Clinical results of ab interno trabeculotomy using the trabectome in patients with uveitic glaucoma.

IMPORTANCE: To evaluate the safety and efficacy of ab interno trabeculotomy (AIT) (trabecular ablation) with the trabectome in patients with uveitic glaucoma. BACKGROUND: Traditional glaucoma filtration surgeries in the uveitic patient population come with a higher risk of complications such as failure and hypotony. DESIGN: Retrospective observational cohort study. PARTICIPANTS: All patients diagnosed with uveitic glaucoma were included in this study. Patients were excluded if they have less than 12 months of follow-up. METHODS: All patients who received AIT alone or combined with phacoemulsification. MAIN OUTCOME MEASURES: Major outcomes include intraocular pressure (IOP), number of glaucoma medications and secondary glaucoma surgery, if any. Kaplan-Meier method was used for survival analysis and success was defined as IOP ≤21 mmHg, at least 20% IOP reduction from baseline for any two consecutive visits after 3 months, no additional glaucoma medications, and no secondary glaucoma surgery. RESULTS: A total of 45 eyes, 45 patients, with an average age of 52 years were included in the study. The majority were Japanese (40%) and underwent AIT alone (71%). IOP was reduced from 29.2 ± 8.0 to 16.7 ± 4.6 mmHg at 12 months (P < .01*), while the number of glaucoma medications was reduced from 4.0 ± 1.0 to 2.5 ± 1.6 (P < .01*). Survival rate at 12 months was 91%. Six cases required secondary glaucoma surgery and no other serious complication were reported. CONCLUSIONS AND RELEVANCE: The trabectome AIT procedure appears to be effective in reducing IOP in uveitic glaucoma patients. Although no statistically significant difference was found in the number of glaucoma medications, a decreasing trend was found.

Feedback-controlled constant-pressure anterior chamber perfusion in live mice.

PURPOSE: To describe live mouse, anterior chamber constant-pressure perfusion by an approach using feedback-controlled coupling of pressure and flow to maintain a preset pressure. METHODS: We established a microperfusion system that maintains a constant preset pressure in the anterior chamber of live mice by automatically regulating the microsyringe pump flow rate with a computer-controlled voltage feedback loop. Perfusion was by single-needle cannulation. We characterized the following in C57BL/6 mice aged 3-4 months in vivo: (i) pressure stability, (ii) pressure and flow rate reproducibility, (iii) total outflow facility, and (iv) anterior segment histology after perfusion. RESULTS: Twenty live mice underwent perfusion. Constant pressure was quickly attained and stably maintained. The coefficient of pressure variation over time during perfusion at a preset pressure was <0.001. The average coefficient of variation for repeat pressure and flow rate measurements was 0.0005 and 0.127, respectively. The relationship between flow rate and pressure was linear for perfusions between 15 and 35 mmHg. The total outflow facility was 0.0066 µl/min/mmHg. Perfusion system resistance (0.5 mmHg/min/µl) was negligible relative to the ocular outflow resistance (147 mmHg/min/µl) at physiologically relevant perfusion pressures of 15-35 mmHg. No histological disruption of the drainage tissue was seen following perfusion. CONCLUSIONS: Predetermined pressure was stably maintained during constant-pressure perfusion of live mouse eyes by a method using feedback-controlled coupling of pressure and flow along with single-needle anterior chamber cannulation. Perfusion measurements were reproducible. This approach is potentially useful for exploring aqueous drainage tissue biology, physiology, and pharmacology in live mice.

Endoscopic Cyclophotocoagulation and Other Cyclodestructive Methods: Histopathologic Comparison of In Vivo Treatment in Humans and Monkeys.

