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Biomedical subjects

R B Vajpayee

Publications and source records attributed to R B Vajpayee.

At least 19 recordsLinked to original sources
PubMed2006

Risk factors for postoperative cylindrical prediction error after laser in situ keratomileusis for myopia and myopic astigmatism.

PURPOSE: To study the risk factors for the occurrence of cylindrical prediction error (PE) after laser in situkeratomileusis (LASIK) for myopia and myopic astigmatism. METHODS: The study was a nested case-control study. Five hundred eyes of 252 consecutive patients who underwent LASIK for myopia and myopic astigmatism on the Chiron Technolas 217C laser and completed 6 months of follow-up. There were 435 controls and 65 cases based on the postoperative refractive cylindrical PE. The probable risk factors studied included preoperative sphere and cylinder, keratometry, pachymetry, suction ring used, flap thickness, hinge centeration, optic zone, ablation depth, and intraoperative complications. RESULTS: By univariate analysis, the cylindrical PE was found to be associated with preoperative spherical equivalent higher than -6 D (chi(2)=10.83; P=0.001), preoperative sphere higher than -6 D (chi(2)=6.15, P=0.013), preoperative cylinder more than -0.75 D (chi(2)=6.61; P-value=0.010), and an optic zone less than 5.5 mm (chi(2)=19.3; P=0.001). Risk factors for postoperative astigmatism by stepwise multivariate logistic regression analysis were an optic zone of less than 5.5 mm with an odds ratio (OR) of 2.81 (95% confidence interval (CI)=1.62-4.86) and preoperative cylinder more than -0.75 D with an OR of 1.60 (95% CI=0.92-2.77). CONCLUSION: Postoperative astigmatism (as indicated by the cylindrical PE) is more likely to occur with an optic zone of less than 5.5 mm and a higher preoperative cylindrical error.

Adult↗
PubMed2006

Phacoemulsification with nondominant hand.

PURPOSE: Evaluation of on axis phacoemulsification surgery through temporal incision using nondominant hand with surgeon sitting at the head end, inpatients with against-the-rule astigmatism. METHODS: Eighty eyes of 80 patients who underwent phacoemulsification through a temporal clear corneal tunnel for age-related cataract and against-the-rule astigmatism were enrolled and divided into four equal groups. In Group 1A, the surgeon was sitting at the head end for the left eye performing surgery with the left hand (nondominant hand). In group 1B, the surgeon was seated at the temporal side and surgery was performed in the left eye with dominant right hand. In group 2A, the surgeon was sitting at the head end for the right eye and performed surgery holding the phacoemulsification hand piece in his right hand. In group 2B, the surgeon sat on the temporal side of the right eye and performed phacoemulsification with his right hand. The patients were followed up on day 7, 1 month, and 3 months. Parameters evaluated included average phaco power, effective phaco time, uncorrected and best-corrected visual acuity, keratometry, intraocular pressure, surgically induced astigmatism, pachymetry, and endothelial cell counts. RESULTS: The phaco time and phaco power among the four groups were comparable (phaco time: P=0.368; phaco power: P=0.294). The four groups were also comparable on parameters like surgically induced astigmatism (P=0.674), change in postoperative keratometric astigmatism (P=0.584), endothelial cell loss (0.921), change in ultrasonic pachymetry (P=0.476), and intraocular pressure (P=0.942). No intraoperative or postoperative complications were observed in any of the groups. The mean uncorrected visual acuity at 3 months in group 1 was 0.723+/-0.21; in group 2 it was 0.756+/-0.21; in group 3 it was 0.748+/-0.22, and in group 4 it was 0.732+/-0.23. The best-corrected visual acuity was 0.96+/-0.10, 0.97+/-0.11, 0.95+/-0.13, and 0.96+/-0.10 in the four groups at 3 months. CONCLUSION: Phacoemulsification surgery can be successfully performed with nondominant hand with a good surgical outcome. The technique gives an alternative approach where surgeon does not have to shift the position to perform on-axis phacoemulsification.

Aged↗
PubMed2006

Risk factors for perforation in microbial corneal ulcers in north India.

