Comparison of Contrast Sensitivity and Central Corneal Thickness in Primary Open Angle Glaucoma Suspects and Visually Normal Participants

Abstract

Introduction: Glaucoma causes a reduction of contrast sensitivity (CS) while thinner central corneal thickness is (CCT) associated with the risk of glaucoma. Thus, in glaucoma suspect patients, CS and CCT measurements may better evaluate and monitor the disease. The purpose of this study was to compare CS and CCT between a Primary Open Angle Glaucoma (POAG) suspect group and a normal group of similar age. Methods: CS was measured with the Pelli-Robson CS chart, while CCT was measured with a hand-held pachymeter. In total, 115 glaucoma suspects and 102 normal participants were included. Results: There was a significant effect of the clinical condition on CS [F(1,209)=5.409, p=0.02]. The effect of age on CS was also significant [F(3,209)=20.419, p<0.001]. The interaction between age and clinical condition was not statistically significant [F(3,209)=0.815, p=0.49]. CS of POAG suspects was significantly lower than that of the normal group for the younger age groups (40 to 59 years old) but not for the older age groups (50 to 80 years old). There was no significant effect of clinical condition on CCT [F(3,209)=0.754, p=0.39]. However, there was a significant effect of age on CCT [F(3,209)=3.789, p=0.01]. Conclusion: Contrast sensitivity measurement is potentially useful to be integrated with routine investigations for POAG suspect patients, especially those who are younger than 60 years old. Measurements of central corneal thickness alone may not be able to differentiate between POAG suspects and visually normal individuals.