Frequency of Anisometropia and Associated Factors Among Adult Patients Attending Tertiary Eye Hospital, Karachi

Background: Anisometropia is a variation in ocular refraction between both eyes. Two percent difference in the size of the two retinal pictures is created by a 1 diopter difference in two eyes. Objective: To find out the frequency of anisometropia and related factors among adult patients visiting tertiary eye hospital, Karachi. Methodology: A cross sectional study was commenced from June to August 2023 in refraction department of Al Ibrahim Eye Hospital, Karachi. Sample was collected through non-probability convenient sampling. Patients underwent detailed examination, objective and subjective refraction was done. Near and distance visual acuity was taken and spherical equivalent was also computed. Data was analyzed through SPSS Version 26.0. Result: A total 410 patients were included in the study. Mean age was 23.35±3.56. Majority of the participants were females 64.6% (n=265). The frequency of Anisometropia was 23.65%(n=97). Anisometropia was commonly found in high age groups 26-30 in 49.5% (n=48). Females found to be more prone from anisometropia than males (OR: 1.52,95% CI: 1.26–2.78). Odds of having anisometropia is 1.881 times higher in hyperopia patients (OR: 1.881, 95% CI: 0.088–3.425), whereas patients with myopia were 3.50 times at more risk of anisometropia (OR: 3.50, 95% CI: 1.513–5.891) as compared to Emmetropia. Conclusion: Our study concludes the frequency of Anisometropia is 23.65%. Among other refractive status, myopia found to be the commonest associated factor for the presence of Anisometropia.