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Biomedical subjects

R B Vajpayee

Publications and source records attributed to R B Vajpayee.

At least 55 records · Page 3Linked to original sources
PubMed2000

Comparison of various calpain inhibitors in reduction of light scattering, protein precipitation and nuclear cataract in vitro.

PURPOSE: To compare effects of calpain inhibitors on in vitro light-scattering in rat lens soluble protein and calcium-ionophore (A23187)-induced cataract formation in cultured rat lenses. METHODS: Rat lens soluble protein was hydrolyzed for 24 hours by activation of endogenous lens calpain. Ten calpain inhibitors were tested in this model at 10 and 25 microM concentration. As an index of protein precipitation, light scattering was measured daily at 405 nm for 8 days. Lens proteins were analyzed by isoelectric-focussing. Subsequently, rat lenses were cultured for 5 days with 10 microM A23187. Calpain inhibitors (SJA6017, MDL28170, AK295 and PD150606), which inhibited light-scattering were tested at 100 microM concentration in this model. Cataract evaluation, isoelectric-focussing and calcium determinations were performed. RESULTS: At 25 microM concentration AK295, SJA6017, E-64, PD-150606 and MDL28170 produced greater than 25% inhibition of light-scattering. Isoelectric-focussing revealed that addition of Ca(2+) produced characteristic crystallin proteolysis and aggregation patterns. AK295, SJA6017, MDL28170 and E64c prevented these changes. Lenses cultured in A23187 exhibited nuclear cataract, elevated calcium and proteolysis and aggregation of crystallins. Co-culture with SJA6017, MDL28170 and E64c reduced A23187-induced nuclear opacities, proteolysis and aggregation of crystallins without affecting increased total calcium. CONCLUSIONS: Endogenous calpain-activation model and A23187-induced cataract model can be used sequentially to screen calpain inhibitors for potential anti-cataract activity. Proteolytic changes in lens cortex after exposure to A23187 are also due to calpain activation. AK295, SJA6017 and MDL28170 possess efficacy against calcium-induced models of rodent cataracts. Use of calpain inhibitors represents a promising approach to cataract therapy.

Animals↗
PubMed2000

Study of the first contact management profile of cases of infectious keratitis: a hospital-based study.

PURPOSE: To study the management pattern and examine the role of cultures and antibiotic sensitivity testing in infectious keratitis. METHODS: A retrospective analysis of the demographic, clinical, and microbiological data was performed in 100 consecutive patients with infectious keratitis. The main parameters evaluated were nature of first contact with the health care services, investigations undertaken, treatment initiated, and the time interval between presentation to the first medical contact and to our center. Finally, the reports of culture and antibiotic sensitivity testing undertaken at our center were evaluated. RESULTS: In 70% of cases, ophthalmologists in independent practice were the first medical contact. Direct microscopy of the corneal scraping was undertaken in only 6% of cases, whereas culture and sensitivity studies had not been performed in any of the patients. Forty-six percent of the patients were prescribed 0.3% ciprofloxacin eyedrops in an inadequate dosage. Broad-spectrum fortified antibiotics eye drops had not been prescribed in any of the cases. At our center, positive cultures were obtained in 73.86% of cases and the most common organism isolated was coagulase-negative Staphylococcus (33.84%), followed by Pseudomonas aeruginosa (15.38%). A large number of the isolates demonstrated resistance to the recommended antibiotic therapy. CONCLUSIONS: Failure to implement standard management protocol for infectious keratitis at first contact is a major factor contributing to ocular morbidity in India.

Adult↗
PubMed2000

Sterile central disciform keratopathy after LASIK.

