New Meniscus IOL

New meniscus-shaped IOL may improve peripheral contrast and astigmatism. Roibeard Ó hÉineacháin reports

Patients implanted with a new meniscus-shaped intraocular lens (ArtIOL, Voptica SL) appear to have a reduced amount of peripheral astigmatism compared to patients implanted with standard lenses, according to a study presented by Pablo Artal PhD at the ARVO 2021 Congress.

“This new intraocular lens provides reduced astigmatism and better contrast detection in the peripheral retina. This may have a positive impact in everyday tasks in patients after cataract surgery,” said Artal, Laboratorio de Óptica, Universidad de Murcia, Murcia, Spain.

The study involved 87 cataract patients who underwent implantation of the ArtIOL and a control group of 38 patients who were implanted with a standard monofocal IOL. Dr Pedro Taña and Dr José María Marín of the Oftalvist clinic in Spain performed the surgeries. Prof Artal noted the new meniscusshaped IOLs’ optics mimic that of the natural lens to provide optimised field curvature and then better vision. Composed of a hydrophobic acrylic material with UV-protection, the lenses have an optic diameter of 6.0 mm and a total diameter of 13 mm and range in power from 18.0 D to 24.5 D.

Prof Artal and his associates measured the patients’ peripheral refraction on the horizontal meridian using a scanning Hartmann-Shack wavefront sensor and measured the contrast detection threshold at 45 degrees of visual angle (both horizontally and vertically) psychophysically by means of an adaptive staircase technique, using a 30-arc min. round stimulus 1 m in front of the patient’s eyes and a green LED for foveal fixation.

REDUCED PERIPHERAL ASTIGMATISM AND IMPROVED CONTRAST SENSITIVITY The researchers found that eyes implanted with ArtIOLs had a reduced amount of peripheral astigmatism compared to eyes in the control group. At 30 degrees, the average cylinder in the control group was 3.0 D, compared to 2.0 D in the ArtIOL group. At 45 degrees, mean cylinder values were 6.0 D and 3.5 D respectively.

This reduction in astigmatism had a positive impact in contrast sensitivity, Prof Artal noted. In the horizontal meridian, average sensitivity values were 0.07 (SD=0.04) and 0.10 (SD=0.05) for the control and ArtIOL groups respectively. In the vertical meridian, average sensitivity values were 0.06 (SD=0.03) and 0.08 (SD=0.03) for the control and ArtIOL groups respectively.

Prof Artal noted the clinical results obtained thus far with the ArtIOL mirror those obtained with bench testing, showing superior optical quality compared to standard IOLs.

“Further research would be required to evaluate how this IOL may also have an impact in the patient’s functional vision,” he concluded.

Pablo Artal: pablo@um.es

Images of letter chart recorded in a model eye at 40 degrees in an eye with a standard IOL and with ArtIOL. The image quality is clearly superior with the meniscus lens.