Abstract
Abstract: :
Purpose:to measure the effect of a surgical reduction of IOP on spatial contrast sensitivity threshold in eyes showing a IOP ≷ 30 mmHg and no glaucomatous visual field defect on white-on-white computer-assisted static perimetry Methods:prospective clinical trial, lasting 36 months; 10 consecutive subjects with untreated IOP ≷ 30 mmHg in one eye, IOP 20/20 in both eyes and scheduled for a primary trabeculectomy in the eye showing a high IOP . Spatial contrast sensitivity threshold (CSV1000 chart, Vector Vision, Daytona OH, USA) was measured before surgery and at each follow up visit. Results:pre-operative spatial contrast sensitivity was worse in those eyes bearing a high IOP with respect to the normal fellow eyes (paired samples t test, p < 0.0005); an improvement of contrast sensitivity threshold, exceeding the 95% confidence limits of the pre-operative test-retest variability, was observed at 3, 6 and 12 cyc / deg in each operated eye at the end of follow up. No change was observed in the fellow untreated normal eyes. The improvement was directly correlated with the amount of pressure drop obtained by surgery. Conclusion:eyes with no field defects, but bearing a IOP ≷ 30 mmHg, showed a decreased spatial contrast sensitivity. A surgically-obtained reduction of IOP could restore the sensitivity into the normal range.
Keywords: 368 contrast sensitivity • 444 intraocular pressure