Nibaran Gangopadhyay

Autosomal recessive corneal endothelial dystrophy (CHED2) is associated with mutations in SLC4A11

Objective: To map and identify the gene for autosomal recessive congenital hereditary endothelial dystrophy (CHED2, OMIM 217700), a disorder characterised by diffuse bilateral corneal clouding that may lead to visual impairment and requiring corneal transplantation. Methods: Members of 16 families with autosomal recessive CHED were genotyped for 13 microsatellite markers at the CHED2 locus on chromosome 20p13-12. Two-point linkage analysis was carried out using the FASTLINK version of the MLINK program. Mutation screening was carried out by amplification of exons and flanking regions by polymerase chain reaction, followed by direct automated sequencing. Results: Linkage and haplotype analysis placed the disease locus within a 2.2 cM (1.3 Mb) interval flanked by D20S198 and D20S889, including SLC4A11. The maximum limit of detection score of 11.1 was obtained with D20S117 at θu200a=u200a0. Sequencing of SLC4A11 showed homozygotic mutations in affected members from 12 of 16 families. Conclusion: These results confirm that mutations in the SLC4A11 gene cause autosomal recessive CHED.

Cultivated corneal epithelial transplantation for severe ocular surface disease in vernal keratoconjunctivitis

Purpose: To report cultivated epithelial transplantation in 2 patients with vernal keratoconjunctivitis (VKC) with severe ocular surface disease. Methods: Two patients initially diagnosed with burnt-out VKC presented with bilateral photophobia, decreased vision, and corneal neovascularization. The first patient underwent living-related conjunctival-limbal allograft in the left eye and cultivated limbal epithelial cell allotransplant in the right. The second patient underwent unsuccessful amniotic membrane transplantation (AMT) followed by autologous cultivated limbal epithelial cell transplantation in the worse eye. Results: Both patients had onset of VKC in the first decade. Surgical intervention in both led to marked amelioration in symptoms and improvement in vision. In patient 1, vision improved from 20/800 (both eyes) to 20/30 in the right and 20/100 in the left eye at a follow-up of 34 months. In patient 2, it improved from 20/400 to 20/50 after the second procedure, 25 months postoperatively. Histopathology of the excised pannus revealed fibrosis and mononuclear cell infiltrates in all 3 eyes. Conclusions: Severe ocular surface disease may occur in persistent VKC, leading to marked visual loss. AMT alone may be insufficient to restore the ocular surface, and limbal epithelial cell transplantation is warranted.

Outcome of pterygium surgery: analysis over 14 years

AimTo report the outcome of pterygium surgery performed at a tertiary eye care centre in South India.MethodsRetrospective analysis of medical records of 920 patients (989 eyes) with primary and recurrent pterygia operated between January 1988 and December 2001. The demographic variables, surgical technique (bare sclera, primary closure, amniotic membrane transplantation (AMT), conjunctival autograft (CAG), conjunctival–limbal autograft (CLAG), or surgical adjuvants), recurrences and postoperative complications were analysed.ResultsA total of 496 (53.9%) were male and 69 (7.5%) had bilateral pterygia. Bare sclera technique was performed in 267 (27.0%) eyes, primary conjunctival closure in 32 (3.2%), AMG in 123 (12.4%), CAG in 429 (43.4%), and CLAG in 70 (7.1%). Adjuvant mitomycin C was used in 44 (4.4%) cases. The mean duration of follow-up was 8.9±17.0 and 5.9±8.8 months for unilateral primary and recurrent pterygia, respectively. The overall recurrence rate was 178 (18.0%). Following primary and recurrent unilateral pterygium excision respectively, recurrences were noted in 46 (19.4%) and 1 (33.3%) eyes after bare sclera technique, five (16.7%) and 0 after primary closure, 28 (26.7%) and 0 with AMG, 42 (12.2%) and five (31.3%) with CAG, and nine (17.3%) and two (40%) with CLAG. Recurrences were significantly more in males with primary (23.3 vs10.7%, P<0.0001) and recurrent (26.7 vs0%, P=0.034) pterygia, and in those below 40 years (25.2 vs14.8%, P=0.003).ConclusionCAG appears to be an effective modality for primary and recurrent pterygia. Males and patients below 40 years face greater risk of recurrence. Bare sclera technique has an unacceptably high recurrence. Prospective studies comparing CAG, CLAG, and AMG for primary and recurrent pterygia are needed.

