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Biomedical subjects

H K Tewari

Publications and source records attributed to H K Tewari.

At least 37 records · Page 2Linked to original sources
PubMed1997

Evaluation of visual function following argon laser photocoagulation in central serous retinopathy.

The authors of previous studies on the role of photocoagulation for central serous chorioretinopathy (CSR) have based their deductions on the premise that a Snellen visual acuity of 6/6 is the end point of recovery. It is now known that patients with a visual acuity of 6/6 may have defective contrast sensitivity indicative of a visual function deficit. The present study was a prospective, controlled, and randomized evaluation of patients suffering from their first attack of CSR, in which contrast sensitivity was used to determine the effectiveness of argon laser photocoagulation as compared with more conservative treatment. Although long-term studies are necessary, the results of this study showed that while photocoagulation increases the rate of recovery for visual acuity, it is also linked with significant loss and slower recovery of contrast sensitivity.

Adult↗
PubMed1995

Lactic acid production from molasses by Sporolactobacillus cellulosolvens.

Sporolactobacillus cellulosolvens (NCIMB 12173) isolated from an anaerobic digester and characterised biochemically is being reported for homofermentative lactic acid production from molasses in a batch culture. The effect of various process parameters on lactic acid production were optimized. A maximum lactic acid (24.2 g/l) and yield coefficient (0.79) was achieved using 3% (v/v) inoculum of 36 h old culture in molasses medium containing sugars (5%; w/v) supplemented with peptone (2.5 g/l) and (NH4)2SO4 (7.5 g/l), pH 6.5 at 40 degrees C after 72 h of fermentation.

Bacillaceae↗
PubMed1994

Topical atropine and timolol therapy in failed retinal detachment surgery.

We conducted a double-blind randomized prospective study to evaluate the efficacy of topical timolol alone and topical timolol and atropine combined in cases of operated failed retinal detachment surgery cases in which no apparent open break explained the surgical failure. In both groups with and without proliferative vitreoretinopathy no statistically significant difference in retinal reattachment was found.

Administration, Topical↗
PubMed1994

Metabolic factors in the development of retinopathy of juvenile-onset type I diabetes mellitus.

Thirty-five patients of insulin-dependent diabetes mellitus (IDDM) were investigated for the effect of various metabolic factors on retinopathy. The severity of retinopathy increased with duration and age of onset of IDDM. Degree of glycaemia (fasting blood sugar, FBS) was similar in patients with or without retinopathy. All IDDM patients as a group showed severe carbohydrate intolerance with lower basal and post glucose serum immunoreactive insulin (IRI) levels and serum C-peptide radioimmunoreactivity (CPR) as compared to controls. The insulin secretory response was similar in no retinopathy, mild retinopathy and severe retinopathy groups. Patients with retinopathy had higher incidence of hyperlipidemia but mean serum levels of cholesterol and triglyceride were similar. This study does not suggest a direct relationship between the various metabolic factors studied and retinopathy due to IDDM.

Adult↗
PubMed1994

Eales' disease.

Explore the source record for details and available documents.

Humans↗
PubMed1994

Experimental inhibition of proliferative vitreoretinopathy in retinal detachment using daunorubicin.

Proliferative vitreoretinopathy (PVR) remains the most common cause of failure in retinal detachment surgery. Surgical procedures for its repair entails complex and extensive instrumentation besides technical skill. The success rate varies widely with high incidence of redetachment. Keeping this in view, we evaluated the role of intravitreal daunorubicin as an anti-mitiotic agent in the inhibition of PVR. Our study concluded that 5 micrograms of intravitreal daunorubicin effectively inhibited PVR in the rabbit eye and the dosage was safe and nontoxic. The half-life of the drug was determined to be about 140 minutes, suggesting a prolonged intravitreal concentration sufficient to prevent fibroblast proliferation.

Animals↗
PubMed1994

Contrast sensitivity in diabetic retinopathy after panretinal photocoagulation.

Reports of changes in contrast sensitivity in proliferative diabetic retinopathy (PDR) patients after panretinal photocoagulation (PRP) have considered only relatively short-term results, and these have been conflicting. We evaluated contrast sensitivity changes in 30 eyes of 29 PDR patients after PRP. The patients were divided into two groups. One, group A, received PRP at one sitting, and the other, group B, at two sittings. Before and at regular intervals after PRP, all of the patients underwent a battery of macular function tests for best-corrected visual acuity, color vision, contrast sensitivity, and photostress. Contrast sensitivity was significantly affected (P < .001) in both groups immediately after PRP, but stabilized to prelaser levels by the end of 3 months. Color-vision-error scores also were significantly higher (P < .001) immediately after PRP. Best-corrected Snellen visual acuity, however, remained stable at prelaser levels. Contrast sensitivity appears to provide a more sensitive measurement of visual acuity than the Snellen chart for monitoring foveal integrity in patients undergoing PRP.

Adult↗
PubMed1994

Eye casualty department.

A retrospective analysis of all new patients attending our eye casualty department was carried out during the 1 year period, from January to December 1987. During this time the casualty unit saw and treated 4905 new patients. Of these 40.61% were traumatic in origin, 30.52% comprised various ocular infections and the remaining 28.87% had miscellaneous ocular problems. On average, 13 new patients and seven consultations from other departments were seen and treated daily. Apart from the management of ocular emergencies, other functions provided by our department included glaucoma screening, donor eye collection, attending to referrals from other departments and eye health education.

