Optimization of the uveoscleral outflow in the patients with primary open-angle glaucoma and resistant to latanoprost intraocular pressure

Abstract

Background. The aim of our study was to investigate the role of visual load levels in the IOP elevation in the patients taking prostaglandin analogues and to try to optimize the conditions for their effects on the uveoscleral outflow. Material and Methods. 33 patients (40 eyes) with first diagnosed primary open-angle glaucoma and resistance to latanoprost 0,005 % intraocular pressure were included in this study. These patients were pre-examined with the definition of visual and reading acuity, refraction, true, tolerant and target IOP with perimetry and ophthalmoscopy. Subjects were divided into 2 groups of comparable age, sex, refraction. In each group the thickness of the ciliary body by ultrasound biomicroscopy was investigated, level of near visual load and tolerated correction for near were defined. Results. It was found, that in both groups 85% of the eyes with POAG had moderately high (3-6 hours per day) and high (more than 6 hours a day) near visual load. Maximal ciliary body thickness in both groups was significantly higher than the results received by other authors: 0.881±0.039 mm in group 1 and 0.889±0.049 mm in group 2. Also a direct dependence of the ciliary body thickness and the true value of intraocular pressure (r=0.52) was observed. The hypercorrection of presbyopia was made in group 1 gradually, in steps of 0.25 diopters. The value of additional correction averaged 0.5 ± 0.13 diopters. The magnitude of additional correction was inversely related to age (r=0.79). To assess the effectiveness of presbyopia overcorrection in reducing IOP one year later tonometry, the checking of visual acuity, perimetry (MD/year method), ophthalmoscopy, the thickness of the ciliary body were estimated. In the group 1 the reduction of intraocular pressure (17.3 ± 0.84 mm Hg) was statistically significant (p <0.01), its value was close to the average tolerant IOP (17.0 ± 0.67 mm Hg), but was higher than the target (14.3 ± 0.67 mm Hg). Also in this group statistically significant (p <0.01) decrease in the thickness of the ciliary body was observed, more marked in patients with high near visual load (r = 0.47). Progression of glaucoma according to perimetry was significantly less (p <0.01) in the group with a hypercorrection of presbyopia as compared with group with ordinary correction. Conclusions. Overcorrection of presbyopia, as a way to regulate IOP may be in addition to antihypertensive therapy for patients with high near visual load and POAG.