Accuracy of the refractive prediction determined by multiple currently available intraocular lens power calculation formulas in small eyes.

PURPOSE: To observe the refractive outcomes of cataract surgery in small adult eyes, and to investigate the accuracy of different intraocular lens (IOL) power prediction formulas. DESIGN: Retrospective interventional case series. METHODS: We included consecutive small eyes undergoing uneventful phacoemulsification cataract surgery with a single highly powerful IOL (Acrysof SA60AT) implanted in the capsular bag (range of powers +35.0 to +40.0 diopters [D]), at the Cataract Centre for Moorfields Eye Hospital. Exclusion criteria were combined or previous intraocular surgical procedures, and any type of intraoperative complications. Main outcome measures were mean prediction errors with Hoffer Q, Holladay 1, Holladay 2, Haigis, SRK-T, and SRK-II IOL power prediction formulas and proportions of eyes achieving absolute errors within the dioptric ranges of 0.5, 1.0, and 2.0 D of target and emmetropia, respectively. The ANOVA test was used to compare the refractive results among various formulas. RESULTS: Twenty-eight eyes were studied; the mean numerical error was 0.22 ± 1.22 D and the mean absolute error was 0.95 ± 0.78 D with the adopted Hoffer Q formula; 39%, 61%, and 89% of the eyes had a final refraction within 0.5 D, 1.0 D, and 2.0 D of target, respectively. None of the latest-generation formulas significantly outperformed the others (P = .245). CONCLUSIONS: The Hoffer Q formula led to good or fair refractive outcomes in less than two thirds of the cases. With Holladay 1 and 2 and Haigis formulas, outcomes would have not been significantly different. The SRK formulas yielded less accurate predictions. Possible reasons are discussed.

The toxic effect of air on primary human retinal pigment epithelium cells.

PURPOSE: To investigate the toxic effect of air on primary human retinal pigment epithelium cells (RPE) over time. METHODS: RPE cultures were retrieved from six donor eyes and cultivated at 37 °C in 5% CO(2) and 95% humidified air. The RPE were divided in six groups with each group containing four samples. Six groups of RPE cultures were set up and four samples were enclosed in each group: group 1 consisted of samples in which RPE were exposed to air for 1 hour. Group 2 consisted of RPE exposed to air for 3 hours, group 3 for 6 hours group 4 for 12 hours group 5 for 24 hours and group 6 for 36 hours respectively. RESULTS: Six hours after exposure, the morphology of the cells was still intact. At 12 hours few cells appeared enlarged. 24 hours after exposure to air the cells started losing their typical morphology and appeared deformed. Viability was higher than 95% in groups 1-3 while for groups 4-6 was 75.5%, 15.5% and 7.3%, respectively. CONCLUSION: The toxic effect of air for the studied in vitro model of RPE is not significant for the first 6 hours. The morphology of the cells progressively changed after 12 hours of exposure and almost all cells appeared apoptotic at 36 hours.

Complications and outcomes of phacoemulsification cataract surgery complicated by anterior capsule tear.

PURPOSE: To study the results of phacoemulsification cataract surgery complicated by anterior capsule tear. DESIGN: Retrospective interventional controlled case series. METHODS: Consecutive series of eyes suffering intraoperative anterior capsule tear and others with uneventful cataract surgery at Moorfields Eye Hospital were investigated. Biometric, intraoperative, and postoperative details were recorded. The exclusion criteria were combined surgical procedures, planned manual extracapsular cataract extraction, and history of previous intraocular surgery or eye trauma. The main outcome measures were intraoperative capsule complication rates, refractive and visual outcomes, and incidence of short-term postoperative complications. Two-sided Fisher exact and paired t tests were used for categorical and continuous data, respectively. RESULTS: The study and control groups included 239 and 212 eyes, respectively. In the study group, planned phacoemulsification was converted to manual extraction in 5 cases (2%); a concurrent posterior capsule rupture occurred in 58 eyes (24%) with a rate of nuclear lens material drop in the posterior segment of 5% (11 cases). Over 11% of eyes (n = 27) underwent unplanned secondary surgical procedures. Overall, the refractive outcomes were poor in 22.4% of eyes (postoperative refraction ≥1 diopter of target), and were statistically worse (P < .0001). A significant visual improvement was observed in the majority of the study group eyes (71%); permanent visual loss occurred in 4 eyes (1.7%). CONCLUSIONS: Anterior capsule tear can lead to additional intraoperative complications, with a relatively high incidence of secondary interventions. Overall, permanent visual loss can be observed and worse refractive outcomes are to be expected, particularly if the lens is being implanted out of the bag.

Phacoemulsification using 8 flexible iris hooks in a patient with a short eye, small pupil, and phacodonesis.

UNLABELLED: We describe a technique that uses flexible iris hooks to dilate and stabilize the capsular bag in a patient with a very deep set and small eye, narrow palpebral fissure, shallow anterior chamber, and very small pupil, who was scheduled for routine phacoemulsification for a white cataract. At the time of iris hook placement, the capsular bag was noted to be markedly unstable. The patient was managed successfully with phacoemulsification of the lens using 4 iris hooks to dilate the pupil and 4 iris hooks to stabilize the capsular bag during surgery. A foldable posterior chamber 3-piece intraocular lens was fixated in the ciliary sulcus. FINANCIAL DISCLOSURE: Neither author has a financial or proprietary interest in any material or method mentioned.

Cataract surgery in small adult eyes.

AIM: To evaluate the clinical outcomes of phacoemulsification cataract surgery in microphthalmos. METHODS: Retrospective consecutive case series of eyes with axial length <20.9 mm, and requiring a high intraocular lens (IOL) power (≥30 or ≥35 dioptres for anterior or posterior chamber fixation, respectively), with no history of previous ocular surgery, and undergoing planned phacoemulsification cataract surgery with IOL implantation at Moorfields Eye Hospital was investigated to observe the incidence of intraoperative and postoperative complications. RESULTS: During a 5-year study period, 47 of 22,093 eyes were treated in two locations (0.21%). Thirty-nine eyes met the study inclusion criteria. No serious intraoperative adverse events were recorded. Severe postoperative complications (retinal detachment and chronic postoperative uveitis) occurred in two cases. The postoperative corrected distance visual acuity (CDVA) was logMAR 0.30 or better in 24 eyes (62%), and only three eyes obtained worse vision. The overall ocular comorbitidy rate was 53%; 10 microphthalmic eyes (26%) presented with associated congenital or hereditary pathology, and had worse visual outcomes (p<0.0001). CONCLUSIONS: Microphthalmic eyes requiring high IOL power are rare, and their presence is often associated with other ocular congenital or acquired disorders. Overall, the clinical outcomes were satisfactory and the surgical procedure affected by a low complication rate.