Biomedical subjects
Publications and source records attributed to Hajib N Madhavan.
Blood specimens collected at the time of enucleation of the eyes from 483 consecutive eye donors were tested for sero-markers of Human Immunodeficiency Virus (HIV), Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV). Antibodies to HIV1 were detected in 3 (0.62%), HBsAg in 17 (3.52%) and antibodies to HCV in 7 (1.45%).
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PURPOSE: To report the use of eye wall resection in the management of tuberculous granuloma. DESIGN: Interventional case report. METHODS: In a 26-year-old man with biopsy-proven tuberculous granuloma of the left eye, total eye wall resection and donor scleral grafting was performed for management of tuberculous granuloma involving the sclera, part of the cornea, the iris, the chamber angle, and the ciliary body. Adjuvant therapy included oral antitubercular medication. RESULTS: The treatment of the infection was successful. The scleral graft healed well, and the crystalline lens was preserved. CONCLUSIONS: Total eye wall resection, a technique described in the management of uveal tumors, can be adopted to manage selected cases of tuberculous granuloma of the eye.
PURPOSE: To evaluate the diagnostic usefulness of enzyme linked immuno-sorbent assay (ELISA) in single serum samples to associate herpes simplex virus (HSV), varicella zoster virus (VZV) or cytomegalovirus (CMV) with viral retinitis as against polymerase chain reaction (PCR) on intraocular specimens. It was also designed to study the seroprevalence in normal healthy individuals, and the genomic prevalence of HSV, VZV and CMV in patients without an active viral inflammatory process. METHODS: PCR for the detection of HSV, VZV and CMV genomes was done on 33 and 90 intraocular fluids from viral retinal patients and non-viral controls respectively. ELISA was done on 30 and 100 serum samples from viral retinitis patients and normal healthy controls respectively. RESULTS: PCR did not detect HSV, VZV and CMV genomes except one, in which VZV-DNA was detected. ELISA showed prevalence rates of 28%, 83% and 90% for antibodies against HSV, VZV and CMV respectively in the normal population. In the 30 viral retinitis patients, PCR detected HSV-DNA in 2 (6.7%), VZV-DNA in 7 (23.3%) and CMV-DNA in 6 (20.0%) patients, while ELISA detected antibodies against HSV, VZV and CMV in 13 (43.3%), 24 (80.0%) and 23 (76.7%) patients respectively. ELISA was of value in indirect diagnosis only in 6 (20.0%) as compared to 15 (50.0%) of 30 patients by PCR, this difference was statistically significant (McNemar test, P value = 0.005). CONCLUSION: Serology by ELISA is no longer a useful diagnostic tool to associate HSV, VZV and CMV viruses with viral retinitis.
PURPOSE: To report the clinical and microbiological profile of endophthalmitis caused by Acinetobacter calcoaceticus. METHODS: A retrospective study of case series of Acinetobacter calcoaceticus endophthalmitis. Outcome measures included ability to sterilise the eye, anatomical result (clear media and attached retina) and visual recovery (visual acuity > 6/60). RESULTS: Of the 20 cases studied, 10 were cases of postoperative endophthalmitis, 3 were posttraumatic, 6 were endogenous and one was bleb-related endophthalmitis. Specific features of interest observed were relative chronicity of presentation and absence of any obvious predisposing factor in endogenous endophthalmitis cases. All cases could be sterilised except one, which needed evisceration. Cases with postoperative endophthalmitis had better anatomical outcome (7/10 with attached retina and clear media) and visual outcome (4/10 regained vision > 6/18). Higher smear positivity was seen in vitreous samples (72.2%) compared to aqueous samples (37.5%). Culture positivity was higher from the vitreous cavity compared to aqueous. The organism was sensitive to ciprofloxacin in a high percentage (88.9%) of cases. CONCLUSIONS: Visual recovery in Acinetobacter calcoaceticus endophthalmitis is modest. Ciprofloxacin is the antibiotic of choice.
PURPOSE: To determine the presence of herpesvirus DNA in the aqueous humor (AH) of patients with serpiginous choroiditis using polymerase chain reaction (PCR). METHODS: AH from nine patients previously diagnosed with serpiginous choroiditis were investigated for herpes simplex virus (HSV), varicella zoster virus (VZV), and cytomegalovirus (CMV) by conventional virological methods and PCR. The PCR-positive DNA was gel-purified, extracted, and sequenced using a dye-based Applied Biosystems procedure. The sequences were processed through the National Cancer Institute's BLAST inquiry for species identification. RESULTS: Culture and cytological examination of AH from all nine patients were negative for HSV, VZV, and CMV. Five were positive for VZV, one was positive for HSV, and three were wholly negative using PCR. Subsequent DNA sequencing of the positive samples authenticated the presence of VZV and HSV DNA in the respective patients. CONCLUSION: VZV and HSV DNA were detected in a subset of patients with serpiginous choroiditis, suggesting that these viruses may function in the pathogenesis of this disease.
