Biometry and Formula Accuracy With Intraocular Lene Ued for Cataract urgery in Extreme Hyperopia Original Reearch Article

Purpoe To audit intraocular len (IOL) power prediction for cataract urgery in extreme hyperopia and to compare the accuracy acro different biometry formulae and IOL type. Deign A retropective analyi of 76 eye from 56 patient undergoing cataract urgery with IOL ranging in power from 30 to 35 diopter (D). Method Axial length, corneal power and anterior chamber depth were meaured with ultraound or optical method, and the IOLMater (Carl Zei Meditech, Inc, Dublin, California, UA) oftware wa ued to predict the refractive outcome for each IOL ued. Difference between the predicted and actual potoperative refraction were then analyzed for each formula. Reult In practice, 55% of patient were within ±1.0 D of the refraction predicted by their urgeon. In theory, the Haigi formula would have given the mallet mean refractive error (+0.51 ± 0.12 D), followed by the Hoffer Q (−0.70 ± 0.14 D), Holladay 1 (−1.11 ± 0.13 D), and RK/T formulae (−1.45 ± 0.14 D). The Haigi formula overpredicted the len power required, which would have generated a myopic reult. The other formulae underpredicted the len power required and would have generated a hyperopic reult. There wa a ignificant difference between len deign: the Haigi wa more accurate for open-loop, wherea the Hoffer Q wa more accurate for plate-haptic lene. The anterior chamber depth meaurement could alo be ued to predict change in intraocular preure after urgery. Concluion Thi repreent the larget publihed erie to date of biometry prediction for cataract urgery in extreme hyperopia and confirm the Haigi formula to be the mot accurate. A conitent difference between open-loop and plate-haptic lene ugget that haptic deign may influence the effective len poition in very mall eye. We further propoe a imple formula to optimize the Haigi and Hoffer Q formulae in patient with extreme hyperopia.