Calculating Quadrifocal Iols Using A Recently Introduced Online Tool

To evaluate a recently introduced online calculation tool for intraocular lens (IOL) calculation of a quadrifocal IOL in refractive lens exchange and cataract surgery

Department of Ophthalmology, Goethe University Frankfurt, Germany

Prospective, consecutive case series.

We included eyes that received lens extraction and IOL implantation (Panoptix, Alcon, Fort Worth, Tx, USA). We compared the mean prediction error (MPE), mean and median absolute prediction error (MAE, MedAE) of formulas provided by the recently introduced online calculator provided by the European Society of Cataract and Refractive Surgeons (ESCRS), and number of eyes within ±0.5, ±1.0, ±2.0 diopters (D) of target refraction. Postoperative spherical equivalent was measured prospectively at 3 months after surgery. Only one eye per patient was included.

Eighty-eight eyes from 88 patients were included. The MedAE was low for all formulas and ranged from 0.26D (Kane) to 0.30D (Pearl DGS). Hill-RBF (0.27D), Hoffer QST (0.27D), Barrett (0.28D), EVO (0.29D), and Cooke K6 (0.27D) ranged in-between. No statistical significance was found between the formulas (p = 0.90). 

Considering the number of eyes within ±0.5D of the calculated refraction the best performing was again the Hill-RBF (84%, 74 eyes), again followed by Kane (71, 81%), EVO, Pearl DGS, Hoffer QST, and Barrett (each 80%, 70 eyes) and Cooke K6 (78%, 69 eyes). There was no statistically significant difference found, using the Cochran Q test (p = 0.597). The same does account for eyes within ±1.0D and ±2.0D of calculated refraction.

Using this recently introduced online tool for IOL calculation in quadrifocal intraocular lenses leads to a high number of eyes reaching target refraction and low prediction errors. All formulas performed similar well. However, Hill-RBF showed the highest number of eyes within ±0.5D, but no significance was found regarding this.