Biomedical subjects
Publications and source records attributed to P Namperumalsamy.
Prepapillary arterial loops are congenital vascular anomalies that have been noted to cause arterial occlusions. We report a case of superior branch macular artery occlusion in an eye with two independent prepapillary arterial loops, following a Valsalva-like mechanism.
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With the increase in life expectancy across the world, the magnitude of blindness due to age-related macular degeneration (AMD) is expected to rise. Exudative form is the major cause of visual loss from AMD. Several treatment options are available for this form of the disease. However, all treatment strategies aim at preservation of residual vision rather than regaining the lost vision. Two well-proven strategies are laser photocoagulation and photodynamic therapy. Other viable options are submacular surgery, transpupillary thermotherapy and pharmacological modalities like angiostatic-steroids. Oral anti-oxidants and zinc appear to be beneficial in preventing disease progression in early cases. Further research is on to explore more efficient treatments and to prove the safety and efficacy of large number of emerging newer treatment options.
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OBJECTIVES: To test the hypothesis that mutations in the CRB1 gene cause Leber congenital amaurosis (LCA) and, if so, to describe the ocular phenotype of patients with LCA who harbor CRB1 sequence variations. PATIENTS: One hundred ninety probands with a clinical diagnosis of LCA were selected from a cohort of 233 probands ascertained in 5 different countries. The remaining 43 probands (18%) were excluded because they harbored sequence variations in previously identified LCA genes. METHODS: One hundred ninety unrelated individuals with LCA were screened for coding sequence mutations in the CRB1 gene with single-strand conformation polymorphism analysis followed by automated DNA sequencing. RESULTS: Twenty-one of the 190 probands (9% of the total cohort of 233) and 2 (1.4%) of 140 controls harbored amino acid-altering sequence variations in the CRB1 gene (P =.003). CONCLUSIONS: In our cohort of patients with LCA, coding sequence variations were observed in the CRB1 gene more frequently than in any of the other 5 known LCA-associated genes. Likely disease-causing sequence variations have now been identified in 64 (28%) of 233 subjects in this cohort. CLINICAL RELEVANCE: Molecular diagnosis can confirm and clarify the diagnosis in an increasing fraction of patients with LCA. As genotype data accumulate, clinical phenotypes associated with specific mutations may be established. This will facilitate the counseling of patients regarding their visual prognosis and the likelihood of associated systemic anomalies.
PURPOSE: To describe the epidemiologic, clinical, and histopathologic features of trematode granulomas of the conjunctiva, eyelid, and anterior chamber in pediatric patients. DESIGN: Prospective noncomparative case series. PARTICIPANTS: Forty-one children from a southern Indian village with conjunctival granulomas. METHODS: The village of Sellananthal was selected for a field visit after analysis of earlier hospital-based allergic conjunctival granuloma cases. Children with ocular diseases were examined, and histories of exposure to assumed risk factors and clinical findings were evaluated. Selected patients were brought to the base hospital for excisional biopsy. Serial sections obtained from the excised nodules were examined for the presence of a parasite. MAIN OUTCOME MEASURES: Histopathologic examination of excised conjunctival lesions or response of lesions to local medical therapy. RESULTS: In this year-long prospective study, 41 children (16 years or younger; 38 boys and 3 girls) with clinical features of allergic conjunctival granulomas were examined. Thirty-four patients were from a single village located in the southern Indian state of Tamil Nadu; the remaining 7 were from various parts of the same state. All children swam in their village's freshwater pond. Twenty patients with nodules less than 5 mm in diameter received medical treatment; 13 with larger nodules underwent surgical excision of the lesions. Nine of these 13 cases revealed a zonal granulomatous inflammation admixed with eosinophilic leukocytes; 4 of these 9 displayed fragments of the tegument and internal structures of a trematode and Splendore-Hoeppli phenomenon. The remaining 4 of the 13 cases revealed nongranulomatous inflammation made up of lymphocytes, histiocytes, and eosinophils. Eight patients refused surgical treatment. CONCLUSIONS: In southern India, one cause of allergic conjunctival granulomas in children seems to be trematode infection. The clustering of cases in a single village and exposure to a village freshwater pond indicate the need for an epidemiologic investigation and study of the parasite's life cycle. Sporadic cases from other parts of the state with similar histories of exposure to their local pond or river water suggest a widespread distribution of the etiologic agent.
