The best method readily available to the clinician for performing this examination is high plus lens fundus biomicroscopy. Optimal magnification can be achieved by using a +60D lens which provides 1.5 times the magnification of a 90D lens. During this examination the patient's pupils must be maximally dilated with a combination of mydriatic agents such as 1% Tropicamide and 2.5% Phenylephrine.
open-globe injuries in palestinePalestine: epidemiology and factors associate...Riyad Banayot
Background: The purpose was to describe the epidemiology of open-globe injury (OGI) in Palestine and identify
the prognostic factors associated with profound visual loss.
Materia l and methods: The current study is a retrospective review of hospital files for 83 consecutive patients
with OGI who presented to St. John Eye Hospital, Jerusalem, within 5 years, between 2009 and 2013. Demographic
details included age, gender, wound characteristics, and visual acuity (VA). The Ocular Trauma Classification Group
was used for wound location, classification, and scoring for each case.
Results: We identified 83 OGI that presented to St. John eye hospital. The study group included 62 males and
21 females. The mean age was 16.66 years ± 3.216. The most frequent injuries were playground injuries (59%),
followed by workplace injuries (26.5%). Penetrating injuries represented 45.8% of injuries, and rupture globes
occurred in 39.8% of cases. The most frequent objects causing injury were metal (31.3%) and stone (20.5%). Kinetic
impact projectiles were a statistically significant poor prognostic factor for the visual outcome. Variables that
were statistically significant poor prognostic factors for visual outcome included: retinal detachment, macular scar,
vitreous hemorrhage.
Conclusi on: This study showed that the act of demonstration, street injuries, kinetic impact projectiles, zone III
injuries, globe disruption, retinal detachment, vitreous hemorrhage, and a poor VA at the first visit are poor prognostic
factors for OGI. Recognition of these prognostic factors will help the ophthalmologist evaluate the injury
and its prognosis.
open-globe injuries in palestinePalestine: epidemiology and factors associate...Riyad Banayot
Background: The purpose was to describe the epidemiology of open-globe injury (OGI) in Palestine and identify
the prognostic factors associated with profound visual loss.
Materia l and methods: The current study is a retrospective review of hospital files for 83 consecutive patients
with OGI who presented to St. John Eye Hospital, Jerusalem, within 5 years, between 2009 and 2013. Demographic
details included age, gender, wound characteristics, and visual acuity (VA). The Ocular Trauma Classification Group
was used for wound location, classification, and scoring for each case.
Results: We identified 83 OGI that presented to St. John eye hospital. The study group included 62 males and
21 females. The mean age was 16.66 years ± 3.216. The most frequent injuries were playground injuries (59%),
followed by workplace injuries (26.5%). Penetrating injuries represented 45.8% of injuries, and rupture globes
occurred in 39.8% of cases. The most frequent objects causing injury were metal (31.3%) and stone (20.5%). Kinetic
impact projectiles were a statistically significant poor prognostic factor for the visual outcome. Variables that
were statistically significant poor prognostic factors for visual outcome included: retinal detachment, macular scar,
vitreous hemorrhage.
Conclusi on: This study showed that the act of demonstration, street injuries, kinetic impact projectiles, zone III
injuries, globe disruption, retinal detachment, vitreous hemorrhage, and a poor VA at the first visit are poor prognostic
factors for OGI. Recognition of these prognostic factors will help the ophthalmologist evaluate the injury
and its prognosis.
Optometric examination and management of geriatric problems.pptxAnisha Heka
Normal age related changes
Common pathological changes with age
Optometric examination of geriatric population
Complications in examination of older patient
Vision Corrections in older patient
Clinical and dermographics profile of glaucoma patients in Hebron - Palestin...Riyad Banayot
ABSTRACT
BACKGROUND: The purpose of the study was to describe the clinical profile of glaucoma types, treatment modalities, visual outcomes, and intraocular pressure (IOP) control for patients in Palestine.MATERIAL AND METHODS: Data collection was done through the hospital record review, which included basic demographics including file number, age, sex, family history of glaucoma, history of anti-glaucoma and steroid medication, history of ocular trauma or surgery, etiology of secondary glaucoma and history of systemic illness. All the patients had a comprehensive eye examination, including visual acuity, intraocular pressure, vertical cup-disc ratio, and gonioscopy. Data were obtained, tabulated, and organized using Microsoft Excel, and statistical analyses were done using Wizard Version 1.9.49 by Evan Miller.RESULTS: There were 100 females with a mean age of 53 and 101 males with a mean age of 67. Primary open-angle glaucoma and its variants represented 45.3% of all patients, while secondary glaucoma represented 40.3% and primary angle closure glaucoma represented 10.4%. The prevalence of glaucoma increased with age, and the last visual acuity (VA) showed that 39.2% of eyes had Normal/near normal VA. The highest average IOP of 25 mm Hg was recorded among secondary glaucoma patients. Of all glaucoma eyes studied, 64% were on one or two medications, and the most common surgical procedures performed were peripheral iridectomy 18.2% followed by trabeculectomy 15.5%. CONCLUSION: Primary open-angle glaucoma (POAG) was the predominant glaucoma. Glaucoma increased significantly with advancing age. Pseudoexfoliation and neovascular glaucoma comprised the majority of secondary glaucoma.
