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Background/objectives: Posterior Capsule Opacification (PCO) is the most common long-term post-operative adverse occurrence after cataract surgery often requiring treatment with YAG laser posterior capsulotomy. This study aimed to identify potential risk factors, known at the time of cataract surgery, that influence the development of PCO., Subject/methods: A retrospective study of publicly funded cataract surgery from The Royal College of Ophthalmologists' National Ophthalmology Database. Eligible for analysis were 500,872 cataract operations performed in 41 participating centres., Results: The 500,872 operations were performed on 243,167 (48.5%) left eyes and 257,705 (51.5%) right eyes from 373,579 patients by 2196 surgeons. Post-cataract PCO was recorded for 61,778 (12.3%) eyes and the six month, one, three, five and nine year observed rates of PCO were 2.3%, 4.4%, 19.7%, 34.0% and 46.9% respectively. Different PCO profiles were observed between IOL materials and the identified risk factors that increased the risk of developing PCO included hydrophilic IOL material, axial length >26 mm, the presence of high myopia and implantation of lower IOL powers and previous vitrectomy surgery, along with younger age and female gender., Conclusions: Many factors influence the development of PCO relating to the patient, the eye, the lens and the surgery. Some factors are modifiable such as IOL material, therefore the opportunity exists to attempt to reduce PCO rates, benefitting patients and the UK NHS., (© 2022. The Author(s), under exclusive licence to The Royal College of Ophthalmologists.)

Objective: To define theoretical correction factors for second-eye intraocular lens (IOL) power adjustment based on first eye refractive prediction error (PE)., Design: Database study., Participants: We included 2129 patients who underwent bilateral sequential phacoemulsification cataract surgery with the same IOL model., Methods: Retrospectively calculated PEs (Hoffer Q, Holladay 1, SRK/T) were analyzed for association between paired eyes, examining the effect of interocular differences in axial length (AL) and corneal power. A range of correction factors (CF) derived from the first eye PE were applied to the second eye PE using optimized and non-optimized IOL constants (IOLCs)., Main Outcome Measures: Second eye mean absolute error (MAE)., Results: Prediction errors of paired eyes were correlated. Interocular corneal power differences exceeding 0.60 diopters (D) were associated with a weaker correlation but interocular AL differences did not affect the correlation. When a 50% CF was applied to second eyes of patients with a first eye PE between ±0.50 and ±1.50 D, it improved refractive outcomes from 30%, 56%, and 92% to 42%, 75%, and 96% within ±0.25 D, ±0.50 D and ±1.00 D, respectively, and reduced the MAE from 0.49 to 0.37 D (P<0.0001). For first eye PE below ±0.50 D, a 50% CF reduced the MAE from 0.32 to 0.30 D (P<0.00001). A 50% CF also reduces second eye MAE for eyes with nonoptimized IOLCs., Conclusions: A 50% CF reduces second eye PE when either first eye optimized PE is within ±1.50 D or when nonoptimized IOLCs are used. The correlation is weaker when interocular corneal power differences are >0.60 D., (Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Purpose: To assess the benefits of intraocular lens (IOL)-constant optimization for IOLMaster biometry on refractive outcomes after cataract surgery for all surgeons and individual surgeons, define acceptable levels of error in IOL-constant optimization, and calculate the minimum number of eyes required for IOL-constant optimization., Setting: Department of Ophthalmology, Gloucestershire Hospitals NHS Foundation Trust, Cheltenham, United Kingdom., Design: Database study., Methods: Hypothetical prediction errors were retrospectively calculated on prospectively collected data extracted from electronic medical records using manufacturers' and optimized IOL constants with Hoffer Q, Holladay 1, and SRK/T formulas for 2 IOLs. The acceptable IOL-constant optimization error margins, personalized IOL constants for individual surgeons, and minimum sample sizes for IOL-constant optimization were evaluated., Results: Optimization of IOL constants reduced the mean absolute errors from 0.66 diopters (D) and 0.52 D to 0.40 D and 0.42 D for the Sofport AO IOL and Akreos Fit IOL, respectively. The percentage of eyes within ±0.25 D, ±0.50 D, and ±1.00 D of target refraction improved from for both IOL models. The IOL-constant errors exceeding 0.09 for the Hoffer Q, 0.09 for the Holladay 1, and 0.15 for the SRK/T produced inferior outcomes. Differences in personalized IOL constants between most surgeons were clinically insignificant. Calculating IOL constants to within 0.06, 0.06, and 0.10 for the Hoffer Q, Holladay 1, and SRK/T, respectively, required 148 to 257 eyes., Conclusions: Optimizing IOL constants for IOLMaster biometry substantially improved refractive outcomes, far exceeding any additional benefit of personalizing IOL constants for individual surgeons., Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes., (Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.)

