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Biomedical subjects

Geeta K Vemuganti

Publications and source records attributed to Geeta K Vemuganti.

At least 19 recordsLinked to original sources

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 LOD score of 11.1 was obtained with D20S117 at theta = 0. 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.

Anion Transport Proteins↗

Histopathological evaluation of ocular microsporidiosis by different stains.

BACKGROUND: There is limited data on comparing stains in the detection of microsporidia in corneal biopsies. Hence we wanted to evaluate various stains for their ability to detect microsporidia in corneal tissue sections. METHODS: Four cases diagnosed with microsporidiosis on Hematoxylin and Eosin and Periodic Acid Schiff's stained sections of the corneal button between January 2002 and December 2004, were included. Further sections were prospectively stained with calcofluor white, Gram, Giemsa, Masson's trichrome, acridine orange, Gomori's methenamine silver, Gram's chromotrope and modified acid fast stain. The stained sections were analyzed for the spore characteristics in terms of size, shape, color contrast, cell wall morphology, waist band in cytoplasm and ease of detection. RESULTS: All sections showed microsporidial spores as 3-5 microm, oval bodies. 1% acid fast, Gram's chromotrope and GMS stains provided a reliable diagnosis of microsporidia as diagnostic waist band could be identified and good contrast helped distinguish the spores from inflammatory debris. CONCLUSION: Considering the ease of performance, cost effectiveness and rapidity of the technique, 1% acid fast stain and Gram's chromotrope stain are ideal for the detection of microsporidia.

Journal Article↗

Pseudoepitheliomatous hyperplasia mimicking ocular surface squamous neoplasia following cultivated limbal epithelium transplantation.

A 12-year-old girl with total limbal stem cell deficiency in the right eye following chemical burns underwent autologous cultivated limbal epithelium transplantation from the healthy left eye. Postoperatively at 6 weeks a mass at the limbus was noted, which increased in size and involved infero-nasal limbus extending over 5 mm on bulbar conjunctiva. It was a gelatinous, placoid freely movable mass with irregular surface, multiple intralesional cysts without feeder vessels or intrinsic vascularization and stained brilliantly with rose bengal. Histopathology following excision biopsy showed hyperplastic epithelium with stratified columnar cells and goblet cells. At the last follow-up, 6 months following cultivated limbal epithelium transplantation the ocular surface was stable without any recurrence of the lesion. We herein report a rare complication of epithelial hyperplasia presenting as leukoplakia following cultivated limbal epithelium transplantation mimicking ocular surface squamous neoplasia.

Carcinoma, Squamous Cell↗

Acanthamoeba keratitis after LASIK.

PURPOSE: To report a case of Acanthamoeba infection following LASIK. METHODS: A 20-year-old woman developed pain, redness, decreased vision, and corneal infiltrate in the right eye 15 days after bilateral LASIK. She did not use contact lenses postoperatively. Patient examination 3 months after surgery revealed a large, central, full-thickness corneal infiltrate with multiple satellite lesions in the right eye. Corneal scrapings were taken and the flap excised, and submitted for histopathologic examination. RESULTS: Microscopic examination of smears revealed Acanthamoeba cysts and non-nutrient agar showed a significant growth of Acanthamoeba. Histopathology examination of the excised flap demonstrated numerous Acanthamoeba cysts in tissue sections. The infiltrate was treated with a combination of topical polyhexamethylene biguanide, chlorhexidine, atropine sulfate, and oral itraconazole and resolved within 2 months. CONCLUSIONS: Laser in situ keratomileusis can be complicated by Acanthamoeba infection. Microbiologic evaluation is essential for accurate early diagnosis and treatment.

Acanthamoeba↗

Clinical outcome of autologous cultivated limbal epithelium transplantation.

