Browsing by Author "Velpandian, T"

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    Comparative evaluation of possible ocular photochemical toxicity of fluoroquinolones meant for ocular use in experimental models.
    (2006-05-20) Velpandian, T; Bankoti, R; Humayun, S; Ravi, A K; Kumari, S S; Biswas, N R
    Fluoroquinolones (FQs) are extensively used in bacterial keratitis and other intraocular infections. Since eye is constantly exposed to light, incidence of ocular phototoxicity due to commonly used FQs is of great interest for their safe use. Phototoxicity of commonly used FQs (ciprofloxacin, lomefloxacin, pefloxacin, ofloxacin, sparfloxacin and gatifloxacin), has been evaluated by using HET-CAM-UV model (Photo Hen Egg Test-C Chorioallantoic Membrane model). This study was further extended by adding lomefloxacin dissolved in bovine vitreous (0.5 ml) on the chorioallantoic membrane (CAM). Using a standard scale, the phototoxic damage was assessed at different time intervals. Respective controls were kept in dark to distinguish the toxicity of the drugs per se. The results showed that the phototoxicity induced by lomefloxacin was very high followed by gatifloxacin and sparfloxacin and least for other drugs studied. Interestingly, lomefloxacin along with vitreous showed significantly low phototoxicity. This could be due to the antioxidant property of ascorbic acid present in the vitreous.
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    Comparison of questionnaire and clinician-based assessment of Prakriti/body constitution in young adults: an observational study
    (Medip Academy, 2024-11) Khuntia, BK; Rathore, S; Sharma, V; Rani, A; Agarwal, A; Rengarajan, K; Upadhyay, AD; Jat, M; Madhu, N; Velpandian, T; Sharma, G.
    Background: Ayurveda emphasizes a personalized medicine approach based on Prakriti (body constitution) assessment which involves morphological observation and detailed history of physiological, behavioural, and psychological attributes. In Ayurveda research, two commonly used prakriti questionnaires are developed by CSIR (Q1) and CCRAS (Q2). These questionnaires are presumed to have similar predictive capabilities, but no study has compared them with the clinician-based prakriti assessment method for suitability in clinical settings. This study aimed to compare Q1, Q2, and their agreement levels with the clinician-based prakriti assessment (CPA) method. Methods: This observational study was conducted from July 2022 to January 2023, involving adults of both sexes aged aged 18-35 years. Upon obtaining written informed consent, trained Ayurvedic clinicians assessed the prakriti of all participants using Q1, Q2 and CPA methods. Results: Out of 138 participants recruited, 67% were female. The mean±SD age for males and females was 27.80±4.43 and 26.58±4.56, respectively. Mixed prakriti types were more common than predominant types among participants. The CPA method substantially agrees with Q1 (Cohen’s kappa=0.75) and moderately agrees with Q2 (Cohen’s kappa=0.59). The positive predictive value ranges for Q1 and Q2 were (46.2-100%) and (48-100%), respectively. Conclusions: Q1 and Q2 are consistent with the CPA method, with Q1 showing better agreement. Further studies including other questionnaires is required to validate the results.
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    Delayed manifestation of ultra violet radiation induced erythema in guinea pigs by sodium pyruvate--a free radical scavenger.
    (1998-04-04) Gupta, S K; Awor, L; Rastogi, S; Prakash, J; Gupta, Y K; Varma, S D; Velpandian, T
    Sodium pyruvate, a free radical scavenger was evaluated for anti-inflammatory activity using UV radiation induced dermal erythema on guinea pig and compared with that of standard naproxen. Oral as well as topical pyruvate exhibited significant activity against UV induced dermal erythema model and the activity was comparable to that of naproxen. In the other pharmacodynamic studies, such as the studies on rat blood pressure, isolated guinea pig ileum and rat uterus, it showed no effect on any of these. In conclusion, sodium pyruvate showed a significant protection in the UV induced dermal erythema in guinea pigs. It also showed good absorption in UV-B range and this property can be utilised to develop the sodium pyruvate as a sunscreening agent.