Acute ocular chemical injury: a descriptive assessment and management review ...Riyad Banayot
Background: The purpose of the study was to assess caregivers’ compliance with the management protocol for
chemical injury at St. John Eye Hospital, Jerusalem.
Materia l and methods: Charts of all new chemical injury patients who presented to St. John Eye Hospital,
Jerusalem, between January and December 2019 were retrospectively reviewed. Data categories collected included:
Presentation, age, sex, injury, irrigation, lids, visual acuity, slit-lamp examination (SLE), management plan, and
medications given. Data were stored and analysed using Excel.
Results: Patients’ presentation date and time, sex, and age were recorded in over 90% of cases. The mechanism of
injury and type of offending chemical were recorded in 65% of cases. The irrigating solution was identified in 50%
of cases. Corrected visual acuity was recorded in both eyes in almost 50% of cases. Limbal ischemia was documented
in 45% of cases, and intraocular pressure (IOP) was recorded in 25%. The management plan and explanation of the
condition to patients were documented in less than 50% of cases. Antibiotics and steroids (drops/ointment) were
prescribed in 92.5% of cases.
Conclusi ons: The results of this study reveal that our documentation needs improvement for several parameters.
Several recommendations were formulated:
1. Emphasize to caregivers that irrigation must be done first.
2. Corrected visual acuity should be attempted for both eyes in all cases, and reasons for not recording it should be
documented.
3. It is important to document and record limbus details, iris details, and IOP in all cases.
Use of digital retinal camera to detect prevalence and severity of diabetic ...Riyad Banayot
ABStrAct
BAckGround: The purpose of this study was to determine the prevalence of diabetic retinopathy among Palestinian
refugees serviced by the Diabetic Retinopathy Screening Program in the Occupied Palestinian Territories (DRS-
-OPT).
MAterIAl And MethodS: This is a retrospective study of retinal images of 1891 diabetic patients in 15 urban
UNRWA clinics participating in the DRS-OPT program in Palestine over 12 months. A nonmydriatic Canon CR-2
fundus retinal camera was used to capture two 450 non-stereo fundus images for each eye. Qualified graders (nurses)
performed the grading based on the DRS-OPT grading system.
reSultS: Out of the 1891 diabetic patients screened, 1694 had at least one gradable eye. 16% of patients had
diabetic retinopathy (5.7% had mild nonproliferative diabetic retinopathy, 4.3% had moderate nonproliferative
diabetic retinopathy, 1.1% had severe, moderate nonproliferative diabetic retinopathy, and 1.7% had proliferative
diabetic retinopathy. Maculopathy without retinopathy amounted to 3%. Other findings included the identification
of blinding diseases such as age-related macular degeneration and optic disc glaucomatous cupping.
concluSIonS: The retinopathy screening program using a nonmydriatic fundus camera identified diabetic retino-
pathy in 16% of diabetic Palestinian refugees. A total of 72% of these patients were diabetics with nonproliferative
retinopathy. This program can be used to prevent progression by facilitating the education of patients and early
intervention.
Bilateral lens capsule rupture in a patient with previously undiagnosed alpor...Riyad Banayot
Ophthalmologists may be the first to consider the diagnosis of Alport’s Syndrome based on lens changes. Uncontrolled Blood pressure can delay surgery during which time IOP should be monitored closely. Results of lensectomies with foldable IOL implantation are successful. To our knowledge, this is the second report of a case of bilateral lens capsule rupture in a patient with previously undiagnosed Alport’s Syndrome.
