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Biomedical subjects

V K Dada

Publications and source records attributed to V K Dada.

At least 19 recordsLinked to original sources

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↗

A population-based eye survey of older adults in a rural district of Rajasthan: II. Outcomes of cataract surgery.

PURPOSE: To assess the outcomes of cataract surgery in rural northwest India. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: A total of 549 cataract-operated persons (723 operated eyes). METHODS: Cluster sampling was used in randomly selecting a cross-sectional sample of persons 50 years of age or older for visual acuity measurement, refraction, and slit-lamp and direct ophthalmoscope examination early in 1999. Those operated on for cataract were queried as to the date and place of surgery. The principal cause of reduced vision was identified for all examined eyes with presenting visual acuity worse than 6/18. MAIN OUTCOME MEASURES: Presenting and best-corrected visual acuity and cause of vision loss. RESULTS: Presenting visual acuity was less than 6/60 in the better eye in 33.7% of cataract-operated persons and greater than or equal to 6/18 in both eyes in 8.2%; 31.7% were bilaterally operated on. Of cataract-operated eyes, 44.1% initially had visual acuity less than 6/60 and 31.5% greater than or equal to 6/18; with best correction, the corresponding percentages were 14.0% and 61.5%. Intracapsular cataract extraction was used in 92% of cases, and 66% had been operated on in surgery camps. Surgical complications were common and a major cause of vision impairment. In multiple logistic regression modeling, female gender and residence in a rural area were associated negatively with both presenting and best-corrected visual acuity outcomes, and surgery conducted before 1990 was associated negatively with best-corrected visual acuity. Place of surgery and subject schooling were not associated with vision outcomes. CONCLUSIONS: Cataract surgery subjects in rural areas of India that are without adequately equipped facilities and skilled surgeons, and lack of availability of intraocular lenses, are not realizing the full sight-restoring potential of modern-day surgery. Emphasis on the quality of cataract surgery outcomes must be increased to keep pace with that being given to increasing surgical volume.

Aged↗

A population-based eye survey of older adults in a rural district of Rajasthan: I. Central vision impairment, blindness, and cataract surgery.

PURPOSE: To assess the prevalence of central vision blindness and cataract surgery in older adults in rural northwest India. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: A total of 4284 examined persons 50 years of age or older. METHODS: A random selection of village-based clusters was used to identify a population sample in the predominantly rural Bharatpur district of Rajasthan. Eligible subjects in the 25 selected clusters were enumerated through a door-to-door household survey and invited to village sites for visual acuity testing and eye examination early in 1999. The principal cause of reduced central vision was identified for eyes that had visual acuity worse than 6/18. Independent replicate testing for quality assurance monitoring took place in participants with reduced vision and in a sample of those with normal vision in five of the study clusters. MAIN OUTCOME MEASURES: Presenting and best-corrected visual acuity and lens status. RESULTS: A total of 4728 eligible persons in 2821 households were enumerated, and 4284 (90.6%) were examined. The prevalence of presenting and best-corrected visual acuity worse than 6/60 in both eyes was 11.9% (95% confidence interval: 10.0%-13.9%) and 6.1% (95% CI: 4.7%-7.4%), respectively. Presenting blindness was associated with increasing age, female gender, lack of schooling, and rural residence. Cataract was the principal cause of blindness in one or both eyes in 67.5% of blind persons, with uncorrected aphakia and other refractive error affecting 18.4% in at least one eye. The prevalence of cataract surgery was 12.8% (95% CI: 11.6%-14.0%), with an estimated 65.7% of the cataract blind operated on; low surgical coverage was associated with lack of schooling. CONCLUSIONS: Blindness, particularly blindness because of cataract, continues to be a significant problem among the elderly living in remote areas of rural northwest India. Increased attention should be given to reaching women and the illiterate.

Age Factors↗

Phacoemulsification combined with silicone oil removal through a posterior capsulorhexis.

