Risk factors for exposure of glaucoma drainage devices: a retrospective observational study.

OBJECTIVES: The purpose of this study was to identify risk factors for exposure of glaucoma drainage devices (GDD). SETTING: This retrospective, observational study was conducted in the eye clinic of an academic medical centre. PARTICIPANTS: Participants included 1073 consecutive adults who underwent GDD surgery between 1 January 2005 and 1 January 2011. Participants were included if chart review indicated GDD surgery during the study period and excluded if at least 12 months of clinical follow-up was not available in the medical record. PRIMARY OUTCOME MEASURE: The primary outcome measure was exposure of the GDD occurring at least 1 month after implant surgery. The characteristics of participants who experienced exposure of the implant were compared to the characteristics of participants who did not experience exposure. RESULTS: Of the 1073 participants having undergone GDD surgery, 67 experienced exposure of the device. Neither the type of GDD, type of patch graft (eye bank sclera, Tutoplast sclera and Tutoplast pericardium), surgeon, location of GDD, number of GDD previously implanted into the eye, nor history of diabetes or uveitis were associated with likelihood of exposure. Women were more likely than men to experience exposure of the GDD (OR 2.004 (95% CI1.170 to 3.431)) in both univariable (p=0.011) and multivariable (p=0.013) analyses. In survival analysis, exposure of the GDD occurred earlier for women than for men (58 vs 61 months; p=0.024).White race (vs black) was also associated with increased risk of GDD exposure (OR 1.693 (95% CI 1.011 to 2.833)) in univariable (p=0.044) and multivariable (p=0.046) analyses. CONCLUSIONS: Women are two times more likely to experience GDD exposure than men, independent of age. White race is also a risk factor for exposure.

Selective laser trabeculoplasty reduces mean IOP and IOP variation in normal tension glaucoma patients.

PURPOSE: To evaluate the effect of selective laser trabeculoplasty (SLT) in normal tension glaucoma (NTG) patients. PATIENTS AND METHODS: A retrospective review was performed of NTG patients who had undergone SLT at the Duke University Eye Center between 12/2002 and 7/2005. For each eye of each patient at pre-laser and post-laser time points, the IOP measurements were summarized by mean, standard deviation, and range. Then for each of these descriptive statistics, the differences between pre-laser and post-laser values were obtained. Statistical analysis was performed using a random effects model. MAIN OUTCOME MEASURES: difference in mean IOP, standard deviation of IOP, and range of IOP. RESULTS: Thirty-one eyes of 18 patients were included for analysis. The average of the mean pre-operative IOP measurements was 14.3 +/- 2.6 mmHg compared to 12.2 +/- 1.7 mmHg (P < 0.001) post-operatively. The mean pre-operative standard deviation was 1.9 +/- 0.9 mmHg compared to 1.0 +/- 0.6 mmHg (P = 0.002) post-operatively while the mean IOP range prior to treatment was 4.5 +/- 2.5 mmHg compared to 2.5 +/- 1.9 mmHg (P = 0.017) after treatment. CONCLUSION: In this pilot study, SLT was found to lower mean IOP and intervisit IOP variation in NTG patients. Given the importance of IOP variation and its association with glaucoma progression, measurement of IOP variation following treatment with SLT may be considered.

Gene and protein expression pilot profiling and biomarkers in an experimental mouse model of hypertensive glaucoma.

Glaucoma is a group of genetically heterogeneous neurodegenerative disorders causing the degeneration of the ganglion neurons of the retina. Increased intraocular pressure (IOP) is a hallmark risk factor promoting the death of ganglion neurons of the retina in glaucoma. Yet, the molecular processes underlying the degeneration of these neurons by increased IOP are not understood. To gain insight into the early molecular events and discover biomarkers induced by IOP, we performed gene and protein expression profiling to compare retinas of eyes with and without high IOP in a rodent model of experimental glaucoma. This pilot study found that the IOP-mediated changes in the transcription levels of a restricted set of genes implicated in peroxisomal and mitochondrial function, modulation of neuron survival and inflammatory processes, were also accompanied by changes in the levels of proteins encoded by the same genes. With the exception of the inflammatory markers, serum amyloid-A1 (SAA1) and serum amyloid-A2 (SAA2), the IOP-induced changes in protein expression were restricted to ganglion neurons of the retina and they were detected also in the vitreous, thus suggesting an early IOP-mediated loss of ganglion cell integrity. Interestingly, SAA1 and SAA2 were induced in retinal microglia cells, whereas they were reduced in sera of IOP-responsive mice. Hence, this study defines novel IOP-induced molecular processes, biomarkers and sources thereof, and it further validates the extension of the analyses herein reported to other genes modulated by IOP.