India Clinical Trials Market: Industry Size and Growth Trends [2030] Analyzed...Kumar Satyam
According to TechSci Research report, "India Clinical Trials Market- By Region, Competition, Forecast & Opportunities, 2030F," the India Clinical Trials Market was valued at USD 2.05 billion in 2024 and is projected to grow at a compound annual growth rate (CAGR) of 8.64% through 2030. The market is driven by a variety of factors, making India an attractive destination for pharmaceutical companies and researchers. India's vast and diverse patient population, cost-effective operational environment, and a large pool of skilled medical professionals contribute significantly to the market's growth. Additionally, increasing government support in streamlining regulations and the growing prevalence of lifestyle diseases further propel the clinical trials market.
Growing Prevalence of Lifestyle Diseases
The rising incidence of lifestyle diseases such as diabetes, cardiovascular diseases, and cancer is a major trend driving the clinical trials market in India. These conditions necessitate the development and testing of new treatment methods, creating a robust demand for clinical trials. The increasing burden of these diseases highlights the need for innovative therapies and underscores the importance of India as a key player in global clinical research.
Antibiotic Stewardship by Anushri Srivastava.pptxAnushriSrivastav
Stewardship is the act of taking good care of something.
Antimicrobial stewardship is a coordinated program that promotes the appropriate use of antimicrobials (including antibiotics), improves patient outcomes, reduces microbial resistance, and decreases the spread of infections caused by multidrug-resistant organisms.
WHO launched the Global Antimicrobial Resistance and Use Surveillance System (GLASS) in 2015 to fill knowledge gaps and inform strategies at all levels.
ACCORDING TO apic.org,
Antimicrobial stewardship is a coordinated program that promotes the appropriate use of antimicrobials (including antibiotics), improves patient outcomes, reduces microbial resistance, and decreases the spread of infections caused by multidrug-resistant organisms.
ACCORDING TO pewtrusts.org,
Antibiotic stewardship refers to efforts in doctors’ offices, hospitals, long term care facilities, and other health care settings to ensure that antibiotics are used only when necessary and appropriate
According to WHO,
Antimicrobial stewardship is a systematic approach to educate and support health care professionals to follow evidence-based guidelines for prescribing and administering antimicrobials
In 1996, John McGowan and Dale Gerding first applied the term antimicrobial stewardship, where they suggested a causal association between antimicrobial agent use and resistance. They also focused on the urgency of large-scale controlled trials of antimicrobial-use regulation employing sophisticated epidemiologic methods, molecular typing, and precise resistance mechanism analysis.
Antimicrobial Stewardship(AMS) refers to the optimal selection, dosing, and duration of antimicrobial treatment resulting in the best clinical outcome with minimal side effects to the patients and minimal impact on subsequent resistance.
According to the 2019 report, in the US, more than 2.8 million antibiotic-resistant infections occur each year, and more than 35000 people die. In addition to this, it also mentioned that 223,900 cases of Clostridoides difficile occurred in 2017, of which 12800 people died. The report did not include viruses or parasites
VISION
Being proactive
Supporting optimal animal and human health
Exploring ways to reduce overall use of antimicrobials
Using the drugs that prevent and treat disease by killing microscopic organisms in a responsible way
GOAL
to prevent the generation and spread of antimicrobial resistance (AMR). Doing so will preserve the effectiveness of these drugs in animals and humans for years to come.
being to preserve human and animal health and the effectiveness of antimicrobial medications.
to implement a multidisciplinary approach in assembling a stewardship team to include an infectious disease physician, a clinical pharmacist with infectious diseases training, infection preventionist, and a close collaboration with the staff in the clinical microbiology laboratory
to prevent antimicrobial overuse, misuse and abuse.
to minimize the developme
CRISPR-Cas9, a revolutionary gene-editing tool, holds immense potential to reshape medicine, agriculture, and our understanding of life. But like any powerful tool, it comes with ethical considerations.
Unveiling CRISPR: This naturally occurring bacterial defense system (crRNA & Cas9 protein) fights viruses. Scientists repurposed it for precise gene editing (correction, deletion, insertion) by targeting specific DNA sequences.
The Promise: CRISPR offers exciting possibilities:
Gene Therapy: Correcting genetic diseases like cystic fibrosis.
Agriculture: Engineering crops resistant to pests and harsh environments.
Research: Studying gene function to unlock new knowledge.
The Peril: Ethical concerns demand attention:
Off-target Effects: Unintended DNA edits can have unforeseen consequences.
Eugenics: Misusing CRISPR for designer babies raises social and ethical questions.
Equity: High costs could limit access to this potentially life-saving technology.
The Path Forward: Responsible development is crucial:
International Collaboration: Clear guidelines are needed for research and human trials.
