ESCRS - PO114 - Comparison Of Pre-Operative Biometry Measurements With Intraoperative Aberrometry In Patients With Ectasia

Comparison Of Pre-Operative Biometry Measurements With Intraoperative Aberrometry In Patients With Ectasia

Published 2022 - 40th Congress of the ESCRS

Reference: PO114 | Type: Free paper | DOI: 10.82333/0mdk-d091

Authors: Victoria Liu* 1 , Shakeel Qazi 2 , Saama Sabeti 3 , Darrell Lewis 4 , Milad Modabber 5 , Kashif Baig 3

1Department of Ophthalmology,University of Ottawa,Ottawa,Canada, 2Precision Cornea Centre,Ottawa,Canada, 3Precision Cornea Centre,Ottawa,Canada;Department of Ophthalmology,University of Ottawa,Ottawa,Canada;Herzig Eye Institute,Ottawa,Canada, 4Precision Cornea Centre,Ottawa,Canada;Herzig Eye Institute,Ottawa,Canada, 5Herzig Eye Institute,Toronto,Canada

Purpose

To compare pre-operative biometry measurements using the Barrett Universal II, and Kane for keratoconus formulas with intraoperative aberrometry predictions using Optiwave Refractive Analysis (ORA) in patients with ectasia.

Setting

Herzig Eye Institute, ON, Canada

Methods

Retrospective chart review of patients with ectasia who underwent a lens-based refractive procedure with intraoperative aberrometry (ORA). The primary outcome assessed was the difference between the mean absolute error of intraoperative aberrometry predictions (ORA) and the mean absolute error of preoperative calculation predictions at 3 months. Absolute error above was calculated from the difference in predicted refraction versus postoperative manifest refraction spherical equivalent using intraoperative aberrometry and intraocular lens formulas the Barrett Universal II, and Kane keratoconus formulas, respectively.

Results

Nineteen eyes (11 patients) with corneal ectasia that had undergone a lens-based procedure with intraoperative aberrometry measurements were included in this study. The mean absolute error ± standard error (SE) associated with intraoperative aberrometry and the preoperative Barrett Universal II and Kane keratoconus formulas were 0.73289 ± 0.181, 0.979 ± 0.220, 0.994 ± 0.213, respectively. The differences between the mean absolute error (± SE) associated with ORA and the Barrett Universal II formula, and ORA and Kane keratoconus formulas were -0.246 ± 0.069 (P = 0.002) and -0.262 ± 0.072 (P = 0.002), respectively. 

Conclusions

ORA provides accurate refractive results comparable to preoperative biometric formulas for lens selection in patients with ectasia. As compared to Kane keratoconus formula and the Barrett Universal II formula, ORA was better at predicting postoperative refractive error. This study provides information to help improve accuracy of IOL selection in abnormal corneas.