Prospective study of surgical outcomes and bleb morphology using indocyanine green as a surgical dye in trabeculectomy with mitomycin C.

BACKGROUND: To investigate the effect of adding indocyanine green to mitomycin C in augmented trabeculectomy. DESIGN: A prospective, non-comparative interventional case series. PARTICIPANTS: A total of 37 eyes of 37 patients followed up for 1 year. METHODS: A solution containing 12.5 mg/mL of indocyanine green was added to mitomycin C, resulting in an mitomycin C concentration of 0.2-0.4 mg/mL, which was applied to bare sclera and Tenon's capsule for 3 min during trabeculectomy. MAIN OUTCOME MEASURES: Visual acuity, intraocular pressure, bleb morphology, Moorfields Bleb Grading System scores and complications. RESULTS: Indocyanine green could be visualized on clinical examination for all eyes on the first postoperative day. Mean intraocular pressure decreased from 22.9 ± 6.2 mmHg to 12.1 ± 4.4 mmHg postoperatively (P < 0.001) at 1 year. Thirty-four eyes (91.9%) achieved an intraocular pressure of less than 21 mmHg at final visit without additional topical intraocular pressure-lowering medications. Three eyes (8.1%) developed bleb failure and required Baerveldt device implantation. There were no cases of blebitis or late bleb leak. No adverse effects attributable to indocyanine green could be identified postoperatively. CONCLUSION: The addition of indocyanine green during trabeculectomy improves the visibility of antimetabolites intraoperatively and allows for the estimation of antimetabolite treatment area intraoperatively and postoperatively. It appears to have no adverse effect on surgical outcomes and complication rates, while improving safety of antimetabolite use.

Comparison of standard trabeculectomy versus microtrabeculectomy as a surgical treatment for glaucoma: a randomized clinical trial.

BACKGROUND: To determine the effect of scleral flap size on the medium-term intraocular pressure control and complication rates after augmented trabeculectomy. DESIGN: Prospective randomized clinical trial. PARTICIPANTS: Glaucoma patients undergoing primary trabeculectomy. Exclusion criteria included previous ocular surgery apart from cataract surgery, secondary glaucoma and age under 18. METHODS: Patients were randomized to either standard trabeculectomy (4 × 4 mm scleral flap) or microtrabeculectomy (2 × 2 mm scleral flap), both with adjustable sutures and antimetabolites. Bleb needling was performed as required. Patients were evaluated at day 1, weeks 1, 3, 6 and months 3, 6, 12, 18 and 24 postoperatively. MAIN OUTCOME MEASURES: Vision, intraocular pressure, complications and failure (intraocular pressure ≥ 21 mmHg or not reduced by ≥20% from baseline, intraocular pressure ≤ 5 mmHg, repeat glaucoma surgery and no light perception vision). RESULTS: Forty-one patients were recruited; 20 had standard trabeculectomy, and 21 had microtrabeculectomy. At 2 years, the mean intraocular pressure and cumulative probability of failure was 12.4 ± 4.6 mmHg and 0.28 for standard trabeculectomy, and 11.5 ± 3.6 mmHg and 0.27 for microtrabeculectomy (P = 0.50 and 0.89, respectively). One patient in each group required Baerveldt device implantation. Vision reduced ≥2 Snellen lines in 15% in the standard trabeculectomy group and 25% in the microtrabeculectomy group, mainly from cataract (P = 0.48). CONCLUSION: Both trabeculectomy techniques achieved good intraocular pressure reduction and had similar complication rates. Scleral flap size had no significant effect on medium-term intraocular pressure control and complication profile.

In vivo fluorescence mode confocal microscopy of subepithelial tissues in glaucoma filtering blebs.

BACKGROUND AND OBJECTIVE: The miniaturization of confocal imaging technology has resulted in the development of a handheld confocal microscope probe capable of fluorescence mode imaging. Findings in the subepithelial tissues of glaucoma filtering blebs using this novel approach for proof of concept are described. PATIENTS AND METHODS: A fiberoptic confocal imaging probe using an illumination wavelength of 488 nm was applied to the bleb surface of 11 eyes after topical or subconjunctival administration of sodium fluorescein. The imaging plane was moved to the subepithelial region and multiple images from multiple bleb regions were captured at a resolution of 1,024 x 1,024 pixels per square inch. RESULTS: High-quality images of the bleb wall structure, vasculature, and superficial sclera were obtained and demonstrated subcellular detail. Lateral resolution was between 1 and 1.5 microm and axial resolution was approximately 30 microm. Identifiable structures in the failing blebs included vasculature (including individual erythrocytes, pericytes, and vascular endothelium); microcystic structures; and cells within the Tenon's tissue, some of which resembled fibroblasts. CONCLUSION: Fluorescence mode imaging of ocular subsurface detail is a viable and promising tool for assessment of wound healing and other processes in trabeculectomy blebs. The ability to image fluorophores creates the possibility of functional imaging.

