Factors Associated with Improved BCVA in OCA1A
Laura May, CO; Kimberly Merrill, CO; John E. Connett, PhD; Carole G. Summers, MD
University of Minnesota
Introduction: OCA1A, with lifelong absent melanin in skin, hair, and eyes, is the most severe type of albinism with greatest ametropic refraction and poorest visual outcomes.1,2 Our study evaluates the relationship between refraction and age when spectacles were begun on BCVA in OCA1A.
Methods: After IRB approval, retrospective chart review of 70 consecutive patients with OCA1A identified 21 fitting inclusion criteria of BCVA recorded at age 12. Excluded were those with other vision-threatening diagnoses. We also recorded age at beginning glasses, refraction, most recent BCVA, and gender.
Results: Regression analysis showed monocular astigmatism was significantly associated with logMAR BCVA at age 12 (p=0.029); gender, spherical equivalent, and age when glasses were started were not. There was a positive relationship between most recent logMAR BCVA and age at glasses initiation (p=0.061). Best BCVA (20/50) occurred in a patient beginning glasses at age 3 months. Poorest BCVA (20/250) was in a patient beginning glasses at age 4 years. When glasses were begun by age 12 months (n=9), mean BCVA was 20/85; when begun later (n=12), mean BCVA was 20/106 (p=0.287). All in the first group and only half in the second group had improved visual acuity from age 12 to last follow up.
Discussion: BCVA in OCA1A is occasionally reported to be about 20/50-60.1,3 Earlier glasses wear may be related to the severity of refractive error, yielding better BCVA. Overall, BCVA was better when glasses were initiated by age 1 in this small cohort.
Conclusion: Several factors influence visual outcome in albinism. BCVA may be better than expected in OCA1A when refractive error is great and glasses wear begins by age 1.
References: 1.Anderson J, Lavoie J, Merrill K et al. Efficacy of spectacles in persons with albinism. J AAPOS 2004; 8:515.
2.Yahalom C, Tzur V, Blumenfeld A, et al. Refractive profile in oculocutaneous albinism and its correlation with final visual outcome. Br J Ophthalmol 2012;96:537.
3.Winsor CN, Holleschau AM, Connett JE, et al. A cross sectional examination of visual acuity by specific type of albinism. J AAPOS 2016; 20:419.