Impact Of Corneal Spherical Aberration: Monofocal Vs Monofocal Plus Iols

To simulate the impact of the corneal spherical aberration of two different IOL monofocal designs (Eyhance and Clareon)

Alcon Fort Worth, TX. US

The optical performance (polychromatic MTF defocus curve at 50cpmm) of two monofocal IOLs (Tecnis Eyhance and Clareon) was simulated using corneal spherical aberrations (SA) ranging from 0.0um to 0.57um, and for large (4.5mm) and small (3.0mm) pupils. Performance was considered as “optimal” when the MTF values were equal or better than 90% and “acceptable” when equal or better than 80% of the maximum value (peak). The population distribution of corneal SA was then used to predict the percentage of human eyes that may obtain an “optimal” and “acceptable” performance for each lens and pupil size.

For large pupils, approximately 77% of the population may have a refractive outcome of +/-0.25D when implanted with Eyhance, versus a 96% of the population when implanted with Clareon. With small pupils the difference is lower (96% vs 98%). Analyzing the MTF performance at 0.0D defocus, for large pupils, Clareon provides an “optimal” performance to 18% more of the population than Eyhance and an “acceptable” to 20% of the population. Whereas for small pupils the population is 10%  and 9% higher with Clareon than with Eyhance for “optimal” and “acceptable” respectively.

The central refractive optical component of the Eyhance makes the lens more pupil dependent and also more corneal spherical aberration dependent than Clareon. This may have a significant impact on visual outcomes by reducing the refractive predictability and increasing the variability among patients implanted with Eyhance. Further clinical investigations are needed to confirm these results.