Profiling of Cytokines Secreted by Conventional Aqueous Outflow Pathway Endothelial Cells Activated In Vitro and Ex Vivo With Laser Irradiation.

PURPOSE: To profile which cytokine genes are differentially expressed (DE) as up- or downregulated by cultured human trabecular meshwork (TMEs) and Schlemm's canal endothelial cells (SCEs) after three experimental treatments consisting of selective laser trabeculoplasty (SLT) irradiation, exposure to media conditioned either by SLT-irradiated TMEs (TME-cm) or by SCEs (SCE-cm). Also, to profile which cytokines are upregulated ex vivo in SLT-irradiated human conventional aqueous outflow pathway (CAOP) tissues. METHODS: After each treatment, Affymetrix microarray assays were used to detect upregulated and downregulated genes for cytokines and their receptors in TMEs and SCEs. ELISA and protein antibody arrays were used to detect upregulated cytokines secreted in SLT-irradiated CAOP tissues ex vivo. RESULTS: The SLT irradiation upregulated numerous cytokine genes in TMEs, but only a few in SCEs. Exposure to TME- and SCE-cm induced SCEs to upregulate many more cytokine genes than TMEs. Selective laser trabeculoplasty irradiation and exposure to TME-cm downregulated several cytokine genes in TMEs but none in SCEs. Selective laser trabeculoplasty irradiation induced one upregulated and three downregulated cytokine-receptor genes in TMEs but none in SCEs. Exposure to TME-cm induced upregulation of one and downregulation of another receptor gene in TMEs, whereas two unique cytokine-receptor genes were upregulated in SCEs. Cytokine protein expression analysis showed that at least eight cytokines were upregulated in SLT-irradiated human CAOP tissues in situ/ex vivo. CONCLUSIONS: This study has helped us identify a cytokine signaling pathway and to consider newly identified mechanisms regulating aqueous outflow that may lay the foundation for the future development of cytokine-based glaucoma therapies.

From the bedside to the bench and back again: predicting and improving the outcomes of SLT glaucoma therapy.

PURPOSE: To determine whether selective laser trabeculoplasty (SLT) and prostaglandin analogues (PGAs) have a common mechanism of action that involves increasing conductivity across Schlemm's canal endothelial cells (SCEs) and inducing a similar decrease in intraocular pressure (IOP) in a given patient. METHODS: The intercellular junctions in SCEs were made visible by transfection of a plasmid containing a GFP-tagged gene for ZO-1 protein. Transfected SCEs were treated with media conditioned by lasered trabecular meshwork endothelial cells (TMEs), or with latanoprost, bimatoprost, or travoprost. Non-transfected SCEs were exposed to brimonidine, timolol, or brinzolamide. Confocal microscopy and conductivity measurements documented the in vitro treatment effects. Clinically, the IOP in the first SLT-treated eye of 24 patients was measured (1) while on PGA therapy, (2) at "baseline" several weeks after discontinuing PGA therapy, and (3) approximately 90 days after SLT treatment. RESULTS: Both the in vitro addition of any of the 3 PGAs and of media conditioned by lasered TMEs induced similar SCE effects involving junction disassembly, paracellular pathway widening, and increased conductivity. Clinically, PGAs decreased IOP by a mean of 5.58 mmHg and SLT decreased IOP by 6.60 mmHg from a baseline of 21.52 mmHg. CONCLUSIONS: Exposure to media conditioned by lasered TMEs, or the addition of PGAs, induces the disassembly of intercellular junctions opening up the SCE barrier. Clinically, a positive PGA response predicts both a successful SLT outcome and the magnitude of the decrease in IOP after SLT. We hypothesize that SLT and PGA therapies may share a common mechanism of action.

Ahmed valve implantation with adjunctive mitomycin C and 5-fluorouracil: long-term outcomes.

PURPOSE: To evaluate long-term outcomes after Ahmed valve implantation in patients with glaucoma when using adjunctive intraoperative mitomycin C (MMC) and postoperative 5-fluorouracil (5-FU). DESIGN: Retrospective, interventional, consecutive case series. METHODS: A consecutive series of eyes undergoing Ahmed valve implantation, either alone (AHMED eyes) or in combination with cataract surgery (AHMED+PHACO), using both intraoperative MMC and postoperative 5-FU were evaluated. Failure was defined as the first occurrence of any of the following: 1) the first of three consecutive visits where intraocular pressure (IOP) was >18 mm Hg or <20% IOP reduction from baseline and the final number of topical medications was not reduced by at least two from baseline, 2) the need for additional surgery, or 3) the development of serious complications. RESULTS: A total of 130 eyes underwent Ahmed valve implantation with intraoperative exposure to 0.5 mg/ml MMC (median time: eight minutes; range, four to 10) and postoperative subconjunctival injections of 5 mg of 5-FU (median: five injections; range, zero to nine). Kaplan-Meier estimates of the cumulative probability of valve success and confidence interval (CI) at the sixth follow-up year were 0.72 (95% CI, 0.59 to 0.82) for AHMED eyes (n = 88), 0.84 (95% CI, 0.65 to 0.93) for AHMED+PHACO eyes (n = 42). A median of two fewer medications were required relative to baseline for both AHMED and AHMED+PHACO eyes. CONCLUSIONS: The adjunctive use of both intraoperative MMC and postoperative 5-FU with Ahmed valve implantation results in high success rates. IOP was well controlled in the majority of patients within the six-year postoperative period.

Long-term follow-up of initially successful trabeculectomy with 5-fluorouracil injections.

PURPOSE: To study the long-term results (1-14 years) of trabeculectomies with 5-fluorouracil injections that were successful at 1 year. DESIGN: A retrospective noncomparative case series. INTERVENTION/PARTICIPANTS: We identified 87 patients (87 eyes) who had trabeculectomies with 5-fluorouracil injections from 1984 to 1989 that were successful at 1 year and had a follow-up range of 1.0 to 14.7 years (mean, 8.1, standard deviation of 4.4 years). All patients had previously failed glaucoma surgery (66.7%), cataract surgery (47.1%), or other diagnoses making them at high risk for failure. MAIN OUTCOME MEASURES: Successful control of intraocular pressure (IOP) was defined as IOP less than 21 mmHg or a reduction of 33% if preoperative pressure was less than 21 mmHg. Statistical analysis was performed using Kaplan-Meier life table analysis. RESULTS: If an eye is considered successful by IOP at 1 year, the probability of successful control is 61% at 5 years, 44% at 10 years, and 41% at 14 years. CONCLUSIONS: Despite successful IOP control at 1 year, trabeculectomies with 5-fluorouracil injections show a continual loss of IOP control over time.