Successful goniosynechialysis for angle-closure glaucoma after vitreoretinal surgery.

PURPOSE: To describe 2 cases of long-term successful clinical outcome after goniosynechialysis for secondary angle-closure glaucoma after vitreoretinal surgery. METHODS: Case reports. Goniosynechialysis was performed bilaterally in 1 patient and unilaterally in another for uncontrolled angle-closure glaucoma after vitreoretinal surgery. RESULTS: Angle reopening was performed 2 to 4 months after initial closure. After follow-up of between 3 and 5 years, intraocular pressure has remained below 21 mm Hg without medication in all three eyes. CONCLUSION: Goniosynechialysis should be considered a viable therapeutic alternative to filtration surgery in selected patients with a recent history of angle-closure glaucoma after vitreoretinal surgery.

A comparative study of the chemical stability of various mitomycin C solutions used in glaucoma filtering surgery.

OBJECTIVE: To determine the chemical stability of various mitomycin C (MMC) solutions used in glaucoma filtering surgery. METHODS: A survey of the MMC solutions currently in use in 21 hospitals (11 in Canada, 10 in the United States) was conducted. A comparative study of the chemical stability of five different representative solutions was performed. The effects of buffer and storage variables on the chemical breakdown of MMC in the solutions were studied by means of high-performance liquid chromatography (HPLC). RESULTS: The survey revealed 33 different variations (including recipes and storage conditions) in the preparation of MMC solutions. Although the majority of the hospitals (15 of 21; 72%) were preparing stable solutions, six of the hospitals (28%) were preparing potentially unstable solutions. The stability of the solutions varied in a nonuniform manner when stored at different temperatures in different buffers. CONCLUSION: The lack of standardization and quality control of MMC solutions used in filtering surgery allows for the possibility of hospitals preparing unstable solutions.

Apraclonidine 0.5% versus brimonidine 0.2% for the control of intraocular pressure elevation following anterior segment laser procedures.

BACKGROUND AND OBJECTIVE: Both apraclonidine hydrochloride 0.5% and brimonidine tartrate 0.5% are potent alpha-2 agonists, effective in controlling the intraocular pressure (IOP) rise following argon laser trabeculoplasty (ALT). Brimonidine has recently become available commercially as a 0.2% solution. Our goal in this study was to compare the efficacy and side effect profile of 0.2% brimonidine to that of 0.5% apraclonidine in the prevention of IOP spikes following anterior segment laser procedures. PATIENTS AND METHODS: Patients undergoing argon laser trabeculoplasty, Nd:Yag peripheral iridectomy or posterior capsulotomy were prospectively randomized to receive either apraclonidine 0.5% or brimonidine 0.2%, approximately 10 minutes prior to laser surgery. Intraocular pressure was measured by a masked observer, using Goldmann applanation tonometry, before and 1 hour after the treatment. RESULTS: 51 ALTs, 21 peripheral iridectomies, and 13 posterior capsulotomies were performed. The incidence of an IOP rise greater than 5 mmHg was 3/43 (7.0%) in the brimonidine group and 0/42 (0%) in the apraclonidine group (P = 0.08, chi-squared). There were no IOP elevations greater than 8 mmHg. All IOP rises of greater than 5 mmHg occurred in the ALT sub-group, and within this sub-group, the mean change in IOP from pre- to post-op was -4.00 +/- 5.87 in the brimonidine group versus -4.29 +/- 3.86 in the apraclonidine group (P = 0.84). There was a statistically significant decrease in IOP from baseline in both drug groups (P < .0001). CONCLUSIONS: Both drugs are highly effective in controlling IOP spikes following anterior segment laser procedures. There is a tendency toward higher risk of IOP rise following argon laser trabeculoplasty with 0.2% brimonidine as compared to 0.5% apraclonidine, however, this was not statistically significant.

Histology of conjunctival vascular endothelium after filtering surgery with mitomycin C in rabbits.

OBJECTIVE: To examine histologic changes in conjunctival vasculature during the first 72 hours following filtering surgery with adjunctive mitomycin C in rabbits. DESIGN: Thirty-six New Zealand white rabbits underwent unilateral posterior lip sclerectomy. In 18 rabbits mitomycin C (0.5 mg/mL) was applied subconjunctivally for 5 minutes. The remaining 18 animals were treated with the phosphate-buffered saline vehicle for 5 minutes. Three rabbits from either group were killed at 0, 4, 12, 24, 48 and 72 hours postoperatively. OUTCOME MEASURES: Degree of vascularity of filtering blebs on gross examination and appearance of conjunctival vascular specimens on light and transmission electron microscopy, as assessed by three masked observers. RESULTS: On gross examination the filtering blebs in the mitomycin C group were slightly less hyperemic than those in the control group at 12, 24 and 48 hours and were markedly less hyperemic at 72 hours. Light microscopy showed tightly packed erythrocytes within the conjunctival vessels of the experimental blebs and an almost total absence of endothelium within many of the vascular channels by 72 hours. Transmission electron microscopy showed focal loss of vascular endothelial cells and thrombus formation in the experimental blebs, as early as 12 hours postoperatively. CONCLUSIONS: Our findings suggest that the decreased vascularity of filtering blebs observed after trabeculectomy with adjunctive mitomycin C is at least partially due to a toxic effect of the agent on the endothelial cells of the conjunctival vessels.

