Ocular biometry and power of intra ocular lens among cataract patients in rural Eastern Ethiopia

Abstract

Abstract Background : The main objective of the study was to report on the main parameters of ocular biometry and Intra ocular lens power of patients attending a cataract surgical program in Eastern Ethiopia. Methods : The study was a cross sectional study on 765 eyes which were legible for cataract surgery during a mass eye camp conducted from April 04 to April 10, 2018 at Bisidimo Hospital,Eastern Ethiopia.Ocular biometric parameters such as axial length (AL), anterior chamber depth (ACD), mean corneal curvature (MCC) were measured using automated keratorefractometer(Retinomax) and Sonomed A - Scan. Analysis of variance and multivariate analysis were done to determine association of ocular biometry components with socio demography of the study subjects. Results : A total of 765 eyes were enrolled in this study. The mean corneal curvature and the mean anterior chamber depth were found to be 7.61 mm and 2.88mm respectively. The mean axial length was estimated to be 22.98 mm. The mean refractive power of Intra ocular lenses was calculated to be 19.34D. The mean axial length in females was shorter than that of males by 0.24 and this was statistically significant ( P - value = 0.01). Under multiple linear regression model gender had a statistically significant impact on the axial length. The mean Anterior chamber depth in males was also larger than that of females by nearly 0.1 and this was statistically significant (P - value = 0.001). Under multiple linear regression model both age and gender had a statistically significant impact on the anterior chamber depth. There was no a statistically significant difference on the mean Intra ocular lens power required for male and female patients.Conclusion : This study is the first of its kind to provide a larger population based normative data on the most important parameters of ocular biometry in Ethiopia.The female sex was a strong predictor of small axial length and shallow anterior chamber. Increasing age had no effect on the axial length but was found to be a stronger predictor of shallow anterior chamber. Key words : Axial length, Anterior chamber depth, Corneal curvature, Intra ocular lens.