyes and healthy
animals and measurement of ICP in response
29.
30.
31. 1-1;Fifteen matured healthy out-bred dogs (
mean: 10 kg) provided from laboratory animal
center related to shiraz university of medical
sciences , were enrolled. The study was approved
in the university ethic committee and all
procedures were performed in accordance to
ARVO statement for the use of animals.
In the supine position all the dogs underwent
general anesthesia using Nesdonal (Sandoz,
Gmbh , Kundl, Austria )
32. 1-2:The mean IOP was recorded by double
measurements in both eyes and considered as a
primary IOP. The animals were allocated to three
groups. Group 1 received Timolol ( Timolol sina
darou) one drop each 12 hours, As topical anti
glaucoma medication only in the right eye.
Group 2, received latanoprost (Xalatan , Farmacin ,
Belgium) ; one drop once a day. And group 3
underwent Trabeculectomy in the right eye to reduce
IOP. The IOP was determine using tonopen (Roichert
TONO-PEN XL Applanation) for both eyes except for
group 3 where the mean pressure was recorded by
double measurement of IOP in the right eye . (Table
3-1)
33. 1_3:To measure the ICP, the hairs were
clipped in the back of the head and the neck
area of the dogs. For cerebromedullary
approach, the land mark for midline position
( the occipital protuberance) was marked and
the neck of the animal was positioned in
hands and flexed up to optimal position for
palpation of the space .
34. 1_4:A 22 gauge needle was inserted in
midline near the cranial borders of the wing
of atlas. (C1)When a slight loss of resistance
was determined the needle was inserted
further. A 3 way tube was connected to the
needle and when a flow of CSF was observed
in the tube, the CSF pressure was measured
against a water column.
35. Table 3-1: type of intervention in each group
Groups Type of intervention in
right eye
Group 1 Timolol drop 0.5% twice a
day
Group 2 Latanoprest(xalatan )drop
daily
Group 3 Trabeculectomy operation
36. 1_6:Trabeculectomy
Trabeculectomy was performed using Watson’s
modification of the Cairns technique (16) first, a
limbus-based conjuctival flap was prepared, the
sclera was exposed and a rectangular 3*4 mm
sclera flap was made. Then a 1 mm sclerosomy
was made followed by peripheral iridectomy and
finally the conjunctiva was closed with a
continuous 10-0 nylon suture.
37.
38. 1_7:In the same manner, after 2 and 4 weeks
of drug administration or surgical procedure,
the IOP was measured with tonopen in the
right eye. The procedure was similarly carried
out four weeks later.
39. 1_8:To show the correlation between IOP and
ICP, all results were sorted while ignoring the
methods of reduction of IOP and also the
time of measurements.
All the dogs underwent a same method of
anesthesia, and measurement of IOP and ICP
was the same in all groups so bias effect of
these materials will be at least.
40. 1_9:An analysis of variables with repeated measure
design was used to determine changes in parameters
over time (day 0, 14, and 28). An independent t-test
was used to determine possible differences in various
parameters in IOP and ICP on day 0, 14, and 28.
Pearson correlation coefficient was used to
determine the strength of the relationship existing
among various parameters. On the other hand we
used General linear model to evaluate ghanges in
each group separately.
The data were analyzed, using the statistical package
for social science series (SPSS 15.0) and p≤ 0.05 was
considered as significant.
41.
42.
43. 1_1:There were 15 skeletally mature healthy dogs
enrolled in this study .All dogs were remained
lived till end of study .The overall mean age was
2.1years± 0.28 (range: 1.5-2.5 years) with a
mean weight of 17.5 ± 1.18 kg (16-19 kg).
