Nystagmus Treatment

Here is a quick overview of ways to treat Nystagmus. Always keep this in mind!

1. Yolk Prism
2. Biofeedback (auditory or physical sensation)
3. Surgery
4. Medications (muscle relaxers are used for some types of nystagmus)

Largest contributor to dry eye syndrome

According to the Beaver Dam Eye Study, age is the largest contributor to dry eye syndrome.

Plain and simple, but important to remember!

During the 5-year interval between examinations, a history of dry eye developed in 322 of 2414 subjects, for an incidence of 13.3% (95% confidence interval [CI], 12.0%-14.7%). Incidence was significantly associated with age (P
.001).

After adjusting for age, incidence was greater in subjects with a history of allergy or diabetes, who used antihistamines or diuretics, and with poorer self-rated health (P
.05).

Pain versus Presentation

Some corneal disease’s must be cultured in order to know the infecting bug, and some presentations may seem infectious although they are not. Understanding presentation vs. pain can help you to make a diagnosis.

Reported pain worse than corneal presentation

1. Acanthomeba infection
2. Superior Limbic Keratoconjunctivitis (SLK)
Presentation of cornea worse than reported pain

1. Nuerotrophic Keratitis
2. Fungal Keratitis

Remember that these are generalities and not steadfast rules, you can use them to point you in the right direction.

ADDs in General

AGE AVE ADD
40-44: +0.75 – 1.00 D
45-49: +1.00 – 1.50
50-54: +1.50 – 2.00
55-59: +2.00 – 2.25
60+: +2.25 – 2.50

(Tip from Professor CC: For the ADD prescription in progressives (not bifocals et al), providing +0.25 D extra to the ADD RX will increase the comfortable range for patient’s near work.)

Adding +0.25D to the ADD Rx for progressive lenses

Optic Neuritis Sorted by Age

Likely Diagnosis for Optic Neuritis for Different Age Ranges

• 1‐10 years old – Inflammatory/hereditary disease
• 11‐20 years old - Infection/Leber’s Optic Neuropathy
• 21‐40 years old - MS/toxic
• 50‐70 years old - AION/toxic
• 60‐80 years old - GCA

Refractive Shifts Due to Cataracts

Advanced nuclear cataract
- tends to increase the thickness of the center of the lens
-> lens resembles plus lens
-> more likely to cause myopic shift

Cortical Cataract
- tends to increase thickness of edges of lens
-> resembles minus lens
-> more likely to cause hyperopic shift

Breaking Alternating Intermittent Exo Tropia

The nature of this binocular condition is that it is not always present; to make the strab easier to spot, do alternating CT FIRST, and then proceed to the unilateral CT.

Infiltrates of the Cornea

Clinical Pearl by: Yuliya Bababekova, SUNY 2013

In order to differentiate between sterile versus infectious keratitis, look for several important distinctions.

• Sterile infiltrates are located in the periphery.
• These are typically small, grey lesions that are separated from the limbus by about 1 mm of clear space.
• Immune cells are thought to be more readily available because of the location of capillaries in the peripheral cornea.
• Infectious infiltrates are located in the central region of the cornea.
• Clinical signs of infectious infiltrates include fluorescein staining, and raised appearance with a surrounding haze.

Symptoms are also very different: 

• Pts with sterile infiltrates are mildly symptomatic
• Those with infectious keratitis are often photophobic and in pain.

Note: When examining these patients, it’s important to consider that sub-epithelial infiltrates are a distinguishing feature of EKC (epidemic keratoconjunctivitis).

Exam Shortcuts

So it’s taking you way too long to finish an eye exam; your classmates are done charting and you’re just putting in the dilating drops; your preceptor is always rushing you. “WHY AM I SO SLOW?? HOW CAN I SPEED UP MY EXAM?” you ask.