PURPOSE: To report the clinical outcome of autologous cultivated limbal epithelial transplantation. METHODS: Eighty-six patients' records and their clinical photographs were reviewed for demographics, primary etiology, type of limbal transplantation, ocular surface stability, visual acuity, final outcome and possible factors affecting outcome and complications. RESULTS: Eighty-eight eyes of 86 patients with limbal stem cell deficiency (LSCD) underwent autologous cultivated limbal epithelium transplantation between March 2001 and May 2003, with a mean follow-up of 18.3 months. The etiology of LSCD was alkali burns in 64% patients. Sixty-one eyes had total LSCD. Thirty-two of the 88 eyes had undergone amniotic membrane transplantation and 10 eyes had previously undergone limbal transplantation with unfavorable outcome. Nineteen eyes underwent penetrating keratoplasty, of which 11 grafts survived at the final follow-up. Finally, 57 eyes (73.1%, 95% CI: 63.3-82.9) had a successful outcome with a stable ocular surface without conjunctivalization, 21 eyes (26.9%, 95%CI: 17.1-36.7) were considered failures and 10 patients were lost to follow-up. CONCLUSION: LSCD can be successfully treated by autologous cultivated limbal epithelium transplantation in majority of the cases.

Adolescent↗

Is microsporidial keratitis an emerging cause of stromal keratitis? A case series study.

BACKGROUND: Microsporidial keratitis is a rare cause of stromal keratitis. We present a series of five cases of microsporidial keratitis from a single centre in southern India with microbiologic and histopathologic features. CASE PRESENTATION: Patient charts of five cases of microsporidial stromal keratitis diagnosed between January 2002 and June 2004 were reviewed retrospectively for clinical data, microbiologic and histopathologic data. The presence of microsporidia was confirmed by special stains on corneal scrapings and/or corneal tissues, and electron microscopy. All patients were immunocompetent with a preceding history of trauma in three. Four patients presented with unilateral, small, persisting deep stromal infiltrates, of uncertain etiology, in the cornea, which were not responding to conventional antimicrobial treatment and required penetrating keratoplasty in three. Fifth case was unsuspected and underwent keratoplasty for post-traumatic scar. Three of five cases were diagnosed on corneal scrapings, prior to keratoplasty, while two were diagnosed only on histology. The microsporidia appeared as oval well defined bodies with dense staining at one pole. None of the patients showed recurrence following keratoplasty. CONCLUSION: Microsporidia, though rare, should be suspected in chronic culture-negative stromal keratitis. Organisms could lie dormant without associated inflammation.

Adult↗

Early results of penetrating keratoplasty after cultivated limbal epithelium transplantation.

OBJECTIVE: To describe the early results of penetrating keratoplasty (PKP) in patients who had previously undergone cultivated limbal epithelium transplantation. METHODS: Medical records of patients with limbal stem cell deficiency due to chemical burns who underwent PKP after cultivated limbal epithelium transplantation were reviewed for demographics, primary etiology, type of limbal transplantation, ocular surface stability, visual acuity, graft clarity, and complications. Histopathologic features of the recipient corneal buttons were studied with special attention to epithelial status. RESULTS: Of the 125 patients with limbal stem cell deficiency treated with cultivated limbal epithelium transplantation, 15 underwent PKP at a mean interval of 7 months (range, 2-12 months) following cultivated limbal epithelium transplantation (autologous, n = 11; allogenic, n = 4). All 4 patients treated with allogenic cultivated limbal epithelium transplantation were undergoing immunosuppressive therapy. Fourteen (93%) of the 15 eyes had a successful corneal graft with a stable corneal epithelium. Preoperative best-corrected visual acuity was less than 20/200 in 14 of the 15 eyes. At a mean +/- SD follow-up of 8.3 +/- 5.0 months after PKP, the best-corrected visual acuity was more than 20/60 in 8 eyes, 20/200 to 20/60 in 5 eyes, and less than 20/200 in 2 eyes. Three of the 15 eyes experienced corneal allograft rejection, which was managed successfully. One eye with graft rejection also had glaucoma. None of the limbal epithelial allografts showed signs of rejection. CONCLUSIONS: Early results of PKP following cultivated limbal epithelium transplantation are favorable when performed after stabilizing the ocular surface. Adequate immunosuppression is essential for allogenic cultivated limbal epithelium transplantation to avoid rejection. Corneal allografts can separately reject the limbal allografts.