PURPOSE: To report a case with bilateral disciform keratopathy after laser in situ keratomileusis (LASIK). RESULTS: A 28-year-old man was referred to us with complaints of progressive painless diminution of vision, 5 days after having undergone bilateral simultaneous LASIK for hyperopia. The surgery was performed on the Chiron Technolas 217 excimer laser machine along with the hansatome, in which previously used blades were installed. Slit-lamp biomicroscopy revealed bilateral translucent disc-shaped lesions in the central cornea of both eyes. The lesions resolved after intense topical steroid therapy over a period of 3 weeks. CONCLUSION: Reuse of the microkeratome blade may have been the cause of this complication. The use of a new blade and meticulous cleaning of the microkeratome prior to use in each eye may help to prevent this complication.

Adult↗
PubMed2000

Stevens-Johnson syndrome in India - risk factors, ocular manifestations and management.

We conducted a study to analyse the presentation, risk factors, ocular manifestations and ophthalmic management results of Stevens-Johnson syndrome (SJS) in Indian patients. A total of 20 patients with SJS with ocular involvement were studied. Female predominance (70%) was observed. The age ranged from 10 to 30 years (mean +/- SD: 16.85 +/- 5.96). The commonest precipitating risk factor was oral drug intake (80%), sulphonamide (30%; sulphamethoxazole-trimethoprim) being the commonest. One patient had reaction to ciprofloxacin which has not been reported previously. Four patients (20%) had spontaneous onset with no identifiable risk factor. None of the patients had specific infection per se as a risk factor. Conjunctival involvement and its sequelae were the major ocular manifestations. At presentation, the majority of the eyes (68%) had visual acuity less than 3/60. Despite appropriate medical treatment and surgical interventions (11 eyes; 28%) vision continued to deteriorate. In 1 eye, the vision improved after stem cell transplantation. Therapeutic penetrating keratoplasty could preserve ocular integrity in 1 patient.

Adolescent↗
PubMed2000

Infectious crystalline keratopathy.

PURPOSE: To review the diagnosis, microbial and pathological features, pathogenesis, and treatment of infectious crystalline keratopathy (ICK). METHODS: We reviewed the literature on infectious crystalline keratopathy. RESULTS AND CONCLUSIONS: ICK is an indolent corneal infection in which needle-like, branching crystalline opacities are seen within the corneal stroma, in the absence of appreciable corneal or anterior segment inflammation. In most cases it occurs as a complication of corneal surgery and keratitis, with an alpha-hemolytic Streptococcus being the cause of infection. Discontinuation of topical steroids with aggressive antibiotic therapy may suffice, but continued infection, vascularization, or scar formation may affect visual acuity and require penetrating keratoplasty.

Administration, Topical↗
PubMed1999

Oversized grafts in children.

OBJECTIVE: To evaluate the efficacy of oversized corneal grafts in the pediatric age group. DESIGN: Prospective, nonrandomized clinical trial. PARTICIPANTS AND INTERVENTION: Forty pediatric patients with unilateral or bilateral corneal opacification of congenital or acquired origin underwent corneal grafting surgery over a period of 2 years using donor corneal buttons oversized by 1 mm. MAIN OUTCOME MEASURES: The parameters evaluated were indications for keratoplasty, graft clarity, visual acuity, keratometry, spherical equivalent, anterior chamber depth, and complications. RESULTS: Corneal ulceration was the most common cause of corneal opacification (25%), followed by trauma (20%) and sclerocornea (20%). At 1 year, clear grafts were achieved in 85% of the cohort. The average keratometry at the end of 1 year was 43.28 +/- 1.65 diopters (D) in the congenital opacity group and 43.04 +/- 2.20 D in the acquired group. The keratometric astigmatism was 3.60 +/- 2.60 D in the congenital group and 2.52 +/- 2.20 D in the acquired group. Oversized grafts provided an adequate anterior chamber depth of 2.20 +/- 0.612 mm in the congenital group and 2.36 +/- 0.302 mm in the acquired group. Visual acuity of 20/80 or better was recorded in only 30% of cases in the congenital group as opposed to 47% with acquired opacities. Nine cases had episodes of graft rejection. CONCLUSION: Oversizing donor buttons by 1 mm provides adequate anterior chamber depth and increases the morphologic success of corneal grafting in children.