Apraclonidine 0.5% versus 1% for controlling intraocular pressure elevation after argon laser trabeculoplasty.

BACKGROUND AND OBJECTIVE: Topical apraclonidine hydrochloride 1% is effective for controlling the intraocular pressure (IOP) rise following argon laser trabeculoplasty (ALT). The 0.5% formulation has recently become available commercially. The objective of this study was to compare the efficacy of these two concentrations for controlling IOP after ALT. PATIENTS AND METHODS: All patients undergoing ALT were prospectively randomized to receive either 1% or 0.5% apraclonidine 1 hour before and immediately after the laser surgery. IOP was measured before and 2 and 24 hours after the treatment. RESULTS: No statistically significant difference in mean IOPs was found between the two treatment groups at any time. CONCLUSION: These data suggest that 0.5% and 1% apraclonidine are equally effective for preventing IOP rise after ALT.

Drug-induced transient myopia and angle-closure glaucoma associated with supraciliary choroidal effusion.

PURPOSE: We investigated the mechanism of drug-induced transient myopia, anterior chamber shallowing, and secondary angle-closure glaucoma in a young woman. METHODS: Ultrasound biomicroscopy was performed and the effects of cycloplegic eyedrops and unilateral laser iridotomy were evaluated. RESULTS: Cycloplegic eyedrops and unilateral laser iridotomy had no effect. Ultrasound biomicroscopy identified the presence of a supraciliary choroidal effusion that caused forward displacement of the lens-iris diaphragm, resulting in increased myopia, anterior chamber shallowing, and angle-closure glaucoma. Discontinuance of trimethoprim and sulfamethoxazole combination led to the complete resolution of the condition. CONCLUSIONS: Idiosyncratic drug reactions may produce a supraciliary choroidal effusion, resulting in myopia and secondary angle-closure glaucoma from the induced forward shift in the position of the crystalline lens and ciliary body.

Inhibition by rapamycin of PDGF- and bFGF-induced human tenon fibroblast proliferation in vitro.

PURPOSE: Fibrosis of subconjunctival tissues is a major cause of bleb failure following glaucoma filtration surgery. The aim of the present investigation was to demonstrate the effect of Rapamycin, a clinically relevant macrolide antibiotic with potent immunosuppressive properties, on human Tenon fibroblast proliferation induced by platelet-derived growth factor and basic fibroblast growth factor. METHODS: Primary Tenon fibroblast cultures were derived from patients undergoing trabeculectomies or routine cataract extractions. Rapamycin was added in concentrations of 0.1-100 ng/ml with or without 3-30 ng/ml of porcine platelet-derived growth factor or of human recombinant basic fibroblast growth factor. Two days after treatment, the cells were examined and counted. The results were expressed as the percent of cell growth in treated culture relative to its untreated control. RESULTS: Rapamycin was not cytotoxic at any of the concentrations tested. Inhibition of platelet-derived growth factor-induced Tenon fibroblast proliferation occurred with all doses of Rapamycin, the most marked effect being observed with 30 ng/ml (60% inhibition, p < 0.001). In contrast, optimal inhibition of basic fibroblast growth factor-induced proliferation was only 37% (p < 0.01), achieved with 10 ng/ml of the peptide. CONCLUSION: Rapamycin potently inhibits platelet-derived growth factor-induced fibroblast proliferation in vitro without any apparent cytotoxicity. It may eventually prove to be a useful adjunct to glaucoma filtration surgery.

Anterior chamber fluid contamination after uncomplicated phacoemulsification.

This study determined the rate of anterior chamber aerobic bacterial contamination in 103 eyes that had uncomplicated posterior chamber phacoemulsification. Anterior chamber fluid was aspirated on completion of surgery. Cultures of sterile balanced salt solution served as a control. Of 103 anterior chamber cultures, 4 (3.9%) showed contamination; however, 3 of 103 control cultures (2.9%) also grew micro-organisms. These findings suggest a very low rate of aerobic bacterial contamination after uncomplicated phacoemulsification and underscore the importance of control cultures when determining contamination rates.