Adolescent↗

Genotype-phenotype correlation in 2 Indian families with severe granular corneal dystrophy.

OBJECTIVES: To determine genotypes in 2 Indian families with severe granular corneal dystrophy, to document clinical and histopathologic features, and to attempt a genotype-phenotype correlation. METHODS: Mutation analysis of exon 12 of the TGFBI gene was carried out in 9 individuals from 2 families. RESULTS: A C-->T mutation at residue 1710 of TGFBI complementary DNA, corresponding to an Arg555Trp mutation in keratoepithelin, was found in affected members of both families. In 5 patients, this mutation was homozygous, and it was heterozygous in the other 4. Clinical examination revealed a severe form of granular corneal dystrophy with early onset and superficial lesions in the homozygous individuals and a milder phenotype in the heterozygous individuals. Histopathologic evaluation of corneal specimens from 2 homozygous patients confirmed the presence of superficial granular deposits. CONCLUSIONS: To our knowledge, this is the first molecular and clinical characterization of severe granular corneal dystrophy in India. Genotype-phenotype correlation and comparison with earlier reports on this entity highlight the uniform expressivity of the Arg555Trp allele in homozygous individuals. CLINICAL RELEVANCE: Homozygous granular corneal dystrophy has a severe phenotype and can be recognized based on clinical and histopathologic features, especially in association with consanguinity or inbreeding.

Adolescent↗

Ocular surface squamous neoplasia in Papillon-Lefevre syndrome.

PURPOSE: To report the occurrence of ocular surface squamous neoplasia (OSSN) in a patient with Papillon-Lefevre syndrome. DESIGN: Interventional case report. METHODS: A 14-year-old boy presented with a progressively growing limbal lesion in the right eye for 2 months. He had associated erythematous scaly lesions on the elbows, knees, and feet with periodontosis suggestive of Papillon-Lefevre syndrome. An excision biopsy of the limbal tumor and a skin biopsy was performed. RESULTS: The limbal tumor showed features of carcinoma in situ with clear margins. The skin biopsy showed epidermal hyperplasia and hyperkeratosis with perivascular infiltrates, consistent with Papillon-Lefevre syndrome. CONCLUSIONS: Ocular surface squamous neoplasia may occur in patients with Papillon-Lefevre syndrome, an association that to the best of our knowledge has not been previously reported.

Adolescent↗

Polycystic echinococcosis of the orbit.

PURPOSE: To report a case of polycystic echinococcosis of the orbit caused by Echinococcus oligarthrus. DESIGN: Interventional case report. METHODS: A 14-year-old girl presented with a massive proptosis of the right eye of 9 years duration and loss of vision. The eye was phthisic, and a cystic mass was palpable. Computed tomography scan showed closely packed multiple orbital cysts with destruction of the medial orbital wall. Surgical exploration was performed. RESULTS: The phthisic eye was enucleated. Dissection of the outer fibrous capsule yielded approximately 30 intact translucent white cysts of various sizes that were suggestive of polycystic echinococcosis. The diagnosis of echinococcosis was confirmed on histopathologic evaluation. The specific diagnosis of E oligarthrus was made on the basis of the presence of straight-backed hooks and central guards. CONCLUSION: Polycystic echinococcosis of the orbit caused by E oligarthrus is rare. It may be an entirely new entity or hitherto unrecognized form of orbital echinococcosis.

Adolescent↗

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.

Adolescent↗

Neoadjuvant chemotherapy in the management of sebaceous gland carcinoma of the eyelid with regional lymph node metastasis.

A 55-year-old Asian Indian woman who had recurrent sebaceous gland carcinoma of the left lower eyelid with orbital extension and regional lymph node metastasis was treated with neoadjuvant chemotherapy, using a combination of carboplatin and 5-fluorouracil. Eyelid-sparing orbital exenteration was performed after 3 cycles of chemotherapy, followed by radiotherapy to the regional lymph nodes. Subsequently, 3 cycles of adjuvant chemotherapy were administered. Significant eyelid and orbital tumor volume reduction was achieved with neoadjuvant chemotherapy, making eyelid-sparing orbital exenteration possible. Chemotherapy also spared the patient from radical neck dissection. The patient had limited morbidity and was free of local, regional, and systemic disease at 26 months of follow-up.