OBJECTIVE: To assess the frequency of mutations in the CRX, GUCY2D, and RPE65 genes in patients with Leber congenital amaurosis (LCA). PATIENTS: One hundred seventy-six probands with a clinical diagnosis of LCA were from 9 countries, with the largest subgroup being 39 probands from India. METHODS: Samples were screened with single-strand conformation polymorphism analysis followed by DNA sequencing of 3 genes (CRX, GUCY2D, and RPE65) known to be associated with LCA. RESULTS: Of the 176 probands, 28 (15.9%) harbored possible disease-causing mutations. The relative contribution of each gene to the total number of mutations was as follows: CRX, 2.8%; GUCY2D, 6.3%; and RPE65, 6.8%. No patients who harbored mutations in these genes had associated systemic abnormalities. Molecular diagnosis allowed definitive genetic counseling in a family affected with Best disease and LCA. CONCLUSIONS: Molecular diagnosis may be of benefit to patients affected with LCA. The relative paucity of mutations found in this study suggests that more LCA-associated genes remain to be discovered. CLINICAL RELEVANCE: Molecular diagnosis can confirm and clarify the diagnosis of LCA. As genotype data accumulate, clinical phenotypes associated with specific mutations will be established. This will facilitate the counseling of patients on their visual prognosis and the likelihood of associated systemic anomalies.
AIMS: To describe the occurrence of spontaneous cataract absorption in patients with leptospiral uveitis. METHODS: The records of patients with seropositive leptospiral uveitis seen in the uveitis clinic at Aravind Eye Hospital between January 1994 and December 1997 were reviewed retrospectively. RESULTS: During the 4 years of the study, 394 eyes of 276 patients with seropositive leptospiral uveitis were identified. Of these, 54 eyes (13.7%) of 41 patients (14.9%) had a final visual acuity of 20/40 or worse attributable to cataract formation. Of these 54 eyes, 41 eyes (75.9%) had visually significant cataract on their first visit to the uveitis clinic, and 13 eyes (24.1%) were noted to have cataract 1-6 months after presentation. Spontaneous absorption was observed in 10 eyes (18.5%) of eight patients (19.5%), and occurred from 6 weeks to 18 months, with a median of 5 months, after the onset of cataract. Of 12 035 consecutive, non-leptospiral, non-traumatic, uveitic, control patients seen during the same 4 years of the study, none showed spontaneous cataract absorption. CONCLUSION: Spontaneous cataract absorption occurs in a significant number of patients with leptospiral uveitis, and appears to be unique to this form of non-traumatic uveitis.
BACKGROUND: Spontaneous bullous serous retinal detachment (RD) with subretinal exudation complicating idiopathic central serous chorioretinopathy (ICSC) is a rare and infrequently described clinical entity. Clinical observations are described on this variant form in 11 patients, the largest series reported to date. METHODS: 13 eyes of 11 Indian patients having this entity were followed up clinically and angiographically for 12-24 months (retrospective, longitudinal). None of the patients had any previous history of other diseases nor were they on any medications. Four eyes received laser treatment (group A); nine eyes were not treated (group B). RESULTS: All 11 patients were male, aged 23-49 years (median 37 years). The clinical and photographic records revealed subretinal exudation and inferior bullous serous RD complicating ICSC with evidence of large, single or multiple, leaking retinal pigment epithelial detachments (PEDs) in all the cases. In group A, resolution of serous RD occurred in 12 weeks (median) with a visual recovery of >/=20/30 in three out of four eyes while in group B resolution of serous retinal detachment was observed in 14 weeks (median) with eight out of nine eyes achieving a visual acuity of >/=20/30. Subretinal fibrosis developed in two eyes in group A and none of the eyes in group B. CONCLUSION: The disease is an exaggerated form of ICSC and can occur spontaneously without any history of corticosteroid therapy. Recognition of this atypical presentation is important to avoid inappropriate treatment. These observations suggest that with respect to the duration of the disease and the final visual outcome laser therapy offers no additional benefit over the natural course of this variant form of ICSC.
OBJECTIVE: To describe three patients who developed Vogt-Koyanagi-Harada syndrome (VKH) after cutaneous injury. DESIGN: Retrospective case series. PARTICIPANTS: Three patients seen in the uveitis clinic at Aravind Eye Hospital and Postgraduate Institute of Ophthalmology, Madurai, India, participated. MAIN OUTCOME MEASURES: The history, evaluation, and management of the three patients were summarized. RESULTS: Three patients developed VKH syndrome shortly after cutaneous injury. In each case, the affected area of skin became vitiliginous on healing and simultaneous with the onset of ocular symptoms. One patient developed additional ectopic areas of vitiligo. All three patients developed chronic, bilateral, diffuse uveitis, one associated with an exudative retinal detachment and two with Dalen-Fuchs-like nodules. Well-recognized complications of VKH syndrome that occurred in the authors' patients included geographic atrophy of the retinal pigment epithelium (3 of 3), cataract (3 of 3), and glaucoma (1 of 3). Ocular inflammation was well controlled in each patient with local or systemic corticosteroids or both. In one patient, the area of vitiligo showed increased pigmentation in response to systemic corticosteroid treatment. CONCLUSIONS: Vogt-Koyanagi-Harada syndrome may follow cutaneous injury, supporting the notion that this disorder may result from systemic sensitization to shared melanocytic antigens.
