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Biomedical subjects

S R Chandra

Publications and source records attributed to S R Chandra.

At least 19 recordsLinked to original sources
PubMed2001

Treatment of submacular hemorrhage with low-dose intravitreal tissue plasminogen activator injection and pneumatic displacement.

OBJECTIVE: To investigate the safety and efficacy of low-dose intravitreal tissue plasminogen activator (tPA) and an expansile gas bubble in displacing submacular hemorrhage in patients with age-related macular degeneration (ARMD). PATIENTS AND METHODS: We reviewed retrospectively the medical records of 14 consecutive patients with ARMD from 1 academic center who received low-dose intravitreal tPA (18-50 microg) and expansile gas (0.3-0.4 mL of perfluoropropane) for thrombolysis and displacement of submacular hemorrhage. After the procedure, patients maintained face-down positioning for 1 to 3 days. MAIN OUTCOME MEASURES: Displacement of blood from the fovea, early and final visual acuity, and toxicity of tPA. RESULTS: Submacular blood was completely displaced from the fovea in 10 (71%) of the 14 patients and partially displaced in 3 (21%). In 1 patient, no displacement occurred. Early (<2 months) postoperative visual acuity improved by 2 or more lines in 8 patients (57%). With a mean follow-up of 7.7 months, 2 (15%) of 13 patients maintained 2 or more lines of improvement and 69% (9 patients) maintained preoperative visual acuity. No clinical evidence of retinal toxicity was seen at this low-dose of tPA. CONCLUSIONS: Doses of intravitreal tPA ranging from 18 to 50 microg and an expansile gas bubble are safe and effective in displacing submacular hemorrhage in patients with ARMD. Final visual acuity was limited by the underlying presence of end-stage ARMD.

Aged↗
PubMed1999

Treatment choice and quality of life in patients with choroidal melanoma.

OBJECTIVE: To determine if quality of life differs between patients with choroidal melanoma treated with enucleation and those treated with radiation therapy. MATERIALS AND METHODS: Patients treated for choroidal melanoma at 5 Midwest centers were asked to participate. There were 65 participants treated with enucleation and 82 treated with radiation therapy. Quality of life was assessed using the Medical Outcome Study Short Form 36 and the National Eye Institute Visual Function Questionnaire and by the Time-Tradeoff interview method. RESULTS: The average length of follow-up was 4.9 years for the group treated with radiation therapy and 6.3 years for the group treated with enucleation (P = .05). After adjusting for age, sex, years of follow-up, and the number of chronic conditions, there were few differences in any of the quality-of-life measures by treatment status. Participants in the group treated with radiation therapy were more likely to have higher (better) scores on the Vitality and Mental Component subscales of the Medical Outcome Study Short Form 36 than participants treated with enucleation. There were no differences on the National Eye Institute Visual Function Questionnaire or the Time-Tradeoff measures of quality of life. CONCLUSION: Choice of treatment for choroidal melanoma does not seem to be associated with large differences in quality of life in long-term follow-up.

Aged↗
PubMed1997

Histopathologic study of eyes after iodine I 125 episcleral plaque irradiation for uveal melanoma.

OBJECTIVES: To describe the histopathologic findings attributable to irradiation in eyes with uveal malignant melanoma treated with iodine I 125 brachytherapy and to compare these findings with those reviewed in a previous study that compared histopathologic findings in eyes enucleated after proton beam teletherapy with those seen in eyes in a nonirradiated control group. METHODS: The slides from 22 eyes with uveal melanoma that had undergone enucleation after the administration of 125I brachytherapy were studied. The histopathologic features of the tumor and the retina were graded. Results were compared with findings from a previously reported group of 47 proton beam-treated eyes and its control group. RESULTS: Patient age, time between irradiation and enucleation, and ciliary body involvement were similar for the 125I brachytherapy-treated group and the proton beam-treated group and its control group. This allows comparison of the histopathologic findings. Comparing the 125I brachytherapy- and proton beam-treated groups, most histopathologic features were similar with nominally statistically significant differences only for cell type, number of mitotic figures, and fibrous metaplasia of the retinal pigment epithelium adjacent to the tumor. CONCLUSIONS: Irradiation of uveal melanoma induces changes in the tumor and in the surrounding retina. Brachytherapy and charged particle therapy are the 2 principal methods of irradiation. This study demonstrates that similar changes are produced by 125I plaque irradiation and proton beam irradiation.

Adult↗
PubMed1987

Effect of peripheral cryocoagulation on ocular blood flow.

Using the labeled microsphere impaction technique, we studied the effect of peripheral panretinal transscleral cryocoagulation in pigmented rabbits. One eye of each animal received peripheral cryocoagulation, and the fellow eye of the same animal was used as the control. Thirty-two animals received 40 exposures of peripheral cryocoagulation; twenty-six rabbits received 20 exposures. After 40 exposures of cryocoagulation, choroidal-retinal blood flow was significantly decreased when measured at one to two hours, 24 hours, and two weeks; normal flow recovered by four weeks. After 20 exposures of cryocoagulation, there was a significant reduction in choroidal-retinal blood flow at the earliest measurement time (one to two hours) only. The iris-ciliary body blood flow also was substantially decreased only at the earliest measurement time (one to two hours) and only after 40 exposures.