Emergency Service, Hospital↗
PubMed1993

Functional outcome of branch retinal vein occlusion after photocoagulation with various laser wavelengths--an automated perimetric analysis.

This study highlights the comparative efficacy of three different laser wavelengths--argon green, argon blue-green, and krypton red--for sector photocoagulation in fresh cases of branch retinal vein occlusion. The mean Logarithm of minimal angle of resolution (LogMAR) improved in the argon green and argon blue-green groups but decreased in the krypton red group. Statistical analysis of the automated visual fields in these eyes showed a mean change in corrected pattern standard deviation value, with increase in all three groups--minimal increase in the argon blue-green group and maximal in the krypton red group, suggesting maximum visual field defect in the krypton laser group. To conclude, the green and the blue-green wavelengths gave results that were decidedly superior to those given by krypton red: further, argon blue-green had an edge over the green wavelength.

Fluorescein Angiography↗
PubMed1993

Automated perimetric changes following panretinal photocoagulation in diabetic retinopathy.

Sixty eyes--30 with severe nonproliferative diabetic retinopathy (NPDR) and 30 with proliferative diabetic retinopathy (PDR)--underwent argon laser panretinal photocoagulation (PRP). Static perimetry (Humphrey automated visual field analyzer 630, Threshold Prog Central 30-1 and Peri 30/60-1) was done 1 day before and 6 weeks after the initial laser treatment. One day before treatment, the fields of the NPDR and PDR eyes differed mainly in the central field affection: the PDR eyes had more localized areas of markedly decreased retinal sensitivity and, therefore, a higher initial mean deviation value and higher corrected pattern standard deviation values. However, peripheral retinal sensitivity was equally depressed in the NPDR and PDR eyes. Six weeks after treatment, central retinal sensitivity had significantly improved in all of the eyes, although more so in the eyes with severe NPDR. This study suggests that static-perimetry-guided PRP is an effective treatment for diabetic retinopathy, especially severe NPDR.

Diabetic Retinopathy↗
PubMed1993

Ocular ethambutol toxicity: is it reversible?

Delayed onset ocular ethambutol toxicity is usually considered to be reversible following prompt withdrawal of the drug. However, in a series of seven consecutive patients with severe visual deficit due to ethambutol toxicity, only 42.2% (3 of the 7 patients) achieved a visual recovery of better than 20/200 after an average follow-up of 8.3 +/- 2.1 months after stoppage of the drug. On fluorescein angiography, three cases (42.2%) progressed to optic atrophy during the follow-up with permanent visual damage. There were no predisposing or risk factors to contribute toward the poor visual gain. In this background, we recommend discontinuation of ethambutol from the antituberculous regimen. As an additional sidelight, the value of visually evoked potential in the monitoring of patients on ethambutol, especially in cases with early periaxial neuritis, has been emphasised.

Adolescent↗
PubMed1992

Bilateral branch vein occlusion.

Bilateral branch retinal vein occlusion is a relatively rare occurrence. We report 4 patients who presented with bilateral branch retinal vein occlusion and in each of these cases the fellow eyes were involved within 6 months of the initial episode. The patients were relatively young and all of them had associated essential hypertension. The patients maintained a relatively good visual acuity through a 6-months to 1-year follow-up. This report highlights this rare entity, the associated risk factors and visual prognosis.

Adult↗
PubMed1992

Peribulbar anesthesia in retinal reattachment surgery.

We prospectively evaluated the effectiveness of peribulbar anesthesia in retinal reattachment surgery. Of the 24 patients studied, 2 required retrobulbar supplementation during the latter part of the surgery. Our results show that peribulbar anesthesia can be effectively used for retinal reattachment surgery and probably should be the preferred form of local anesthesia for this surgery, since the eyes involved have a relatively high incidence of axial myopia and posterior staphyloma.

Adult↗
PubMed1992

Sudden vision loss following retinal detachment surgery.

A 22-year-old man with Eales' disease with secondary rhegmatogenous retinal detachment with a break five disc diameters from the disc underwent radial scleral buckling using a silicone sponge episcleral explant with local cryopexy. Five hours after surgery the patient had no light perception. There was no intraoperative or postoperative rise of intraocular pressure or central retinal artery ischemia. Immediate removal of the explant brought a return of light perception and postoperative visual acuity improvement. The episcleral explant may have caused the direct optic nerve trauma that resulted in loss of vision.

Adult↗
PubMed1991

Ultrasonography in optic nerve head avulsion.

The diagnosis of post traumatic optic nerve avulsion is often obscured by the presence of concomitant vitreous haemorrhage. Electrodiagnostic tests, CT scan and fluorescein angiography have not proved helpful in substantiating the diagnosis of this entity in the early stages. We herein present the echographic features in a case of post traumatic optic nerve avulsion that, to the best of our knowledge, have not been previously described. The role of ultrasonography in the diagnosis of suspected optic nerve head avulsion has been high-lighted.

Adolescent↗
PubMed1991

Cryopexy in pars planitis.

Cryotherapy has been reported to be of benefit in pars planitis. We studied 16 eyes with classic pars planitis unresponsive to corticosteroid therapy. Eight eyes continued with systemic and periocular steroid therapy, and in the remaining eight eyes transconjunctival cryopexy of the peripheral retina and vitreous base was done as an additional procedure. At 6 months four of the eyes that received cryopexy showed an improvement in Snellen visual acuity, and in the other four the acuity was unchanged; none of the eyes showed any vitreous base neovascularization. Among the eyes that received steroid therapy only, the acuity was unchanged in five, improved in one and reduced in two.

Adolescent↗