Comparison of IOL formulae in extreme long axial lengths
Session Details
Session Title: Presented Poster Session: Cataract Surgery Outcomes
Venue: Poster Village: Pod 1
First Author: : T.Yeo SINGAPORE
Co Author(s): : H. Fam
Abstract Details
Purpose:
To compare the performance of different formulae in eyes of extreme long axial lengths.
Setting:
Department of Ophthalmology, Tan Tock Seng Hospital, Singapore
Methods:
44 long eyes (>28.5mm) were analyzed. The new EVO formula, Barrett Universal II (BUII), Haigis, Holladay I, SRK/T and Hoffer Q were compared. Lens constant was optimized for each IOL type for Haigis, Holladay I, SRK/T and Hoffer Q. EVO and BUII used ULIB or recommended constants. Wang and Koch axial length adjustment was also applied to Haigis, Holladay I, SRK/T and Hoffer Q. The predicted refraction for each formula was subtracted from the post-operative refraction to obtain the error in prediction.
Results:
Axial length range was 28.51mm to 35.82mm. IOL range was -10D to 4D (AR40e, AR40M). Without optimization, all formulae had hyperopic mean errors part from EVO and BUII. Median absolute errors were 0.263, 0.283, 0.584, 0.281, 0.295, 0.382, 0.629 and 0.411 for EVO, BUII, Haigis ULIB, Haigis triple-optimized, Haigis single-optimized, optimized Holladay I, SRK/T and Hoffer Q respectively. With axial length adjustment, the median absolute errors were 0.459, 0.487, 0.497 and 0.396 for Haigis, Holladay I, SRK/T and Hoffer Q. EVO and BUII performed statistically better than all formulae (p < 0.05), apart from Haigis single or triple-optimized.
Conclusions:
EVO, BUII and Haigis (single or triple-optimized) performed the best in long eyes.
Financial Disclosure:
NONE