PURPOSE: To evaluate the technique of silicone oil removal through a posterior capsulorhexis combined with phacoemulsification and intraocular lens (IOL) implantation. SETTING: Dr. Rajendra Prasad Center for Ophthalmic Sciences, New Delhi, India. METHODS: Fifteen eyes of 15 patients had phacoemulsification with removal of silicone oil, which had been used for intraocular tamponade after a previous pars plana vitrectomy. Eyes with a stable retina were included in the series. In all eyes, the silicone oil was removed through a planned posterior capsulorhexis after phacoemulsification. The parameters evaluated were the primary diagnosis, duration between silicone oil instillation and phacoemulsification, type of cataract, preoperative and postoperative best corrected visual acuities (BCVAs), and complications such as frequency of retinal redetachment and secondary cataract. RESULTS: Vitreoretinal surgery with silicone oil instillation was performed for rhegmatogenous-tractional detachment resulting from Eales' disease in 6 eyes and from proliferative diabetic retinopathy in 2 eyes, for primary rhegmatogenous retinal detachment in 6 eyes, and for traumatic rhegmatogenous detachment in 1 eye. The mean duration between the silicone oil instillation and phacoemulsification was 7.5 months +/- 3.8 (SD). Fourteen eyes had posterior subcapsular cataract, and 10 had nuclear sclerosis. Preoperative BCVA was worse than 6/60 in all eyes. The BCVA was 6/60 or better in 9 eyes after a minimum follow-up of 6 months. Two eyes had choroidal detachment in the early postoperative period. No eye had vitreous hemorrhage, retinal redetachment, secondary cataract, clinically significant endothelial decompensation or macular edema, or a dislocated IOL. CONCLUSION: The results indicate that silicone oil removal through a posterior capsulorhexis during phacoemulsification is a viable option and can be performed in selected cases of cataract with previous silicone oil instillation and a stable retina.

Adolescent↗

Bimanual Sinskey hook technique to enlarge a preexisting capsulorhexis.

We describe a technique of enlarging a small primary capsulorhexis. Two Sinskey hooks are introduced through the side ports. One hook is placed above the anterior capsulorhexis margin with its tip pointing down, and the other is placed beneath the anterior capsulorhexis margin with its tip pointing up. A small nick is made between the tips of the 2 hooks, and the capsulorhexis is extended with a Utrata capsulorhexis forceps. This technique does not require additional instrumentation, impart zonular stress, or disturb wound architecture or integrity.

Capsulorhexis↗

The use of a newspaper insertion to promote DIY testing of vision in India.

BACKGROUND: The mass media have the potential to motivate people to participate in self appraisal of their own health status. An innovative communication package was designed to help people to examine vision at home. The impact of publishing the "do it yourself" (DIY) kit in Indian newspapers was evaluated. METHODS: A pretested bilingual vision testing kit was published in three newspapers. The kit comprised four tumbling Es corresponding to 6/12 line of Snellen's optotypes. Directions on using the kit were enclosed. 3 -7 days after publication of the kit, a telephone survey of newspaper readers was undertaken to evaluate the impact and cost effectiveness. RESULTS: 603 people were contacted over the telephone. 125 (20.73%) subscribed to the newspaper carrying the DIY insertion. 43.2% (54) noticed the insertion of which 88.89% (48) read the enclosed instructions carefully. 58.33% respondents felt sufficiently motivated to contact an ophthalmologist. Graduates had a 3.83 times higher probability of reading the communication insertion compared with others. Differences in relation to other demographic variables were not statistically significant. CONCLUSIONS: Newspapers are an excellent medium for communicating self appraisal kits for vision testing. The medium is cost effective and has significant reach in the urban agglomerates of India.

Adolescent↗

Visual performance of rigid gas permeable contact lenses in patients with corneal opacity.

PURPOSE: To evaluate the visual performance of rigid gas permeable (RGP) contact lenses in patients with nebular and nebulo-macular corneal opacity and correlate the improvement in visual acuity with other visual parameters. METHODS: In a prospective study, visual performance of RGP contact lenses was evaluated in eyes with corneal opacity involving the pupillary area. The baseline visual acuity and other visual parameters with glasses were compared with those recorded with RGP contact lenses. The visual functions evaluated were visual acuity, contrast sensitivity, glare acuity, and mesopic vision. Binocular status with RGP contact lenses was assessed. All patients were followed up for 3 months. RESULTS: Twenty-eight eyes (26 patients) with nebular or nebulo-macular corneal opacity were included in this study. All eyes (100%) achieved significantly better visual performance with RGP contact lenses than with glasses (P< 0.0020). Visual acuity of 6/9 or better was achieved in 50% of patients with RGP contact lenses compared to none with glasses. RGP contact lenses improved the visual acuity by 0.27 decimals over the baseline value with glasses, butthe improvement for mesopic vision and glare acuity was significantly lower at 0.15 and 0.06 decimals respectively. Similarly, contrast sensitivity did not improve to the same extent as visual acuity. Stereopsis was present only in patients with best corrected visual acuity of 6/9 or better with RGP lenses. CONCLUSION: RGP contact lenses improved the visual acuity and other visual performance in patients with reduced vision due to nebular or nebulo-macular corneal opacity. However, contrast sensitivity, glare acuity, and mesopic vision did not improve to the same extent as visual acuity.

Adolescent↗

Cataract in enucleated goat eyes: training model for phacoemulsification.

