Abstract
Purpose :
To evaluate the structural aspects of highly myopic patients with albinism in Tanzania. OCAII is much more common in Tanzania and the prevalence of OCA in East Africa has been documented as high as 1 in 1400 compared to 1 in 20,000 in the U.S. Recently, studies have identified myopia as comprising a high percentage of the refractive findings of patients with OCA in the region.
Methods :
Children and adults with albinism in and around Dar es Salaam in Tanzania participated in a study during a low vision clinic delivered by Standing Voice, an International NGO based in Tanzania. The low vision clinic was part of the NGO’s program which provides clinical care and training to people with albinism. One hundred and fourteen patients with OCA, primarily OCAII, ages 6 to 45 were evaluated in a dilated exam by Tanzanian ophthalmologists after they received low vision evaluations. The additional exam included a brief retinal evaluation, axial length, and corneal curvature.
Results :
Of 114 patients, 70 were female and 44 were male (mean age 18.2 yrs). Overall prevalence of myopia as defined by >/=2D eq sphere and extended up to -24.0 D was 50% (95%CI 59.9-40.5%). Significant correlation was found between the magnitude of myopia and axial length (r=0.85, p<0.0001) and myopia and age (r=0.31, p=0.001). No retinal detachments were detected in any of the patients. Corneal curvature was primarily with-the-rule in the 34 patients with astigmatism (30% of population) but the sample was too small for enough power to correlate with corneal curvature.
Conclusions :
Although the sample was not randomly selected, these results indicate a high occurrence of myopia in patients with OCAII in Tanzania that is highly related to axial length and not to corneal curvature. Therefore, further studies are needed to explore the mechanism of myopia development. A strong emphasis on accurate spectacle correction should be included in any low vision interventions.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.