PURPOSE: To develop a reliable in vitro drug susceptibility test against Acanthamoeba isolates and to determine the minimum cysticidal concentration (MCC) of the drug. METHODS: Doubling dilutions of polyhexamethylene biguanide (PHMB) from 3,200 microg/mL to 3.125 microg/mL and chlorhexidine from 3,200 microg/mL to 1.5625 microg/mL were made in Durham tubes and tested against cysts of 19 Acanthamoeba isolates from keratitis. After the exposure to the drugs for 48 hours, the cysts were washed free of drugs by centrifugation. The deposit (cysts) was cultured on nonnutrient agar plates seeded with heat-killed Escherichia coli. The growth of trophozoites from cysts exposed to each of the dilution was recorded by microscopy to estimate the MCC of the drug. RESULTS: The minimum cysticidal concentration of PHMB varied from 25 microg/mL to 100 microg/mL and that of chlorhexidine varied from 1.56 microg/mL to 100 microg/mL. The mean MCC value for PHMB was 55.26 microg/mL and that for chlorhexidine 32.81 microg/mL. Minimum cysticidal concentration 50 (MCC50) of PHMB and chlorhexidine on Acanthamoeba isolates was 50.0 microg/mL and 25.0 microg/mL, respectively. Anti-Acanthamoeba activity of chlorhexidine was higher than that of PHMB and this was statistically significant (p = 0.036). The end point of the results of this method was the detection of the viable cysts undergoing excystment and multiplication of trophozoites with a reproducible and clear-cut estimation of the MCC of PHMB and chlorhexidine. CONCLUSION: The in vitro method described can be used as a standard test for assay of MCC of drugs on Acanthamoeba isolates and to study the susceptibility pattern of newer water-soluble anti-Acanthamoeba drugs.
PURPOSE: To report bilateral corneal endotheliitis caused by a vesicular virus (family Rhabdoviridae). METHODS: Case report of a 49-year-old man with a complaint of sudden onset of decreased vision in both eyes had diffuse corneal stromal edema with extensive folds in Descemet's membrane and was diagnosed as having bilateral viral endotheliitis. Virologic investigations were performed using aqueous humor from the right eye. RESULTS: An ether- and chloroform-sensitive cytopathic agent was isolated in Vero and BHK-21 cell lines from the aqueous humor. It was identified as a vesicular virus belonging to the family Rhabdoviridae by electron microscopy. Neutralizing antibody was demonstrated at a titer greater than 1 in 4,096 dilutions in the convalescent serum. Neurologic complications included loss of hearing and postinfectious polyradiculopathy affecting both lower limbs. Best-corrected visual acuity was 20/120 OD and 20/20 OS. Six months later, he developed glaucoma in the right eye. Trabeculectomy with intraoperative application of 5-fluorouracil was performed. CONCLUSION: This is the first report of bilateral endotheliitis caused by a vesicular virus and confirmed by virus isolation from the aqueous humor of the affected eye.
PURPOSE: To apply polymerase chain reaction (PCR) on vitreous fluid (VF) from Eales' disease to further confirm its association with Mycobacterium tuberculosis. METHODS: Sixty nine VF samples from 69 patients (24 Eales' disease and 45 Non-Eales' as controls) were processed by conventional methods for detection of mycobacteria. Polymerase chain reaction (PCR) specific for IS 6110 and nested PCR (nPCR) using primers coding for MPB 64 gene were applied on all 69 VF. PCR based dot-blot hybridisation was applied on the IS 6110 amplified products of n PCR-positive VFs. RESULTS: Conventional methods (direct smear and culture) did not detect mycobacteria in any of the 69 VF samples. Five (20.8%) of 24 VF from Eales' and 2 (4.2%) of 45 VF from control patients tested positive for M. tuberculosis DNA by nPCR. This difference was statistically significant (P < 0.05). All 69 VF were negative by PCR for IS 6110. Two VF of Eales' patients positive by nPCR were also positive by DNA probe dot-blot hybridisation for IS 6110. CONCLUSION: Detection of M. tuberculosis DNA by PCR in a significant number of VF of Eales' disease patients reemphasizes the association of this bacterium with Eales' disease.
