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

PURPOSE

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.

METHODS

Prospective.

SETTING

Institutional.

STUDY POPULATION

Twenty-two eyes of 22 consecutive patients without ocular pathology, other than cataract, known to influence visual field undergoing cataract surgery.

OBSERVATION PROCEDURES

Both white-on-white (W-W) and blue-on-yellow (B-Y) perimetries.

MAIN OUTCOME MEASURES

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.

RESULTS

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.

CONCLUSION

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.