Purpose: To assess how intraocular lens (IOL) formula choice affects refractive outcomes after cataract surgery using IOLMaster biometry., Setting: Department of Ophthalmology, Gloucestershire Hospitals NHS Foundation Trust, Cheltenham, United Kingdom., Design: Database study., Methods: Hypothetical prediction errors were retrospectively calculated on prospectively collected data from electronic medical records using optimized Hoffer Q, Holladay 1, and SRK/T formulas (Sofport AO and Akreos Fit IOLs) across a range of 0.5 mm or 1.0 mm axial length (AL) subgroups., Results: In short eyes, the Hoffer Q had the lowest mean absolute error (MAE) for ALs from 20.00 to 20.99 mm. The Hoffer Q and Holladay 1 had a lower MAE than the SRK/T for ALs from 21.00 to 21.49 mm. There were no statistically significant differences in MAE for ALs from 21.50 to 21.99 mm. In medium eyes, there were no statistically significant differences in MAE for any IOL formula for ALs from 22.00 to 23.49 mm. For ALs from 23.50 to 25.99 mm, there was a trend toward lower MAEs for the Holladay 1, with statistically significant differences in 2 subgroups. In long eyes, the SRK/T had the lowest MAE, with statistically significant differences for ALs of 27.00 mm or longer., Conclusions: The Hoffer Q performed best for ALs from 20.00 to 20.99 mm, the Hoffer Q and Holladay 1 for ALs from 21.00 to 21.49 mm, and the SRK/T for ALs of 27.00 mm or longer. Using optimized constants, refractive outcomes of 40%, 75%, and 95% within ±0.25 diopter (D), ±0.50 D, and ±1.00 D, respectively, were achievable., Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes., (Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.)

Purpose: Calculation of intraocular lens (IOL) power for implantation during cataract surgery depends on ocular biometric measurements. The aim of this study was to characterise the normal range of intra- and interindividual variation in axial length (AL) and corneal power (K) when IOLMaster measurements were possible and to derive recommendations as to which outlying measurements merit verification before acceptance., Methods: The Medisoft electronic patient database contains prospectively collected data conforming to the United Kingdom (UK) Cataract National Dataset on 55,567 cataract operations. From this AL and K information on the 32,556 eyes (14,016 paired) of patients older than 25 years, without corneal pathology, history of intraocular surgery and who had all biometric measurements taken with the Zeiss IOLMaster (Carl Zeiss Meditec) were extracted. R 2.8.1 (R Foundation for Statistical Computing) was used for statistical analysis., Results: Mean age was 76.4 years and 62.0% were female. Mean (95% confidence interval) values for AL, mean K and corneal astigmatism were 23.40 (21.27-26.59) mm, 43.90 (40.94-47.01) D and 1.04 (<2.50) D. Nearly all astigmatism was either with or against the rule. Differences between paired eyes were not statistically significant. 95% individuals had asymmetry of AL and mean K<0.70 mm and 0.92 D, respectively., Conclusions: On the basis of approximation of the 95% CI above, it is suggested that AL, mean K and keratometric astigmatism measurements outside the ranges 21.30-26.60 mm, 41.00-47.00 D and >2.50 D, respectively, and intraindividual asymmetry of AL >0.70 mm or mean K>0.90 D should be verified before acceptance.

Aim: To describe the ultrastructural appearance of explanted opacified Hydroview H60M intraocular lenses., Methods: 14 explanted lenses were examined by scanning electron microscopy, and their appearance compared with a non-implanted H60M lens from the same time period. Wavelength-dispersive x ray spectroscopy (WDX) was performed on two opacified lenses., Results: Subsurface deposits were seen in all explanted opacified lenses. These deposits broke only onto the surface of more densely opacified lenses. WDX confirmed that the deposits contained both calcium and phosphorous, consistent with their being calcium apatite., Conclusion: These findings challenge the widely accepted opinion that H60M intraocular lens opacification begins on the surface of the optic.