Ocular findings and vision status of learners with oculocutaneous albinism

Abstract

Background: Oculocutaneous albinism results in defects of the visual pathway and ocular structures.

Aim: To determine the ocular findings and vision status of learners with oculocutaneous albinism (OCA) as well as to establish the level of visual acuity, contrast sensitivity and reading rate improvements following optical correction.

Setting: Three special education schools in KwaZulu-Natal, South Africa.

Methods: A total of 81 learners with OCA participated in this study. Testing procedures included logMAR distance and near visual acuity (VA) measurements, cover tests, retinoscopy (dry), subjective refraction, tangent screen, ophthalmoscopy, contrast sensitivity and reading rate determination.

Results: The majority of participants (96.3%) had wheat straw coloured hair and 95.1% had grey irides. All the learners presented with iris-transillumination and an absent foveal reflex and all but one exhibited nystagmus. Esophoria and esotropia represented 72.8% of binocular vision anomalies. Myopic astigmatism was noted in 41.4% of the learners while with the rule astigmatism was predominant (64%). Following optical correction, VA significantly improved from a range of 0.50 to 1.40 logMAR to a range of 0.5 to 1.06 logMAR for distance (p < 0.05) and from a range of 0.40 to 1.30 logMAR to a range of 0.30 to 1.08 logMAR) for near (p < 0.05). In addition, contrast sensitivity improved from a range of 0.48 to 1.92 logCS to a range of 0.88 to 1.92 logCS (p < 0.05). However, the reading rate did not show any significant improvement following optical correction (p> 0.05).

Conclusion: Learners with OCA exhibited various ocular and vision defects which impair visual functions. Their VA and contrast sensitivity could be significantly improved with optical correction; however, their reading rate was not improved.