Biomedical subjects
Publications and source records attributed to J Biswas.
A case of cryptococcal meningitis in an AIDS patient who presented with optic disc edema, bilateral retinal and peripapillary haemorrhages is reported.
A case of postoperative endophthalmitis caused by micrococci, after phacoemulsification and foldable silicone intraocular lens (IOL) implantation is reported.
Anterior uveitis is a known clinical entity in herpes zoster ophthalmicus associated with AIDS. However, reports of acute haemorrhagic hypopyon uveitis in such cases are lacking. Herein we describe a young male patient presenting with acute panuveitis with haemorrhagic hypopyon, who was found HIV positive on investigation.
Immune reconstitution in acquired immunodeficiency syndrome (AIDS) patients on highly active anti-retroviral therapy (HAART) with cytomegalovirus (CMV) retinitis manifested as posterior segment intraocular inflammation has been reported. We report an adult HIV-positive Indian male with clinically inactive CMV retinitis who developed panuveitis with hypopyon. This was related to immune recovery mediated by combination anti-retroviral treatment, including protease inhibitors.
We performed a retrospective analysis on the effect of neoadjuvant chemotherapy with three cycles of methotrexate (100 mg/m2 on day 1), cisplatin (90 mg/m2 on day 1) and bleomycin (20mg/m2 on day 1-5) with 21 d gap between each cycle in 44 patients with advanced squamous cell carcinoma of the cheek, lip and tongue followed by surgery and adjuvant chemotherapy consisting of cisplatin (90 mg/m2 on day 1), Mitomycin C (6 mg/m2 on day 1) and 5-fluorouracil (1000 mg/m2 120 h continuous infusion from day 1) repeated every 3 weeks for three cycles. Following induction chemotherapy, complete response was observed in 11 out of 44 patients (25%), and a partial response in a further 28 patients (64%). The overall median survival of all patients was 29 months and those in stage III and stage IV were 30 and 15 months respectively (P< 0.001). The median duration of the time to relapse in patients who responded to adjuvant chemotherapy was 28 months. The main toxic effect was vomiting followed by hematological toxicity. No treatment-related deaths occurred. The regimen showed a significant response, encouraging median survival and a good tolerability profile.
PURPOSE: To measure the levels of oxidation and peroxidation products of membrane constituents chiefly lipids produced by oxygen and lipid free radicals as thiobarbituric acid reacting substances (TBARS), reduced glutathione (GSH) and the antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GP) in vitreous samples from patients with Eales' disease and estimate GSH, SOD, GP in the erythrocytes of patients with Eales' disease with active perivasculitis and healed perivasculitis. METHODS: Vitreous samples on vitrectomy from 11 patients with Eales' disease and 11 patients with diabetic vitreous hemorrhage were used for comparison. For study on erythrocytes, 30 patients of Eales' disease at the active vasculitis stage (group-I), 33 of healed vasculitis stage (group-II) and 25 controls (group-III) were used. The male female ratio was kept the same among the patients and the controls. Oxidation and peroxidation products of membrane constituents chiefly lipids were estimated as TBARS, SOD by its activity to inhibit auto-oxidation of epinephrine, GP by estimating the reduction in the level of GSH and GSH by its colour reaction with 5,5'-dithio bis (2-nitro) benzoic acid (DTNB). RESULTS: TBARS were increased 6 fold in the vitreous of Eales' patients compared to the samples from those with diabetic vitreous hemorrhage while there was a reduction of 95.9% of SOD and 84.2% of GSH. Activity of SOD, GP and the levels of GSH in the erythrocytes were reduced (%) by 81.6, 65 and 56.5 respectively in group I and 22,46.4 and 29.2% respectively in group II. The values are statistically significant. CONCLUSIONS: Increased levels of TBARS and decreased levels of SOD and GSH in the vitreous could explain inflammation, retinal damage and neovascularization in patients with Eales' disease. Decrease of SOD, GP and GSH is found in erythrocytes both in the active perivasculitis stage and the healed perivasculitis stage. Treatment of Eales' disease with antioxidants vitamin E, C as also vitamin A may have a beneficial effect.
PURPOSE: To report the surgical anatomy of vitreoretinal adhesions as observed intraoperatively in patients undergoing vitreous surgery for complications of Eales' disease. METHODS: Eighteen consecutive male patients (18 eyes) undergoing vitrectomy for Eales' disease were studied prospectively. Intraoperative diagnosis was vitreous hemorrhage (VH) in nine cases, traction retinal detachment (TRD) in four, VH and TRD in three, and combined traction-rhegmatogenous retinal detachment in two. Epiretinal membranes (ERMs) obtained during surgery were studied using light microscopy and immunohistochemistry. RESULTS: An incomplete posterior vitreous detachment was observed in all eyes. Multifocal vitreoretinal adhesions were evident in 83.3% of eyes. The proliferation was fibrovascular in 10 eyes and fibrous in eight. A radial traction fold extending from optic disk to periphery was observed in three eyes. A double-layered membrane, probably the result of vitreoschisis, caused tangential traction. ERMs consisted principally of type II collagen and the cellular element was predominantly composed of lymphocytes, glial cells, and macrophage-like cells (probably hyalocytes). CONCLUSIONS: Fibrous and fibrovascular proliferations have multiple areas of adhesions to the posterior vitreous cortex. The presence of type II collagen in the ERM indicates a possible vitreous collagen component to the double-layered membranes (vitreoschisis). Recognition of the double-layered membranes aids in relief of traction during surgery by delamination.
