The effect of treatment on the results of high-pass resolution perimetry in glaucoma

In order to find out to which extent high-pass resolution perimetry would detect any changes in patients treated for glaucoma, resolution perimetry results were evaluated from 56 glaucoma patients and 15 untreated ocular hypertensive patients followed for 2 to 3 years. Fifty-nine of the 71 examined patients showed lower resolution thresholds, i.e. increased sensitivity, after 2 years, compared to initial values. The threshold decrease was significantly larger in the treated glaucoma patients (median 1.22 dB) than in the untreated ocular hypertensive patients (0.48 dB). The threshold decrease in the untreated ocular hypertensive group corresponds to the previously described learning effect. In 35 of the 56 treated glaucoma patients the thresholds improved more than 0.84 dB, the upper confidence limit in the untreated group, which may indicate a beneficial effect of antiglaucoma therapy in these patients. The threshold change was unrelated to initial resolution threshold and cannot be explained by a 'sorting' effect. The observations in the current study using resolution perimetry indicate that improved visual function can be demonstrated in many patients treated for early glaucoma, at least during the first 2 years of treatment.