Comparison Of Refractive Outcomes Using Pre-Operative Biometry Measurements And Intraoperative Aberrometry In Patients With Ectasia
Published 2024 - 42nd Congress of the ESCRS
Reference: PP05.05 | Type: Free paper | DOI: 10.82333/stax-kh52
Authors: Victoria Liu* 1 , Andrew Samuel 2 , Shakeel Qazi 3 , Hikmat Jami 1 , Saama Sabeti 4 , Darrell Lewis 5 , Sheldon Herzig 6 , Kashif Baig 7
1Ophthalmology,University of Ottawa,Ottawa,Canada, 2Precision Cornea Centre,Ottawa,Canada, 3Family Medicine,University of Alberta,Edmonton,Canada, 4Ophthalmology,University of Ottawa,Ottawa,Canada;Precision Cornea Centre,Ottawa,Canada;Herzig Eye Institute,Ottawa,Canada, 5Ophthalmology,Precision Cornea Centre,Ottawa,Canada, 6Herzig Eye Institute,Toronto,Canada, 7Ophthalmology,University of Ottawa,Ottawa,Canada;Herzig Eye Institute,Ottawa,Canada;Precision Cornea Centre,Ottawa,Canada
Purpose
To compare refractive outcomes using pre-operative biometric measurements and the Barrett Universal II formula with intraoperative aberrometry using Optiwave Refractive Analysis (ORA) in patients with ectasia.
Setting
Herzig Eye Institute Ottawa and Toronto, Canada
Methods
Retrospective-prospective 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 pre-operative 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 the Barrett Universal II formula with Lenstar biometric data.
Results
Twenty-five eyes (13 patients) with corneal ectasia that had undergone a lens-based procedure with intraoperative aberrometry measurements were included in this study. Ectasia types included pellucid marginal degeneration (2 eyes), and keratoconus (23 eyes). The mean age of patients included was 68.04 years, with mean axial length of 24.40 mm, and mean steep K of 48.59 D. The mean absolute error ± standard error (SE) associated with intraoperative aberrometry and the preoperative Barrett Universal II formulas were 0.0798 ± 0.2546, 0.6062 ± 0.2060, respectively. The difference between the mean absolute error (± SE) associated with ORA and the Barrett Universal II formula was 0.5264 ± 0.250 (P = 0.0457) (95% CI 0.0108 to CI 1.0419).
Conclusions
ORA provides accurate refractive results comparable to pre-operative biometric formulas for lens selection in patients with ectasia. As compared the Barrett Universal II formula, ORA was better at predicting post-operative refractive error. This may both be statistically and clinically significant in the context of accurate prediction of intraocular lens power in patients with ectasia, which can help to improve accuracy of IOL selection in abnormal corneas.