AIM: To identify predisposing factors leading to corneal perforation in patients with microbial keratitis. METHOD: Two groups of 60 patients each, with perforated corneal ulcers and healed/healing corneal ulcers, respectively, were recruited in a case-control study conducted in northern India. The cases and controls were matched by age and time of presentation. A standardised proforma was used to identify potential predisposing factors for demographic, social, medical, ocular, and treatment history. All participants underwent a detailed ocular examination. Corneal scrapings were performed where relevant. RESULTS: The characteristics associated with corneal perforation in microbial keratitis were outdoor occupation (p = 0.005), illiteracy (p = 0.02), excessive alcohol use (p = 0.03), history of "something falling into eye" (p = 0.003), trauma with vegetable matter (p = 0.008), vision less than counting fingers at referral (p<0.001), central location of ulcer (p<0.001), lack of corneal vascularisation (p<0.001), delay in starting initial treatment (p<0.001), failure to start fortified antibiotics (p<0.001), and monotherapy with fluoroquinolones (p = 0.002). The lack of corneal vascularisation (OR 6.4, 95% CI 4.2 to 13.5), delay in starting initial treatment (OR 35.6, 95% CI 6.9 to 68.2), and failure to start fortified antibiotics (OR 19.9, 95% CI 2.7 to 64.7) retained significance on a logistic regression model. CONCLUSIONS: This study characterises microbial keratitis cases at increased risk of corneal perforation and reinforces the need for standardised referral and treatment protocols for patients with corneal ulcer on their first contact at primary care level in the developing world.

Adult↗
PubMed2005

Outcome of penetrating keratoplasty in patients with bilateral corneal blindness.

PURPOSE: To evaluate the outcome of penetrating keratoplasty in patients with bilateral corneal blindness. METHODS: Bilaterally blind patients who had undergone optical penetrating keratoplasty (PK) were evaluated on optical and refractive parameters and presence of complications if any. The results at 3 months, 6 months, and 1 year were compared with age-matched and indication-matched unilaterally blind controls. RESULTS: The most common indication for surgery in both the groups was the presence of a corneoiridic scar. Best corrected visual acuity of > or =6/18 was seen in five (16.66%) patients in the study group and in 11 (36.66%) patients in the control group (P = 0.14). In all, 15 (50%) grafts in the study group and six (20%) in the control group failed (P = 0.03). The most common cause of failure was graft infection (40%) in the study group and post-PK glaucoma (20%) in the control group. The percentage of graft rejection as a cause of graft failure was the same in both the groups. A composite socioeconomic status scale based on family literacy and income suggested that 70% of the cases in the study group and 30% in the control group belonged to the low socioeconomic group (P = 0.004). CONCLUSION: The outcome of optical penetrating keratoplasty in patients with bilaterally blinding corneal disease is poorer than those who are unilaterally blind. Low socioeconomic status may be a contributing factor for the poor outcome.

Adult↗
PubMed2003

Evaluation of umbilical cord serum therapy for persistent corneal epithelial defects.

AIMS: To evaluate umbilical cord serum therapy as a means of promoting the healing of persistent corneal epithelial defects. METHODS: Umbilical cord serum or autologous serum drops were used to promote the healing of persistent epithelial defects. The study design was a prospective randomised controlled clinical trial. 60 eyes of 59 patients were divided into two groups, 31 in the cord serum group and 29 in the autologous serum control group. Epithelial defects measuring at least 2 mm in linear dimension resistant to conventional medical management were included. Serial measurements of the size of the epithelial defects-namely, two maximum linear dimensions perpendicular to each other, and the area and perimeter was done at start of therapy and follow up days 3, 7, 14, 21. Rate of healing of the epithelial defects were measured as percentage decrease from the baseline parameter at each subsequent follow up. The data were analysed by the non-parametric Wilcoxon rank sum test using STATA 7.0. RESULTS: The median percentage decrease in the size of the epithelial defect was significantly greater in the cord serum group at days 7, 14 and 21 (p<0.05) when measured in terms of the area and perimeter. A greater number of patients showed complete re-epithelialisation with umbilical cord serum (n = 18) than with autologous serum (n = 11) (Pearson chi = 0.19). None of the patients reported any side effects or discomfort with either treatment. CONCLUSIONS: Umbilical cord serum leads to faster healing of the persistent corneal epithelial defects refractory to all medical management compared to autologous serum.