Anterior Chamber↗
PubMed1999

Phacoemulsification of white hypermature cataract.

PURPOSE: To evaluate the safety of phacoemulsification of white hypermature cataract, which is common in developing countries. SETTING: Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India. METHODS: In a teaching hospital setting, a prospective evaluation of phacoemulsification in 25 eyes of 25 consecutive patients with hypermature cataract was done. Patients with good pupil dilation, optimal endothelial cell count, and disease-free ocular and systemic status were included. High magnification, sodium hyaluronate, and a Utrata capsulorhexis forceps were used to perform continuous curvilinear capsulorhexis (CCC). The stop and chop technique was used for nuclear emulsification. A 5.5 mm optic allpoly(methyl methacrylate) intraocular lens (IOL) was implanted, and wound closure was sutureless. RESULTS: Successful CCC was performed in 23 of 25 cases. In 2 cases, the CCC edge extended toward the periphery and a Vannas scissors was used to achieve an even cut. No complications were seen during nuclear emulsification and IOL implantation. Eighty percent of the patients had a visual acuity of 20/40 or better on the first postoperative day. Five patients had significant corneal edema that resolved within 1 week in all cases. CONCLUSION: Phacoemulsification was successfully and safely performed in appropriately selected patients with white hypermature cataract.

Aged↗
PubMed1999

Complications of pediatric cataract surgery and intraocular lens implantation.

PURPOSE: To study the pattern of postoperative complications following extracapsular cataract extraction (ECCE) with intraocular lens (IOL) implantation in pediatric eyes. SETTING: Tertiary eye care center, New Delhi, India. METHODS: A retrospective analysis of 39 eyes of 28 children referred for complications after ECCE with IOL implantation was performed. The results evaluated were visual acuity, iridocapsular problems, and IOL-related complications. Additional interventions such as neodymium:YAG (Nd:YAG) capsulotomy, surgical membranectomy, and penetrating keratoplasty (PKP) were done when necessary. Visual acuity was measured 1 week following intervention and at the last follow-up. RESULTS: Congenital (17 eyes, 43.6%), developmental (11 eyes, 28.2%), and traumatic (11 eyes, 28.2%) cataract were the indications for surgery. Posterior capsule opacification (34 eyes, 87.2%), updrawn pupil (15 eyes, 38.5%), decentered IOL (13 eyes, 33.3%), and pupillary capture (12 eyes, 30.8%) were the major complications. An Nd:YAG capsulotomy was attempted in 19 eyes (48.7%). Surgical membranectomy was performed in 10 eyes (25.6%); PKP was performed in 2 eyes (5.1%) to treat pseudophakic bullous keratopathy. One eye had to be eviscerated because of uncontrolled endophthalmitis. In 31 eyes in which visual acuity could be measured, 27 had an acuity of 6/60 or worse at the time of presentation. Following intervention and amblyopia therapy, 19 eyes achieved a visual acuity of 6/18 or better. CONCLUSION: Routine ECCE with IOL implantation in pediatric eyes is associated with various problems and may lead to permanent visual disability.

Capsulorhexis↗
PubMed1999

Comparative evaluation of plate haptic lenses with smaller and larger positioning holes.

