Peripheral astigmatism in pseudopakic eyes measured with a novel double-pass system

Journal:
IOVS
Year:
2023
Link:
Authors:
Dimitrios Christaras; Harilaos S Ginis; Spyridon Tsoukalas; Lucia Hervella; Jose Maria Marin; Pablo Artal
PDF:

Purpose: Pseudophakic eyes implanted with standard intraocular lenses (IOLs) presents significantly higher peripheral astigmatism compared to the phakic eye (Jaeken et al., IOVS, 2013). This deteriorates peripheral image quality and may affect quality of vision. New inverted meniscus IOLs are designed to reduce induced peripheral astigmatism. In this context, the purpose of this work is twofold: to measure peripheral astigmatism in pseudophakic eyes implanted with standard biconvex and inverted meniscus IOLs, and to evaluate the capability of a novel double pass instrument to assess peripheral image quality.

Methods:Three groups of were included in the study: a group of 5 normal controls, 5 patients implanted with standard biconvex monofocal IOLs and 5 patients who have previously been implanted with a meniscus type hydrophobic acrylic IOL (ArtIOL (Art40), Voptica SL, Murcia, Spain) were tested. This lens has been reported to have reduced peripheral astigmatism (Villegas et al., JRS, 2022). Peripheral astigmatism was measured using an open-view peripheral custom-made double-pass instrument featuring a 780nm laser source, a tunable lens and a camera to record the double-pass retinal images of a point source. Through-focus retinal images at a given eccentricity were recorded fast without speckle noise thanks to a rotating mirror. By applying the appropriate image processing, defocus and astigmatism at the specific eccentricity are accurately obtained.

Results: At the fovea (0 degrees), mean astigmatism was below 1 D for the 3 groups. At 30 degrees, mean astigmatism was found to be 3.4D, 4.3D and 5.7 D for the normal controls, ArtIOL group and standard monofocal IOL respectively. The relative peripheral defocus and depth of focus for each group has been also determined.

Conclusions: A novel double pass instrument for the measurement of peripheral image quality was successfully used to measure peripheral astigmatism, defocus and depth of focus at 0 and 30 degrees in a normal control group and in two groups with patients implant ted with IOLs. The IOLs group shows elevated astigmatism at 30 degrees compared to the normal eye, with lower values for the inverted meniscus IOLs.