ACCURACY OF INTRAOCULAR LENS CALCULATION FORMULAS FOR CARLEVALE LENS IMPLANTATION.

To evaluate the accuracy of intraocular lens (IOL) calculation formulas in the  sutureless scleral fixation (SSF) of Carlevale (Soleko) IOL.

Institut Català de Retina, Barcelona, Spain

Four IOL prediction formulas (SRK/T, Barrett Universal II, Hoffer Q and Holladay 1) were used to calculate the IOL power in patients with capsular or zonular defects who had undergone 25-gauge pars plana vitrectomy with SSF of Carlevale IOL and had postoperative corrected distance visual acuity (CDVA) of 20/40 or better. The main outcome measures were mean prediction error (PE), median absolute error (MedAE), mean absolute er­ror (MAE) and percentage of eyes with a PE within ±0.50 and ±1.0 diopters (D).

Sixty patients (60 eyes) were included. All formulas produced myopic PE, but PE with Hoffer Q and Holladay 1 were significantly closer to target emmetropy. Although not significant a trend toward more accuracy of the prediction by MAE was observed with Hoffer Q. There was no difference in the percentage of eyes with PE within ±0.50 and ±1.00 D for assessed formulas oscillating between 46.6 and 56.7%, and 80 and 86.6%, respectively. When analyzing PE in the eyes with average axial length (AL) Hoffer Q was the most accurate, meanwhile, in long eyes, Barret II was significantly closer to emmetropy.

Good refractive outcomes can be obtained when implanting SSF-IOLs in eyes with no capsular support, although the accuracy is lower than the reported for in-the-bag IOL implantation. The IOL prediction formula should be chosen based on AL.