Public Education: Open discussions ensure informed decisions about CRISPR.
Prioritize Safety and Ethics: Safety and ethical principles must be paramount.
CRISPR offers a powerful tool for a better future, but responsible development and addressing ethical concerns are essential. By prioritizing safety, fostering open dialogue, and ensuring equitable access, we can harness CRISPR's power for the benefit of all. (2998 characters)
One of the most developed cities of India, the city of Chennai is the capital of Tamilnadu and many people from different parts of India come here to earn their bread and butter. Being a metropolitan, the city is filled with towering building and beaches but the sad part as with almost every Indian city
Defecation
Normal defecation begins with movement in the left colon, moving stool toward the anus. When stool reaches the rectum, the distention causes relaxation of the internal sphincter and an awareness of the need to defecate. At the time of defecation, the external sphincter relaxes, and abdominal muscles contract, increasing intrarectal pressure and forcing the stool out
The Valsalva maneuver exerts pressure to expel faeces through a voluntary contraction of the abdominal muscles while maintaining forced expiration against a closed airway. Patients with cardiovascular disease, glaucoma, increased intracranial pressure, or a new surgical wound are at greater risk for cardiac dysrhythmias and elevated blood pressure with the Valsalva maneuver and need to avoid straining to pass the stool.
Normal defecation is painless, resulting in passage of soft, formed stool
CONSTIPATION
Constipation is a symptom, not a disease. Improper diet, reduced fluid intake, lack of exercise, and certain medications can cause constipation. For example, patients receiving opiates for pain after surgery often require a stool softener or laxative to prevent constipation. The signs of constipation include infrequent bowel movements (less than every 3 days), difficulty passing stools, excessive straining, inability to defecate at will, and hard feaces
IMPACTION
Fecal impaction results from unrelieved constipation. It is a collection of hardened feces wedged in the rectum that a person cannot expel. In cases of severe impaction the mass extends up into the sigmoid colon.
DIARRHEA
Diarrhea is an increase in the number of stools and the passage of liquid, unformed feces. It is associated with disorders affecting digestion, absorption, and secretion in the GI tract. Intestinal contents pass through the small and large intestine too quickly to allow for the usual absorption of fluid and nutrients. Irritation within the colon results in increased mucus secretion. As a result, feces become watery, and the patient is unable to control the urge to defecate. Normally an anal bag is safe and effective in long-term treatment of patients with fecal incontinence at home, in hospice, or in the hospital. Fecal incontinence is expensive and a potentially dangerous condition in terms of contamination and risk of skin ulceration
HEMORRHOIDS
Hemorrhoids are dilated, engorged veins in the lining of the rectum. They are either external or internal.
FLATULENCE
As gas accumulates in the lumen of the intestines, the bowel wall stretches and distends (flatulence). It is a common cause of abdominal fullness, pain, and cramping. Normally intestinal gas escapes through the mouth (belching) or the anus (passing of flatus)
FECAL INCONTINENCE
Fecal incontinence is the inability to control passage of feces and gas from the anus. Incontinence harms a patient’s body image
PREPARATION AND GIVING OF LAXATIVESACCORDING TO POTTER AND PERRY,
An enema is the instillation of a solution into the rectum and sig
CHAPTER 1 SEMESTER V - ROLE OF PEADIATRIC NURSE.pdfSachin Sharma
Pediatric nurses play a vital role in the health and well-being of children. Their responsibilities are wide-ranging, and their objectives can be categorized into several key areas:
1. Direct Patient Care:
Objective: Provide comprehensive and compassionate care to infants, children, and adolescents in various healthcare settings (hospitals, clinics, etc.).
This includes tasks like:
Monitoring vital signs and physical condition.
Administering medications and treatments.
Performing procedures as directed by doctors.
Assisting with daily living activities (bathing, feeding).
Providing emotional support and pain management.
2. Health Promotion and Education:
Objective: Promote healthy behaviors and educate children, families, and communities about preventive healthcare.
This includes tasks like:
Administering vaccinations.
Providing education on nutrition, hygiene, and development.
Offering breastfeeding and childbirth support.
Counseling families on safety and injury prevention.
3. Collaboration and Advocacy:
Objective: Collaborate effectively with doctors, social workers, therapists, and other healthcare professionals to ensure coordinated care for children.
Objective: Advocate for the rights and best interests of their patients, especially when children cannot speak for themselves.
This includes tasks like:
Communicating effectively with healthcare teams.
Identifying and addressing potential risks to child welfare.