The influence of scleral flap position and dimensions on intraocular pressure control in experimental trabeculectomy.

PURPOSE: To assess the effect on intraocular pressure (IOP) of varying the length of the side incisions of the scleral flap during trabeculectomy. MATERIALS AND METHODS: Trabeculectomy operations were performed with adjustable sutures on 8 donor human eyes connected to a constant flow infusion with real-time IOP monitoring, using either a large (4 x 4 mm, 16 mm, n=8) or a small (3 x 2 mm, 6 mm, n=8) scleral flap. For each flap the side incisions began 1 mm behind the limbus and extended to the posterior edge of the flap. The side incisions were extended sequentially in 0.5-mm steps up to the limbus, then each flap dissected 1 mm further into clear cornea. RESULTS: Mean IOP after sclerostomy fashioning was 0.84 mm Hg (range 0 to 2.7 mm Hg). After flap closure, with side incisions extending to 1 mm behind the limbus, mean IOP was 21.6 mm Hg (79.5% of baseline) and 23.03 mm Hg (79.2% of baseline) for large and small flaps (P=0.26). In each size group, extending flap side incisions to the limbus produced a small nonsignificant fall in mean IOP, whereas flap extension 1 mm into clear cornea led to a significantly lower mean IOP relative to baseline of 43.2% (P<0.05) for large flaps and 35.4% for small flaps (P<0.01). CONCLUSIONS: Using this adjustable suture technique, IOP is well maintained for both flap sizes if the flap and side incisions do not extend beyond the limbus. Excessive forward dissection of a scleral flap into the clear cornea, anterior to the sclerostomy may result in increased aqueous outflow and lower IOP.

A comparison of several methods of macular hole measurement using optical coherence tomography, and their value in predicting anatomical and visual outcomes.

BACKGROUND/AIMS: To compare several methods of macular hole measurement using optical coherence tomography (OCT), and to assess their predictive capability against anatomical and visual outcomes in a single cohort of patients. METHODS: A retrospective study of 50 eyes undergoing standardised macular hole surgery. All patients underwent preoperative OCT scanning with measurement of macular hole inner opening diameter, minimum linear diameter, base diameter and macular hole height. Values were calculated for the macular hole index and the tractional hole index. RESULTS: Logistic regression analyses indicated that the preoperative base diameter, macular hole inner opening and minimum linear diameter were associated with both anatomical and visual success. Derived parameters as alternatives to these basic ophthalmic parameters add little to the modelling of either anatomical or visual success. CONCLUSION: Base diameter, macular hole inner opening and minimum linear diameter can each be used to predict anatomical and/or functional success in macular hole surgery. Preoperative base diameter is the most useful variable in this regard, as it holds the strongest association with anatomical and visual outcome and is easily measured on a OCT scan.

Use of a cyclo-oxygenase 2 inhibitor for prophylaxis of cystoid macular oedema following cataract surgery: a randomized placebo-controlled trial.

BACKGROUND: To assess the efficacy of Celecoxib, a cyclo-oxygenase 2 (COX-2) inhibitor, as prophylaxis for cystoid macular oedema after routine cataract surgery. METHODS: A prospective, randomized, double-blind placebo-controlled trial of 69 hospital patients undergoing cataract surgery. Celecoxib 200 mg twice daily or placebo was given immediately after surgery for 14 days. Optical coherence tomography was used to quantify macular thickness before surgery and on day 1, week 2 and week 6 after surgery. RESULTS: Sixty-nine patients were enrolled, of which 33 received placebo and 36 received active drug. Clinically apparent cystoid macular oedema occurred in four of the treatment group and two of the placebo group (P = 0.68). No difference in best-corrected visual acuity was seen at 6 weeks (P = 0.37). Covariate analysis of the results at 2 weeks and 6 weeks showed a macular thickness of 3% less in the treatment group compared with placebo (P = 0.050). CONCLUSION: Celecoxib may decrease macular thickening following routine cataract surgery at 2 and 6 weeks after surgery as measured by Stratus OCT III. No difference in best-corrected visual acuity or clinically apparent cystoid macular oedema was seen. Further investigation of COX-2 inhibitors in a larger prospective randomized trial is required.