Outcome of penetrating keratoplasty for Peters anomaly.

Purpose: To determine the results of corneal graft survival after penetrating keratoplasty for Peters anomaly. Methods: Retrospective review of records of children 12 years of age or younger who underwent penetrating keratoplasty for Peters anomaly between March 1988 and December 2003. The data were analyzed regarding graft survival. The survival probabilities were estimated by using the Kaplan-Meier method. The main outcome measure was graft clarity. Results: Forty corneal transplants were performed in 32 children with Peters anomaly whose mean age at keratoplasty was 8.6 ± 3.9 months (range, 2.5-22 months). The mean follow-up period was 1.9 ± 2.9 years (range, 1 month to 15 years). Seventeen (42.5%) of the 40 grafts retained full clarity. Survival analysis showed a 52% probability of the graft remaining clear at the end of 6 months, which dropped to 22% at 2 years. The predicted mean survival time of grafts was 20.1 months (95% confidence interval, 4.9-36.3). Allograft rejection was the most frequently identified cause of graft failure, accounting for 15 (65%) of the 23 failed grafts, with 93.3% of episodes occurring in the first year. Poor graft survival correlated with age younger than 6 months (P = 0.04). Conclusions: The overall probability of maintaining a clear corneal transplant in Peters anomaly is 22% at 2 years and may be adversely affected by younger age at surgery. Because most episodes of rejection occurred in the first year, follow-up is recommended during this period.

Multiplex polymerase chain reaction for the detection of herpes simplex virus, varicella-zoster virus and cytomegalovirus in ocular specimens

Purpose. A majority of ocular viral diseases are caused by herpes group of viruses. Such infections, especially atypical herpetic keratitis, iridocyclitis and intra-ocular inflammations, can often present with overlapping clinical manifestations misleading the diagnosis. Molecular techniques are most useful in such instances for an accurate and rapid diagnosis since conventional methods are time consuming and less sensitive. A multiplex PCR was developed and used for the detection of herpes simplex virus (HSV), varicella zoster virus (VZV), and cytomegalovirus (CMV) in ocular samples. Methods. One hundred and forty six ocular samples (corneal scrapings – 52, aqueous fluid – 36, vitreous fluid – 31, tissues – 26, skin vesicle scraping – 1) were included in the study. The sensitivity of the assay was determined using serial dilutions of standard strains of HSV, VZV, and CMV vis-à-vis plaque forming assay. Results. The sensitivity of the assay was 4, 4 and 12PFU/ml or 20, 20 and 60 genome copy numbers of HSV, VZV and CMV respectively. Using DNA from various sources (fungal, bacterial, human leukocytes, tissues) along with standard positive controls, the assay was found to be highly specific. HSV DNA was detected in majority of the clinical samples (33.6%), most frequent being corneal samples. Comparatively, VZV and CMV infections were detected in small number of samples (VZV-3, CMV-2). Conclusions. We found the assay very useful in our set-up whenever a differential diagnosis of herpetic infections was suggested by the ophthalmologist. The multiplex PCR we have described here can be of greater value in clinics with larger number of patients suspected of having HSV, VZV or CMV infections.

Clinico-microbiological correlation of suture-related graft infection following penetrating keratoplasty

PURPOSEnTo report the clinical and microbiological profiles of suture-related graft infections following penetrating keratoplasty.nnnDESIGNnInterventional case series.nnnMETHODSnThe medical and microbiology records of all patients who presented with suture-related graft infections and were seen between January 1999 and December 2001 were reviewed.nnnRESULTSnOf 105 patients (105 eyes) who developed corneal infiltrates following penetrating keratoplasty, 37 patients (24 optical and 13 therapeutic) were identified as having suture-related graft infection. The median onset of infiltrates after penetrating keratoplasty was 87 days for 31 patients who presented within one year. Gram-stained smears of corneal scrapings were positive in 27 (73%) of 37 patients, whereas cultures were positive in 32 (only bacteria, 30; mixed bacteria and fungi, 2). Thirty-seven isolates were obtained from 32 patients (gram-positive bacteria, 32; gram-negative bacteria, 3; fungus, 2). All gram-positive isolates were sensitive to cefazolin, chloramphenicol, and vancomycin, whereas one of three gram-negative isolates (Pseudomanas species) was resistant to all the antibiotics tested. Of 32 patients, 30 (82%) responded satisfactorily to medical management.nnnCONCLUSIONSnSuture-related graft infections are usually caused by bacteria that are sensitive to ciprofloxacin, cefazolin, and gentamicin, and the patients respond satisfactorily to medical therapy.