Educating families about their child's condition and treatment options.
4. Professional Development and Research:
Objective: Stay up-to-date on the latest advancements in pediatric healthcare through continuing education and research.
Objective: Contribute to improving the quality of care for children by participating in research initiatives.
This includes tasks like:
Attending workshops and conferences on pediatric nursing.
Participating in clinical trials related to child health.
Implementing evidence-based practices into their daily routines.
By fulfilling these objectives, pediatric nurses play a crucial role in ensuring the optimal health and well-being of children throughout all stages of their development.
CHAPTER 1 SEMESTER V PREVENTIVE-PEDIATRICS.pdfSachin Sharma
This content provides an overview of preventive pediatrics. It defines preventive pediatrics as preventing disease and promoting children's physical, mental, and social well-being to achieve positive health. It discusses antenatal, postnatal, and social preventive pediatrics. It also covers various child health programs like immunization, breastfeeding, ICDS, and the roles of organizations like WHO, UNICEF, and nurses in preventive pediatrics.
QA Paediatric dentistry department, Hospital Melaka 2020Azreen Aj
QA study - To improve the 6th monthly recall rate post-comprehensive dental treatment under general anaesthesia in paediatric dentistry department, Hospital Melaka
Leading the Way in Nephrology: Dr. David Greene's Work with Stem Cells for Ki...Dr. David Greene Arizona
As we watch Dr. Greene's continued efforts and research in Arizona, it's clear that stem cell therapy holds a promising key to unlocking new doors in the treatment of kidney disease. With each study and trial, we step closer to a world where kidney disease is no longer a life sentence but a treatable condition, thanks to pioneers like Dr. David Greene.
How many patients does case series should have In comparison to case reports.pdfpubrica101
Pubrica’s team of researchers and writers create scientific and medical research articles, which may be important resources for authors and practitioners. Pubrica medical writers assist you in creating and revising the introduction by alerting the reader to gaps in the chosen study subject. Our professionals understand the order in which the hypothesis topic is followed by the broad subject, the issue, and the backdrop.
https://pubrica.com/academy/case-study-or-series/how-many-patients-does-case-series-should-have-in-comparison-to-case-reports/
1. Evaluating the Optic Nerve Head in Glaucoma
The best method readily available to the clinician for performing this examination is
high plus lens fundus biomicroscopy. Optimal magnification can be achieved by using
a +60D lens which provides 1.5 times the magnification of a 90D lens. During this
examination the patient's pupils must be maximally dilated with a combination of
mydriatic agents such as 1% Tropicamide and 2.5% Phenylephrine.
It is important to remember that the image seen through a high plus lens is a virtual
image, and will be inverted with the right on the left, and the top on the bottom.
The normal optic nerve diameter varies in size from 1.2 mm to 2.5 mm with the
average being 1.88 mm vertically and 1.77 mm horizontally. The area of the disc varies
in normal patients from 0.92 to 5.54 square millimeters.
This variation in normal optic disc sizes can affect the cup/disc ratio in two ways. First
in a larger disc, there is more area for the nerve fibers to fill, allowing for a larger cup.
Secondly, the size of the disc is used as the denominator of the ratio. It has been
suggested, that patients with larger optic disc size may have an increased
susceptibility to glaucoma. However, a recent study found no correlation between the
size of the optic nerve and the likelihood of visual field loss. Nevertheless, the
importance of a large or small C/D can only be determined when considered in the
context of the size of the optic nerve head. Therefore, it is essential to evaluate the
size of the optic disc in all patients who are glaucoma suspects. An easy way to do this
clinically is to use the direct ophthalmoscope. A relatively normal sized optic nerve
head will be approximately equal to the spot size projected onto the retina through the
small aperture of the scope.
Knowing that each optic nerve head is normal in size also allows the examiner to be
sure that any asymmetry in C/D ratios between the two eyes of a patient is due to a
difference in the number of axons. Asymmetry in C/D size between the two eyes of a
normal patient has been shown to be rare. Cup-to-disc ratios differ by 0.2 or less in
96% of normal eyes, so asymmetry of more than 0.2 in a patient with symmetrical disc
sizes and no anisometropia, greatly increases the suspicion of glaucoma.
A study of cup to disc ratios performed in the 1960's indicated that only 7% of the
normal population had C/D ratios of 0.5 or greater. This study also indicated that 86%
of normal C/D ratios were below 0.4. Because of this study, anyone with a C/D greater
than 0.4 was automatically considered a glaucoma suspect.
