Comparison Of The Predictability Of Five Methods For Intraocular Lens Calculation In Eyes With Previous Myopic Keratorefractive Lenticule Extraction (Klex)

To evaluate and compare the predictability of 5 methods of intraocular lens (IOL) calculation in eyes with previous keratorefractive lenticule extraction (KLEx) for the treatment of myopia

Victoria de Rojas Instituto Oftalmológico, Policlínica Assistens, A Coruña, Spain

Retrospective study including 100 eyes which underwent KLEx (SMILE®) for myopia. The spherical equivalent of the refractive change induced by surgery was converted to corneal plane (SMILE-Ind). A theoretical model was developed in which the same IOL model was implanted before and after KLEx. IOL power was calculated with ray-tracing (TR-Sirius), Kane, EVO/EVO Post Myopic LASIK/PRK, Barrett/Barrett True K, Hoffer QST before and after surgery. The difference between the refractive error induced by the IOL before and after KLEx in the corneal plane (IOL-ind) was compared with SMILE-Ind. Predicted error (PE) was the difference between SMILE-Ind and IOL-Ind.

The PE obtained was 0.26 ± 0.55 diopters (D), 0,10 ± 0,45 D, 0,40 ± 0,37 D, -0,03 ± 0,36 D, 0,02 ± 0,51 D, with TR-Sirius, Kane, EVO, Barrett, and Hoffer QST respectively. PE was not statistically significantly different between Barrett and Hoffer QST, being differences more homogeneous with Barrett, (variance σ2=0,13). The absolute EP obtained with Barrett achieved 84% of cases within ± 0.5 D, followed by Kane (72%), Hoffer QST (65%), EVO (61%) and TR-Sirius (59%)

Barrett True K formula was the most accurate method for IOL calculation in eyes which had undergone KLEx for the correction of myopia. 

FINANCIAL DISCOUSURE: The authors have no financial or industrial interest in the matter or have received remuneration from any company mentioned