PURPOSE: To compare the histologic effects of endoscopic cyclophotocoagulation (ECP) with other ciliary body ablative procedures. A secondary aim was to correlate these findings with historical clinical success and complication rates. DESIGN: Prospective, qualitative comparison of histopathologic tissue analysis. PARTICIPANTS: Two eyes of two patients who had undergone ECP for open-angle glaucoma were studied. Two eyes from a healthy monkey were treated with ECP and studied. For comparison, 1 eye each of patients who had undergone contact and noncontact neodymium:yttrium-aluminum-garnet transscleral cyclophotocoagulation (TCP) for open-angle glaucoma were analyzed. METHODS: The human globes were enucleated and submitted for analysis by gross examination and light and electron microscopy. Monkey eyes were studied by gross examination and light microscopy 1 week, 2 weeks, and 1 month after ECP. MAIN OUTCOME MEASURES: Gross and histopathologic specimens of all eyes were analyzed with respect to location and type of tissue effects and degree of collateral damage. RESULTS: The gross analysis of all ECP specimens showed a uniform anterior-to-posterior whitening of each treated ciliary process. This correlated with microscopic evidence of loss of pigmentation from the pigmented ciliary epithelial cells seen with mostly preserved architecture and vasculature of the ciliary processes. By comparison, the TCP specimens showed erratic treatment of the ciliary processes with overlap into the pars plicata of the ciliary body. Microscopic analysis revealed significant disruption of the cells throughout the ciliary processes and loss of vessels within the stroma. CONCLUSIONS: Treatment with ECP results in less overall tissue destruction and a targeted effect on the pigmented ciliary epithelium of the ciliary processes when compared with TCP.

Micropulse Transscleral Diode Laser Cyclophotocoagulation in Refractory Glaucoma: Short-Term Efficacy, Safety, and Impact of Surgical History on Outcomes.

PURPOSE: To assess the short-term efficacy and safety of micropulse transscleral diode laser cyclophotocoagulation (MP-TSCPC) in the management of refractory glaucoma and to compare outcomes based on prior glaucoma surgeries. DESIGN: Retrospective analysis. PARTICIPANTS: Patients with refractory glaucoma who underwent MP-TSCPC at a single institution by 1 of 4 surgeons. METHODS: Chart review of cases of MP-TSCPC using the Iridex Cyclo G6 (Mountain View, CA) laser with standard parameters and laser duration at the discretion of each treating physician. MAIN OUTCOME MEASURES: Probability of postoperative success was estimated by the Kaplan-Meier method. Success parameters included intraocular pressure (IOP) 6 to 21 mmHg with or without topical antihypertensive therapy, 20% or more IOP reduction from baseline for any 2 consecutive visits after 3 postoperative months, and no subsequent glaucoma surgery. RESULTS: One hundred sixteen eyes of 116 patients (mean age, 65.8±16.9 years) were included. Baseline IOP was 22.2±7.9 mmHg, and mean postoperative follow-up time was 6.3±3.4 months (range, 3-12 months.) Postoperative IOP at the final follow up was 15.3±6.6 mmHg (P < 0.01), corresponding to a reduction of approximately 6.9 mmHg (31.1%). Most eyes (66.4%) underwent at least 6 months of follow-up. Short-term probability of success was 93.1% at 3 months and 74.3% at 6 months. Eyes that had undergone prior traditional glaucoma surgery (trabeculectomy, tube shunt, excessive pressure-regulating shunt system miniature glaucoma shunt [Alcon, Fort Worth, TX], or a combination thereof) demonstrated a higher probability of success (67.6%) compared with eyes that had not (41.4%; P = 0.014). The most common complications were decline in best-corrected visual acuity (7.8%) and hypotony (1.7%). CONCLUSIONS: Micropulse transscleral diode laser cyclophotocoagulation has a significant short-term ocular hypotensive effect and favorable safety profile in eyes with refractory glaucoma. The probability of successful outcome was greater in eyes that had undergone prior traditional glaucoma surgery.

Patient Outcomes Following Micropulse Transscleral Cyclophotocoagulation: Intermediate-term Results.

