Ab interno Schlemm's canal surgery: trabectome and i-stent.

In primary open-angle glaucoma, the site of greatest resistance to aqueous outflow is thought to be the trabecular meshwork. Augmentation of the conventional (trabecular) outflow pathway would facilitate physiologic outflow and subsequently lower intraocular pressure. Ab interno Schlemm's canal surgery including two novel surgical modalities, Trabectome (trabeculotomy internal approach) and Trabecular Micro-bypass Stent (iStent), is designed to reduce intraocular pressure by this approach. In contrast to external filtration surgeries such as trabeculectomy and aqueous tube shunt, these procedures are categorized as internal filtration surgeries and are both performed from an internal approach via gonioscopic guidance. Published results suggest that these surgical procedures are both safe and efficacious for the treatment of open-angle glaucoma.

Vision loss and recovery after trabeculectomy: risk and associated risk factors.

OBJECTIVES: To assess the risk of long-term vision loss after trabeculectomy and to determine the course of long-term vision loss vs transient loss and recovery. METHODS: The medical records of 301 eyes in 262 patients undergoing trabeculectomy between January 1999 and September 2003 were retrospectively reviewed. Postoperative vision loss was categorized as mild or moderate (decrease in Snellen visual acuity of 3-5 lines) vs severe (decrease of >5 lines). Postoperative vision loss was considered permanent if visual acuity did not have a return of 3 lines within a 6-month follow-up period. RESULTS: Permanent vision loss occurred in 24 of 301 eyes (8.0%): 13 (4.3%) had mild or moderate vision loss, and 11 (3.7%) had severe vision loss. Ten eyes (3.3%) with permanent mild or moderate vision loss and 6 eyes (2.0%) with permanent severe vision loss had no identifiable cause. Significant risk factors for permanent severe unexplained vision loss were preoperative split fixation on visual fields, preoperative number of quadrants with split fixation, and postoperative choroidal effusions with eventual resolution. Transient vision loss occurred in 170 of 301 eyes (56.5%): 79 (26.2%) had mild or moderate vision loss, with a mean time to recovery of 88 days (range, 6-720 days), and 91 (30.2%) had severe vision loss, with a mean time to recovery of 78 days (range, 6-720 days). CONCLUSIONS: Transient vision loss after trabeculectomy is common and may take up to 2 years for recovery. The risk of permanent vision loss is less common but significant. Two percent of our study population experienced permanent severe unexplained vision loss ("snuff-out"), and risk factors included preoperative split fixation on visual fields, preoperative number of quadrants with split fixation, and postoperative choroidal effusions with eventual resolution.

Population and high-risk group screening for glaucoma: the Los Angeles Latino Eye Study.

PURPOSE: To evaluate the ability of various screening tests, both individually and in combination, to detect glaucoma in the general Latino population and high-risk subgroups. METHODS: The Los Angeles Latino Eye Study is a population-based study of eye disease in Latinos 40 years of age and older. Participants (n = 6082) underwent Humphrey visual field testing (HVF), frequency doubling technology (FDT) perimetry, measurement of intraocular pressure (IOP) and central corneal thickness (CCT), and independent assessment of optic nerve vertical cup disc (C/D) ratio. Screening parameters were evaluated for three definitions of glaucoma based on optic disc, visual field, and a combination of both. Analyses were also conducted for high-risk subgroups (family history of glaucoma, diabetes mellitus, and age ≥65 years). Sensitivity, specificity, and receiver operating characteristic curves were calculated for those continuous parameters independently associated with glaucoma. Classification and regression tree (CART) analysis was used to develop a multivariate algorithm for glaucoma screening. RESULTS: Preset cutoffs for screening parameters yielded a generally poor balance of sensitivity and specificity (sensitivity/specificity for IOP ≥21 mm Hg and C/D ≥0.8 was 0.24/0.97 and 0.60/0.98, respectively). Assessment of high-risk subgroups did not improve the sensitivity/specificity of individual screening parameters. A CART analysis using multiple screening parameters-C/D, HVF, and IOP-substantially improved the balance of sensitivity and specificity (sensitivity/specificity 0.92/0.92). CONCLUSIONS: No single screening parameter is useful for glaucoma screening. However, a combination of vertical C/D ratio, HVF, and IOP provides the best balance of sensitivity/specificity and is likely to provide the highest yield in glaucoma screening programs.

Concentration of latanoprost ophthalmic solution after 4 to 6 weeks' use in an eye clinic setting.

PURPOSE: To determine the concentration of latanoprost in bottles of latanoprost ophthalmic solution 0.005% after 4 or 6 weeks of use in patients in an eye clinic setting. METHODS: Patients treated with latanoprost for open-angle glaucoma or ocular hypertension were randomly assigned to refill their prescriptions either at the Doheny Eye Institute clinic or a local pharmacy. Patients who used latanoprost binocularly were asked to return bottles to the clinic after 4 weeks of use and nonrefrigerated storage, and those who used latanoprost monocularly were asked to return used bottles after 6 weeks. Patients were then interviewed to determine bottle storage information and doses missed. Latanoprost concentration in residual solution was analyzed in a masked fashion, by reversed-phase high-performance liquid chromatography (HPLC). RESULTS: In all, 110 patients were enrolled and 89 returned their bottles. Sixty-nine bottles had sufficient residual volume to conduct HPLC analysis. All patients reported that bottles were stored at room temperature (average high from 70-95 degrees F during the daytime). The mean +/- SD latanoprost concentration measured in the residual solutions was 48.31 +/- 2.31 microg/mL. Ninety-four percent of the bottles had concentrations within 90% to 110% of the labeled amount. No difference in latanoprost concentrations was found between the bottles used for 4 weeks versus those used for 6 weeks. CONCLUSIONS: In an eye clinic setting, latanoprost ophthalmic solution 0.005% remains stable after 4 or 6 weeks of patient use from the same bottle when stored at room temperature.