Candida keratitis: emerging problem in India.

Purpose To determine the epidemiological characteristics and outcome of Candida keratitis in a Cornea Care Unit of Kolkata-based tertiary eye hospital. Methods A retrospective, noncomparative, observational case series involving patients of culture-proven fungal keratitis from January 2008 to December 2008. A total of 85 cases of culture-proven fungal keratitis were identified. Of these, 16 cases were caused by Candida sp and selected for the study. The records were analyzed for demographics, risk factors, mode of management (medical or surgical), indication of surgical therapy, and the response to treatment with final outcome. Medical therapy consisted of topical amphotericin B with or without intracameral application after obtaining culture reports. Surgical therapy included application of tissue adhesive with bandage contact lens and therapeutic keratoplasty. Results All cases of Candida keratitis were caused by Candida albicans accounting for 16 cases [18.81%; 95% confidence interval (CI), 11.8–28.5] of total culture-positive fungal keratitis. We found postsurgical steroid therapy in 8 cases as most important association, followed by diabetes and trauma (4 cases each) as next common comorbidities. All patients required therapeutic keratoplasty. Surgical indications were corneal melt in 10 cases (62.5%; 95% CI, 38.5–81.6), extension up to limbus in 2 cases (12.5%; 95% CI, 12.2–37.2) and nonresponse with worsening in 4 cases (25%; 95% CI, 19.7–49.9). Final outcome consists of phthisis bulbi in 3 cases (18.8%; 95% CI, 5.8–43.8), failed graft in 7 cases (43.7%; 95% CI, 23–66.8), and clear graft in 6 cases (37.5%; 95% CI, 18.4–61.5). Conclusions Candida is a new concern in developing countries like India. We are concerned about the poorer outcome, probably resulting from our unpreparedness and failure of medical therapy leading to more complication and requiring surgical intervention in higher numbers.

Characteristics of microsporidial keratoconjunctivitis in an eastern indian cohort: A case series

BACKGROUNDnMicrosporidia are intracellular parasites responsible for human infections. Recently, there has been an increase in the incidence of microsporidial keratoconjunctivitis (MKC) affecting normal individuals worldwide.nnnAIMnTo determine the characteristics of MKC in an Indian cohort.nnnMATERIALS AND METHODSnThis is a retrospective, noncomparative, observational case series, involving patients with MKC between June and September 2009. Of the 24 patients identified, microbiological confirmation in direct smear was obtained in 22 cases and selected. Standard microbiological workup was performed in all the cases. We studied the demographics, predisposing conditions, antecedent treatment received before presentation, clinical characteristics, treatment offered, and resolution time with sequel. The management consisted of simple debridement and application of chloramphenicol ointment (1%) two times a day.nnnRESULTSnMean age of onset was 18.7 years (95% CI, 15.7-21.7; range, 11-36 s years). All patients gave history of prior outdoor activity and exposure to rain water/mud. Antecedent treatment comprised of Acyclovir eye ointment (45.4%) and antibiotic eye drop (27.3%) most commonly. Microsporidia were identified in Gram stain (81.8%), 10% potassium hydroxide mount (72.7%), modified Ziehl-Neelsen staining (36.4%), and Giemsa (18.2%). Majority presented as unilateral superficial keratoconjunctivitis with punctate epithelial keratitis. Mean resolution time was 9 days (95%CI, 7.9-10.2).nnnCONCLUSIONSnMKC can occur in normal patients with exposure to rain and mud, related to outdoor activity often misdiagnosed as viral ocular infections. Strong clinical suspicion with proper microbiological evaluation helps to diagnose this commonly misdiagnosed condition.