Abstract
Purpose :
Intraocular lens (IOL) calcification is a serious condition that may degrade patients’ vision. Despite its relatively low incidence rate, it may result in significant patient complaints and IOL exchange. One of the complaints that patients with opacified lenses may report is increased sensitivity to (glaring) light sources, which may originate from light scattering by lens opacities. Therefore, in this laboratory study, we aimed to assess the scattering effects of five opacified lenses by qualitatively visualizing the ray propagation and quantitatively measuring the level of light scatter.
Methods :
Four opacified-IOL explants were studied Euromaxx ALI313Y (Argonoptics), Acri.Lyc 44S (Acri.Tec), LS-312 MF 30 (Oculentis), and Adatomed 88 TI (Adatomed) as well as one lens with laboratory-induced glistenings (PC-60AD [Hoya]) and a clear control IOL. To identify the type of opacification, gross examination of the explanted lenses was performed using light microscopy. Each IOL was placed in an eye model on an optical bench set-up and illuminated by green laser light. Images of the optical pathway, which were made visible by fluorescein solution, were taken with a digital camera. Straylight levels were measured using the C-Quant device (Oculus) adapted for in vitro evaluation of IOLs. Measurements were performed at a 7 degree scatter angle. Results were compared to those of the control lens.
Results :
The light-visualization set-up showed more light scatter in the opacified lenses than in the control, which was visible as increased light intensity outside the main lens focus. Each opacified lens demonstrated its own characteristic ray propagation behavior. The average straylight parameter (s) was 76.6±107.8 deg^2/sr. The highest straylight was observed in Euromaxx (s=289.71 deg^2/sr), which exhibited extensive granular deposits throughout its optic. In Adatomed and Acri.Ly lenses opacification was limited to the lens center with a straylight level of 18.7 deg^2/sr and 48.1 deg^2/sr, respectively. The IOL with glistenings showed s=22.6 deg^2/sr, and for the control lens it was s=1.7 deg^2/sr.
Conclusions :
We found that straylight was increased in all opacified lenses as compared to that of the control. A veil of light that results from increased light scattering could be qualitatively assessed by the optical pathway visualization. The studied IOL opacifications appear to be significant sources of glare.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.