Comparison Of Intraocular Lens Power Formulae In A Population With Equally Weighted Intraocular Lens Powers
Published 2026 - 44th Congress of the ESCRS
Reference: FP13.08 | Type: Free paper | DOI: 10.82333/6288-1e66
Authors: Dr Lin Ru Koong* 1 , Dr Aaron Ng 2 , Dr Tun Kuan Yeo 3
1NHG Eye Institute,Singapore,Singapore;Ophthalmology,Tan Tock Seng Hospital ,Singapore,Singapore, 2NHG Eye Institute,Singapore,Singapore;Tan Tock Seng Hospital ,Singapore,Singapore, 3NHG Eye Institute,Singapore,Singapore;Tan Tock Seng Hospital,Singapore,Singapore;Eye and Retina Surgeons,Singapore,Singapore
Purpose
To report the performance of intraocular lens (IOL) power formulae in a population of eyes with evenly distributed IOL powers so that the performance of extreme IOL powers are taken into account.
Setting
Tertiary healthcare institution
Methods
Retrospective review of 390 eyes after uncomplicated cataract surgery, implanted with the Tecnis one-piece IOL. We included 10 eyes of each power from +8.0D to +27.0D. Pre-operative biometric data and manifest refraction from at least one-month post-surgery was obtained. Formulae assessed were Barrett Universal II(BUII), Cooke K6, EVO2.0, Hill RBF 3.0, PEARL-DGS. Two variants of EVO2.0 were evaluated: a standard formula using manual A-constant input (EVO), and an adjusted formula utilizing the Tecnis IOL option (EVO(Tecnis)). Constants were optimized to a mean error of 0. Outcomes were assessed with the Eyetemis tool and with regards to axial length, average keratometry and IOL power.
Results
For threshold of absolute SEQ-PE within 0.5D, the best performing formulae were EVO(Tecnis)(85.6%), EVO (85.4%) and Hill-RBF 3.0(84.9%). For precision (Precision of SEQ-PE), the best performing formulae (trimmed mean) were EVO(Tecnis)(0.240), BUII (0.245) and EVO(0.248). For accuracy (absolute SEQ-PE), the best performing formulae were EVO(Tecnis)(0.240), BUII(0.245) and EVO(0.248). For precision and accuracy, no statistically significant differences were noted between the formulae. At higher IOL powers Cooke K6 and PEARL-DGS had hyperopic tendencies, while BUII and EVO had myopic tendencies. EVO(Tecnis) did not share the same myopic tendency as EVO.
Conclusions
Across a dataset of Tecnis IOLs with a range of equally weighted IOL powers, EVO(Tecnis), BUII and EVO had the best precision and accuracy. Tecnis specific adjustments improved the EVO formula. For precision and accuracy, no statistically significant differences were noted between the formulae.