The Distribution of Ocular Biometry in Iranian School Children

Purpose: To determine the distribution of axial length (AL), vitreous chamber depth (VCD), anterior chamber depth (ACD), lens thickness (LT), lens power (LP), radius of curvature (CR), and white-towhite corneal diameter (WTW) in the 14-20 year age range Methods: In a cross-sectional study, sampling was done from Aligoodarz high schools using multistage simple cluster sampling. For all students, visual acuity and non-cycloplegic refraction tests were performed. Biometric components were measured using Allegro Biograph (WaveLight AG, Erlangen, Germany). Results: In this report, data from 434 cases was used in the analysis; of these 222 (51.2%) were females. Mean and 95% confidence intervals of AL, VCD, ACD, LT, LP, CR, and WTW in the studied sample were 23.4 mm (23.32 to 23.48), 16.82 mm (16.74 to 16.9), 3.14 mm (3.12 to 3.16), 3.44 mm (3.42 to 3.46), 22.65 diopter (22.47 to 22.83), 7.74 mm (7.72 to 7.76), and 12.26 mm (12.22 to 12.3), respectively. In the multiple regression model, AL, VCD, ACD, CR, and WTW was significantly higher in boys while mean LT and LP were significantly higher in girls. The distributions of AL, ACD, LT, and CR were significantly different from normal. The distributions of AL, LT, and CR were leptokurtic, unlike ACD which had a platykurtic distribution pattern. Conclusion: In this report, we describe the normal ranges of ocular biometric components in a sample population of 14-20 year old Iranians. ACD in this study was shorter and WTW was larger than previous studies and other components were in the midrange. More studies throughout Iran are needed to verify a shorter ACD and larger WTW. All components of ocular biometry showed significant inter-gender differences.