Contrast Sensitivity After Penetrating Keratoplasty Using The Pelli-Robson Chart

Abstract

Corneal transplant surgeons recognize the usefulness of contrast sensitivity measurements in assessment of subjective vision of a penetrating graft recipient especially in real world conditions different from the doctor’s consulting room. A large number of contrast sensitivity measurements either use expensive television monitors or charts that are not very reliable at small letter sizes. The Pelli-Robson chart can offer a
cheap and reliable way of contrast sensitivity testing. Forty-seven (47) eyes with clinically successful penetrating corneal grafts were matched against a control group of 41 eyes with equivalent Snellen visual acuity.
The subjects and control group had Snellen acuity test, early Treatment Diabetic Retinopathy Study (ETDRS) acuity, Pelli-Robson contrast sensitivity tests and also the effect of glare. The effect of other parameters such as astigmatism, graft size and graft age were also assessed. Eyes with penetrating keratoplasty showed consistent and significant depression. Glare had significant effect on eyes with penetrating keratoplasty but had no significant effect in the control group. Contrast sensitivity after penetrating keratoplasty can be measured with the simple, cheap, and easy to use Pelli-Robson chart and will enable corneal graft surgeons to reasonably predict the subjective vision of a grafted eye
with less stress.

Keywords: Penetrating Keratoplasty, contrast sensitivity, Pelli-Robson chart.