CHANGES IN RETINAL NERVE-FIBER LAYER THICKNESS AFTER REDUCTION OF INTRAOCULAR-PRESSURE IN CHRONIC OPEN-ANGLE GLAUCOMA

Purpose: The authors evaluated the relative nerve fiber layer height changes in glaucomatous eyes after reduction of intraocular pressure (IOP) after trabeculectomy using image analysis techniques. Methods: Optic disc topography and relative nerve fiber layer height of 12 eyes of 12 patients with chronic open-angle glaucoma were measured using a Rodenstock optic nerve head analyzer and Caprioli's program for nerve fiber layer height determination before trabeculectomy and at 2 or more months after surgery. Results: Changes in relative nerve fiber layer height after surgery, as well as those in cup volume and rim area, showed statistically significant correlation with the degree of reduction of IOP (Spearman's correlation coefficient = 0.66; P < 0.05). Changes in the mean deviation of Humphrey visual field showed a slight correlation with IOP reduction (Spearman's correlation coefficient = 0.55; P < 0.1). Conclusion: Nerve fiber layer height changes that may occur after trabeculectomy are pressure-dependent.