Keratoprosthesis: Current global scenario and a broad Indian perspective

Keratoprosthesis (Kpro) forms the last resort for bilateral end-stage corneal blindness. The Boston Type 1 and 2 Kpros, the modified osteo-odonto Kpro and the osteo-Kpro are the more frequently and commonly performed Kpros, and this review attempts to compile the current data available on these Kpros worldwide from large single-center studies and compare the indications and outcomes with Kpros in the Indian scenario. Although the indications have significantly expanded over the years and the complications have reduced with modifications in design and postoperative regimen, these are procedures that require an exclusive setup, and a commitment toward long-term follow-up and post-Kpro care. The last decade has seen a surge in the number of Kpro procedures performed worldwide as well as in India. There is a growing need in our country among ophthalmologists to be aware of the indications for Kpro to facilitate appropriate referral as well as of the procedure to enable basic evaluation during follow-ups in case the need arises, and among corneal specialists interested to pursue the field of Kpros in understanding the nuances of these surgeries and to make a judicious decision regarding patient and Kpro selection and more importantly deferral.

Comparison of saccadic reaction time between normal and glaucoma using an eye movement perimeter.

Aim: To compare the saccadic reaction time (SRT) in both the central and peripheral visual fi eld in normal and glaucomatous eyes using eye movement perimetery (EMP). Materials and Methods: Fift y-four normal and 25 glaucoma subjects underwent EMP and visual fi eld testing on the Humphrey Field Analyser (HFA) 24-2 program. The EMP is based on infrared tracking of the corneal refl ex. Fift y-four test locations corresponding to the locations on the 24-2 HFA program were tested. SRTs at diff erent eccentricities and for different severities of glaucoma were compared between normal and glaucoma subjects. Results: Mean SRT was calculated for both normal and glaucoma subjects. Mann-Whitney U test showed statistically signifi cant (P < 0.001) diff erences in SRT’s between normal and glaucoma subjects in all zones. Conclusion: SRT was prolonged in eyes with glaucoma across diff erent eccentricities.

Efficacy and safety of latanoprost for glaucoma treatment: a three-month multicentric study in India.

PURPOSE: To evaluate the short-term efficacy and safety of 0.005% topical latanoprost in Indian eyes. DESIGN: Prospective non-randomised open-label multicentric trial. METHODS: One hundred and fifty patients with ocular hypertension (OHT), primary open-angle, pseudoexfoliation or pigmentary glaucoma were enrolled at four centers. Each center contributed at least 20 patients. Following baseline measurements, 0.005% latanoprost was applied topically once daily in the evening for three months. Patients were examined at 2, 6 and 12 weeks. The primary outcome measure was mean intraocular pressure (IOP) reduction. The mean diurnal variation of IOP (difference between highest and lowest IOP) at baseline and at 12-weeks was compared. RESULTS: One hundred and thirty of 150 enrolled patients completed the study. One randomly selected eye of each patient was included for analysis. At three months, latanoprost reduced the mean IOP from 24.9 (+/- 3.16) mmHg at baseline to 16.10 (+/- 2.7) mmHg, a reduction of 35.25%. 83% had a reduction in IOP of > 25%. The IOP reduction was maintained throughout the study period, and was not affected by gender or age of the patient. One eye did not show any response to the drug. Daytime diurnal variation of IOP was reduced from 4.5 to 2.9 mmHg. 20 patients had conjunctival hyperemia. Six patients had side effects requiring withdrawal from the study. CONCLUSIONS: In this short-term multicentric study, latanoprost effectively reduced IOP and stabilised the diurnal curve in Indian eyes. There were no clinically significant ocular or systemic adverse effects.

Ultrasound Biomiscroscopy in the diagnosis and management of cyclodialysis clefts.

PURPOSE: To report the role of Ultrasound Biomicroscopy (UBM) as a tool in the diagnosis and management of cyclodialysis clefts. METHODS: Six eyes of 6 patients with hypotony and suspected or diagnosed cyclodialysis clefts underwent UBM evaluation. Post-treatment UBM was performed in four eyes to assess the effect of the treatment. RESULTS: Cyclodialysis clefts were accurately diagnosed and delineated in 6 eyes by UBM. Complete closure was documented after treatment in 3 eyes, and a residual cleft in one eye. These findings were compared to gonioscopic findings. CONCLUSIONS: UBM is a safe, accurate and noninvasive diagnostic tool in the diagnosis of cyclodialysis clefts and is of particular use when other conventional methods of diagnosis are inconclusive.