Animals↗
PubMed1985

Diagnosis and pathogenesis of retinal pigment epithelial tears.

Ten cases of retinal pigment epithelial tears were observed in eight patients with serous pigment epithelial detachments associated with age-related macular degeneration. Eight of the ten tears were spontaneous and all occurred at the detachment margin. The resulting area of exposed choroid was sometimes initially mistaken for pigment epithelial atrophy. In two cases it was misdiagnosed as choroidal neovascularization and treated with laser photocoagulation. All but two patients suffered severe visual loss.

Aged↗
PubMed1985

Evolution of lacquer cracks in high myopia.

The evolution of lacquer cracks is documented by serial fundus photography and fluorescein angiography in a 27-year-old man with high myopia. The case report provides some insight into the possible pathogenic mechanism of lacquer crack formation.

Adult↗
PubMed1982

Effect of photocoagulation on ocular blood flow.

The effect of panretinal photocoagulation on ocular blood flow was studied in pigmented rabbits by means of labeled microsphere impaction and in monkeys by indocyanine-green-dye clearance. In the rabbits, one eye of each animal was photocoagulated and the follow eye of the same animal was used as the control. Twenty-six rabbits received full-scatter panretinal photocoagulation (300 +/- 20 burns, one half burn apart) and an additional 32 rabbits received partial-scatter panretinal photocoagulation (150 +/- 20 burns, one burn apart). After full-scatter photocoagulation there was a significant decrease in choroidal-retinal blood flow measured at 1 to 2 hr, 24 hr, 2 weeks, 4 weeks, and 3 months, but no change in iris-ciliary body blood flow. After partial scatter photocoagulation there was no consistent change. In one monkey, 100 burns were placed around the macular area and in a second monkey 100 burns were placed in the inferior half of the ocular fundus. Choroidal blood flow was significantly reduced in both monkeys for the initial hour during which is was continually measured.

Animals↗
PubMed1980

Diabetic papillopathy.

A 13-year-old girl and a 20-year-old man with juvenile-onset diabetes mellitus developed transient bilateral optic disk edema with minimal impairment of optic nerve function and with minimal diabetic retinopathy. This conditions, termed diabetic papillopathy appears to be a local optic disk vasculopathy, and generally resolves without treatment. Diabetic papillopathy should not be mistaken for papilledema or for the optic disk neovascularization of diabetic retinopathy.

Adolescent↗
PubMed1979

Conjunctival capillary fragility: a preliminary study.

Conjunctival capillary fragility (CCF) and skin capillary fragility (SCF) were studied by a negative-pressure suction cup method in 25 normal subjects and 38 diabetic patients with diabetic retinopathy. The CCF was significantly higher (P less than .001) in patients with diabetic retinopathy than in normal subjects; there was no significant difference in the SCF.

Adult↗
PubMed1979

Choroidal blood flow. IV. effect of vasodilating agents.

The effect of vasodilators on choroidal blood flow (CBF) was studied by the krypton clathrate Kr 85 desaturation technique in anesthetized cats. Niacin, papaverine hydrochloride, phentolamine mesylate, and tolazoline hydrochloride were injected via the lateral long posterior ciliary artery (LLPCA) and the femoral artery. The systemic administration of these drugs via the femoral artery, in the doses used, had no significant effect on mean arterial pressure, choroidal vascular resistance (CVR), or CBF. Local administration of the same agents via the LLPCA caused a decrease in CVR with a corresponding increase in CBF.

Animals↗
PubMed1976

Disciform degeneration of the macula. II. Pathogenesis.

Of 84 patients with unilateral disciform macular degeneration, 36 were followed up for one to four years (average, 22 months). The fellow eye in 13 cases developed disciform lesions during that follow-up period. A significantly greater number of drusen were found in the fellow eyes of patients with unilateral disciform macular degeneration than in the eyes of a comparable control group of patients (P less than .001). Furthermore, the eyes with unilateral disciform macular degeneration that developed disciform lesions in the other eye were characterized as a group by a significantly larger number of drusen than those that did not. We postulate that drusen are precursors of disciform macular degeneration in fellow eyes and are probably manifestations of the same exudative process.

Aged↗
PubMed1976

Choroidal neovascular membrane in Best's vitelliform macular dystrophy.

The right eye of a 9-year-old white boy with Best's vitelliform macular dystrophy had an intact egg-yolk lesion and a retinal pigment epithelial defect superiorly, suggesting an early pseudohypopyon stage. The disruptive phase of the left eye showed subretinal hemorrhages, a "signet ring," and a subretinal neovascular membrane.

Child↗