We developed an inexpensive, reproducible technique of inducing cataract in enucleated animal eyes for phacoemulsification training. Injection of 0.3 to 0.5 mL of formalin 20% in the central and paracentral portion of the crystalline lens in a goat's eye induced cataract in about 5 to 10 minutes. Varying the interval would enable novice surgeons to practice different techniques of phacoemulsification based on cataract hardness.

Animals↗

Phaco-chop versus stop-and-chop nucleotomy for phacoemulsification.

PURPOSE: To perform a comparative evaluation of phaco-chop versus stop-and-chop nucleotomy techniques of phacoemulsification. SETTING: Dr. Rajendra Prasad Center for Ophthalmic Sciences, New Delhi, India. METHODS: Forty eyes of 40 patients with immature senile cataract were included in the study. Twenty eyes each were randomly assigned to have phaco-chop (Group 1) or stop-and-chop (Group 2) nucleotomy during phacoemulsification. The main parameters were corneal endothelial count, effective phaco time, volume of infusion fluid used, central corneal pachymetry, best corrected visual acuity (BCVA), and intraoperative complications during nucleotomy. Follow-up visits were scheduled at 1, 4, and 12 weeks. RESULTS: The mean effective phaco time was 27 seconds +/- 18 (SD) in Group 1 and 28 +/- 16 seconds in Group 2. The mean corneal endothelial cell loss was 6.89% and 7.17%, respectively, at the end of 12 weeks. The difference between groups was not significant. An anterior capsule tear occurred in 3 eyes in Group 1 and 1 eye in Group 2. All eyes achieved a BCVA of 20/20 at the end of 4 weeks. There were no significant between-group differences in any intraoperative or postoperative parameter. CONCLUSIONS: The phaco-chop and the stop-and-chop nucleotomy techniques were equally efficacious for nuclear management during phacoemulsification.

Cell Count↗

Pneumococcal keratitis after laser in situ keratomileusis.

A 20-year-old man developed keratitis in his right eye 2 days after laser in situ keratomileusis (LASIK). The patient had rubbed the eye with unclean fingers the night before the onset of symptoms. Examination showed an inferior corneal ulcer with dense infiltration at the junction of the lamellar flap and the surrounding cornea associated with a hypopyon. Streptococcus pneumoniae was isolated on culture. The ulcer resolved with combination therapy of cephazolin 5% and tobramycin 1.3% eyedrops. Patients having LASIK should be instructed that inadequate patient hygiene may predispose to bacterial keratitis.

Adult↗

Primary posterior capsulorhexis with optic capture and intracameral heparin in paediatric cataract surgery.

PURPOSE: To study the efficacy of using a primary posterior capsulorhexis with optic capture and intracameral heparin in preventing secondary posterior capsule opacification, in paediatric cataract surgery. METHODS: Primary posterior capsulorhexis and optic capture with a heparin-coated intraocular lens (IOL) was performed after lens aspiration in 14 cataractous eyes of 13 children (group I). Ten international units of heparin were added in the irrigating solution. The results were compared with 14 eyes of 11 children who underwent a similar surgical procedure but without a posterior capsulorhexis (group 2). RESULTS: The mean age of the patients in group I was 4.2+/-1.5 years (mean +/- SD) and in group 2 was 4.5+/-1.8 years (range 3-6 years in both the groups). The mean duration of follow up was 36+/-6.4 months in group I and 38+/-8.1 months in group 2. A best corrected visual acuity of 6/24 or better was achieved in 12 eyes in group I and II eyes in group 2. The visual axis remained clear in all the eyes in group I, while 8 eyes (57.14%) in group 2 developed posterior capsule opacification (P = 0.0034) which required a neodymium:yttrium-aluminum-garnet laser capsulotomy. CONCLUSIONS: Lens aspiration using intracameral heparin, combined with primary posterior capsulorhexis and optic capture of a heparin-coated IOL, is a useful technique to prevent secondary visual axis opacification in paediatric cataracts.

Anterior Chamber↗

Acute haemorrhagic keratoconjunctivitis following laser in situ keratomileusis.

We report two cases of acute haemorrhagic keratoconjunctivitis which occurred following laser in situ keratomileusis (LASIK) during an ongoing epidemic. Both cases underwent preoperative investigation and surgery on the same day. The possible sources of contamination include the paramedical staff, the contact instruments used for performing preoperative investigation, surgeon, nurse, surgical instruments and eye drops. However, the flap was intact with no haze or regression and at 1 year follow up, the visual acuity was maintained at 6/6 in both the patients. We recommend greater caution while performing contact investigations and strict surgical asepsis during LASIK surgery, routinely as well as during epidemics of conjunctivitis.

Acute Disease↗