Recent studies have changed our views. Evaluation of the contour of the cup with
stereoscopic viewing and image analyzers has shown that the average C/D ratio is
quite a bit larger than previously thought. In a recent study of normal individuals, the
average horizontal C/D ratio was found to be 0.47 in Caucasians and 0.57 in African-
Americans. The average vertical meridians found in this study, were 0.49 for
Caucasians and 0.56 for African-Americans. Another recent study supports these
results with averages of 0.51 in the horizontal and 0.43 in the vertical meridian. This
investigation indicates that in order to include 84% of the population, C/D ratios less
2. than 0.74 horizontally and 0.64 vertically should be considered normal. Also, in
this study, patients with steeply bordered cups were found to have even larger average
C/D's, with a horizontal average of 0.65 and a vertical average of 0.57.
These studies also show that when determining the amount of cupping, it is very
important to evaluate the contour and not the pallor of the cup. This is because the
optic nerve head damaged by glaucoma typically has cupping which is larger than the
pallor, whereas the normal eye has cupping equal to the area of pallor.
Because it is recognized that the average size of a normal C/D ratio is larger than
previously accepted and that a large cup/disc size is not definitive as a diagnosis of
glaucoma, less attention is being placed on the size of the cup, and more is being
focused on the appearance and configuration of the neural rim tissue found
between the cup and the edge of the disc.
The rim tissue is often the first area to show changes in glaucoma, and must be
examined very critically during an optic nerve head evaluation. The normal neuroretinal
rim tissue is uniformly pink in color indicating good vascular perfusion. Because there
is a round cup located in a vertically elongated oval optic disc, the width of the neural
rim tissue varies by quadrant. In the normal eye, the Inferior quadrant has the widest
rim tissue with the Superior portion second in width. The nasal tissue is slightly
thinner than the superior tissue and the tissue in the Temporal quadrant is the
thinnest. This variation in rim sizes will cause large physiologic cups to appear
elongated horizontally. A disc with the normal configuration of rim tissue despite a
large cup/disc ratio can be seen in Figure 1. It is very important to remember that, the
superior rim tissue will appear inferior and the inferior tissue will appear on top in your
view. The reversal will also affect the nasal and temporal rim, which will be switched in
your view.
Figure 1: Normal rim tissue in a disc with a large cup.
The rim tissue will thin as nerve fibers atrophy. This results in pallor in the area of
atrophy and a decrease in the size of the rim tissue over time. If the nerve fiber loss is
generalized, the atrophy of nerve fibers will cause an overall decrease in the width of
3. rim tissue and an increase in the size of the cup. This generalized atrophy can be seen
in Figure 2, and is typical in moderate to advanced glaucoma, with corresponding
visual field loss. Because these changes are obvious only in the later stages of the
condition, the increase in cup size is not very helpful in making a diagnosis of
glaucoma early in the disease process.
Figure 2: Generalized atrophy which is typical in moderate to advanced glaucoma.
The focal nerve fiber loss in early glaucoma is more subtle and requires close
observation to detect. In early glaucoma, the inferior rim is usually affected first,
with the superior rim a close second. The next tissue to be damaged is typically the
temporal rim, with the nasal rim the last affected. Thinning in one focal area of the
disc can cause a "notch" to develop in the rim tissue over time. Since the inferior and
superior rim tissues are affected first, notching is typically seen in one of these
quadrants (I & S). When evaluating the optic nerve, it is helpful to have the results of a
visual field test performed on the same day readily available. This allows the
comparison of areas of potential visual field defects to the nerve fiber responsible for
that area of the field. It is estimated that 20% of the nerve fibers must be atrophied to
cause a visual field defect of 5 dB and 40% to cause a 10 dB loss. Because of this,
visual field results are best when used in conjunction with the optic nerve head and
nerve fiber layer evaluation.
4. Figure 3: Notching of the inferior optic rim tissue.
Figure 4: Subtle changes of the optic nerve head in the 11 o'clock position
Figure 3 shows obvious notching of the inferior optic rim tissue. Figure 4 shows a much
more subtle area of notching in the 11 o'clock position. This notching would be very
easy to overlook without the aid of the visual field. Figure 5 shows the visual field for
the patient in figure 4. Although the patient performed poorly on this visual field,
making the results of questionable value, it is interesting to note that there is a
corresponding change in the patient's inferior nasal visual field, as would be expected
from the optic nerve head appearance. When using the visual field as a tool to help
evaluate the optic nerve rim tissue, it is essential to remember that the superior rim
tissue consists of those fibers responsible for the inferior visual field. Because this
visual field reversal matches the reversal in the view of the high plus lens, the area of
rim tissue affected in the high plus lens view will be in the same quadrant as the
visual field loss.
