Iol Calculation Using A Recently Introduced Online Tool In Pediatric Eyes Undergoing Lens Extraction

To evaluate a recently introduced online calculation tool for intraocular lens (IOL) calculation in children undergoing phacoemulsification and IOL implantation

Department of Ophthalmology, Goethe University Frankfurt, Germany

Retrospective, consecutive case series

We included eyes that received phacoemulsification and IOL implantation (Acrysof SN60AT, Alcon, Fort Worth, Tx, USA) due to congenital or juvenile cataract. 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) to the SRK/T formula, and number of eyes within ±0.5, ±1.0, ±2.0 diopters (D) of target refraction. Postoperative spherical equivalent was measured by retinoscopy 4 to 12 weeks after surgery.

Sixty eyes from forty-seven patients with a mean age of 6.5 years ± 3.2 met the inclusion criteria. Mean axial length was 22.27mm ± 1.19. Mean preoperative spherical equivalent (SE) was -0.25 D ± 3.78 and mean postoperative SE was 0.69 D ± 1.53. The MedAE was lowest in the SRK/T formula (0.56 D, ± 1.03) performed significantly better (p = 0.037) than Hoffer QST and Kane, followed by BUII (0.64D, ± 0.92), Pearl DGS (0.65D, ± 0.94), EVO (0.69D, ± 0.94), Hoffer QST (0.75D, ± 0.99), and Kane (0.78D, ± 0.99). All of those were significantly above zero (p < 0.001). Forty-one eyes received an intraoperative optic capture (68%). When excluding eyes that did not receive intraoperative optic capture (n=19; 32%) the MedAE was shown to be lower.

Using modern IOL calculation formulas provided by the ESCRS calculator provides good refractive predictability and compares for most of the formulas to the results with SRK/T. Additionally the formulas seem to anticipate the postoperative refraction better for eyes that receive a posterior optic capture.