The mean primary IOP was 20.40± 4.70 and that
of ICP was 7.46± 2.09. As is shown in table 4-1
dogs randomly allocated in 3 groups were
matched in terms of weight, age, and also in
both primary IOP and ICP. (Table 4-1)
44. Groups Age Weight Primary IOP Primary ICP
Group A 2-2.5
2.2± 0.27
16-19
17±1.41
15-27
22.80±4.71
5-9
6.6±1.81
Group B 1.5-2
1.90±0.22
16-19
17.8±1.09
15-27
21.8±4.65
5-10
7.6±2.07
Group C 2-2.5
2.20±0.27
16-19
17.7±1.09
14-20
16.6±2.40
5-10
8.2±2.48
P value 3.65 1.01 4.76 1.90
Table4-1: primary
measurements of the
parameters
45. 1_3:According to drug administration and
trabeculectomy to changes IOP and
subsequently evaluate changes in ICP
multiple liner repeated measurement was
performed that showed statistically
considerable deference in IOP after drug
administration for 2 weeks and even after 4
weeks indicative of effective application of
drugs and confirmed the study to full fill our
idea (Table 4-2, figure 4-1).
46. Groups
IOP
Primary IOP IOP after 2
weeks of drug
administration
IOP after 4
weeks of drug
administration
P value
Group A 15-27
22.80±4.71
10-19
16.2 ±3.70
10-18
14.8±3.27
0.003
Group B 15-27
21.8±4.65
10-18
14.2±3.89
9-14
11.4±2.40
0.00
Group C 14-20
16.6±2.40
3-6
4.4±1.14
3-5
4±0.70
0.00
Table 4-2: secondary
measurements of the
parameters
47. 0
5
10
15
20
25
30
Intera Ocular Pressure
Intera Cranial Pressure
Prior to drug adminstration
or surgery
2 weeks after to drug
adminstration or surgery
4 weeks after to drug
adminstration or surgery
48. 0
5
10
15
20
25
30
Intera Ocular Pressure
Intera Cranial Pressure
Prior to drug adminstration
or surgery
2 weeks after to drug
adminstration or surgery
4 weeks after to drug
adminstration or surgery
49. 0
5
10
15
20
25
30
Intera Ocular Pressure
Intera Cranial Pressure
4 weeks after to drug
adminstration or surgery
2 weeks after to drug
adminstration or surgery
Prior to drug adminstration
or surgery
51. 1_5:In this regard the correlation of primary
IOP and primary ICP was not statistically
significant ( 17.50 vs. 20.40; P Value:
0.95 ); however after 2 weeks these
measures become considerable ( 11.06
vs. 11.73 ; P value : 0.02 ) . Subsequently;
after 4 weeks again results were infavor of
considerable negative correlation of IOP and
ICP ( 10.06 vs. 11.83 ; P value: 0.02 ).
52. 1_6:On the other hand ; as we encounter with
statistically considerable correlation between
IOP and ICP in order to be able to make a
model for the relation we joined all the
results of IOP and ICP ignoring methods of
induced IOP changes and also time of
measurement in order to IOP in 45 samples .
53. 1_7:Therefore , according to Pearson
correlation analysis there was considerable
negative correlation between IOP ( v= -0.67 ;
P value =0.00 )(fig. 4-5) .As was shown in
table 3 , felting a multiple regression model
to the data , where ICP was the dependent
variable and IOP was the continuous predictor
variable and generated the model to show
correlation as follows:
54. 1_8:(^ICPi) =15.66 - 0.337 IOP, ( R2 =0.448 )
and according to the table 4 the regression
analysis acceptable statistically.
55. Table 4-4: Measures was indicated that the regression analysis
acceptable statistically.
Model Un
standardiz
ed
coefficients
Standardiz
ed
coefficients
t Significant
Constant
IOP
B Std.Error Beta 242.034 34.939
15.066 0.890 -0.670 16.930 0.00
-0.337 0.057 -0.670 -5.911 0.00
59. 1_1:According to what mentioned in the
introduction and review of the articles it
seems that the compression of posterior of
glob may led to a transient event which can
temporary causes increased in the IOP.
In contrast IOP may have some effects in the
ICP. As the best of our knowledge IOP can
controlled by many factors in this study we
tried to investigate this relation and also the
effect of decreasing in the IOP on ICP.
60. 1_2:The relation of ICP and IOP is a subject of
controversy till now. Sajjadi and colleagues
claimed that there was a strong positive
correlation between IOP and ICP (r= 0.955)
and introduced IOP measurement as a reliable
non invasive procedure for evaluation of ICP
in patients with neurosurgical problems.
