A Proposal for the Use of a Fixed Low-Energy Selective Laser Trabeculoplasty for Open Angle Glaucoma.

Selective laser trabeculoplasty (SLT) has been in routine clinical use for over 20 years with millions of patients successfully treated and a low rate of clinically significant complications. The procedure requires the clinician to manually position the laser beam on the trabecular meshwork using a gonioscopy lens and to titrate the SLT laser energy based on the amount of pigmentation in the angle, as well as the observation of small bubbles produced by the laser effect. We propose that SLT energy titration is unnecessary either to achieve intraocular pressure (IOP) reduction or to minimize potential side effects. Ample evidence to support our proposal includes multiple clinical reports demonstrating comparable levels of IOP reduction resulting from different laser energies, a large variety of energy and other laser parameters used in commercially available SLT lasers, and the nature of the laser-induced changes in the trabecular meshwork tissue with respect to energy. Despite these variations in laser parameters, SLT consistently reduces IOP with a low complication rate. We propose that using low fixed energy for all patients will effectively and safely lower patients' IOP while reducing the complexity of the SLT procedure, potentially making SLT accessible to more patients.

Intraocular pressure control after the implantation of a second Ahmed glaucoma valve.

The objective of this study is to evaluate the efficacy and safety of a second Ahmed glaucoma valve (AGV) in eyes with refractory glaucoma that had undergone prior Ahmed device implantation. This multicenter, retrospective study evaluated 58 eyes (58 patients) that underwent a second AGV (model S2-n = 50, model FP7-n = 8) due to uncontrolled IOP under maximal medical therapy. Outcome measures included IOP, visual acuity, number of glaucoma medications, and postoperative complications. Success was defined as IOP <21 mmHg (criterion 1) or 30 % reduction of IOP (criterion 2) with or without hypotensive medications. Persistent hypotony (IOP <5 mmHg after 3 months of follow-up), loss of light perception, and reintervention for IOP control were defined as failure. Mean preoperative IOP and mean IOPs at 12 and 30 months were 27.55 ± 1.16 mmHg (n = 58), 14.45 ± 0.83 mmHg (n = 42), and 14.81 ± 0.87 mmHg (n = 16), respectively. The mean numbers of glaucoma medications preoperatively at 12 and 30 months were 3.17 ± 0.16 (n = 58), 1.81 ± 0.2 (n = 42), and 1.83 ± 0.35 (n = 18), respectively. The reductions in mean IOP and number of medications were statistically significant at all time intervals (P < 0.001). According to criterion 1, Kaplan-Meier survival curves disclosed success rates of 62.9 % at 12 months and 56.6 % at 30 months. According to criterion 2, Kaplan-Meier survival curves disclosed success rates of 43.9 % at 12 months and 32.9 % at 30 months. The most frequent early complication was hypertensive phase (10.3 %) and the most frequent late complication was corneal edema (17.2 %). Second AGV implantation may effectively reduce IOP in eyes with uncontrolled glaucoma, and is associated with relatively few complications.

Brain antioxidant status in a high pressure-induced rat model of glaucoma.

PURPOSE: The goal of the present study is to establish the antioxidant status in the brain of a high pressure-induced rat model. METHODS: Ocular hypertension was induced in rats (n = 12) cauterizing two episcleral veins under a surgical microscope. A sham procedure (n = 12) was performed in the control group. The markers evaluated in the brain 7 days after surgery were as follows: spontaneous chemiluminescence, protein carbonylation, nitrite concentration, total reactive antioxidant potential (TRAP), ascorbic acid, glutathione, vitamin E and activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase. RESULTS: Chemiluminescence in glaucoma was 55% higher than in controls (393 ± 20 cpm/mg protein, p < 0.001). Protein carbonylation in glaucoma was 93% higher than in controls (1.15 ± 0.18 nmol/mg protein, p < 0.001). Nitrite concentration was 5.30 ± 0.25 µM for glaucoma (controls 4.41 ± 0.24 µM, p < 0.05). Total reactive antioxidant potential decreased by 42% in glaucoma (controls 153 ± 14 µM Trolox, p < 0.001). Ascorbic acid was 67 ± 26 µM for glaucoma (controls 275 ± 22 µM, p < 0.001). Vitamin E was 0.58 ± 0.05 µmol/g organ for glaucoma (controls 1.10 ± 0.06 µmol/g organ, p < 0.01). Glutathione was 1.98 ± 0.13 µmol/g organ for glaucoma (controls 8.19 ± 0.71 µmol/g organ, p < 0.001). Superoxide dismutase and GPx were increased in glaucoma by 42 and 59%, respectively (p < 0.05). CONCLUSIONS: Reactive oxygen and nitrogen species were increased in glaucoma, the increase in chemiluminescence, protein carbonylation and nitrite levels could be evidenced by this situation. The decrease in nonenzymatic antioxidants and a compensatory increase in SOD and GPx activity may have been a consequence of an increase in oxidative processes.

A 3-month randomized controlled trial of bimatoprost (LUMIGAN) versus combined timolol and dorzolamide (Cosopt) in patients with glaucoma or ocular hypertension.

PURPOSE: To compare the efficacy and safety of topical bimatoprost (LUMIGAN; Allergan, Inc., Irvine, CA) once daily with that of topical combined timolol and dorzolamide (Cosopt; Merck and Co, Inc., Whitehouse Station, NJ) twice daily. DESIGN: Prospective, randomized, double-masked, multicenter clinical trial. PARTICIPANTS: One hundred seventy-seven patients with a diagnosis of glaucoma or ocular hypertension and inadequate control of intraocular pressure (IOP) after at least 2 weeks of topical timolol maleate 0.5% monotherapy. METHODS: Patients were randomized to receive bimatoprost 0.03% once daily (n = 90) or combined timolol 0.5% and dorzolamide 2% twice daily (n = 87) over a 3-month period. MAIN OUTCOME MEASURES: Intraocular pressure, the primary end point, was measured at 8 AM and 10 AM at baseline, week 1, and months 1, 2, and 3, and also at 4 PM and 8 PM at baseline and month 3. RESULTS: Bimatoprost provided significantly greater IOP lowering compared with combined timolol and dorzolamide. At the 8 AM measurements, bimatoprost lowered mean IOP 6.8 mmHg to 7.6 mmHg from baseline, whereas combined timolol and dorzolamide lowered mean IOP 4.4 to 5.0 mmHg from baseline (P<0.001). At the last follow-up, patients had better diurnal IOP control with bimatoprost than combined timolol and dorzolamide. At 8 AM at the 3-month visit, the percentages of patients achieving IOPs of