Clinical Pearl: Observe your peers! Find a time when you can go into clinic and observe your classmates or upperclassmen performing an eye exam. You may find out that you don’t have to do color vision, stereo, or binocular balance on all patients. Likewise, there are definitely refraction techniques you never learned in labs.

In return, share what you do in an exam room with them. Invite those with whom you have clinic into your exam room when there is down time. An efficient clinic will give you all more learning opportunities and get you home on time

Pearls for Ocular Prosthetics

1. Test EOMs: prosthetic should move fairly well in comparison to the intact eye

2. Hirschberg test: to verify alignment of prosthesis

3. Remove the prosthesis: Check for hygiene! Patients must be advised to clean the device once a week or at least once a month. If a patient complains of itching behind the prosthesis, remove the device and check for bacterial conjunctivitis or GPC (often, the conjunctiva is left intact). Treat the patient according to standard protocols for either conjunctivitis or GPC. If treating with steroids, use of the prosthesis is to be discontinued for 1-2 weeks.

4. Lubricants: The conjunctiva and remaining tissues (if present) may be dry. Enuclene is a lubricant specifically made for prosthetic ocular devices and is recommended for this special population.

5. Wear and Tear of Prosthetic: check for cracks and accumulation of surface protein; these may irritate the conjunctiva.

Strabismus Epidemiology

• 5% of the general population has some kind of strabismus
• 25% of TBI patients have some kind of strabismus
• 50% or more of patients with neurological disorders (e.g., CP, MS) have some kind of strabismus

Central Vein Occlusion Study

Central Vein Occlusion Study (1995)

Vein occlusion is likely ischemic if…

1. Abnormal ERG
2. +RAPD
3. Large amounts of hemes

VA is equally as good about telling us about ischemia as IVFA.

1. 20/200 to start –> Likely to end at 20/200 = Likely Ischemic
2. 20/30 to start    –> Likely to end at 20/30 = Likely non‐ischemic
3. 20/middle acuity range to start –> Can progress either way.

Percival / Sheard’s / 1:1 Rule for Prism

When Rxing prism for your patients, don’t just pick an arbitrary value! Use one of these criteria.

Sheard’s

• Best for EXO patients
• The fusional reserve must be at least 2 times the demand
• Prism Needed = 2/3(Demand) – 1/3(Reserve)
• ex) @40cm = 10xp  || BO: 12/20/10
• So Demand = 10 || Reserve = 12

1:1 Rule

Percival’s

• Comfort zone is the middle third of the width of the Zone of Clear Single Binocular Vision, from the 0–>3.00D stimulus to accommodation level.
• Prism Needed = 1/3(Greater of lateral range blur limit BI or BO) – 2/3(Lesser of lateral range blur limit BI or BO)
• ex) BI: 26/30/20 || BO: 6/14/8
• So G= 26 || L= 6

Keep in mind: once you give the prism to the patient, the phoria and ranges will change by the amount of prism you prescribed. Make sure to re-check your patient’s phoria and ranges.

Recent Onset Diplopia – Pathological or PSC

A patient who presents with recent onset diplopia can be a cause of concern. It is possible a patient with a PSC cataract could experience diplopia. A good way to differentiate PSC as the cause of diplopia from a potential pathological cause is by utilizing case history and your occluder.

A patient with diplopia due to a PSC will likely experience the diplopia at both distance and near viewing. In addition, when covering the “non problematic” eye, the diplopia will still be present. In contrast, a patient with a potential pathological cause of recent onset diplopia may only experience diplopia at distance or near, and the diplopia may resolve by simply covering either of the eyes. It is crucial to obtain a good case history in helping you determine whether or not recent onset diplopa could be a very dangerous situation.

Retinitis Pigmentosa Genetics

RP can either be Autosomal Dominant, Autosomal Recessive or X-Linked.

Mutations typically cluster in 3 domains of Rhodopsin.
1. The CYS110-CYS187 Bond
2. The Chromophore Binding Pocket
3. Amino Acids in the cytoplasmic tail that interacts with transducin