Adenocarcinoma, Sebaceous↗

TGFBI gene mutations causing lattice and granular corneal dystrophies in Indian patients.

PURPOSE: To identify mutations in the TGFBI gene in Indian patients with lattice corneal dystrophy (LCD) or granular corneal dystrophy (GCD) and to look for genotype-phenotype correlations. METHODS: Thirty-seven unrelated patients were studied, 18 with LCD and 19 with GCD. The diagnosis of LCD or GCD was made on the basis of clinical and/or histopathological evaluation. Exons and flanking intron sequences of the TGFBI gene were amplified by PCR with specific primers. PCR products were screened by the method of single-strand conformation polymorphism followed by sequencing. Mutations were confirmed by screening at least 100 unrelated normal control subjects. RESULTS: Mutations were identified in 14 of 18 patients with LCD and in all 19 patients with GCD. In LCD, three novel heterozygous mutations found were glycine-594-valine (Gly594Val) in 2 of 18 patients, valine-539-aspartic acid (Val539Asp) in 1 patient, and deletion of valine 624, valine 625 (Val624-Val625del) in 1 patient. In addition, mutation of arginine 124-to-cysteine (Arg124Cys) was found in 8 of 18 patients and histidine 626-to-arginine (His626Arg) in 2 of 18 patients. Atypical clinical features for LCD were noted in patients with the Gly594Val and Val624-Val625del mutations. In GCD, 18 patients with GCD type I had a mutation of arginine 555-to-tryptophan (Arg555Trp) and 1 patient with GCD type III (Reis-Bucklers dystrophy), had the Arg124Leu mutation. Seven novel single-nucleotide polymorphisms (SNPs) were also found, of which a change of leucine 269 to phenylalanine (Leu269Phe) was found in 12 of 18 patients with the Arg555Trp mutation. CONCLUSIONS: Arg124Cys and Arg555Trp appear to be the predominant mutations causing LCD and GCD, respectively, in the population studied. The novel mutations identified in this study are associated with distinct phenotypes.

Adult↗

Early results of penetrating keratoplasty following limbal stem cell transplantation.

PURPOSE: To describe the early results of penetrating keratoplasty (PKP) in patients who had earlier received limbal transplantation (LT). METHODS: Prospective, non-comparative interventional case series comprising of four patients with limbal stem cell deficiency (LSCD) due to chemical injury (Cases 1, 2, 4) and xeroderma pigmentosum (Case 3). Cadaveric kerato-limbal allografts or living-related conjunctival-limbal allografts were done in four eyes followed by PKP for visual rehabilitation 3-4.5 months later. The following details were noted: demographics, primary aetiology, type of limbal transplant (cadaveric or living-related), immunosuppression, vision and ocular surface stability before and after LT and PKP, surgical complications and outcome of PKP. RESULTS: Three eyes received living-related conjunctival-limbal allotransplantation and one received cadaveric kerato-limbal allograft. Duration of follow up after PKP ranged from 4 to 11 months. Visual acuity improved in the early postoperative period in all patients but reduced in 2 due to endothelial rejection and after trans-scleral cyclophotocoagulation for medically uncontrolled glaucoma. The ocular surface remained stable in all patients. All patients were started on immunosuppression on the first postoperative day. This was continued till the last follow-up visit. Post-PKP complications were punctate epithelial keratopathy, corneal allograft rejection and secondary glaucoma (one patient each). CONCLUSION: Satisfactory visual rehabilitation is possible after PKP following LT without compromising ocular surface stability. However, a prolonged and close follow-up is warranted to avert complications.

Adult↗

Primary adult human retinal pigment epithelial cell cultures on human amniotic membranes.

