Bhaskar Srinivasan

Modified osteo-odonto keratoprosthesis--the Indian experience--results of the first 50 cases.

Purpose: To study the results of the modified osteo-odonto keratoprosthesis (MOOKP) surgery in bilateral end-stage ocular surface disorders. Methods: The MOOKP surgery is performed as a routine in 3 stages. Stage 1A involves removal of the iris and anterior vitrectomy with a corneal transplant if indicated. Stage 1B + 1C usually performed simultaneously involves harvesting the buccal mucosa and transplanting it onto the ocular surface along with fashioning of the osteo-odonto alveolar lamina. Stage 2 involves transplanting the osteo-odonto alveolar lamina to the eye 3 months later. Results: The MOOKP surgery was completed in 50 eyes of 47 patients with a mean follow-up of 15.38 months (range: 1-54 months). Anatomic success was achieved in 96% of the eyes. Functional success of visual acuity ≥20/60 was noted in 66% of eyes. Complications included oroantral fistula (6%), trophic mucosal alterations (8%), lamina exposure (central 6% and peripheral 8%), mucous membrane overgrowth (2%), hypotony (2%), expulsion of optic cylinder (4%), endophthalmitis (2%), glaucoma (20%), sterile vitritis (6%), and retinal detachment (2%). Conclusions: MOOKP is the keratoprosthesis of choice in bilateral end-stage ocular surface disorders in the Indian subcontinent. Complications do occur and have to be recognized and treated early.

Lacrimal Proline Rich 4 (LPRR4) Protein in the Tear Fluid Is a Potential Biomarker of Dry Eye Syndrome

Dry eye syndrome (DES) is a complex, multifactorial, immune-associated disorder of the tear and ocular surface. DES with a high prevalence world over needs identification of potential biomarkers so as to understand not only the disease mechanism but also to identify drug targets. In this study we looked for differentially expressed proteins in tear samples of DES to arrive at characteristic biomarkers. As part of a prospective case-control study, tear specimen were collected using Schirmer strips from 129 dry eye cases and 73 age matched controls. 2D electrophoresis (2DE) and Differential gel electrophoresis (DIGE) was done to identify differentially expressed proteins. One of the differentially expressed protein in DES is lacrimal proline rich 4 protein (LPRR4). LPRR4 protein expression was quantified by enzyme immune sorbent assay (ELISA). LPRR4 was down regulated significantly in all types of dry eye cases, correlating with the disease severity as measured by clinical investigations. Further characterization of the protein is required to assess its therapeutic potential in DES.

Mucous membrane grafting for lid margin keratinization in Stevens–Johnson syndrome: results.

Purpose: To study the efficacy of mucous membrane grafting as a surgical technique to address lid margin keratinization, an important cause for chronic blink-related microtrauma in Stevens-Johnson syndrome (SJS). Methods: The keratinized strip of conjunctiva along the lid margin was excised and replaced by lip mucous membrane using fibrin glue in 54 eyes of 31 patients with lid margin keratinization after SJS. This was a retrospective case series carried out between April 2005 and November 2006. Results: In 50 of 54 eyes (92.6%), there was improvement or stabilization in patient comfort, conjunctival hyperemia, ocular surface staining characteristics, and best-corrected visual acuity over a mean follow-up period of 6 months. Conclusions: The authors describe the method of mucous membrane grafting for addressing lid margin keratinization, one of the important causes for persistent inflammation in SJS. This procedure not only improves patient comfort and visual acuity by reducing surface inflammation but also possibly prevents further deterioration of ocular surface in SJS.

Boston keratoprosthesis for keratopathy in eyes with retained silicone oil: a new indication.

Purpose: To analyze the visual outcome of Boston keratoprosthesis for keratopathy in silicone oil-filled eyes. Methods: Retrospective chart review of patients with silicone oil-induced keratopathy undergoing Boston keratoprosthesis between January 2008 and June 2010 was performed. Patients received Boston keratoprosthesis as the primary procedure or after a failed penetrating keratoplasty because of silicone oil-induced keratopathy after assessing possible visual potential. Silicone oil had to be retained in all eyes because of persistent ocular hypotony. Results: Of the 8 eyes that underwent surgery, anatomic retention and visual improvement were noted in 7 eyes (87.5%). The visual acuity improved to 20/200 or better in 6 eyes (66.67%). Repeated corneal melt necessitated the removal of the prosthesis with corneal transplant in 1 eye. Membranectomy was performed twice for retroprosthetic membrane in 1 eye. Conclusions: Boston keratoprosthesis seems to be a viable option for visual rehabilitation in postvitrectomized eyes with a decrease in vision due to retained silicone oil-induced keratopathy.

