Amplitude of Accommodation and its Relation to Refractive Errors

Abstract

To evaluate the relationship between amplitude of accommodation and refractive errors in the peri-presbyopic age group. Three hundred and sixteen right eyes of 316 consecutive patients in the age group 35-50 years who attended our outpatient clinic were studied. Emmetropes, hypermetropes and myopes with best-corrected visual acuity of 6/6 J1 in both eyes were included. The amplitude of accommodation (AA) was calculated by measuring the near point of accommodation (NPA). In patients with more than +/- 2 diopter sphere correction for distance, the NPA was also measured using appropriate soft contact lenses. There was a statistically significant difference in AA between myopes and hypermetropes (P < 0.005) and between myopes and emmetropes (P < 0.005) in the 35-39 year age group. In the 40-44 year age group, there was a significant difference in AA between emmetropes and hypermetropes (P < 0.0001), emmetropes and myopes (P < 0.01) and hypermetropes and myopes (P < 0.0001). In patients above 45 years of age there was no significant difference (P > 0.5). Our study showed higher amplitude of accommodation among myopes between 35 and 44 years compared to emmetropes and hypermetropes.