PURPOSE: To evaluate the visual outcome, intraoperative problems and postoperative complications of plate haptic intraocular lenses with smaller foot plate positioning holes and larger holes. METHODS: Fifty eyes of 50 patients underwent clear corneal phacoemulsification with implantation of either small hole plate haptics (25 eyes) or large hole plate haptic lenses (25 eyes). The intraoperative complications were noted and the postoperative parameters were evaluated on the first day, 1 week, 1 month, 3 months, 6 months and 12 months. These included the best corrected visual acuities, intraocular lens (IOL) decentring, diameter of anterior capsulorhexis and posterior capsule opacification. RESULTS: The mean duration of follow-up was 14.8+/-2.1 months in the group with the small foot plate positioning holes (Chiron C10UB) lens and 15.6+/-3.2 months in the group with the large feet plate positioning holes (Chiron C11UB) lens. The was no significant difference in the visual acuities of the two groups. The mean IOL decentring was 0.42+/-0.28 mm in the C10UB lenses and 0.24+/-0.10 mm in the C11UB lenses (P = 0.05). The mean diameter of the anterior capsulorhexis was 4.68+/-0.23 mm in the former, while it was 4.21+/-0.68 mm in the latter (P = 0.0027). The posterior capsule opacification was significantly increased in the C11UB group (P = 0.0298). Neodymium : yttrium aluminium garnet (Nd: YAG) laser capsulotomy was required in 8% of the C10UB group, compared to 28% in the C11UB group. CONCLUSION: Results are similar with the two types of plate haptic lenses. The lenses with larger holes have a significantly higher posterior capsule opacification and more anterior capsulorhexis contracture, although the IOL decentring is less with these lenses.

Aged↗
PubMed1999

Epikeratoplasty for traumatic corneal ectasia.

PURPOSE: To evaluate the efficacy of epikeratoplasty in a case of traumatic corneal ectasia. METHOD: Epikeratoplasty using a manually dissected donor lenticule was used to treat traumatic corneal ectasia after an iron nail injury. RESULT: No intra- or postoperative complication was encountered. At the end of 6 months' follow-up, the patient's best corrected visual acuity was 6/12. CONCLUSION: Epikeratoplasty is a useful technique to treat traumatic corneal ectasia.

Child↗
PubMed1999

Optical sector iridectomy in corneal opacities.

PURPOSE: To evaluate the visual outcome after optical sector iridectomy in cases of corneal opacities. METHODS: Seventeen eyes of 17 patients with preoperative visual acuity of <6/60 in the affected eye underwent sector iridectomy in a prospective clinical study at a tertiary eye care center. Of 17 cases, 11 had corneal opacities after healed keratitis, four after trauma, and one each due to alkali burns or trachoma. The sector iridectomy was undertaken in cases in which one sector of the cornea and lens was fairly clear. Success was defined as attainment of ambulatory visual acuity of 6/60 or better. RESULTS: Mean age of the patients was 32+/-2.3 years. Most eyes had deep vascularized corneal scars (13 eyes). Optical sector iridectomy was performed most frequently in the lower nasal quadrant (11 eyes) followed by the lower temporal quadrant (four eyes). Of 17 eyes, 16 achieved a visual acuity of 6/60 or better. No intra-or postoperative complications were encountered. CONCLUSION: Optical sector iridectomy in cases of corneal opacities is a simple and safe procedure that can improve visual outcome and provide ambulatory vision to patients. It is a valuable alternative to penetrating keratoplasty if penetrating keratoplasty is not possible or not promising for various reasons.

Adolescent↗
PubMed1999

Indications for pediatric keratoplasty in India.

PURPOSE: To study the associations and indications for pediatric keratoplasty. METHODS: We undertook a retrospective analysis of 415 grafts performed in 393 children, aged 12 years or younger between January 1993 and December 1997. The parameters evaluated were demographic data, socioeconomic status, preoperative diagnosis, and any systemic or ocular associations. RESULTS: Of the 415 eyes operated on, 296 (71.32%) eyes underwent keratoplasty for acquired nontraumatic corneal opacities, 51 (12.28%) had congenital corneal conditions, 45 (10.85%) were regrafts, and 23 (5.54%) eyes had acquired traumatic corneal opacities. The cause of corneal opacification in the acquired nontraumatic group was infectious keratitis in 215 (72.63%) eyes and keratomalacia in 81 (27.36%) eyes. Systemic associations with the onset of the opacity in the acquired nontraumatic group were fever in 74 (25%) cases, diarrhea in 56 (18.9%) cases, and malnutrition in 98 (33.1%) cases. Seventeen (4.32%) children belonged to the lower middle class, 64 (16.28%) were in the upper lower class, and 312 (79.38%) were from the lower socioeconomic families based on the Kuppuswamy scale. CONCLUSIONS: Infectious keratitis is the major indication for pediatric keratoplasty in India. In the majority of the cases, the occurrence of corneal opacification is associated with poverty.

