Comparison of contrast sensitivity in low and high Hypermetropes

Abstract

OBJECTIVE: To compare the level of contrast between low and high hypermetropes.

METHOD: Informed consent was taken from each patient after a verbal and written explanation of the nature and consequences of the study. A performa was filled at the time of the examination with fully detailed ocular history. Fifty four hyperopic patients were examined in 2021. It was descriptive cross sectional study. Visual acuity was checked on standard log MAR chart. The type and amount of refractive error was checked by Retinoscope objectively and subjectively by using trial lenses and trial frame. Fundus was also examined by Opthalmoscope. Contrast sensitivity was measured by Pelli Robson chart. Firstly without spectacles monocularly, then with spectacles monocularly and then binocularly. Patients were called for examination in Mayo Hospital refraction room.

RESULTS: Low hyperopic patients have better contrast than high hyperopic patients. Out of 54 participants of hypermetropia 22(40.7%)
have low contrast value binocularly and 32(59.3%) have normal contrast sensitivity. Out of 54 subjects, 20 were high hypermetropes and 34 were low hypermetropes. In high hypermetropes, 5 participants had normal contrast sensitivity, and 15 had low contrast sensitivity. In low hypermetropes 27 had normal contrast sensitivity and 7 have low contrast sensitivity. The results are statistically significant using Mann Whitney test (p<0.01).

CONCLUSION: Low hypermetropes had significantly higher contrast sensitivity as compared to high hyperopes.