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    Evaluation of liposomal amphotericin B for the treatment of fungal keratitis in a tertiary eye care hospital
    (All India Ophthalmological Society, 2023-02) Kumar, Vishal; Kumari, Pooja; Lomi, Neiwete; Vanathi, Murugesan; Gupta, Noopur; Tandon, Radhika; Velpandian, T; Ahmed, Nishat H; Satpathy, Gita
    Purpose: To evaluate the efficacy of liposomal amphotericin B (L?AMB) for the treatment of fungal keratitis. Methods: Patients with fungal keratitis confirmed by potassium hydroxide (KOH) smear and/ or confocal microscopy were administered topical L?AMB and randomized into three groups treated with three different formulations. The medication was administered two hourly till clinical improvement was achieved, followed by six hourly till complete resolution. The outcome measures were time to clinical improvement, resolution of epithelial defect, stromal infiltrate, hypopyon, extent and density of corneal opacity, neovascularization, and best corrected visual acuity (BCVA) at 3 months. Results: Mean age of the patients was 46.6 ± 14.8 years, and trauma with vegetative matter was the most common predisposing factor. Aspergillus flavus (36%) was the most common fungus cultured, followed by Fusarium (23%). Mean time to clinical improvement, time to resolution of epithelial defect, mean time to resolution of infiltrate, and time to resolution of hypopyon were 3.45 ± 1.38, 25.35 ± 8.46, 37.97 ± 9.94, and 13.33 ± 4.90 days, respectively, and they were comparable among the three groups. There was a significant difference between treatment failure and success cases in terms of days of presentation (P < 0.01), size of the epithelial defect (P?value 0.04), and infiltrate size at presentation (P?value 0.04). At 3 months follow?up, no statistically significant difference was noted in BCVA and mean scar size among groups. Conclusion: L?AMB in a gel form is an effective antifungal agent that promotes the healing of fungal ulcers with notably least vascularization and better tolerance.
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    An experimental study to evaluate safety/toxicity of intravitreal natalizumab
    (All India Ophthalmological Society, 2018-10) Chawla, R; Nath, M; Moksha, L; Nag, TC; Velpandian, T
    Purpose: The purpose of this prospective experimental study was to evaluate the safety/toxicity of ?4?1 integrin blockade in rabbit retina using its monoclonal antibody (Natalizumab). Methods: Twelve New Zealand albino rabbits were divided into three groups (n = 4). Unilateral intravitreal injections of three different concentrations of natalizumab were performed in every rabbit of each group (Group A: 0.625 mg, Group B: 1.25 mg, and Group C: 2.5 mg). Baseline electroretinogram (ERG) and fundus photography were performed prior to injection. At days 1, 7, and 21 postinjection, ERG and fundus photography of each eye were performed. At last follow-up, Group C animals with highest drug concentration were sacrificed and the enucleated eyes were evaluated for retinal toxicity using transmission electron microscopy (TEM). Results: No difference in ERG responses was observed in eyes injected with low and intermediate concentration of natalizumab between day 0 and day 21. Furthermore, rabbits injected intravitreally with highest dose showed reduction in amplitude of “a” wave (P = 0.0017) and a reduction in amplitude of “b” wave of ERG at day 21 (P = 0.0117). TEM revealed changes in the outer plexiform layer and inner nuclear layer, suggestive of toxicity primarily to the photoreceptor synaptic terminals and bipolar cells. Conclusion: Low-dose (0.625 mg) and intermediate-dose (1.25 mg) intravitreal injection of natalizumab appears safe for rabbit retina. However, functional and anatomical changes were observed in rabbit retina following a high-dose (2.5 mg) intravitreal injection of a monoclonal antibody blocking ?4?1 integrin.
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    Pharmacokinetics of Nevirapine, Stavudine and Lamivudine in Indian HIV-infected Children Receiving Generic Fixed Dose Combinations.
