Foveal hypoplasia in oculocutaneous albinism: An optical coherence tomography study

Abstract

Background: Albinism is an inherited condition characterised by a lack of pigmentation. Foveal hypoplasia, which occurs because of disruptions in normal foveal development, is commonly observed in albinism. Previous studies using optical coherence tomography (OCT) have reported variable foveal morphology in individuals with oculocutaneous albinism.

Aim: To evaluate foveal hypoplasia in individuals with oculocutaneous albinism using OCT.

Setting: Eye clinic at the University of KwaZulu-Natal (UKZN).

Methods: The study used a descriptive design and included 30 participants with a clinical diagnosis of oculocutaneous albinism from the UKZN eye clinic. The iVue 100 OCT device was used to assess foveal morphology and measure the foveal thickness. Descriptive statistics were used to summarise the data.

Results: Most participants had wheat blond hair colour (n = 27), grey iris colour (n = 20) and horizontal jerk nystagmus (n = 24). Only one participant had grade 1 foveal hypoplasia, where a shallow foveal pit was observed. The remaining participants had grade 3 (n = 14) or grade 4 (n = 15) foveal hypoplasia, wherein the foveal pit and outer segment lengthening were absent. The binocular visual acuity (VA) and central foveal thickness ranged from 0.50 LogMAR to 1.12 LogMAR and 236 μm to 367 μm, respectively. There was no correlation between central foveal thickness and VA.

Conclusion: Foveal morphology in oculocutaneous albinism varies and ranges from absent development (fovea plana) to near normal development (shallow pit). Spectral-domain OCT devices help evaluate foveal hypoplasia.

Contribution: Foveal hypoplasia is common in oculocutaneous albinism and can be evaluated using OCT.