Adult↗
PubMed2003

Posterior corneal topographic changes after partial flap during laser in situ keratomileusis.

AIM: To study the posterior corneal topographic changes in eyes with partial flaps during laser assisted in situ keratomileusis (LASIK). METHODS: Case records of 16 patients, who had partial flap in one eye during LASIK (group 1) and uncomplicated surgery in the other eye (group 2), were studied. Following occurrence of partial flap intraoperatively, laser ablation was abandoned in all the eyes. A 160/180 micro m flap was attempted during the initial procedure using the Hansatome microkeratome (Bausch & Lomb Surgicals, Munich, Germany). LASIK surgery in all cases was performed using a 180 micro m plate, at the mean interval of 4.16 (SD 1.5) months following the initial procedure. None of the eyes had intraoperative complication during LASIK. Relative posterior corneal surface elevation above the best fit sphere (BFS) before the initial procedure, before, and after LASIK were compared using the Orbscan slit scanning corneal topography/pachymetry system. RESULTS: Posterior corneal elevation was comparable in the two groups, both preoperatively (group 1; 16.4 (4.8) micro m, group 2; 16.1 (4.8) micro m) and after final surgery (group 1; 57.2 (15.6) micro m, group 2; 54.3 (13.1) micro m). In group 1 after occurrence of partial flap, the posterior corneal elevation was 16.9 (4.4) micro m, and this increase was not significant statistically (p=0.4). On multiple linear regression analysis, residual bed thickness (p<0.001) was independently the significant determinant of final posterior corneal elevation in both groups. CONCLUSION: The inadvertent occurrence of partial flap during LASIK procedure does not contribute to the increase in posterior corneal elevation.

Adolescent↗
PubMed2003

Keratoplasty for keratomalacia in preschool children.

AIM: To study the results of surgical management of keratomalacia in children. METHODS: A clinical case series of all children with keratomalacia, admitted to an Indian centre during the period from June 2000 to June 2001 is presented. The parameters evaluated were demographic data, systemic associations, and results of medical and surgical intervention. RESULTS: 29 children with keratomalacia ranging from 2 months to 5 years of age (mean 1.8 (SD 1.4) years) were included in the study. All children belonged to families of lower socioeconomic status. 27 patients (93.1%) had not been immunised at all. The systemic diseases precipitating the onset of keratomalacia included measles (41.37%), pneumonia (31.03%), and acute diarrhoea (37.93%). 36 eyes (66.7%) had total corneal melting and 11 (20.3%) eyes had paracentral corneal melting. In 15 eyes (27.8%) an emergency tectonic penetrating keratoplasty was performed of which only five grafts (33.3%) remained clear at a mean follow up of 7.3 (6.8) months (range 3-24 months). Seven eyes underwent optical penetrating keratoplasty, of which four grafts (57.14%) remained clear at a mean follow up of 6.4 (3.6) months (range 3-12 months). None of these could achieve a visual acuity better than 6/60. CONCLUSIONS: Corneal grafting surgery in keratomalacia is associated with poor visual outcome.

Acute Disease↗
PubMed2003

LASIK after retinal detachment surgery.

AIM: To assess the efficacy and safety of laser in situ keratomileusis (LASIK) for correction of myopic refractive errors in eyes which have previously undergone retinal detachment surgery. METHODS: In a prospective, non-comparative case series, 10 eyes of nine patients who had a myopic refractive error and had previously undergone retinal detachment surgery underwent LASIK surgery according to the standard surgical protocol. The surgery could be completed in eight eyes and in two eyes it was aborted intraoperatively. The parameters evaluated included the uncorrected visual acuity, best corrected visual acuity, refraction, detailed fundus evaluation with indirect ophthalmoscope, slit lamp biomicroscopy, and corneal pachymetry. Any intraoperative or postoperative complications were recorded. Follow up visits were scheduled at day 1, 1 week, 1 month, 3 months, and 6 months after LASIK. RESULTS: Eight eyes underwent successful LASIK surgery. The mean spherical equivalent before surgery was -5.436 (SD 1.6) dioptres (D), which was reduced to +0.42 (0.65) D, -0.07 (1.32) D, -0.06 (1.39) D, and -0.06 (0.65) at 1 week, 1 month, 3 months, and 6 months respectively after LASIK. The uncorrected visual acuity improved in all the eyes and the best corrected visual acuity improved or remained same in all the eyes. There was no retinal complication after LASIK. CONCLUSION: LASIK may be used to correct refractive errors in eyes that have undergone retinal detachment surgery. However, scarred conjunctiva in such cases may prevent generation of optimal suction for the microkeratome.

