Refractive Predictability Of A Secondary Sulcus Iol Compared To A Primary Iol Based On Ray Tracing After Laser Vision Correction

To compare the refractive predictability of an IOL with power calculated using ray tracing to the predictability of a secondary multifocal IOL implanted after a monofocal IOL in patients with a history of myopic laser vision correction (LVC).

Private eye clinic in Haugesund, Norway

This was a retrospective study of cataract patients with a history of myopic laser vision correction (LVC) who were implanted with a monofocal IOL and 2-16 months later had a secondary trifocal sulcus IOL implanted. Primary IOL calculations were performed with ray tracing software (Okulix) based on measurements from an anterior OCT biometer (Heidelberg Anterion). Secondary IOL calculations were performed using the manufacturer’s online calculator based on residual refraction and biometry. The primary outcome measures were the refractive prediction error (RPE) of the primary and secondary IOL calculation. Secondary outcome measures were the spherical equivalent refraction and visual acuity.

27 eyes of 14 patients were included. Mean refractive SE after the primary and secondary implantation was +0,15 D and -0,13 D, respectively (p<0,01). Mean uncorrected distance visual acuity was -0,02 and -0,05 logMAR before and after secondary IOL implantation, respectively. The mean RPE of the primary IOL and the secondary IOL calculations were -0,06 D and -0,11 D respectively (p=0,6). RPE were within ±0.25D in 19 eyes (70%) and 16 eyes (59%) for the primary and secondary IOL calculations, respectively (p = 0,6), and within ± 0.5 D in 26 eyes (96%) for both calculations.

Results here showed that outcomes in post myopic LVC eyes had a very low RPE when the primary IOL was calculated using OCT biometry and ray tracing. Results were not improved with a secondary IOL. This suggests that a multifocal IOL may be used as the primary lens without significant risk of refractive surprise in post LVC cataract patients.