Age of Onset↗
PubMed1999

Epidemiology of cataract in India: combating plans and strategies.

Blindness due to cataract presents an enormous problem in India not only in terms of human morbidity but also in terms of economic loss and social burden. The WHO/NPCB (National Programme for Control of Blindness) survey has shown that there is a backlog of over 22 million blind eyes (12 million blind people) in India, and 80.1% of these are blind due to cataract. The annual incidence of cataract blindness is about 3.8 million. The present annual level of performance is in the order of about 1.6-1.9 million cataract operations. To clear the backlog of cataract cases by the year 2000 and to tackle the rising incidence, 5-6 million cataract operations annually will have to be performed as against the present rate of 1. 7 million per year. India is undertaking a new long-term initiative to expand the capability of cataract surgery and service levels with financial assistance from the World Bank. An important feature of this initiative is the attention given to spread the cataract blindness programme in rural and tribal areas. The second feature is the emphasis placed on modern extracapsular cataract extraction with intra-ocular lens implantation as the preferred surgical technique. Another noteworthy feature is developing institutional capacity and appropriate co-ordination mechanisms for collaboration between the non-government organization and the public sector to expand coverage to the most disadvantaged populations. The fourth and the most important strategy is to carry out intensive campaigns at the state and national levels against cataract blindness in order to substantially increase the demand for cataract services. A country like India has more significance for such a plan in view of the fact that various social, economic and environmental factors contribute to cataract blindness in populations at a much younger age.

Blindness↗
PubMed1999

Animal study on the effects of catalin on aftercataract and posterior capsule opacification.

PURPOSE: To find out the role of Catalin in the prevention of posterior capsular opacification (PCO), we undertook this experimental study in rabbits. METHODS: Twenty rabbits (10 for the Catalin group and 10 for the placebo group) were operated on for extracapsular clear lens extraction in an aseptic environment. In all cases, capsulorrhexis of 8 mm diameter was carried out. Both the test drug and placebo were given at a dose of 4 times/day from the first postoperative day for 8 weeks. Common drugs in both groups were topical corticosteroid, antibiotic and cycloplegic drops. Periodic slitlamp examinations and photographic documentations were carried out to find any evidence of aftercataract. At the end ot 8 weeks, histopathological examination was carried out to document any evidence of aftercataract. RESULT: Overall, evidence of aftercataract was seen in 6 rabbits in the control group and 3 in the Catalin group; the degree of PCO was higher in the placebo group. CONCLUSION: We found that Catalin played some role in preventing PCO.

Animals↗
PubMed1999

Risk factors for pediatric presumed microbial keratitis: a case-control study.

PURPOSE: To evaluate risk factors for pediatric presumed microbial keratitis and to describe the clinical picture, microbiologic spectrum, treatment modalities, posttreatment sequelae, and visual outcome in cases of pediatric presumed microbial keratitis. METHODS: A case-control study design was used to identify the risk factors associated with pediatric presumed microbial keratitis. Fifty cases of fresh corneal ulceration aged 12 years or younger were compared with 50 controls. The study variables included were age, gender, immunization status, nutritional status (weight for height), and socioeconomic status. The clinical presentation of the cases with corneal ulceration, microbiologic spectrum, and treatment modalities also were evaluated. All the cases were followed up for a minimum of 3 months, and the posttreatment sequelae and visual outcome were analyzed. RESULTS: The mean (+/- standard deviation) age of children with corneal ulceration and controls was 4.8 (+/-3.8) years and 5.1 (+/-2.8) years, respectively. Incomplete immunization status (AOR [95% confidence interval (CI)], 1.34 [0.62-2.9]) and poor nutritional status [AOR (95% CI) 1.06 (0.68-1.6)] were not found to be the predictors of corneal ulceration. Lower socioeconomic status was significantly associated with the occurrence of corneal ulceration [AOR (95% CI) 1.52 (1.1-2.3)]. Corneal trauma (38%) and systemic illness (24%) were the most often associated predisposing factors. Seventy percent of the cases were culture positive. Staphylococcus (70%) species was the most frequently isolated, followed by Pseudomonas aeruginosa (10%). Fungi were isolated in five eyes. Postresolution visual acuity at 3 months could be recorded only in 31 eyes and a visual acuity of 6/18 or better was achieved in 22% of these cases. CONCLUSION: Corneal ulceration in pediatric age group in India is associated with poverty.