Leptospirosis, a waterborne spirochetal illness, is common in tropical climates. Rodents and wild animals are the most common reservoirs for this widespread zoonosis. Human disease is acquired by contact with urine or tissues of an infected animal or through contaminated water and soil. Systemic leptospirosis is characterized by its multisystem involvement, protean manifestation, and varying severity. The clinical presentation ranges from occult infection to fatal complications like hepatorenal failure. Early diagnosis is important to halt the fulminate course. The microagglutination test is considered the gold standard serological test for leptospirosis, although molecular techniques are now under study. Treatment of systemic leptospirosis includes penicillin or tetracycline in addition to supportive treatment. Ocular involvement occurs during the immunological phase of the disease. One or both eyes may be involved, typically with a panuveitis often accompanied by retinal periphlebitis and hypopyon. In general, leptospiral uveitis has a good prognosis and the patient recovers full vision in spite of severe panuveal inflammation. Awareness of this infectious uveitic entity is essential not only in order to differentiate it from other severe autoimmune uveitides, but also to reduce the percentage of idiopathic uveitis in endemic areas.
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This report describes a case of unilateral spontaneous vitreous haemorrhage associated with congenital retinal arterial loops.
PURPOSE: To describe the clinical presentation and natural history of Vogt-Koyanagi-Harada (VKH) syndrome in children, an often unrecognized cause of pediatric uveitis. METHODS: We performed a clinic-based cross-sectional survey and retrospective review of pediatric patients with VHK seen in the uveitis clinic at the Aravind Eye Hospital, Madurai, India, between January 1993 and December 1995. RESULTS: A total of 98 patients with VKH syndrome were seen in the uveitis clinic at the Aravind Eye Hospital during the three years covered by the survey, of whom three (about 3%, with an approximate incidence of 1 case/year) were children 16 years of age or younger. Initial symptoms included eye pain, redness, and blurred vision in all three patients. Headache and dysacusis accompanied the onset of visual symptoms in one patient. Each patient eventually developed areas of vitiligo and poliosis, although these signs were not present at the time of presentation in any of our patients. Signs of active uveitis included anterior chamber and vitreous inflammation, optic disc edema, exudative retinal detachments, and Dalen-Fuchs'-like nodules. All three patients developed cataracts, two developed retinal pigment epithelium atrophy, and one developed glaucoma. Each patient responded well, with good visual recovery, to topical and/or systemic corticosteroids. CONCLUSIONS: Although frequently unrecognized, VKH syndrome may affect children. As with adults, visual loss occurs most typically as the result of cataract, glaucoma, or retinal pigment epithelium atrophy.
Uveitis is considered a rare complication of leptospirosis. This report describes an epidemic of uveitis among patients with leptospirosis and provides data, using polymerase chain reaction (PCR) amplification of Leptospira DNA, that the pathogenesis is associated with anterior chamber spirochetes. Forty-six uveitis patients, 49 uveitis controls, and 54 cataract controls were enrolled at Aravind Eye Hospital (Madurai, India). Leptospiral DNA was detected by PCR of aqueous humor; serum antibody titers were determined by ELISA and microagglutination (MAT). Thirty-seven uveitis patients (80%) demonstrated leptospiral DNA compared with 5 controls (8%; P < .001). Thirty-three uveitis patients (72%) had positive serology compared with 10 uveitis controls (20%) and 13 cataract controls (24%; P < .001). This report describes the largest cluster of patients with leptospiral uveitis and identifies six clinical characteristics that provide a diagnostic profile for leptospiral uveitis. This profile will be important for determining treatment regimens in countries where PCR and MAT are not available.
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PURPOSE: To define uveitis associated with leptospirosis in a clinical setting. METHODS: We present the clinical features of 73 consecutive cases of uveitis linked clinically to an outbreak of systemic leptospirosis in patients with antibodies to Leptospira species who were examined from January to September 1994. RESULTS: In 73 patients, the pattern of ocular involvement was unilateral in 35 and bilateral in 38. Panuveitis was seen in 106 eyes (95.5%), retinal periphlebitis in 57 eyes (51.4%), and hypopyon in 14 eyes (12.6%). Anterior uveitis alone without hypopyon was observed in three eyes (2.7%), whereas vitreous inflammatory reaction alone was seen in two eyes (1.8%). Sixty of 73 patients (82.2%) or 91 of 111 eyes (82.0%) were followed up for 8 months. Final visual acuity was 6/6 (20/20) in 47 eyes (52%) and improved during treatment, although not up to 6/6, in 15 eyes (16%). Twenty-eight eyes (31%) maintained same vision, and one eye showed deterioration of vision. CONCLUSION: Uveitis associated with leptospirosis may manifest as unilateral or bilateral uveitis, anterior uveitis, or panuveitis. The prognosis is generally good in this entity, even when the inflammation is severe. Awareness of this disease in endemic areas is important in order to differentiate it from other uveitic entities, especially in young male patients in whom other immunologic uveitides are also common.
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