Adult↗
PubMed2003

Visual performance after interface haemorrhage during laser in situ keratomileusis.

AIM: To study the visual performance in eyes with interface haemorrhage during laser assisted in situ keratomileusis (LASIK). METHODS: Case records of 20 patients, who had bleeding from the limbal vessels in one eye during LASIK (group 1) and uncomplicated surgery in the fellow eye (group 2) were studied. The parameters evaluated were uncorrected visual acuity (UCVA) best corrected visual acuity (BCVA), spherical equivalent of refraction (SEQ), contrast sensitivity, and glare acuity preoperatively and at 1, 3, and 6 months postoperatively. RESULTS: The mean preoperative SEQ in group 1 and 2 eyes was -5.79 (2.3) D and -5.27 (1.68) D, respectively. The mean decimal UCVA at 6 months after LASIK in group 1 and 2 eyes were 0.6 (0.2) and 1.0 respectively (p<0.001). The mean decimal BCVA at 1 week after LASIK in group 1 and 2 eyes were 0.89 (0.04) and 1.0 respectively (p<0.05). However, all eyes had a BCVA of 6/6 at 1, 3, and 6 months after LASIK. The mean contrast sensitivity values preoperatively in group 1 and 2 eyes were 161.3 (8.7) and 172 (68.2) respectively. There was a significant decrease in group 1 at 6 months (102 (60.5) (p<0.01)) compared to group 2. The decimal glare acuity preoperatively in group 1 and 2 eyes was 0.95 (0.11) and 0.89 (0.12), respectively. It decreased significantly in group 1 (0.7) (0.1 (p<0.01)) compared to group 2 at the 6 month follow up. CONCLUSION: Occurrence of intraoperative interface haemorrhage may affect the visual performance following LASIK surgery.

Adolescent↗
PubMed2003

Causes and temporal trends of blindness and severe visual impairment in children in schools for the blind in North India.

AIMS: To describe the causes of severe visual impairment and blindness (SVI/BL) in children in schools for the blind in north India, and explore temporal trends in the major causes. METHODS: A total of 703 children were examined in 13 blind schools in Delhi. A modified WHO/PBL eye examination record for children with blindness and low vision which included sections on visual acuity, additional non-ocular disabilities, onset of visual loss, the most affected anatomical part of the eye concerning visual impairment, and the aetiological category of the child's disorder based on the timing of insult leading to visual loss was administered in all children. RESULTS: With best correction, 22 (3.1%) were severely visually impaired (visual acuity in the better eye of <6/60) and 628 (89.3%) children were blind (visual acuity in the better eye of <3/60). Anatomical sites of SVI/BL were whole globe in 27.4% children, cornea 21.7%, retina 15.1%, and lens 10.9%. The underlying cause of visual loss was undetermined in 56.5% children (mainly abnormality since birth 42.3% and cataract 8.3%), childhood disorders were responsible in 28.0% (mainly vitamin A deficiency/measles 20.5%), and hereditary factors were identified in 13.4%. Study of temporal trends of SVI/BL by comparing causes in children in three different age groups-5-8 years, 9-12 years, and 13-16 years-suggests that retinal disorders have become more important while childhood onset disorders (particularly vitamin A deficiency) have declined. CONCLUSIONS: Almost half of the children suffered from potentially preventable and/or treatable conditions, with vitamin A deficiency/measles and cataract the leading causes. Retinal disorders seem to be increasing in importance while childhood disorders have declined over a period of 10 years.

Adolescent↗
PubMed2003

Ultrasound biomicroscopy in lens "coloboma".

