Prediction of visual outcomes using virtual implantation of a trifocal intraocular lens in presbyopic lens exchange patients

PURPOSE: To assess the reliability of a new virtual intraocular lens (IOL) implantation device to predict the outcomes of a trifocal IOL. SETTING: Clinical sites in Spain and Germany. DESIGN: Prospective multicenter study. METHODS: Preoperative measurements obtained by the virtual implantation of AT LISA tri 839MP IOL with Virtual IOL (VirtIOL) device were compared with postoperative (month 3) outcomes after the IOL implantation. The evaluated metrics were defocus curve, contrast sensitivity (CS) (both in photopic conditions), and visual phenomena (visual angle size of burst and annular pattern) in mesopic conditions. RESULTS: 45 presbyopic noncataract patients (mean age 56.16 ± 5.03 years) were included in this study. The VirtIOL device reasonably predicted the shape of the defocus curve, especially in the intermediate vision range, but underestimated postoperative visual acuities (VAs) mainly at the defocus range between +1.0 diopters (D) and -3.5 D. The difference between predicted and achieved VA was -0.11 ± 0.13 logMAR ( P < .001) for 0.0 D defocus and -0.16 ± 0.15 D logMAR ( P < .001) for -2.50 D defocus. The shape of the CS curve was almost identical for predicted and achieved measurements, but the device underestimated the values by ≈0.3 logCS units for each spatial frequency. Visual phenomena were similar between the predicted and achieved outcome (predicted vs achieved: burst pattern 2.65 ± 0.97 degrees vs 2.74 ± 0.95 degrees, P = .63; annular pattern: 0.88 ± 0.42 degrees vs 0.93 ± 0.49 degrees, P = .59). CONCLUSIONS: The device reasonably predicted the pattern of measured variables. VA/CS reduction might be attributed to viewing the objects through a more complex optical system and would need to be accounted for in clinical studies.