Laminar Resorption in Modified Osteo-odonto-keratoprosthesis Procedure: A Cause for Concern

PURPOSE To analyze the cases of lamina resorption following the modified osteo-odonto-keratoprosthesis (MOOKP) procedure. DESIGN Retrospective case series. PATIENTS AND METHODS Case records of 18 eyes (20 laminae) of 17 patients who showed evidence of lamina resorption out of the 85 eyes (87 laminae) of 82 patients that underwent MOOKP procedure between March 2003 and March 2013 were analyzed. RESULTS Of the 17 patients (20 laminae), 1 underwent MOOKP procedure following multiple graft failures, 6 (7 laminae) belonged to the chemical injury group, and 10 (12 laminae) to the Stevens-Johnson syndrome (SJS) group. Resorption was noted in 20 out of 87 laminae (22.98%). The need for removal of lamina/extrusion was noted in 3 out of the 7 laminae in the chemical injury group and 8 out of the 12 laminae in the SJS group. The mean duration to the first sign suggestive of resorption among patients of SJS was 36.7 months and among patients of chemical injury was 43 months. Vitritis was the presenting feature (7 of 20 laminae, 35%) indicative of early resorption, and the occurrence of the same in eyes with lamina resorption was noted to be statistically significant in comparison to controls (P<.001). Sixteen out of 20 laminae showed evidence of resorption superiorly. CONCLUSION Vitritis was the most common presenting feature of lamina resorption and could be an indicator of lamina resorption. Resorption of the laminae was noted to occur along the aspect with thinner bone support in all eyes. Incidence of severe resorption with extrusion of cylinder/requiring lamina removal was noted to be higher among patients with SJS.

Corneal changes following collagen cross linking and simultaneous topography guided photoablation with collagen cross linking for keratoconus

Purpose: To compare the outcome of Collagen cross-linking (CXL) with that following topography-guided customized ablation treatment (T-CAT) with simultaneous CXL in eyes with progressive keratoconus. Materials and Methods: This was a prospective, non-randomized single centre study of 66 eyes with progressive keratoconus. Of these, 40 eyes underwent CXL and 26 eyes underwent T-CAT + CXL. The refractive, topographic, tomographic and aberrometric changes measured at baseline, 1, 3 and 6 months post-operatively were compared between both groups. Results: After a mean follow-up of 7.7 ± 1.3 months, the mean retinoscopic cylinder decreased by 1.02 ± 3.16 D in the CXL group (P = 0.1) and 2.87 ± 3.22 D in the T-CAT + CXL group (P = 0.04). The Best corrected visual acuity increased by 2 lines or more in 10% of eyes in the CXL group and in 23.3% of eyes in the T-CAT + CXL group. The mean steepest-K reduced by 0.40 ± 3.71 D (P = 0.77) in the CXL group and by 2.91 ± 2.01D (P = 0.03) in the T-CAT + CXL group. The sag factor and surface asymmetry index showed no significant change in the CXL group but reduced by 3.59 ± 5.94 D (P = 0.01) and 0.72 ± 1.18 (P = 0.02) respectively in the T-CAT + CXL group. There was a significant increase in the highest posterior corneal elevation in both groups (9.57 ± 14.93 μ in the CXL group and 7.85 ± 9.25 μ in the T-CAT + CXL group, P ≤ 0.001 for both). There was significantly greater reduction of mean coma (P < 0.001) and mean higher-order aberrations (P = 0.01) following T-CAT + CXL compared to CXL. Conclusions: CAT + CXL is an effective approach to confer biomechanical stability and to improve the corneal contour in eyes with keratoconus and results in better refractive, topographic and aberrometric outcomes than CXL alone.

Our experience of fibrin sealant-assisted implantation of Ahmed glaucoma valve

Aim: To report our experience with the fibrin sealant as a suture substitute for securing the human scleral patch graft during implantation of Ahmed glaucoma valve (AGV). Materials and Methods: A retrospective, non-comparative study of 12 eyes of 12 patients who underwent an AGV implantation with fibrin sealant for part of the procedure during June 2009 to September 2010. Results: The mean patient age was 21.5 ± 20.6 years. Male: Female ratio was 2 : 1. Seven (58.3%) patients were monocular. The indications for AGV were varied. The mean number of intra-ocular surgeries prior to an implantation of AGV was 1.8. The mean follow-up duration was 24.5 ± 17.9 weeks. There was a statistically significant reduction in the mean IOP and in the mean number of anti-glaucoma medications at the final visit compared to the pre-operative values (P < 0.01, paired t test). Conjunctival retraction was seen in 1 (8.3%) case. The scleral patch graft was retracted posteriorly in another (8.3%) case. There was no case of AGV tube exposure, tube-cornea touch, or conjunctival erosion. Vision threatening complication viz. late post-operative rhegmatogenous retinal detachment, unlikely to be related to the use of the fibrin sealant, occurred in 2 (16.6%) eyes. Conclusion: The fibrin sealant offers the advantages of safety and convenience to the placement of a scleral patch graft during an AGV implantation.

