Modified Clinical Straylight Assessment In Patients With Multifocal Diffractive Intraocular Lenses: A Comparative Study

Using the standard straylight assessment at 7 degrees, the patients with different monofocal and multifocal diffractive intraocular lenses (IOLs) have similar straylight values. The study investigates whether differences in straylight between IOL designs can be detected using a modified clinical straylight measurement technique at a lower angle of 2.5 degrees.

International Vision Correction Research Centre (IVCRC) and the David J. Apple Center for Vision Research, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany.

An ongoing clinical comparative study of patients implanted with Clareon PanOptix (Alcon), TECNIS Synergy (J&J) diffractive multifocal IOLs and monofocal controls, with 36 patients to be included in total. In a randomized order, the straylight measurements are performed in each eye at 7 and 2.5 degrees using the standard and modified C-Quant (Oculus) device. The straylight values between the groups are compared using Kruskal-Wallis test and p<0.05 is considered statistically significant. The mean (±standard deviation) values of the straylight parameter Log(s) are presented. Additional examinations include uncorrected and corrected distance visual acuity, manifest refraction, subjective photic phenomena assessment and slit lamp examination.

The straylight at 7 degrees was 1.10±0.10 Log(s) in eyes implanted with Clareon PanOptix (n=10), 1.00±0.12 with TECNIS Synergy (n=8) and 1.03±0.15 with monofocal IOLs (n=5), p=0.15. Using the modified measurement at 2.5 degrees, the straylight was 1.32±0.09 Log(s) with Clareon PanOptix, 1.53±0.08 with TECNIS Synergy and 1.33±0.11 with monofocal IOLs, p<0.01. Note that a 0.3 Log(s) difference indicates doubling of glare effects. At 2.5 degrees, the highest increase in measured straylight was observed in TECNIS Synergy group, with statistically significantly higher values compared to Clareon PanOptix (p<0.01) and monofocal IOLs (p=0.01). No significant difference was observed between Clareon PanOptix and controls at 2.5 degrees (p=0.78).

The straylight measurement at 2.5 degrees resulted in higher straylight values with both multifocal and monofocal IOLs, compared to the measurement at 7 degrees. This increase was the highest in the TECNIS Synergy group. Straylight testing at smaller angles emerges as a sensitive measure to identify multifocal designs posing an increased risk of inducing photic phenomena in pseudophakic patients.