PURPOSE: To report the safety and efficacy outcomes following micropulse transscleral cyclophotocoagulation (MPTSCPC) procedure in patients with uncontrolled glaucoma. MATERIALS AND METHODS: Longitudinal retrospective cohort, multicenter study. Patients with different types of glaucoma who underwent MPTSCPC with P3 probe between July 2015 and May 2017. Patients were treated by different glaucoma specialists from 5 different locations (Tulane Study Group). Data on preoperative characteristics, surgical procedure(s) performed, and postoperative outcomes were collected and analyzed. Statistical analysis using logistic regression and Kaplan-Meier analysis was performed with Stata software. Intraoperative and postoperative complications, intraocular pressure, visual acuity, need for incisional glaucoma surgery, need for repeat micropulse, and number of topical medications were studied. RESULTS: One hundred ninety-seven eyes from 161 patients were included. Median follow-up was 12 months [interquartile range (IQR), 6 to 14]. Glaucoma diagnosis included 141 primary open-angle glaucoma (POAG), 8 neovascular glaucoma, and 12 others. The total success rate was 71%. Two percent (4 patients) developed postoperative cystoid macular edema. Preoperative mean intraocular pressure (SD) was 22±9 and 16±6 mm Hg at last follow-up (P<0.001). Median preoperative logMAR visual acuity (IQR) was 0.4 (0.2 to 1.0) and 0.3 (0.2 to 1.0) at last follow-up (P=0.65, Wilcoxon signed-rank test). Median number (IQR) of topical medications was 3 (1 to 4) preoperative and 2 (1 to 3) at last follow-up (P<0.001). Kaplan-Meier analysis indicated 90% of patients free from repeat MPTSCPC at 12 months. Multivariable logistic regression identified 3 significant independent predictors of total success: diagnosis (P=0.011) (POAG), previous glaucoma surgery (P=0.003), and other concurrent procedures (P=0.013). CONCLUSIONS: Our large longitudinal cohort study has provided evidence that MPTSCPC is a safe and generally effective option in the treatment of POAG up to 12 months.

Total Outflow Facility in Live C57BL/6 Mice of Different Age.

PURPOSE: To characterize total outflow facility across the live adult mouse lifespan as a reference for mouse glaucoma studies and the common C57BL/6 background strain. METHODS: Microperfusion was performed by single-needle cannulation and feedback-controlled coupling of pressure and flow to maintain a constant pressure in the anterior chambers of live C57BL/6NCrl mice aged 3-4 months (n = 17), 6-9 months (n = 10), and 23-27 months (n = 12). This mouse age range represented an equivalent human age range of young adult to elderly. We characterized the following across age groups in vivo: (1) outflow facility based on constant pressure perfusion in a pressure range of 15-35 mm Hg, (2) perfusion flow rates, and (3) anterior segment tissue histology after perfusion. Thirty-nine live mice underwent perfusion. RESULTS: Pressure-flow rate functions were consistently linear for all age groups (all R 2 > 0.96). Total outflow facility in mice aged 3-4, 6-9, and 23-27 months was 0.0066, 0.0064, and 0.0077 µL/min/mm Hg, respectively. Facility was not significantly different between age groups (all p > 0.4). The groups had closely overlapping frequency distribution profiles with right-sided tails. Post hoc estimates indicated that group facility differences of at least 50% would have been detectable, with this limit set mainly by inherent variability in the strain. A trend toward higher perfusion flow rates was seen in older mice aged 23-27 months, but this was not significantly different from that of mice aged 3-4 months or 6-9 months (p > 0.2). No histological disruption or difference in iridocorneal angle or drainage tissue structure was seen following perfusion in the different age groups. CONCLUSION: We did not find a significant difference in total outflow facility between different age groups across the live C57BL/6 mouse adult lifespan, agreeing with some human studies. The possibility that more subtle differences might exist ought to be judged with respect to the heterogeneity in facility at different ages. Our findings provide reference data for live perfusion studies pertaining to glaucoma involving the C57BL/6 strain.