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IOL-calculation using ray-tracing with OCT-based biometry in patients with a history of myopic laser vision correction (LVC)
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First Author: B.Gjerdrum NORWAY
Co Author(s): K.
Abstract Details
Purpose:
To assess the accuracy of IOL-calculation in patients with previous myopic Laser Vision Correction (LVC) using OCT biometry and ray-tracing calculation. Furthermore, to compare ray-tracing calculation with traditional biometric formulae.
Setting:
Single Surgeon Eye Clinic, Haugesund, Norway
Methods:
This study was an interventional single-arm study of patients attending for cataract or refractive lens exchange who had previous myopic laser vision correction (LVC). Preoperative biometric data was collected using reflectometry- (Lenstar LS 900), and OCT- (Tomey Casia SS-1000) based technology. Traditional biometric formulae (Barret True-K no-history, Haigis-L) with reflectometry data, and Ray-tracing software (Okulix) with OCT-data was used to calculate IOL power. All data were compared to choose implanted IOL power. Follow-up examination was performed 5 weeks to 3 months after surgery. The Main outcome measure was postoperative mean refractive spherical equivalent (MRSE) and mean refractive prediction error (RPE).
Results:
Preliminary results involve 18 eyes from 10 patients. MRSE for the whole study group was 0.08 ± 0.20. This was not significantly different from zero (p > 0.05). RPE was 0.22 ± 0.27, -0,47 ±0,25, and -0,96±0,3 (p < 0.001) for Okulix, Barret True-K no-history and Haigis-L respectively.
Conclusions:
In this cohort of subjects previously treated for myopia using Laser Vision Correction (LVC) we found that a combination of OCT based biometry and Okulix ray-tracing software achieved excellent postoperative refractive precision. RPE appear to be better with OCT and ray tracing than traditional formula-based calculation. The calculated refractive prediction error (PE) was close to results obtained in non-laser treated eyes (virgin eyes).
Financial Disclosure:
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