5. Figure 5: Visual field of the patient seen in Figure 4 with corresponding visual field
When both the inferior and superior rim tissues are damaged in glaucoma, vertical
elongation of the optic cup occurs. This can be seen in Figure 6. This common vertical
elongation of an optic nerve head with glaucomatous damage will have corresponding
inferior and superior visual field defects.
Figure 6: Vertical elongation of the optic cup
6. Another optic nerve change which has significant diagnostic and therapeutic
importance is hemorrhaging. A small disc hemorrhage, known as a splinter or Drance
hemorrhage, is commonly associated with normal tension glaucoma. These
hemorrhages typically appear blot-like when located on the disc, and more flame
shaped if they are in close proximity to the disc. The occurrence of a disc hemorrhage
such as the one seen in Figure 7, should make you suspicious of glaucoma. Although
hemorrhages such as these can also be found in patients with a history of recent
posterior vitreous detachment, branch retinal vein occlusion, or diabetic retinopathy, it
is very rare for them to occur in the normal population. The examiner must be
particularly vigilant in cases where a splinter hemorrhage is noted in a patient with a
history of branch retinal vein occlusion or diabetes as these patients are already at an
increased risk of developing glaucoma. If other risk factors are present, the
appearance of a disk hemorrhage is a strong indicator for the initiation of glaucoma
treatment. They are more likely to occur on the temporal side of the disc, and can be
found either superior temporal or inferior temporal with equal frequency. Splinter
hemorrhages have been shown to precede nerve fiber layer and visual field changes in
some patients. Although the hemorrhages can resolve in as short as 2 weeks or as
long as 35 weeks, the average time to resolution is 10 weeks. It is quite common for an
area of notching to develop after the resolution of one of these hemorrhages, and it is
also common for the hemorrhages to recur in the same area, or within 30 degrees of
the original location. When a Drance hemorrhage is found in a patient who has
already been diagnosed, and is being treated for glaucoma, it indicates an
unfavorable prognosis, and the need for more aggressive therapy.
Figure 7: Splinter hemorrhage in the superior temporal quadrant
Peripapillary atrophy is also an important diagnostic consideration in glaucoma.
Peripapillary atrophy appears as a zone of chorioretinal atrophy with large choroidal
vessels and sclera visible around the optic nerve head. Further from the optic nerve
head, a less pronounced area of irregular hyper- and hypopigmentation can be seen.
As demonstrated in Figure 8, it is most common for this to occur on the temporal side
7. of the disc. The area with sclera and large choroidal vessels visible as is seen in Figure
6, is called the central zone or "zone Beta" and has been shown to be more frequent
and more extensive in eyes with high tension and normal tension glaucoma. In
addition, the location and extent of peripapillary atrophy has been shown to correlate to
visual field loss in both types of glaucoma. A recent study showed that in low
tension glaucoma, the appearance of the zone Beta peripapillary atrophy was
actually correlated more closely with visual field loss than the appearance of the
optic nerve itself. It is believed that peripapillary atrophy is not caused by
glaucomatous damage, but instead indicates that a patient is at an increased risk to
develop glaucoma. Although its etiology is uncertain, peripapillary atrophy seems to be
an indication that this area of the retina has a poor blood supply. To understand this, it
is important to realize that studies have shown a thinned or absent choroid with no
choroidal filling in zone Beta during the choroidal filling phase of fluorescein
angiography. Since the prelaminar portion of the optic nerve head also relies on the
choroid for its blood supply, a compromised choroid could cause ischemia of the optic
nerve head in this area, making the axons more susceptible to damage. In eyes with
small cup to disc ratios, the appearance of peripapillary atrophy may be a more
sensitive indicator of glaucomatous optic nerve damage than cup-to-disc ratios. The
appearance of peripapillary atrophy should raise the suspicion of glaucoma, and be
used in conjunction with other test results when making clinical decisions on the
diagnosis and management of glaucoma.
The examination of the optic nerve head should also include an evaluation for the
presence of acquired pits of the optic nerve. Acquired pits of the optic nerve (APON)
appear as sharply localized depressions of the lamina cribrosa with a loss of laminar
architecture. They are usually found in areas of pallor, and extend to the outer edge of
the disc. They are more likely to be located in the inferior temporal quadrant, with the
second most common location the superior quadrant. Although, it is not known whether
these pits are related to intraocular pressure, a study in 1990, indicates they are more
common in patients with low tension glaucoma than normals. Like peripapillary
atrophy, APON may represent an area of the optic nerve head that is more susceptible
to axonal damage.