61. 1_3:The mechanism painted out by Saladin et al
for direct correlation of IOP and ICP was
attributed to the anatomical and physiological
connection between intracranial fosse and orbit
by detection of the compression of posterior
globe by neuro imaging in some patients with
increased ICP ; however , as was mentioned this
rising of IOP if actually happened was only a
transient event with rapid reversal to baseline
since there was no increasing of IOP was
observed in response to increase of ICP in other
studies.
62. 1_4:One of them was the study was designed by
Han Y, et al 2008 on records of 55 patients
underwent concomitant measurement IOP and
ICP between 1991 and 2007 in the neuro-
ophthalmology clinic at the University of
California San Francisco.
Their results were indicative of no correlation
between IOP and ICP (Pearson correlation
coefficient, r = 0.07; p = 0.59)and they implied
that IOP measurement is not a useful substitute
for ICP measurement.
63. 1_5:As a promising new finding was Berdahl et al
study which was the new detection of low CSF
pressure in patients with open angle glaucoma
and they suggested that low CSF Pressure may
work in concert with IOP to produce an
unacceptably high Tran laminar pressure
gradient (a pressure difference across the lamina
cribrosa), .
they introduced this event as a disrupting
pathway for retinal ganglion cell axoplasmic flow,
ultimately leading to retinal ganglion cell
apoptosis and visual loss in patients with
glaucoma.
64. 1_6:Since then many letters are published
giving variable arguments on the results of
this study and to finding a way for
interpretation of their results.
One of the pitfall points pertained to that
study was the selection of patients with
neurological problem which may have
confounding effect and can be considered as
an obstacle to generalize the results to all
conditions.
65. 1_7:The present study was the first animal model
study to show the pattern of correlation of ICP in
response to iatrogenic reduction of IOP in healthy
mature dogs. The superiority of this study to
others is the selection of normal eyes to be
enabled to measure purely the effect of IOP on
ICP.
Since IOP can be changed in stressful conditions
even in animals and also to measure both IOP
and ICP in all subjected in a similar stable
condition all dogs were received general
anesthesia and measurements began in a
moments after intubations .
66. 1_8:We refused to use Ketamin as a known
drug to affect IOP and ICP.
Instead we use pento barbital and we
consumed that since we measured all
parameters in all dogs in the same condition
with the same medication any possible
confounding effect of anesthesia would be
eliminated.
67. 1_9:Also, two different drugs with different
mechanisms for reduction of IOP as well as
surgical procedure with another alternate
mechanism for lowering IOP was used to
overcome other possible biases in this study.
Our results were confirmed the subject
reported by Berdahl et al in a way that IOP
was correlated with ICP with a statistically
significant negative standardize coefficient i.e
about – 0.67 , pv =0.00
68. 1_10:Also the regression formula estimated
this relation to be ^ICPi = 15.06 – 0.337 IOP
(R² =0.448).The question to be addressed in
this subject is the mechanism this relation
could be interpreted as was expected by
Berdahl et al study.
69. 1_11:There might be some unknown
receptors in the lamina crirosa that function
as detectors of any changes in both IOP and
ICP. Their attempts will be toward
measurements of the sum of IOP and ICP to
be constant.
70. 1_12:Therefore, any reduction or elevation in
pressure of IOP or ICP would result in the
inverse changes of the counterpart to hold
this summation unchanged.
In the other words, in a case of glaucoma,
while the receptors detected high IOP , they
work toward reduction of IOP but because of
the presence of malfunction and pathology
behind glaucoma process , they could reduce
only in ICP.
71. 1_13:Conversely, in the patients with low IOP,
their activation would result in an increase in
ICP. The same mechanism will work toward
any reduction in IOP as shown in this study.
72. 1_14:In conclusion, there was a negative
linear correlation between IOP and ICP when
the multiple regression formula was applied
to make a model.
As reduction of IOP in a single eye
considerably affected ICP, it is reasonable
that changes in IOP in both eyes may have
more effects on ICP.
73.
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