The Effect of Myopic Refractive Error on the Evaluation of Optic Nerve Head Parameters using Topog raphic Scanning System

ABSTRACT

This study was performed to determine the effect of myopic refractive error on optic nerve head parameters using Topographic Scanning System (TopSSTM). One hundred thirty two myopic eyes of 120 subjects with normal visual fields were enrolled in this study.Their visual acuities were better than 0.8 with their corrections.Subjects were divided into four myopic groups.Mean refractive error was -3.8 diopter (range+1.25D ~-1 2.2 5 D ). Total contour area, effective area, volume above, neuro-retinal rim area, and contour variation showed statistically significant correlations with myopic refractive error.The disc area (total contour area)was correlated with the myopic refractive error.However, effective area, volume above, and neuro-retinal rim area showed statisticall correlation with total contour area rather than myopic refractive error.Contour variation was correlated with myopic refractive error.With increased disc contour tilt, nasal and superior neuroretinal rim area also statistically increased. In conclusion, effect of disc area and contour variation should be considered in the evaluation of optic nerve head parameters of myopic patients. However, further evaluation of myopic patients with glaucoma is required through comparison study with control group.