    (2014-03) Mukherjee, Aparna; Singla, Mohit; Velpandian, T; Sirohiwal, Anju; Vajpayee, M; Singh, Ravinder; Kabra, S K; Lodha, Rakesh
    Objective: To determine the trough and two hour plasma levels of nevirapine, stavudine, and lamivudine when administered in fixed dose combinations (FDC). Design: Cross sectional Setting: Tertiary care hospital in Northern India. Participants: 79 HIV-infected children receiving antiretroviral therapy with FDCs for more than month. Intervention: Two-point sampling (0 and 2 hours after the morning dose). Outcome measures: Plasma concentrations of all three drugs were simultaneously assayed by liquid chromatography/mass spectroscopy. Results: Majority (77%) of children were receiving fixed dose combination of stavudine, lamivudine, nevirapine in the ratio of 6:30:50mg. The median (IQR) trough and 2-hour plasma levels (µg/mL) of nevirapine, stavudine and lamivudine were 5.2 (4.0, 6.3) and 7.9 (6.0, 9.7); 0.1 (0.06, 0.16) and 1.1 (0.59, 1.6); 0.1 (0.02, 0.2) and 2.5 (1.4, 3.1), respectively. Very few children had sub-therapeutic plasma drug levels of stavudine (2.5%), lamivudine (7.6%) and nevirapine (10%). Inadequate viral suppression at 6 months follow up was significantly associated with initial high viral load, low CD4 percentage at the time of enrolment in study, and lower doses of lamivudine and stavudine. Conclusion: The currently available generic pediatric fixed dose antiretroviral combinations in India provide adequate drug exposure in majority of children.
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    Protection from ultraviolet radiation by spectacle lenses available in India: a comparative study.
    (2005-09-26) Velpandian, T; Ravi, A K; Kumari, S S; Biswas, N R; Tewari, H K; Ghose, S
    BACKGROUND: Exposure to ultraviolet radiation (UVR) can result in several ocular ailments. We studied the UV absorption (UV-A and -B bands) in 20 lenses (11 hard resin and 9 glass) commonly available in India as uncut lenses for the purpose of prescription as well as non-prescription wear. METHODS: Using a UV-visible spectrophotometer (Thermo-Spectronic, UV-1 model, Thermo Electron Corporation, USA), the percentage transmittance was scanned between 190 and 400 nm, from which the results at 280, 320, 340, 360, 380 and 400 nm were analysed. RESULTS: At 360 nm (UV-A), 75% of the lenses studied failed to offer 95% protection as recommended by the United States Food and Drug Administration (US FDA). At 280 nm (UV-B), 35% of the lenses failed to offer 99% protection against UV-B. Hard resin lenses showed a higher degree of variation in protection from UV-A. CONCLUSONS: Most of the lenses studied failed to meet the US FDA recommendations in terms of protection from UV-A. Glass lenses afforded better protection up to 320 nm compared with hard resin lenses. As the claims of lens manufacturers regarding UVR protection fall short of international standards, certification of UVR protection for different lenses should be introduced in India.
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    Real-life comparison of three intravitreal antibiotic drug regimens in endophthalmitis
    (All India Ophthalmological Society, 2022-05) Bari, Aafreen; Chawla, Rohan; Mishra, Deepanshi; Das, Ujjwalkumar; Hasan, Nasiq; Satpathy, Gita; Velpandian, T; Azad, Shorya V; Venkatesh, Pradeep; Vohra, Rajpal; Kumar, Atul
    Purpose: Real?life comparison of three intravitreal drug regimens used in cases of endophthalmitis at a tertiary care center in India. Methods: In this prospective, comparative study, patients of bacterial endophthalmitis were grouped according to intravitreal antibiotic drug regimens into Group 1 (ceftazidime and vancomycin), Group 2 (piperacillin + tazobactam and vancomycin), and Group 3 (imipenem and vancomycin). Forty?eight hours after injection nonresponding/worsening patients underwent vitrectomy. Vitreous samples were subjected to microbiological and pharmacokinetic tests. Results: A total of 64 patients were included and divided into Group 1: 29, Group 2: 20, and Group 3: 15 cases. Also, 75% of patients were post?surgical endophthalmitis, whereas 25% were post?traumatic. Improvement in vision (V90?0) and vision at 3 months (V90) were comparable between the three groups. Visual recovery was poorer in post?traumatic cases. In post?surgical cases, visual recovery was poorer in those presenting beyond 72 h of onset of symptoms (P = 0.0002). Polymerase chain reaction (PCR) positivity (66%) was higher than BACTECTM (33%) and culture (14%). Antibiotic resistance was comparable amongst the three groups. Most patients (62/64) further underwent vitrectomy. Ceftazidime and vancomycin achieved vitreous concentrations more than the minimum inhibitory concentration (MIC) at 48 h after the first injection. Conclusion: The choice of antibiotics did not affect the rate of vitrectomy and final vision in a real?life scenario. Ceftazidime and vancomycin can still be used as first?line intravitreal antibiotics owing to their comparable microbial sensitivity profile and adequate ocular bioavailability
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    Reply.