Body Height↗
PubMed1998

Phacofracture versus phacoemulsification in eyes with age-related cataract.

PURPOSE: To compare manual phacofracture and phacoemulsification techniques. SETTING: Dr. Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi, India. METHODS: This prospective, randomized study comprised 60 cases of age-related cataract randomly divided into 2 groups: 30 eyes had phacoemulsification and 30, manual phacofracture using a trisection technique. Postoperative evaluation was at 1 day, 1 and 6 weeks, and 3 months. The parameters evaluated were amounts of viscoelastic material and irrigating fluid used, the time required to manage the nucleus, postoperative best corrected visual acuity, endothelial cell loss, and complications. RESULTS: Mean viscoelastic material used intraoperatively (3.69 mL +/- 0.81 [SD] versus 1.76 +/- 0.54 mL) and the time required to manage the nucleus (7.78 +/- 2.07 minutes versus 2.53 +/- 1.18 minutes) were significantly greater in the phacofracture than in the phacoemulsification group, respectively. Best corrected visual acuity was significantly better in the phacoemulsification group on the first postoperative day; 64% had a visual acuity of 6/9 or better versus 37% in the phacofracture group. Endothelial cell loss at 3 months was 17.66 +/- 3.65% in the phacofracture group and 12.03 +/- 3.06% in the phacoemulsification group and central corneal edema persisting for more than 1 week, 7 and 0 cases, respectively. The differences between groups were statistically significant. CONCLUSION: More experience in and further modification of the manual phacofracture technique are required before it can be recommended as a safe alternative to phacoemulsification.

Aging↗
PubMed1998

Evaluation of axis alignment system for correction of myopic astigmatism with the excimer laser.

PURPOSE: To evaluate the efficacy of in situ axis alignment for the treatment of myopic astigmatism with an excimer laser. METHODS: In this prospective clinical trial, 71 eyes with stable astigmatism of -1.00 to -6.00 diopters (D) with or without stable myopia of up to 10.00 D were randomized to receive excimer treatment of their astigmatic component aligned to the axis determined by subjective refraction (control group) or to have the alignment verified and altered is necessary by in situ alignment (axis alignment group). A VISX Twenty-Twenty excimer laser was used for the treatment. Patients were followed for 6 months. RESULTS: In 85% of eyes in the axis alignment group, the axis of cylinder was different from that calculated by routine refraction. Pretreatment mean cylinder was -1.81 D +/- 0.91 (SD) in the axis alignment group and -1.75 +/- 0.60 D in the control group. At 6 months, an undercorrection of cylinder was seen in both groups; the mean residual cylinder was -0.70 +2- 0.56 D in the axis alignment group and -0.59 +/- 0.50 D in the control group. More than 80% of all eyes were within +/- 1.00 D of plano and achieved an uncorrected visual acuity of 6/12 or better. A loss of two or more lines of best corrected visual acuity was recorded in three eyes. CONCLUSION: The in situ alignment technique did not produce better results of photoastigmatic refractive keratectomy than the routine axis alignment technique.

Adult↗