Fellow eye treatment in excimer photo refractive keratectomy.

PURPOSE: To describe symmetry of response in fellow eyes of patients undergoing photorefractive keratectomy (PRK) for myopia, analyse the risk factors leading to asymmetry in response and to determine if delayed treatment of the second eye increases safety and predictability of PRK. METHODS: Retrospective review of case records of 133 patients who underwent bilateral myopic PRK and had a minimum follow up of 6 months in both eyes. RESULTS: Postoperative uncorrected visual acuity, spherical equivalent (SE) refraction within +/- 1 D of emmetropia, best-corrected visual acuity (BCVA) and corneal haze were not significantly different in fellow eyes of patients undergoing PRK for myopia. Of 87 eyes in group 1 (myopia < 6 D), 96.6% had uncorrected visual acuity > or = 6/12, 89.7% were within +/- 1 D of emmetropia, none lost > or = 1 line BCVA, and none had haze > or = grade 3. Similar results for 98 eyes in group II (myopia 6 to 9.9 D) were 75.6%, 55.1%, 2.0% and 2.0% respectively. For 81 eyes in group III (myopia > or = 10 D) the results were 42.7%, 33.3%, 8.6%, and 4.9% respectively. Among 84 patients with similar preoperative myopia in both eyes, 54 (64.3%) patients had a postoperative SE difference < or = 1 D in fellow eyes. Risk factors for asymmetric response among fellow eyes included increasing preoperative myopia (p < 0.001) and dissimilar treatment technique in the two eyes (p = 0.03). Corneal haze did not increase significantly after the third postoperative month. CONCLUSION: This study demonstrates that considerable symmetry of response exists in fellow eyes of patients undergoing myopic PRK. Early PRK in the fellow eye of patients with < 6 D myopia is safe and allows quick visual rehabilitation of the patient. In patients with myopia > or = 6 D, a 3-month interval before treating the second eye may improve the safety of the procedure.

pH-adjusted periocular anaesthesia for primary vitreoretinal surgery.

PURPOSE: To evaluate the efficacy of pH-adjusted bupivacaine in conjunction with medial orbital periconal block (periocular anaesthesia). METHODS: Sixty consecutive patients undergoing primary vitreoretinal surgery were enrolled prospectively. RESULTS: Adequate anaesthesia and akinesia with no intraoperative supplementation was achieved in 53 eyes (88.3%). Factors influencing intraoperative supplementation were combined vitrectomy with scleral buckling (p = 0.005) and duration of surgery of more than 2 hours (p = 0.001). No ocular or systemic complication resulted. CONCLUSION: pH-adjusted periocular anaesthesia is safe and effective in patients undergoing primary vitreoretinal surgery.

Conjunctival-limbal autografts for primary and recurrent pterygia: technique and results.

Our technique of pterygium excision with conjunctival-limbal autografting is described and the safety and efficacy of the procedure in India is analysed. Case records of 51 consecutive patients (53 eyes) who underwent surgery at our institute between November 1992 and September 1994 were retrospectively analysed. Recurrence was defined as fibrovascular tissue crossing the corneoscleral limbus onto clear cornea in the area of previous pterygium excision. 2 (3.8%) of the 53 pterygia (primary 36; recurrent 17) recurred, after a mean follow up of 18.9 +/- 12.1 months (range: 1.5-43 months). Both recurrences occurred within a year of follow up, in patients who were < or = 40 years of age. No major operative or postoperative complications were encountered. The inclusion of limbal tissue in conjunctival autografts following pterygium excision appears to be essential to ensure low recurrence rates. The technique is safe, simple and inexpensive and is recommended for the management of both primary and recurrent pterygia in Indian eyes.

Microbiological assay of ampicillin in serum and aqueous humor of patients given ampicillin-sulbactam injection.

The aim of this study was to determine the bacterial growth inhibitory activities of ampicillin in aqueous humor and serum of patients administered ampicillin-sulbactam combination intramuscularly prior to cataract surgery. 43 patients received a combination of both antibiotics intramuscularly at varying periods (60-140 minutes) prior to surgery. Aqueous humor and venous blood were collected at the beginning of the surgery. For microbiological assay, spores of Bacillus subtilis were incorporated in the agar. The test sample and the standard solutions (calibrators) of ampicillin and ampicillin-sulbactam combination were placed in 3 mm wells in the agar. The diameter zones of growth inhibitory activities of ampicillin of the calibrators and the test samples measured in mm were extrapolated to the standard curve and were recorded as ampicillin activity in micrograms/ml. The results of the assay were placed in 5 groups according to the time intervals between injection and collection of serum and aqueous humor (< or = 70, 75, 80, 90, > 90 minutes). Ampicillin activities in sera and aqueous humor of group 5 (> 90 minutes) were significantly higher than the others (p < 0.001). The ratio of ampicillin activities of sera and aqueous humor in group 5 patients was significantly lower indicating higher concentration of ampicillin activity in aqueous humor during this period. Bacterial growth inhibitory activities of ampicillin-sulbactam combination were adequate in aqueous humor of all patients with highest activity being 90 minutes after intramuscular administration indicating the potential usefulness of this antibiotic combination as chemoprophylaxis prior to cataract surgery.

Endophthalmitis caused by anaerobic bacteria.

A retrospective analysis of 22 patients who underwent pars plana vitrectomy for endophthalmitis and had culture-proven anaerobic bacteria, was done. Elimination of infection with attached retina and recovery of ambulatory vision > or = 2/60 were considered as anatomic success and functional success, respectively. Mean follow-up period was 12.7 months (range, 2 to 48 months). Anatomic success was attained in 14 (63.6%) eyes and functional success in 12 (54.6%) eyes. A poor preoperative visual acuity was found to be associated with poor functional outcome (p < 0.046). In endophthalmitis, a routine anaerobic culture of intraocular specimen is recommended.