Visual Defect in Oculocutaneous Albinism is Not Associated with Gross Structural Anomaly

Abstract

Background: Albinism is a heterogeneous group of inherited non progressive disorders of melanin metabolism. The two main types are Ocular albinism (OA) in which pigment is absent only in the eyes and Oculocutaneous albinism (OCA) in which the eyes, skin and hair lack pigment. The tropical environment, without the protective effect of melanin, predisposes the African OCA to skin cancers. In the eyes fovea maturity is impaired leading to poor vision. All forms of albinism, regardless of the genotype or phenotype, have the same distinctive visual impairment that confers visual acuity ranging from 20/40(6/12) to 20/200(6/60) that significantly limits their education, occupation and recreation. This study set out to use ultrasonography to detect correctable ocular structural anomaly in visually impaired African OCA who also have severe sun-damaged skin. Materials and methods: In a prospective study, the eyes of 57 consenting Nigerian OCA referred from Dermatology to Radiology for ocular scan were investigated with B-mode ultra-sonogram. The results were compared with matched controls and analyzed by simple descriptive statistics. Results: The age range of the study population was 15 to 62 years (mean 24.6 years) and male: female ratio was 1:2. Of the OCA, 98% and of the controls, 91.2% had normal ocular scans. Vitreous echoes were found in 7.0% of all participants and one (1.8%) of the control participants had cataract. No cataract or other gross structural anomaly was detected in any of the orbital structures of the OCA. Conclusion: Ultrasound scan reveals no ocular structural abnormalities peculiar to OCA. Even though not statistically significant, there is an intriguing absence of cataract in OCA that is worthy of further investigation