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PURPOSE: Retinal neovascularization is one of the leading causes of blindness. A crucial event in this process is the remodeling and penetration of the capillary basement membrane by migrating endothelial cells. This process requires proteolysis of basement membrane components by a variety of proteinases. The objective of the present study was to determine the expression of proteinases in human retinal tissues showing active neovascularization. METHODS: Epiretinal neovascular membranes surgically removed from patients with proliferative diabetic retinopathy were analyzed by zymography, and the types and amounts of proteinases present in the tissues were determined. Retinas from nondiabetic donor eyes served as control specimens. RESULTS: Both the high- (54 kDa) and low- (33 kDa) molecular-weight forms of urokinase were present at significantly higher levels in neovascular membranes than in normal retinas. The pro forms of the matrix metalloproteinases (MMP) MMP-2 and MMP-9 were significantly elevated in the neovascular membranes in comparison with levels in normal retinas. In addition, the active forms of these enzymes were present in the membranes, whereas there was no detectable level of the active forms in normal retinas. CONCLUSIONS: Human diabetic neovascular membranes contain high levels of urokinase and MMP. The increased activity of proteinases in the final common pathway of retinal neovascularization indicates that inhibition of these enzymes may be a useful therapeutic target as an alternative approach in the management of proliferative retinopathies.
BACKGROUND AND OBJECTIVE: The authors analyzed the results of cataract surgery performed on patients with intermediate uveitis from January 1990 through January 1997. MATERIALS AND METHODS: Fifty-two eyes of 44 patients with intermediate uveitis underwent cataract surgery during this period. These patients were evaluated with respect to duration of intermediate uveitis, treatment regimen, intraoperative complications and final visual results. RESULTS: Visual acuity improved following surgery in 94.2% eyes and 71.2% eyes achieved a final visual acuity better than or equal to 20/60. Intraocular lens implantation accompanied the surgery in 24 eyes. Regional and systemic steroids were required for control of inflammation. The factors that limited visual recovery were severe cystoid macular edema, epiretinal membrane formation, and secondary retinal detachment. Recurrence of uveitis was noted in 6 cases. CONCLUSION: Absolute control of inflammation, atraumatic surgery, and regular postoperative follow-up can improve the results of cataract extraction. Intraocular lens implantation in selected cases is well tolerated with good visual results.
PURPOSE: To study the occurrence, risk factors and management of subconjunctival cysts formed following the use of intraocular silicone oil as a tamponade. METHODS: We analyzed 5 cases of single and multioculated subconjunctival oil cysts between 1986 and 1996. RESULTS: Cysts were observed 15 days to 4 months following silicone oil injection. Clinically they showed minimal inflammatory signs but histopathology of removed cysts showed emulsified silicone oil globules with chronic inflammatory cellular infiltration. CONCLUSION: Though silicone oil is considered to be nontoxic, it can cause chronic inflammation when spilled into the subconjunctival space.
This report describes a case of frosted branch angiitis associated with AIDS.
A case of bilateral accidental globe penetration during administration of retrobulbar steroid for bilateral optic neuritis is discussed. One eye with bisected macula was managed successfully by vitrectomy, internal gas tamponade, and postoperative laser to the edges of the retinal tear. The fellow eye was blind due to central retinal artery occlusion.
The occurrence of intermediate uveitis in monozygotic twins has rarely been reported in literature. We report the occurrence of this disease condition in identical twins. Twin sisters presented with typical features of intermediate uveitis, which appeared three years earlier in one of the sisters. They were treated with posterior subtenon injection of triamcinolone acetonide and recovered well. Systemic evaluation and laboratory investigations did not reveal any etiology. Cytogenetic high-resolution analysis did not reveal any chromosomal abnormalities. Pedigree analysis revealed no specific transmission pattern. No other family members in three generations had similar ocular disease. Our report indicates that a detailed family history should be taken in intermediate uveitis and examination of other siblings of patients with intermediate uveitis should be performed.
PURPOSE: To describe the clinical features, histopathology, surgical management and possible etiopathogenesis of corneoscleral epithelial cysts. METHODS: Three patients with corneoscleral epithelial cysts underwent surgical ablation of the cysts. Material obtained during surgery was subjected to histopathologic analysis. RESULTS: At last follow-up (mean, 6.3 months), none of the cysts had recurred. All patients had improved visual acuity. Histopathology revealed the occurrence of glandular elements suggestive of lacrimal tissue in one of the cysts. CONCLUSION: The presence of ectopic lacrimal tissue suggests a developmental etiology for such cysts. Marsupialization of the scleral portion of the cyst and chemical ablation of the lining epithelium of the corneal cyst with 20% trichloroacetic acid appears to be a safe and effective technique in the surgical management of corneoscleral epithelial cysts.
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An in-vitro study of wave spectral analysis in 8 enucleated eyes was conducted in order to differentiate histological subtypes of malignant melanoma. To obtain the backscattering coefficient for the tissues, we used a broadband focussed transducer with a frequency range of 7-12 MHz and a centre frequency of 10 MHz. Experimental measurement of backscattering coefficient and attenuation coefficient at various frequencies was done by substitution techniques. The backscattering coefficient, scatterer size, and root mean square velocity fluctuation were derived by the numerical method, while the attenuation coefficient at 1 MHz was derived from attenuation coefficient at different frequencies. This study revealed that backscattering coefficient and attenuation coefficient, over a frequency range of 7-12 MHz, show an increase in the spindle cell type compared to the mixed cell type of malignant melanoma. Particularly, the scatterer size was significantly higher in the spindle cell group (p = 0.013) in contrast to the mixed cell type. Spindle cells have uniform and compact histological pattern which contributes to an increase in scatterer size and root mean square velocity fluctuation. The ultrasonically obtained parameters have been shown to have a good correlation with the histology of malignant melanoma.