PURPOSE: Retinal pigment epithelial (RPE) cells grow well on surfaces that provide an extracellular matrix. Our aim was to establish primary adult human RPE cell cultures that retain their epithelial morphology in vitro using human amniotic membrane (hAM) as substrate. MATERIALS AND METHODS: Human cadaver eyeballs (16) were obtained from the eye bank after corneal trephination. RPE cells were harvested by a) mechanical dissection of the inner choroid surface (10, group 1) or by b) enzymatic digestion using 0.25% Trypsin/0.02% EDTA (6, group 2). The cells were explanted onto de-epithelialized hAM, nourished using DMEM/HAMS F-12 media and monitored for growth under the phase contrast microscope. Cell cultures were characterised by whole mount studies and paraffin sections. Growth data in the two groups were compared using the students' 't' test. RESULTS: Eleven samples (68.75%) showed positive cultures with small, hexagonal cells arising from around the explant which formed a confluent and progressively pigmented monolayer. Whole mounts showed closely placed polygonal cells with heavily pigmented cytoplasm and indistinct nuclei. The histologic sections showed monolayers of cuboidal epithelium with variable pigmentation within the cytoplasm. Growth was seen by day 6-23 (average 11.5 days) in the mechanical group, significantly earlier (P < 0.025) than in the enzymatic group (day 29-35, average 31.6 days). CONCLUSIONS: Primary adult human RPE cell cultures retain epithelial morphology in vitro when cultured on human amniotic membranes. Mechanical dissection of the inner choroid surface appears to be an effective method of isolating RPE cells and yields earlier growth in cultures as compared to isolation by enzymatic digestion.

Amnion↗

Keratocyte loss in corneal infection through apoptosis: a histologic study of 59 cases.

BACKGROUND: Keratocyte loss by apoptosis following epithelial debridement is a well-recognized entity. In a study of corneal buttons obtained from patients of corneal ulcer undergoing therapeutic keratoplasty, we observed loss of keratocytes in the normal appearing corneal stroma, surrounding the zone of inflammation. Based on these observations, we hypothesized that the cell loss in the inflammatory free zone of corneal stroma is by apoptosis that could possibly be a non-specific host response, independent of the nature of infectious agent. METHODS: To test our hypothesis, in this study, we performed Terminal deoxyribonucleotidyl transferase-mediated d-Uridine 5" triphosphate Nick End Labelling (TUNEL) staining on 59 corneal buttons from patients diagnosed as bacterial, fungal, viral and Acanthamoeba keratitis. The corneal sections were reviewed for morphologic changes in the epithelium, stroma, type, degree and depth of inflammation, loss of keratocytes in the surrounding stroma (posterior or peripheral). TUNEL positivity was evaluated in the corneal sections, both in the zone of inflammation as well as the surrounding stroma. A correlation was attempted between the keratocyte loss, histologic, microbiologic and clinical features. RESULTS: The corneal tissues were from 59 patients aged between 16 years and 85 years (mean 46 years) and included fungal (22), viral (15), bacterial (14) and Acanthamoeba (8) keratitis. The morphological changes in corneal tissues noted were: epithelial ulceration (52, 88.1%), destruction of Bowman's layer (58, 99%), mild to moderate (28; 47.5%) to severe inflammation (31; 52.5%). Morphologic evidence of disappearance or reduced number of keratocytic nuclei in the corneal stroma was noted in 49 (83%) cases; while the TUNEL positive brown cells were identified in all cases 53/54 (98%), including cases of fungal (19), bacterial (14), viral (13), and Acanthamoeba keratitis. TUNEL staining was located mostly in the deeper stroma and in few cases the peripheral stroma. TUNEL positivity was also noted with the polymorphonuclear infiltrates and in few epithelial cells (10 of 59, 17%) cases, more with viral infections (6/10; 60%). CONCLUSIONS: We report apoptotic cell death of keratocytes in the corneal stroma in infectious keratitis, a phenomenon independent of type of infectious agent. The inflammatory cells in the zone of inflammation also show evidence of apoptotic cell death. It could be speculated that the infective process possibly triggers keratocyte loss of the surrounding stroma by apoptosis, which could possibly be a protective phenomenon. It also suggests that necrotic cell death and apoptotic cell deaths could occur simultaneously in infective conditions of the cornea.

Adolescent↗