COMPARISON OF INTRAOCULAR LENS FORMULAS IN EYES WITH A HISTORY OF RADIAL KERATOTOMY USING TOTAL KERATOMETRY
Published 2025 - 29th ESCRS Winter Meeting
Reference: PO124 | Type: Presented Poster & Poster | DOI: 10.82333/hbzc-s048
Authors: Catherine Drew* 1 , Stephen Stewart 2 , Richard McNeely 3 , Salissou Moutari 3 , Niraj Mandal 3 , Jonathan Moore 3
1Ophthalmology ,Belfast trust ,Belfast ,United Kingdom, 2Ophthalmology,Cathedral eye clinic,Belfast ,United Kingdom, 3Ophthalmology ,Cathedral eye clinic,Belfast ,United Kingdom
Purpose
This comparative study aimed to evaluate the performance of two modern IOL power formulas in eyes with a history of radial keratotomy (RK) and determine whether using total keratometry (TK) affects the prediction accuracy.
Setting
Fifty-one eyes of 32 patients that had undergone RK and subsequent cataract surgery were included in the study.
Methods
Fifty-one eyes of 32 patients that had undergone RK and subsequent cataract surgery were included in the study. Refractive prediction error and percentages of eyes with absolute prediction error within 0.25D, 0.50D, 0.75D and 1.00D were calculated for Barrett True K RK and EVO RK for all eyes, and also for Barrett True K RK-TK and EVO RK-TK in 18 eyes for which TK data from an optical biometer (IOLMaster 700, Carl Zeiss Meditec) was available.
Results
The median absolute error was 0.905, 0.610, 0.784 and 0.429D for Barrett True K RK, Barrett True K RK-TK, EVO RK and EVO RK-TK respectively. EVO RK-TK had the highest proportion of eyes within 0.50D and 1.00D (56% and 83% respectively). For eyes with TK data available, a higher proportion of eyes within 0.50D was achieved when total keratometry was used compared to standard keratometry for EVO RK (56% vs 39%) but not for Barrett True K RK (44% for both).
Conclusion
The EVO RK formula performed best overall and using total keratometry values improves the prediction accuracy for this formula.