Ben Balzer1, Caroline Catt2,3, Milia Bou-Abdou3, Frank Martin2,3

Purpose: Infantile nystagmus syndromes can have a profound effect on a child’s visual acuity. Extraocular muscle surgery has recently been associated with improved visual acuity in infantile nystagmus syndromes (congenital motor nystagmus, latent nystagmus, oculocutaneous albinism and ocular albinism). There is evidence suggesting a natural history of improvement in visual acuity, though these data are limited by small sample sizes and short follow-up. Our aim was to determine whether such improvements persist through childhood and adolescence.

Method: We performed a retrospective analysis of best-corrected visual acuity (BCVA) for children and adolescents with infantile nystagmus seen at a specialist paediatric ophthalmology centre. BCVA was recorded using a Snellen chart and was converted to logarithm of minimal angle of resolution (LogMAR) using standard values.

Results: One hundred and forty four records of children with infantile nystagmus from 1983-2015 were identified: 61 (41.9%) female and 83 (58.1%) male. Age ranges (years) were 4.01-18.0 for males and 3.92-17.88 for females. Mean (standard deviation; SD) follow-up time was 4.29 (3.19) years. Mean (SD) LogMAR at baseline was 0.54 (0.29) for males and 0.43 (0.28) for females (p=0.07). BCVA improved over the course of follow-up (?=-0.011, p<0.001) for all diagnoses. There was no significant improvement in binocular BCVA when comparing those who had eye surgery and those who had not (p>0.05 for all diagnoses).

Conclusion: BCVA improved over the course of childhood and adolescence in our large cohort with infantile nystagmus syndromes. This improvement was independent of any surgical intervention.