Effect of cataract extraction on blue-on-yellow visual field.

Abstract

It is assumed that cataract can influence the results of blue-on-yellow perimetry. However, actual sensitivity change in blue-on-yellow perimetry before and after cataract surgery has not been fully demonstrated. Prospective. Institutional. Twenty-two eyes of 22 consecutive patients without ocular pathology, other than cataract, known to influence visual field undergoing cataract surgery. Both white-on-white (W-W) and blue-on-yellow (B-Y) perimetries. Global indexes including mean deviation and other pertinent data of white-on-white and blue-on-yellow perimetries were compared before and after cataract surgery. Mean deviation was improved after cataract surgery in both white-on-white perimetry (from -6.88 dB to -3.36 dB, P <.0001) and blue-on-yellow perimetry (from -12.22 dB to -3.64 dB, P <.0001, paired t test). However, the mean difference between preoperative and postoperative mean deviation in blue-on-yellow perimetry (8.58 +/- 3.96 dB) was significantly higher than that of white-on-white perimetry (3.52 +/- 2.69 dB; P <.0001, unpaired t test). That is, the change in mean deviation was greater in blue-on-yellow perimetry than in white-on-white perimetry by a factor of 2.4 times. Cataract causes predominantly a general reduction of sensitivity in both blue-on-yellow and white-on-white perimetries, and the general reduction of blue-on-yellow sensitivity is far greater than that of white-on-white sensitivity.