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.

Visual field changes after transient elevation of intraocular pressure in eyes with and without glaucoma.

PURPOSE: To evaluate visual field (VF) changes in glaucomatous and nonglaucomatous eyes after transient elevation of intraocular pressure (IOP). DESIGN: Prospective experimental study. PARTICIPANTS: One hundred subjects (38 with glaucoma, 62 glaucoma suspects and controls). METHODS: Intraocular pressure elevation was induced in the right eye of all subjects with a modified LASIK suction ring. Intraocular pressure was elevated to an average of 64 mmHg for <30 seconds. Humphrey Matrix perimetry 24-2 threshold tests were performed before and after the procedure. A cohort of patients who demonstrated significant deterioration in postprocedural perimetry was recalled for further testing. MAIN OUTCOME MEASURES: Mean deviation (MD) and pattern standard deviation (PSD) from Humphrey Matrix perimetry. RESULTS: A significant decline in MD of the right eye could be observed on immediate postprocedural perimetry amongst glaucoma and control patients, whereas no significant changes in PSD were seen in either group. Forty-five of 47 patients, whose immediate postprocedural perimetry showed a loss of MD > 2 decibels, attended for repeat perimetric testing with a median follow-up of 6 days. Both eyes among 28 control patients and the left eye among 17 glaucoma patients showed statistically significant improvement in MD. Similar improvement was seen in the right eye of glaucoma patients, but this failed to reach statistical significance. Six patients from the glaucoma group demonstrated deterioration in MD upon recall, compared with 3 in the control group (P = 0.046). These 6 patients were significantly younger than the rest of the group, but no other defining characteristics were identified. CONCLUSIONS: Transient elevation of IOP in adult eyes with and without glaucomatous optic neuropathy did not lead to functional optic nerve change, as measured by Matrix perimetry, in the short term for the majority of patients. It is possible that a small cohort of patients with preexisting glaucomatous optic neuropathy may be more susceptible to transient increase in IOP, although the result is inconclusive. Prominent learning effects may have masked subtle worsening of visual function in our subjects; corresponding structural analyses of the optic nerve and longer-term follow-up may provide further information.

Acute angle closure after implantable contact lens insertion unresponsive to surgical peripheral iridectomy.

We present a case of acute angle closure that occurred after insertion of an implantable contact lens (ICL). The apparent papillary-block angle closure did not resolve after 2 patent iridotomies and a surgical iridectomy, but did respond to pupil dilation (not constriction). Ultrasound biomicroscopy revealed abnormally large and irregular ciliary processes that may have contributed to the unusual behavior of the ICL-iris complex. The condition resolved after the ICL was replaced by one with a smaller haptic diameter. Routine ultrasound biomicroscopic assessment of the ciliary body anatomy preoperatively and ICL haptic positioning postoperatively may identify risk factors that could predispose ICL patients to acute angle closure.

Optic disc diameter increases during acute elevations of intraocular pressure.

PURPOSE: To evaluate optic nerve diameter changes in glaucomatous and nonglaucomatous eyes during transient elevation of intraocular pressure (IOP). METHODS: This prospective experimental study included 100 subjects: 38 with glaucoma and 62 without glaucoma. Elevation of IOP to an average of 64 mm Hg for less than 30 seconds was induced in one eye of all subjects by means of a modified LASIK suction ring. The optic nerve heads were imaged before and during the elevation. RESULTS: During IOP elevation, optic disc area and linear disc measurements increased by a small but significant amount (3.89%, P < 0.0001 and 0.96%, P = 0.01, respectively). Distances between retinal landmarks did not change significantly (P = 0.25). A smaller optic disc at baseline (P = 0.004) and increased central corneal thickness (CCT; P = 0.011) were associated with a greater increase in disc area relative to other fundus dimensions during IOP elevation. Disc area increased less in patients with glaucoma (P = 0.015). In a multivariate model including age, glaucoma status, CCT, and baseline disc area, there was a small but significant negative correlation between disc area enlargement and baseline optic disc diameter (P = 0.017). CONCLUSIONS: Transient elevation of IOP in adult eyes resulted in increases in disc area and linear disc dimensions, but not in retinal dimensions. The degree of enlargement appears to be less in patients with glaucoma than without and greater with increased corneal thickness. A multivariate model showed that the amount of disc area increase was inversely proportional to baseline disc area but was not related to glaucoma status or CCT. (ClinicalTrials.gov number, NCT00328835).

Corneal hysteresis but not corneal thickness correlates with optic nerve surface compliance in glaucoma patients.

PURPOSE: To investigate relationships between acute intraocular pressure (IOP)-induced optic nerve head surface deformation and corneal hysteresis and thickness in glaucomatous and nonglaucomatous human eyes. METHODS: This was a prospective experimental study of 100 subjects (38 with glaucoma, 62 without glaucoma). Data collected included spherical equivalent, optic disc diameter, central corneal thickness (CCT), axial length, cylinder, Goldmann IOP, Pascal IOP, and ocular pulse amplitude and ocular response analyzer (ORA) measurements of corneal hysteresis (CH). Elevation of IOP was induced in the right eye of each subject with a modified LASIK suction ring to an average of 64 mm Hg for less than 30 seconds. Heidelberg Retina Tomography II (HRT) was used to map the optic nerve surface before and during IOP elevation. Mean cup depth was calculated using built-in HRT data analysis software. Change in optic disc depth during IOP elevation was calculated for all right eyes, and tests for correlation with the parameters listed were performed. RESULTS: Both CH and CCT were lower in the glaucoma group (8.8 mm Hg and 532 microm) than in the control group (9.6 mm Hg, P = 0.012; 551 microm, P = 0.011, respectively). There were no statistically significant differences in spherical equivalent, cylinder, axial length, optic disc size, or ocular pulse amplitude between the glaucoma and the control groups. There was no difference between the amount of IOP elevation between the two groups (P = 0.41), and the average difference in mean cup depth between baseline (mean cup depth, 247 microm) and during IOP elevation was 33 microm (29.8 microm in glaucoma and 36.1 microm in control; P = 0.5). Multiple variable analysis, controlling for age and sex, showed that CH was correlated with mean cup depth increase (P = 0.032). This relationship persisted (P = 0.032) after controlling for glaucoma status in addition to age and sex. Other factors, including CCT (P = 0.3), axial length (P = 0.9), ocular pulse amplitude (P = 0.22), and spherical equivalent (P = 0.38), were not significant in this model. CONCLUSIONS: In the glaucoma patients but not the control patients, CH but not CCT or other anterior segment parameters was associated with increased deformation of the optic nerve surface during transient elevations of IOP. (ClinicalTrials.gov number, NCT00328835.).