Abstract
Purpose::
The purpose of this study is to ascertain whether the intraocular lens master (IOLm) or ultrasound biometry provides a more accurate prediction of refractive outcomes in cataract surgery. We also investigated preoperative clinical risk factors which predicted poor prediction of eventual refraction with either technology.
Methods::
This was a retrospective chart review of 421 eyes of 304 patients who underwent IOLm and ultrasound biometry measurements in a standardized prospective fashion. Refractive outcomes were followed for up to six months postoperatively. The mean difference between the prediction with each technology and the final spherical equivalent was compared. The ability of each technology to predict final refraction within 0.25 diopters, 0.50 diopters, and 1.00 diopters was compared. The number of patients in which more postoperative hyperopic correction was needed than predicted was also assessed for each technology.
Results::
The mean difference between predicted refraction and final spherical equivalent (SE) was -0.43 (Standard deviation 0.84) for the IOLm and -0.60 (0.87) for ultrasound biometry. The IOLm was found to have a 5% higher chance of predicting a final SE within 0.25 diopters than ultrasound biometry (p=0.062), a 8% higher chance of predicting a final SE within 0.50 diopters (p<0.001), and a 8% higher chance of predicting a final SE within one diopter (p<0.001). Patients for whom both technologies failed to make accurate predictions of the final spherical equivalent included those with postoperative CME, immediate postoperative corneal decompensation, pre-existing epiretinal membrane, history of macula-off retinal detachment , and history of anterior basement membrane disease. The IOLm was found to be 3% more likely than ultrasound biometry to require more postoperative hyperopic correction than predicted.
Conclusions::
In conclusion, the IOLm is a better predictor of the postoperative refraction than ultrasound biometry (p<0.001). In particular, it is better able to predict the postoperative refraction within close ranges (within 1 diopter) than ultrasound biometry. Patients with epiretinal membranes, corneal epitheliopathy, or a history of retinal detachment are at risk for having postoperative refractions that cannot be predicted by either IOLm or ultrasound biometry and should be counseled as such prior to surgery.
Keywords: cataract • treatment outcomes of cataract surgery • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)