Pediatric Ophthalmology sub-specialty of ophthalmology concerned with eye diseases, visual development, and vision care in children. Handle cases such as amblyopia, starbismus, and nystagmus

TOBI OWOYEMI DR. HEE-JUNG PARK WILMER EYE INSTITUTE Testing Visual Acuity in Nystagmus Patients

Anatomy of Human Eye

What is Nystagmus: Background Information According to the American Association for Pediatric Ophthalmology and Strabismus, Nystagmus is an involuntary, shaking, “to and fro” movement of the eyes Often congenital but can be acquired as an adult— usually as a result of brain issues Can be caused by side effects of seizure medications or disfunctions in the brain

What does a person with nystagmus actually see? Children with nystagmus typically see the world similarly to other children, except with some blurriness. The world does not appear to “shake”. They see the world in flashes at a time due to the fact that their brain completely shuts down for less than a millisecond Individuals with adult onset or acquired nystagmus often report the appearance of movement of the seen world (oscillopsia). Also, adults with nystagmus usually have brain problems as well.

Why do people with nystagmus tilt or turn their head? Nystagmus severity can vary upon direction of gaze; the eyes oscillate more when looking in certain directions. The gaze position of least eye movement is the “null point” and tends to be where vision is best. Tilting or turning the head can thus optimize vision.

Can surgery make nystagmus go away? Eye muscle surgery (strabismus surgery) may be indicated for some individuals with nystagmus. The goal of surgery in most instances is to help alleviate a significantly abnormal head position or to decrease the amplitude of nystagmus. Surgery can sometimes cause vision improvement but does not fully eliminate nystagmus.

What non-surgical treatments exist for nystagmus? Significant refractive error is corrected with glasses or contact lenses. Contact lenses, in some circumstances, can be more visually beneficial than spectacles. Variable success has been noted with medications used to dampen the severity of nystagmus. Unfortunately, the use of these medications is frequently limited by side effects. Botulinum toxin is helpful for some individuals with severe, intractable oscillopsia.

Purpose of Project Plenty of bias when testing visual acuity in nystagmus patients– no good way of measuring nystagmus that compensates for the nystagmus Use ATS or SVAT Ipad software? Ipad software is specialized for nystagmus patients, ATS is not Test patients more effectively

SVAT Ipad Software Presents a staggered full field presentation of letters. Representation dampens nystagmus When snapshot moment occurs, they will be able to see target in their flashes Gets rid of need to try to focus on something—helps us see potential visual acuity Nystagmus gets worse with fixation attempts

ATS (Standard Use of Measuring Visual Acuity) Requires patient to read single letter at a time Distance of six meters Nystagmus gets worse due to fixation attempts Patient is looking at screen while doctor is measuring visual acuity

Overview/ Questions Being Answered Use ATS or Ipad? Are we measuring visual acuity properly? Are the treatments for nystagmus effective? Can we modify visual acuity testing methods to better capture potential visual acuity?

So, To Sum Things Up… In Pediatric Ophthalmology, Nystagmus is one of the disorders that yield very little improvement We want to know why this is, is it because we are not efficiently measuring visual acuity?