Comparison of ultrasound and optic biometry with respect to eye refractive errors after phacoemulsification

Phacoemulsification is one of the best surgical treatments for the cataract. Secondary to the technicaladvances in estimating the intraocular lens (IOL) power, the refractive errors, one of the most important surgical complications after surgery, is now reduced. Currently, two methods of biometry are used to calculate the IOL power, ultrasound biometry and optical biometry. Both methods have their own advantages and it is controversial to use which of them before surgery. We would like to know if there is any difference between these two biometry methods to reduce refractive errors after cataract surgery. Present research was a cohort study on the patients undergone phacoemulsification due to cataract in Feiz and Farabi academic hospitals and Aban ophthalmology clinic. We compared eye refractions after cataract surgery in two groups of patients. Ultrasound biometry was done for the first group and the optical biometry for the second one. Mean absolute refractive error (MAE) was compared in the two groups by t test. Eye refractions of 132 patients were studied; 76 patients in group one and 56 patients in group two. The MAE measured 0.67 ± 0.70 diopters for the first group and 0.79 ± 0.76 diopters for the second one and the difference was not significant (P = 0.342). According to our results the refractive errors after phacoemulsification was the same for both ultrasound and optical biometry methods. The claim of optical biometry, however, to gain a higher precision and thus a significantly better prediction of individual postoperative refraction after cataract surgery is not yet fulfilled. To determine which method is definitely better, more studies are required.