Outcomes of penetrating keratoplasty for macular corneal dystrophy.

PURPOSE: To report the outcomes of penetrating keratoplasty (PKP) in patients with macular corneal dystrophy (MCD). METHODS: This retrospective case series includes consecutive patients with MCD who underwent PKP from 1986 to 2006 with at least 6 months' follow-up. Main outcome measures included best spectacle-corrected visual acuity (BSCVA), postoperative astigmatism and graft survival. RESULTS: Sixty-two eyes of 39 patients with mean age of 34.0±10.5 (range 13-58) years at the time of keratoplasty were included for analysis. After a mean follow-up period of 52.0±47.3 (range 6-190) months, BSCVA improved from 1.4±0.4 logMAR (4/100) preoperatively to 0.2±0.3 logMAR (20/32) at final follow-up (P<0.001).Mean postoperative BSCVA was 0.15±0.40 logMAR in patients (36 eyes) aged less than 35 years at the time of surgery as compared to 0.26±0.25 logMAR in subjects (26 eyes) older than 35 years (P=0.005). Final astigmatism was comparable with different suturing techniques including separate, continuous, and combined sutures (P=0.9). All grafts were clear at final follow-up except a single case of MCD with visually insignificant recurrence.Episodes of immunologic graft rejection occurred in 12 eyes (19.4%) but none led to graft failure. CONCLUSION: PKP for MCD entails favorable outcomes in terms of graft survival and visual improvement. Final visual acuity seems to be better when transplantation is performed before the age of 35 years.

Risk Factors for Posterior Capsule Rupture and Vitreous Loss during Phacoemulsification.

PURPOSE: To determine the rate and risk factors of vitreous loss during phacoemulsification in patients with cataracts operated by ophthalmology residents and fellows at Labbafinejad Medical Center. METHODS: This prospective descriptive study included consecutive patients with cataracts undergoing phacoemulsification over a one year period. All patients were operated under local or general anesthesia using the divide and conquer technique. Preoperatively, all patients underwent a complete ocular examination including measurement of visual acuity, slitlamp biomicroscopy, intraocular pressure measurement, and dilated funduscopy. Main outcome measures included the rate of posterior capsular rupture and vitreous loss as well as associated risk factors such as surgical experience, ocular and systemic conditions, and type and severity of the cataract. RESULTS: Overall, 767 eyes of 767 patients with mean age of 63.7±10.3 (range, 25-91) years were operated. The overall rate of vitreous loss was 7.9% which was 5-fold greater in the hands of residents as compared to fellows. Among different factors, older age, female sex, small pupil, small capsulorrhexis, presence of pseudoexfoliation, and high myopia were significantly associated with vitreous loss. The highest rate of vitreous loss occurred in patients with dense nuclear cataracts. CONCLUSION: Considering the higher rate of vitreous loss in patients operated by ophthalmology residents; patients with known risk factors for vitreous loss should better be operated by more experienced surgeons.

Penetrating keratoplasty in young children with congenital hereditary endothelial dystrophy.

PURPOSE: To report the visual results and success rate of penetrating keratoplasty (PKP) in a series of young children with congenital hereditary endothelial dystrophy (CHED). METHODS: This is a retrospective study on twenty-four eyes of 15 patients (seven male and eight female) operated on for CHED. Children less than 12 years of age at the time of surgery who were followed for at least 6 months were recalled. Characteristics of the patients, indications for PKP, final visual outcome, and graft clarity were evaluated. The following tests were employed: McNemmar test for evaluating visual results, Kaplan-Meyer analysis for determination of graft survival, and Mann-Whitney U test for evaluating the relationship between visual outcome and age at PKP. RESULTS: Patients' age at diagnosis and at initial PKP was 6.5 +/- 3.6 and 8.1 +/- 2.5 years, respectively. Follow-up period was 35.5 +/- 36.2 months. Visual acuity could be evaluated by Snellen chart in 19 eyes. Preoperative visual acuity was less than 20/80 in all of these. Postoperatively, visual acuity was less than 20/80 in nine eyes (47.4%) (P < 0.002). Visual acuity improved in 18 (94.7%) of 19 eyes. There was no relationship between age at initial PKP and final visual outcome (P = 0.35). At the last examination (24 grafts), 19 were clear (79.1%), two were hazy (8.3%), and three were opaque (12.5%). Allograft rejection was seen in 10 eyes (43.4%), seven of which were endothelial. Excluding one case of trauma, all graft failures resulted from endothelial rejection. The probability of primary graft survival was 88% at 3 years and 74% at 5 years. CONCLUSION: Regarding the difficulties in pediatric keratoplasty and the absence of a relationship between postoperative visual outcome and age at keratoplasty, a conservative approach and careful risk-benefit ratio evaluation are recommended in patients with CHED.