PURPOSE: Cytomegalovirus retinitis (CMV) is the most common ocular opportunistic infection in transplant recipients. This retrospective study attempts to report the differences in occurrence of cytomegalovirus retinetis in transplant recipients from those reported in patients with acquired immunodeficiency syndrome (AIDS). METHODS: 25 eyes of 15 transplant recipients (14 renal and one cardiac) with cytomegalovirus retinitis were retrospectively reviewed. Immunological profile included CD4+ and CD8+ T lymphocyte counts, CD4+/CD8+ cell ratio (5 cases) and serology for the viral antibodies (8 cases). RESULTS: A predominantly bilateral presentation (60%) was noted. Active cytomegalovirus retinitis (72%) in zone 2 (92%) of the inferotemporal quadrant (68%) was noted. The average cell counts were within normal limits (mean CD4 cell count-711/microliter), unlike in late stages of AIDS with cytomegalovirus retinitis (CD4 count < 50/microliter). Serology revealed an IgM positivity of 53%. Retinal detachment (52%) was the most common complication occurring after an average of 5.4 months. CONCLUSION: CMV retinitis in organ transplant recipients appears to differ from that in AIDS patients. CMV retinitis presents early and has different immunological profile, probably owing to differences in pathogenesis.
Human immunovirus infection in India is rapidly increasing. Ocular lesions due to highly active antiretroviral therapy have been well recognized. Acquired immunodeficiency syndrome can affect all parts of the eye. However, posterior segment lesions are the most common and of these, Human immunodeficiency virus retinopathy and cytomegalovirus retinitis predominate. Often clinical examination can establish the diagnosis of many ocular lesions in acquired immunodeficiency syndrome; therefore, ophthalmologists need to be aware of the more common ones. Various drugs in different routes can used to treat cytomegalovirus retinitis. Highly active antiretroviral therapy has remarkably reduced systemic and ocular morbidity among acquired immunodeficiency syndrome patients. To facilitate care of these patients aseptic precautions for ophthalmic care personnel are now well established and therefore ophthalmologist should not hesitate to provide ophthalmic care to acquired immunodeficiency syndrome patients.
We describe the preparation and preservation of human amniotic membrane required for transplantation in the management of ocular surface diseases. Informed consent is obtained and the donor is screened to exclude risk of transmissible infections such as human immunodeficiency virus (HIV), hepatitis B virus, hepatitis C virus, and Treponema pallidum infections. Ideally, the media and washing solutions needed for the preparation of amniotic membrane are prepared only a week to 10 days prior to use and not stored in the freezer weeks ahead. The AM obtained under sterile conditions after elective caesarian section is washed free of blood clots and chorion. With the epithelial surface up, amniotic membrane is spread uniformly without folds or tears on individually sterilized 0.22 micron nitrocellulose membranes of the required sizes. The prepared filter membrane with the adherent amniotic membrane is placed in the preservative medium and stored at -80 degrees C. The membranes are released when the repeat serology for HIV after the window period has excluded virus infection in the donor. Depending on consumption they may be used up to 6 months after preparation, though many have recommended storage for an indefinite period. Since the amniotic membrane has only incomplete expression of HLA antigens and amniotic epithelial cells do not express them, it is not rejected after transplantation. The presence of several cytokines in the amniotic membrane promotes epithelialization with reduction of fibrosis during healing.
Eales disease, first described by Henry Eales in 1880, remains an enigma. The disease, observed more commonly in the Indian subcontinent than in the rest of the world, occurs in young healthy adult males, initially presenting as retinal periphlebitis and later as retinal ischemia that may lead to vascular alterations and neovascularization. Recurrent vitreous hemorrhage with or without retinal detachment is the common sequelae. In recent years, immunological, molecular biological, and biochemical studies have indicated the role of human leukocyte antigen, retinal autoimmunity, mycobacterium tuberculosis genome, and free radical mediated damage in the etiopathogenesis of this disease. However, its etiology appears to be multifactorial. The management depends on the stage of the disease and consists of medical treatment with oral corticosteroids in the active inflammatory stage and laser photocoagulation in the advanced retinal ischemia and neovascularization stages. The results of vitreoretinal surgery have been found to be satisfactory in case of vitreous hemorrhage with or without retinal detachment.