PURPOSE: To study the morphology of the Lens "Coloboma" using the technique of ultrasound biomicroscopy. METHODS: We used the Paradigm 40 Ultrasound biomicroscope to study the morphology of the lens "Coloboma". RESULTS: Ultrasound biomicroscopy of the lens "Coloboma" revealed a greatly increased sphericity of the lens and the deficiency of zonules in the "colobomatous" area. CONCLUSIONS: Ultrasound biomicroscopy has helped in elucidating the pathology of the lens "Coloboma".

Coloboma↗
PubMed2002

Risk factors for graft infection in India: a case-control study.

AIM: To study the demographic, clinical, and microbiological profile and the risk factors for graft infection following penetrating keratoplasty. METHODS: 50 eyes of 50 consecutive patients with graft infection after an optical penetrating keratoplasty were included as cases; 50 eyes of 50 patients with no graft infection were included as controls. The main variables evaluated in this study included the clinical and microbiological profile, sociodemographic status, suture related problems, persistent epithelial defects, and ocular surface disorders. RESULTS: Cultures were positive in 43 (86%) eyes and Staphylococcus epidermidis (67.4%) was the most common organism isolated. Infection could be resolved with treatment in 37 (74%) eyes. In eight (16%) eyes the graft melted and a repeat penetrating keratoplasty had to be performed. Only 6% of the cases could achieve a best corrected visual acuity of 6/18 or better after resolution of the infection. In multivariate logistic regression analysis persistent epithelial defect (OR (95% CI): 3.0 (1.17 to 8.33)), suture related problems (OR (95% CI): 3.6 (1.39 to 9.25)), and ocular surface disorders (OR (95% CI): 2.4 (0.93 to 6.03)) were found to be statistically significant risk factors for graft infection following an optical penetrating keratoplasty. CONCLUSIONS: Staphylococcus epidermidis is the commonest organism responsible for post-keratoplasty microbial keratitis. Persistent epithelial defects, suture related problems, and ocular surface disorders are the major risk factors predisposing to graft infection.

Adult↗
PubMed2002

Trypan blue assisted phacoemulsification in corneal opacities.

AIM: To evaluate the efficacy of trypan blue for enhancing visualisation during phacoemulsification and foldable lens implantation in cases of cataract with corneal opacities. METHODS: 11 eyes of 11 patients with nebulomacular corneal opacities involving the visual axis with partially and visually debilitating cataract underwent trypan blue assisted phacoemulsification with foldable intraocular lens implantation. The patients were followed at the first day, first week, first month, and third month postoperatively. Completion of capsulorhexis, phacoemulsification with foldable lens implantation, and postoperative best corrected visual acuity were measured. RESULTS: The dye improved visualisation of the anterior capsule and a complete capsulorhexis could be performed successfully in all eyes. In all but one eye phacoemulsification was accomplished successfully. In one eye with Fuchs' dystrophy penetrating keratoplasty was performed later. Visual acuity was < or = 6/60 preoperatively in all eyes and improved to > or = 6/24 in eight eyes postoperatively. CONCLUSION: Trypan blue assisted phacoemulsification may be performed in selected cases of corneal haze/opacification with cataract. It provides acceptable visual outcome in cases awaiting penetrating keratoplasty or in cases where it is not feasible or promising.

Adult↗
PubMed2001

Microkeratome-induced reduction of astigmatism after penetrating keratoplasty.

PURPOSE: To report the reduction in postpenetrating keratoplasty astigmatism with the use of the microkeratome to create a lamellar corneal flap as the first stage in a two-step laser in situ keratomileusis. METHODS: The hansatome microkeratome was used to create a lamellar corneal flap in a 24-year-old man with a net corneal astigmatism of 7.3 diopters, 2 years after penetrating keratoplasty. No laser ablation was performed. RESULTS: The net corneal astigmatism reduced to 3.9 diopters at 1 month and 2.3 diopters at 3 months of follow-up, without any laser ablation. CONCLUSION: Laser in situ keratomileusis may be performed as a two-stage procedure, because the lamellar corneal flap alone may reduce postpenetrating keratoplasty astigmatism.

Adult↗