Improvement of spatial contrast sensitivity threshold after surgical reduction of intraocular pressure in unilateral high-tension glaucoma.

PURPOSE: To measure the effect of a surgical reduction of IOP on the spatial contrast sensitivity threshold in eyes showing a considerably increased IOP but 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 > or = 30 mmHg in one eye and or =20/20 in both eyes, and scheduled for a primary trabeculectomy in the eye showing a high IOP. The spatial contrast sensitivity threshold was measured before surgery and at each follow-up visit. RESULTS: Preoperative spatial contrast sensitivity was worse in those eyes bearing a high IOP relative 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 preoperative test-retest variability, was observed at 3, 6, and 12 cyc/deg in each surgical eye at the end of follow-up. No change was observed in the fellow untreated normal eyes. The improvement correlated directly with the amount of decrease in pressure obtained by surgery. CONCLUSIONS: Eyes with no field defects on white-on-white computer-assisted static perimetry, but bearing a IOP > or = 30 mmHg, show a decreased spatial contrast sensitivity. A surgically obtained reduction of IOP is paralleled by an improvement of spatial contrast sensitivity

Improvement of spatial contrast sensitivity threshold after surgical reduction of intraocular pressure in unilateral high-tension glaucoma

PURPOSE. To measure the effect of a surgical reduction of IOP on the spatial contrast sensitivity threshold in eyes showing a considerably increased IOP but 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 greater than or equal to 30 mm Hg in one eye and less than or equal to 18 mm Hg in the fellow eye, no evidence of field damage in both eyes, best corrected visual acuity greater than or equal to 20/20 in both eyes, and scheduled for a primary trabeculectomy in the eye showing a high IOP. The spatial contrast sensitivity threshold was measured before surgery and at each follow-up visit. RESULTS. Preoperative spatial contrast sensitivity was worse in those eyes bearing a high IOP relative 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 preoperative test-retest variability, was observed at 3, 6, and 12 cyc/deg in each surgical eye at the end of follow-up. No change was observed in the fellow untreated normal eyes. The improvement correlated directly with the amount of decrease in pressure obtained by surgery. CONCLUSIONS. Eyes with no field defects on white-on-white computer-assisted static perimetry, but bearing a IOP &GE; 30 mm Hg, show a decreased spatial contrast sensitivity. A surgically obtained reduction of IOP is paralleled by an improvement of spatial contrast sensitivity

Bronchial reactivity in healthy individuals undergoing long-term topical treatment with beta-blockers

Objective: To assess the impact of long-term treatment with topical timolol on bronchial reactivity in healthy individuals. Methods: Twenty-one otherwise healthy individuals with high-pressure primary open-angle glaucoma were enrolled in a randomized controlled clinical trial. Eleven patients underwent 3 years of topical 0.5% timolol treatment followed by a 1-year washout period; 10 patients underwent primary argon laser trabeculoplasty. Functional variables and bronchial reactivity (forced expiratory volume in I second and metacholine challenge test results) were assessed in both groups at enrollment and after 3 and 4 years of follow-up. Results: After 3 years, a measurable response to metacholine challenge was recorded in 6 of 11 otherwise symptom-free individuals treated with 0.5% timolol twice daily. A detectable response to metacholine challenge was still present in half of these individuals (3 of 6) when further washed out for 1 year from the topical beta-blocker. No significant variation in bronchial reactivity was measured in the laser-treated group during 4 years of follow-up. Conclusions: Healthy individuals who undergo longterm topical application of a nonselective beta-blocker (0.5% timolol) can develop a subclinical increase in bronchial reactivity. This phenomenon may not be completely reversible on withdrawal of the beta-blocker