Abstract
Purpose :
To compare the SRK/T, Holladay1, and Wang-Koch axial length (AL) optimized Holladay1 formulas to intraoperative aberrometry (Alcon ORA) with respect to accuracy in predicting residual refractive error after cataract surgery in eyes with axial myopia.
Methods :
Retrospective comparative case series including 51 eyes with AL>25.0 mm that underwent cataract extraction with intraocular lens (IOL) implantation. Eyes were ineligible for the study if they had previous ocular surgery or trauma, ocular inflammatory conditions, vision-limiting retinal or optic nerve disease, unreliable optical biometry data, a complication during cataract surgery, a target postoperative refraction other than emmetropia, lack of follow-up, or a postoperative best-corrected visual acuity worse than 20/40. For each eye, the 1-center Wang-Koch AL-optimized Holladay1 formula was used to select an IOL that targeted emmetropia. Residual refractive error was also predicted pre-operatively using the SRK/T and Holladay1 formulas and intraoperatively using the ORA. Refraction was measured 4-6 weeks postoperatively and compared to the three preoperative and intraoperative prediction methods.
Results :
The mean residual refractive error (spherical equivalent) of the study population was 0.012 +/1 0.411 D (range: -0.875 D to 1.250 D). The mean numerical error (MNE) associated with using the SRK/T, Holladay1, AL-optimized Holladay1, and ORA were 0.204 +/- 0.420, 0.330 +/- 0.463, -0.022 +/- 0.383, and 0.055+/- 0.396 D, respectively (p<0.0001). Prediction error was significantly less with the AL-optimized Holladay1 and ORA than with the unmodified Holladay1 formula. The proportion of patients within 0.5 D of predicted was 74.5%, 60.8%, 82.4%, and 80.4% using the SRK/T, Holladay1, AL-optimized Holladay1, and ORA, respectively (p=0.096). Hyperopic outcomes occurred in 70.6%, 76.5%, 49.0%, and 45.1%, respectively (p=0.001). AL-optimized Holladay1 and ORA yielded significantly fewer hyperopic outcomes than the unmodified Holladay1 formula.
Conclusions :
The AL-optimized Holladay1 formula and ORA were more accurate than the unmodified Holladay1 formula in predicting residual refractive error after cataract surgery in eyes with axial myopia. The AL-optimized Holiday1 and ORA are equally effective in reducing MNE and hyperopic outcomes.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.