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

Purpose: To assess the reliability of a novel virtual 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 (Carl Zeiss Meditec AG, Jena, Germany) with VirtIOL device (10Lens S.L.U., Terrassa, Spain) were compared to postoperative (month 3) outcomes following the IOL implantation. Evaluated metrics were defocus curve, contrast sensitivity (both in photopic conditions), and visual phenomena (visual angle size of burst and annular pattern) in mesopic conditions.

Results: The study included 45 presbyopic non-cataract patients (mean age 56.16±5.03 years). VirtIOL device reasonably predicted the shape of the defocus curve, especially in the intermediate vision range, but underestimated postoperative visual acuities mainly at the defocus range between +1.0D and -3.5D. The difference between predicted and achieved visual acuity was -0.11±0.13 logMAR (p<0.001) for 0.0D defocus and -0.16±0.15D logMAR (p<0.001) for -2.50D defocus. The shape of the contrast sensitivity 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° vs. 2.74°±0.95°, p=0.63; annular pattern: 0.88±0.42° vs. 0.93±0.49°, p=0.59).

Conclusion: The device reasonably predicted the pattern of measured variables. Visual acuity/contrast sensitivity reduction might be attributed to viewing the objects through a more complex optical system and would need to be accounted for in clinical studies.