Influence of Cataract Surgery on the Function of Contrast Sensitivity

Overview

The authors examined in a group of patients with cataract the visual acuity onSnellen’s optotypes and contrast sensitivity using Pelli-Robson’s test before cataract surgery and after cataract extraction and implantation of an intraocular lens.A VF-7 questionnaire was used for subjective evaluation of the result of surgery.The values of contrast sensitivity of the pseudophakic eyes were compared withthe contrast sensitivity of eyes of a age-matched control group with a natural lens.After cataract surgery and lens implantation highly significant improvement ofvisual acuity of the operated eye was recorded. There was also significant improvement of binocular contrast sensitivity in the study group. The authors did notdetect a significant difference of the contrast sensitivity of eyes with a PMMAlensand eyes with a silicone lens. There was no significant difference in the contrastsensitivity of pseudophakic eyes and phakic eyes of the control group. The CF-7questionnaire revealed that cataract surgery led to significant improvement ofthe investigated visual activities, as apparent from the subjective evaluation bythe patients. However, no significant correlation was found between objective(contrast sensitivity) and subjective (VF-7 questionnaire) evaluation of cataractsurgery. Only one question in the questionnaire correlated significantly withcontrast sensitivity.The authors found a significant reduction of contrast sensitivity caused by an altered transparency of the lens. The decline of contrast sensitivity in eyes with cataract and relatively good vision on Snellen’s optotypesis the cause of some subjective complaints of the patients and maybe an importantfactor in indication of cataract surgery of eyes with a relatively good visual acuity.

Key words:
cataract, visual acuity, contrast sensitivity, VF-7 questionnaire