Figure 8: Peripapillary atrophy on the temporal side of the disc (glaucoma)
8. Although a single evaluation of the optic nerve head can be very useful in the detection
of glaucoma, most glaucoma diagnoses require an observed change in the optic
nerve head over time. Examples include rim tissue changes, the appearance of
lamina cribrosa which was not previously visible, the shifting of a retinal blood vessel
on the optic nerve head, or the development of baring of a circumlinear vessel.
Because these changes typically occur gradually over several years, and because they
can be quite subtle, no optic nerve head evaluation can be considered complete
without documentation of the nerve head appearance with high magnification stereo
photographs, detailed drawings of specific areas of concern, and good written
descriptions.
Another method of monitoring and documenting the configuration of the optic nerve
head is by using computer assisted imaging. These instruments measure the vertical
and horizontal extent, depth, volume and contour of the cup. Although data is stored
and easily recalled for evaluation of changes over time, these instruments have not
achieved widespread use, possibly due to the large financial investment required.
Since the definitive diagnosis of glaucoma requires that the optic nerve be affected, the
evaluation of the optic nerve head is probably one of the most important tests to
perform when evaluating a patient for glaucoma. When carefully performed, the
stereoscopic evaluation of the optic nerve has high sensitivity and specificity for the
correct diagnosis of glaucoma, but like all other tests for glaucoma, it is best when
used in conjunction with the results of many other tests.
9. Evaluating the Nerve Fiber Layer
Evaluation of the nerve fiber layer is another useful tool to aid in the early diagnosis of
glaucoma. This is because nerve fiber layer defects can occur before visual field
changes are found. The evaluation of the nerve fiber layer can be done with a bright
light source like the binocular indirect ophthalmoscope, or at the biomicroscope with a
high plus lens. A clear condensing lens should be used in either case. Red free light,
which is absorbed by the pigment of the retinal pigment epithelium and the choroid, is
used to provide a dark background. The normal nerve fiber layer reflects light and
appears as a whitish haze over the darker underlying retinal structures. There will be
a striated appearance to the nerve fibers, with thicker nerve fiber layers appearing
brighter. Because the nerve fiber layer is thickest in the superior and inferior arcades
closest to the disc, this area should be the brightest portion of the view. There will be
less brightness in the thinner papillomacular region and the nasal side of the disc.
Symmetry between the reflections in the superior and inferior arcades and between
each of the patient's eyes is expected. A normal appearing nerve fiber layer can be
seen in Figure 9. This is the same eye as is pictured in Figure 1.
Figure 9: Normal appearing nerve fiber layer
When a patient has suffered nerve damage from glaucoma, darker areas or streaks
will appear in the nerve fiber layer. Dark areas which are slightly larger than arterioles
and reach the disc following the normal course of the nerve fiber layer are called slit
defects. They represent retrograde degeneration of the axons due to focal damage of
the optic nerve at the lamina. These can occur in approximately 10% of normal
patients. Wedge defects are caused by atrophy of many ganglion cells in the same
area of the optic nerve. These defects start at the disc as narrow lines and expand as
they get further from the disc. A wedge defect can be seen between 4 and 6 o'clock in
Figure 10. Notching of the neural rim tissue, as well as a visual field defects are
often associated with wedge defects. The most common type of defect, diffuse
atrophy, typically occurs in the superior and inferior arcades. The nerve fiber layer in
these areas loses its consistency and looks like it has been combed or raked with
darker and lighter areas. In severe cases nerve fiber layer reversal can occur in
which the normal pattern of superior and inferior brightness with increasing dimness
10. towards the papillomacular bundle is lost and the papillomacular area becomes the
brightest structure. Nerve fiber layer reversal is associated with thinning of the neural
rim and a diffuse depression or constriction of the visual field. An example of nerve
fiber layer reversal is seen in Figure 11.
Figure 10: A wedge defect in the nerve fiber layer between 4 and 6 o'clock
Figure 11: Nerve fiber layer reversal
Although it can be difficult to see the changes in the nerve fiber layer, especially in
lightly pigmented individuals, the technique provides additional early information for
determining if a patient has glaucoma. Black and white photography of the nerve fiber
layer provides more contrast of the tissue and improves the ability to compare the
health of the nerve fiber layer over time.