    (2011-08) Velpandian, T; Deorari, A K
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    Therapeutic potential of valproic acid in advanced glaucoma: A pilot study
    (All India Ophthalmological Society, 2018-08) Mahalingam, K; Chaurasia, AK; Gowtham, L; Gupta, S; Somarajan, BI; Velpandian, T; Sihota, R; Gupta, V
    Purpose: Oral valproic acid (VPA) used as an anticonvulsant has been shown to improve contrast threshold sensitivities in patients receiving it on long-term. This study aimed to evaluate the efficacy of oral VPA in improving visual function in eyes with advanced stage glaucoma. Methods: In this prospective randomized study, 31 patients (n = 31 eyes) with advanced stage glaucoma (with an intraocular pressure <16 mmHg) in at least one eye received oral VPA 500 mg once a day for 3 months and 33 patients (n = 33 eyes) continued on glaucoma therapy. Patients were followed up at 3 and 12 months (to evaluate the legacy effect of the drug). Blood VPA concentrations were measured at 3 months. Following parameters were assessed at baseline, 3 months and 12 months: log of the minimum angle of resolution (LogMAR) visual acuity, mean deviation on visual fields, and multifocal electroretinogram (ERG). Results: Median LogMar visual acuity in the VPA group improved from 0.3 at baseline to 0.18 and 0.18 at 3 and 12 months, respectively (P < 0.01). In comparison, the median visual acuity in control group at baseline was 0.18 and showed neither worsening nor improvement over 3 and 12 months (P = 0.56). The improvement in VPA group was significant compared to the control group (P < 0.01; Wilcoxon Signed-rank test). An improvement in one line was experienced in 11 out of 31 eyes in the VPA group compared to 1 out of 33 eyes among controls (P = 0.003). No significant improvement was noted in the mean deviation, and the multifocal ERG (Latency and amplitudes) in the VPA-treated patients. The average blood VPA concentration measured at 3 months of therapy was 26 � 8.9 ?g/ml (range 8� ?g/ml) which is much lower than that achieved during anticonvulsant therapy. None of the patients complained of any adverse effects that required stopping VPA therapy. Conclusion: A 3 months oral VPA therapy results in some improvement in visual acuity in a subgroup of eyes with advanced glaucoma and the effect was seen to persist 9 months after the drug was stopped.
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    Transconjunctival penetration of mitomycin C.
    (2008-05-18) Velpandian, T; Sihota, Ramanjit; Sinha, Ankur; Gupta, Viney
    AIMS: The study was performed to estimate transconjunctival penetration of mitomycin C (MMC) to Tenon's tissue following application over the intact conjunctiva before routine trabeculectomy. SETTINGS AND DESIGN: Institution-based case series. MATERIALS AND METHODS: In 41 eyes of 41 patients, MMC (0.4 mg/ml for 3 min) was applied over the intact conjunctiva before beginning trabeculectomy. Tenon's capsule directly beneath the site of application was excised during trabeculectomy and was homogenized, centrifuged and MMC concentrations were analyzed using high-performance liquid chromatography (HPLC). Statistical Analysis Used: Statistical analysis was performed using STATA 8.0 version software (STATA Corporation, Houston, TX, USA). In this study, P -values less than 0.05 were considered as statistically significant. RESULTS: The average weight of the sample of Tenon's tissue excised was 5.51+/-4.42 mg (range: 0.9-17.1) and the average estimated MMC concentration found to be present in Tenon's tissue using HPLC was 18.67+/-32.36 x 10(-6) moles/kg of the tissue (range: 0.38-197.05 x 10(-6)). In 36 of the 41 patients (87.80%), the MMC concentration reached above 2 x 10(-6) moles/kg of the tissue concentration required to inhibit human conjunctival fibroblasts. CONCLUSIONS: Mitomycin C does permeate into the subconjunctival tissue after supraconjunctival application for 3 min. Application of MMC over the conjunctiva may be a useful alternative to subconjunctival or subscleral application during routine trabeculectomy and as an adjunct for failing blebs.