The role of artificial drainage devices in glaucoma surgery.

The use of artificial drainage devices (ADDs) or "setons" in glaucoma surgery is generally restricted to patients with refractory glaucoma at high risk for failure from conventional filtration surgery. ADDs, both valved and nonvalved are currently available in this country. Recently, some of these devices have been propogated as primary treatment even for primary glaucomas. This article examines the role of ADDs in the modern management of the glaucomas. Specific indications for ADDs and methods to reduce the complication of overfiltration are discussed. The use of antimitotics, such as 5-fluorouracil or mitomycin, with traditional filtration has decreased the indications for ADDs. The literature and our experience confirm that currently there is no role for use of ADDs as a primary procedure in most glaucomas.

In vitro effects of mitomycin C on human Tenon's capsule fibroblasts & correlation with surgical outcome in glaucoma patients.

The effects of mitomycin C (MMC, 1 microgram/ml for 5 min) on growth and morphology of six MMC 'sensitive' and four MMC 'resistant' human Tenon's capsule fibroblasts grown from 10 patients who had had trabeculectomy for glaucoma were studied. The surgical outcome of trabeculectomy in these patients were evaluated at the end of 8-10 wk. Both types of fibroblasts showed increase of growth up to 7 days. MMC 'sensitive' fibroblasts degenerated and declined to insignificant numbers in 47 days. MMC 'resistant' fibroblasts after a decline in growth up to 27 days showed remarkable recovery in morphology and growth by day 37. Surgical outcome positively correlated with in vitro results of 'sensitive' fibroblasts. A few clones of MMC 'resistant' fibroblasts survived and multiplied as MMC effect had worn off.

Results of intraoperative 5-fluorouracil in patients undergoing trabeculectomy--pilot trial.

To study the effect of 5-Fluorouracil (5-FU) in glaucoma filtration surgery, 13 eyes of 12 patients with glaucoma were subjected to trabeculectomy with intraoperative one minute exposure of 50 mg/ml 5-FU. The average age of patients was 36.42 +/- 18.78 years. Two of the patients had developed hypotony in the fellow eye following the use of Mitomycin C with trabeculectomy. The mean follow-up period was 9.54 +/- 5.17 weeks. Two patients developed a shallow anterior chamber with choroidals postoperatively which responded to conservative treatment. One patient developed an encysted bleb one month after surgery. Single one minute intraoperative exposure to 5-FU is a convenient and inexpensive method which appears to have no significant side effects. It may be a useful adjunctive treatment to optimise the results of glaucoma filtration surgery particularly in young and myopic patients. The long term effects, however, are not known.

Single-plate Molteno implants in complicated glaucomas: results, survival rates, and complications.

Sixty-two single-plate single-stage Molteno implantations for complicated glaucomas were performed between March 1991 and November 1992. The charts of all these patients were reviewed to determine the intraocular pressure (IOP) control success rate (< 21 mm Hg with or without medications), visual success rate (retention or improvement of visual acuity from preoperative level) and the rate of complications encountered. A Kaplan-Meier life-table (survival) analysis was also performed. IOP control was obtained in 74.2% of cases. Mean postoperative IOP was 16.97 +/- 8.07 mm Hg (Mean +/- SD). Visual success was obtained in 51.6% of the eyes. Eyes with aphakia/pseudophakic glaucomas showed the best response with 80% of them achieving IOP control and 60% achieving visual success. The survival plot for IOP control revealed 75.81% and 74.19% success rates at 48 and 72 weeks, respectively. Complications encountered were either due to the early postoperative hypotony or were tube-related. These results were gratifying considering the severity of the glaucoma in these cases and they reaffirm the usefulness of the Molteno implant in the management of difficult glaucomas.

Familial nanophthalmos: management and complications.

Nanophthalmos is a rare form of congenital hypermetropia, in which, the individual is at a high risk of developing angle-closure glaucoma. We report a family of nanophthalmos affecting a brother and sister, as confirmed by biometry. Genetic analysis revealed an autosomal recessive mode of inheritance. The sister developed angle-closure glaucoma, which was refractory to medical and laser therapy. She underwent surgical interventions which resulted in complications. The clinical presentation, management, and complications encountered are discussed.