Comparison of IOL Power Calculations in Post-Laser Vision Correction Eyes Having Cataract Surgery Using Multiple Methods
Narrative Responses:
Purpose
Post-Post-Laser Vision Correction (LVC) IOL power calculations continue to challenge cataract surgeons. The purpose of this paper is to compare predicted outcomes in post-LVC eyes undergoing cataract surgery using the Haigis-L formula, Fourier-domain OCT-based formula (Optovue, Inc.), intraoperative aberrometry (WaveTec), and Masket regression formula when prior history was available.
Methods
Non-randomized retrospective review of post-LVC eyes undergoing cataract surgery with IOL. IOL Master 500 measured axial length, corneal curvature and anterior chamber depth and supplied Haigis–L post-LVC formula. OCT-based IOL formula measured “true” corneal power and suggested IOL power. Intraoperative aberrometry was used to determine aphakic refraction and IOL power. Masket formula was used when prior LVC history was available. Patients with decentered ablations or ≥ 3 enhancements were excluded. Two week post-operative refraction was chosen as the final BCVA and endpoint. The IOL refractive prediction power and mean absolute error of desired IOL power was compared for all methods.
Results
Thirty-eight eyes with previous LVC undergoing cataract surgery were reviewed. The range of LVC was (+4.21D to -6.00D). Twenty-one eyes had myopic LVC and seventeen had hyperopic LVC. Twenty-one eyes had prior laser history available. All eyes completed the two-week post-operative refraction and obtained BCVA spherical equivalent. Forty-two percent – 57% of eyes were within +/-0.25D and 71%-81% were within +/- 0.50D of targeted IOL refractive prediction error. The MAE was 0.39 for the Haigis-L, 0.37 for ORA, 0.41 for Optovue and 0.32 for the Masket regression formula.
Conclusion
Newer methods such as intraoperative aberrometry and OCT-based IOL formula show promising results in post-LVC IOL calculations in eyes with and without prior data.