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Biomedical subjects

H K Tewari

Publications and source records attributed to H K Tewari.

At least 19 recordsLinked to original sources
PubMed2001

Phototoxic retinopathy.

Although the occurrence of iatrogenic light-induced retinal toxicity is beyond doubt, several issues remain to be studied further. These include conflicting reports regarding the wavelength of light that is most hazardous; what mechanism contributes more significantly in the pathogenesis of light-induced retinal toxicity-photochemical or photothermal; why does it occur in only some patients; and what is the protective role of UV absorbing chromophores in intraocular implants. Nevertheless, it is important for all ophthalmic surgeons to be aware of this complication and take measures that could decrease the risk of its occurrence.

Animals↗
PubMed2001

Comparative study of vitrectomy for dropped nucleus with and without the use of perfluorocarbon liquid. Clinical, electrophysiological and visual field outcomes.

PURPOSE: To compare pars plana vitrectomy for dropped nucleus with and without perfluorocarbon liquid. METHODS: 24 eyes with dropped nucleus were randomized to undergo PPV with perfluorodecalin, (study, n=12) and without it (control, n=12). Visual acuity, IOP, visual evoked response and electroretinography were noted at study entry and up to 3 months after PPV. Humphrey perimetry was done at 3 months. RESULTS: Final visual acuity was >20/60 in 75% of study eyes and 41.6% of controls. The two groups were statistically comparable with regard to the above parameters before PPV and during follow-up. The timing of vitrectomy did not significantly influence the final visual acuity. A higher rate of complications was seen in the control group. CONCLUSIONS: Perfluorodecalin facilitated the procedure and possibly minimized complications, and was found to be safe for intraoperative use in terms of recovery of visual acuity, stable ERG and VER, and normal visual fields.

Adult↗
PubMed2000

Intravitreal pefloxacin therapy in postoperative endophthalmitis.

PURPOSE: To study the efficacy of intravitreal pefloxacin in the management of suspected bacterial endophthalmitis. METHODS: Twenty eyes with suspected postoperative bacterial endophthalmitis were given an intravitreal injection of pefloxacin (200 microg in 0.1 mL). If required the injection was repeated after 24 h. The main parameters evaluated were visual acuity, response to intravitreal therapy and any complications due to intravitreal pefloxacin. RESULTS: Fourteen eyes (70%) responded to intravitreal pefloxacin therapy alone, while an additional pars plana vitrectomy was required in six eyes (30%). Nineteen eyes retained a visual acuity of 6/60 or better at 3 months after the initiation of therapy. A retinal detachment developed in one of the eyes which received intravitreal therapy. CONCLUSIONS: Intravitreal pefloxacin may be a useful aternative therapy in bacteria endophthalmitis.

Aged↗
PubMed2000

Congenital porphyria with necrotizing scleritis in a 9-year-old child.

Porphyria is a rare metabolic disorder that is characterized by the accumulation of photosensitive, toxic intermediates of the heme metabolic pathway in various organs of the body including the skin, eye and neural tissue. Porphyria as a potential cause for bilateral necrotizing scleritis in children is very infrequently emphasized in literature, probably due to the relatively rare occurrence and lack of well-documented cases. A case of a 9-year-old child with congenital porphyria who had developed necrotizing scleral ulceration in both eyes in addition to severe cutaneous hypersensitivity and facial disfigurement is herein presented.

Atropine↗
PubMed2000

Osseous choristoma of the choroid.

Osseous choristoma of the choroid, also called choroidal osteoma, is a very rare and unusual form of intraocular ossification. We report a case of choroidal osteoma in a young healthy male that to the best of our knowledge is the first report from India.

Adult↗
PubMed2000

New approaches in the management of choroidal neovascular membrane in age-related macular degeneration.

Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly population. The prevalence is reported to be 1.2-1.4% in several population-based epidemiological studies. Currently 25-30 million people worldwide are blind due to AMD. With the aging world population it is bound to increase significantly, and could become a significant public health problem in next two decades, with serious socio-economic implications. Several strategies are today available to treat the wet form of AMD, which is responsible for significant visual loss. These were until recently confined to laser photocoagulation, and subretinal surgery, but today two other modalities, namely, radiation and photodynamic therapy, are available. These treatment modalities however, are aimed at preservation of vision only, and not at reversing the process of the disease. Further research on antiangiogenic drugs and gene therapy could significantly help AMD patients.

Blindness↗
PubMed1999

Surgical removal of a free floating cyst of the iris pigment epithelium causing disturbing visual symptoms.

Pigmented cysts in the anterior chamber, fixed or free floating, are considered to be unusual but not very infrequent. However, most of these cases usually do not need any treatment other than a periodic observation. We report the surgical removal of an iris pigment epithelial cyst floating freely in the anterior chamber. The reason for surgical removal was, disturbance in near vision being caused by movement of the cyst across the visual axis. This specific symptom of disturbed near vision, to the best of our knowledge, is a rare indication for surgery that has not been pointed out earlier. Histopathological confirmation of the clinical diagnosis was also obtained.

Adult↗
PubMed1999

Combined central retinal artery and central retinal vein occlusion following pars plana vitrectomy.

Combined occlusion of the central retinal artery and central retinal vein is an infrequently encountered clinical entity. Although there are reports in the literature of a combined occlusion of the central retinal artery and vein, its occurrence following pars plana vitrectomy has not been described. We report the case of an elderly patient who developed this unusual occurrence following an uneventful pars plana vitrectomy for a posteriorly dislocated IOL.

Aged↗
PubMed1998

Efficacy of diode laser for managing diabetic macular oedema.

PURPOSE: To evaluate the effect of photocoagulation for diabetic macular oedema using Diode laser in a prospective randomized fashion and comparing its effects with the Argon green laser. METHODS: 40 eyes with focal and diffuse oedema were randomly treated with Diode and 40 eyes were treated with Argon green. Following investigations were performed: visual acuity, fundus evaluation, flourescein angiography and visual fields. RESULTS: 79% treated with Diode had partial to complete regression of oedema and so also 82% with Argon green at six months post laser. CONCLUSIONS: There was no difference in improvement or worsening of visual acuity between the two lasers. This study is of importance as it has been the first prospective randomized study of its kind using Diode laser in diabetic macular oedema.

Diabetes Mellitus, Type 2↗
PubMed1998

Cataract surgery in India: results of a 1995 survey of ophthalmologists.

The aim of this study was to investigate cataract surgery procedures and caseloads among Indian ophthalmologists in private and government practices. Members of the All India Ophthalmological Society and state ophthalmic societies were surveyed by mail questionnaire in December 1995. Out of 6,800 surveyed, 2,098 responses (31%) were received. Over 61% of the 990,249 reported cataract surgeries were carried out in private facilities with 24% of private patients receiving extracapsular cataract extraction (ECCE) and 41% ECCE with intraocular lens (IOL). Intracapsular cataract extraction remains more common in government facilities with 62% of cases. Over 85% of all surgeons reported some experience with ECCE/IOL. Surgeons operating in both private and government facilities carry an average annual caseload of 861 cataract surgeries, which is twice that of their colleagues operating exclusively in either private or government settings. Although the questionnaire response rate was low, the findings suggest that ECCE is more common in India than in generally recognized, and with the recent availability of low-cost IOLs, its popularity is rapidly expanding.

Cataract Extraction↗
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↗