Treatment Modalities and Clinical Outcomes in Ocular Sequelae of Stevens-Johnson Syndrome Over 25 Years--A Paradigm Shift.

Purpose: To highlight and compare the outcomes of management for the ocular sequelae of Stevens–Johnson syndrome (SJS) over 25 years in a tertiary eye care institute. Methods: A retrospective chart review of 798 eyes of 399 patients with SJS evaluated between January 1990 and December 2004 (group I) and of 847 eyes of 517 patients between January 2005 and December 2014 (group II) was done. The primary and secondary outcome measures were a change in the best-corrected visual acuity (BCVA) and an improvement in the symptoms and the ocular surface status, respectively. The groups were subdivided into procedures for ocular surface stabilization (A) and visual rehabilitation (B) and those managed conservatively (C). Results: In the subgroup A of group II, an improvement/stabilization of BCVA after punctal cautery (231 eyes), mucous membrane grafting for lid margin keratinization (393 eyes), and fornix reconstruction (28 eyes) was noted in 93.6% of eyes. In subgroup B, all 10 eyes that underwent limbal allograft in group I failed when compared with an improvement of BCVA to better than 20/200 in 65.5% of the 61 eyes that underwent keratoprostheses. It was noted that the limbal status worsened in 66.9% of eyes treated conservatively in group I. Conclusions: Stabilization procedures show a beneficial role while conservative management can lead to deterioration in chronic ocular sequelae of SJS. Keratoprosthesis, specifically the modified osteo-odonto-keratoprosthesis, forms the mainstay for visual rehabilitation in the end-stage disease. This study highlights the improved outcomes with a paradigm shift in the management modalities.

Glaucoma in Modified Osteo-odonto-keratoprosthesis Eyes: Role of Additional Stage 1A and Ahmed Glaucoma Drainage Device–Technique and Timing

PURPOSE To report the technique, timing, and outcomes of the Ahmed glaucoma drainage device in eyes with the modified osteo-odonto-keratoprosthesis (MOOKP) and the role of an additional stage 1A to the Rome-Vienna protocol. DESIGN Retrospective interventional case series. METHODS Case records of 22 eyes of 20 patients with high intraocular pressure at various stages of the MOOKP procedure performed in 85 eyes of 82 patients were studied. Stage 1A, which includes total iridodialysis, intracapsular cataract extraction, and anterior vitrectomy, was done in all eyes as the primary stage. RESULTS Seventeen Ahmed glaucoma drainage devices were implanted in 15 eyes of 14 patients (chemical injury in 9 [10 eyes] and Stevens-Johnson syndrome in 5 patients). Implantation was performed during and after stage 1A in 2 and 7 eyes, respectively, after stage 1B+1C in 1 eye, and after stage 2 in 6 eyes. Eleven of 15 eyes (73.3%) remained stable with adequate control of intraocular pressure over a mean follow-up period of 33.68 months (1-90 months). Complications related to the drainage device were hypotony in 1 eye and vitreous block of the tube in 1 eye. CONCLUSION It is ideal to place the Ahmed glaucoma drainage device prior to the mucosal graft when the anatomy of the ocular surface is least altered with best outcomes. The technique of placement of the drainage device during the various stages of the MOOKP procedure has been described. The intraocular pressure stabilized in three quarters of the eyes with pre-existing glaucoma.

Outcome of Boston Keratoprosthesis in a Developing Country-Importance of Patient Selection, Education, and Perioperative Care: The Indian Experience.

Purpose We aim to analyze the results of Boston type 1 keratoprosthesis from the Indian subcontinent, with particular emphasis on patient education and perioperative care. Design Retrospective interventional case series. Methods This was a retrospective study of patients operated on for Boston type 1 keratoprosthesis between January 2008 and April 2011. Results Of 20 patients who underwent surgery, the indications included silicone oil–induced keratopathy (8 eyes; 40%), chemical injury (7 eyes; 35%), repeated graft failures (3 eyes, 15%), and 2 pediatric eyes (10%)—1 sclerocornea and 1 congenital anterior staphyloma. The mean follow-up was 21.8 months ranging from 6 to 45 months. Best corrected postoperative visual acuity was noted to be greater than 20/200 in 16 (80%) of 20 eyes. Anatomic integrity was maintained in 18 eyes (90%). Repeated corneal melt necessitated removal of the prosthesis with corneal transplant in 2 eyes. There was no infection or endophthalmitis in any of the 20 eyes. Conclusions The good anatomic and functional results, with no postoperative infection in our experience with Boston keratoprosthesis over a 3-year period, are encouraging. Strict inclusion criteria and ensuring good patient compliance are important factors in determining good results with a low risk of infection in a tropical developing country.