Abstract
Purpose :
To measure human lens power after treatment of lenses with the deglycating agent fructosyl amino acid oxidase (FAOD) ex vivo in an optical bench.
Methods :
Human lenses were obtained from cadaver eyes that were rejected for corneal transplantation (Biobank Antwerp, Belgium, ID71030031000). Eyes were dissected and lenses were removed and incubated with FAOD (Creative enzymes) or PBS. Lens power was measured before treatment and up to 4 hr. Focal distance measurement is based on the thin lens formula 1/f=1/s1 + 1/s2 (f, focal distance of the lens; s1, object distance from the lens; s2, image distance from the lens). Magnification M of the optical system is M=S2/S1. By measuring the total distance between object and image plane L=S1+S2 and the magnification M, the focal distance of the lens-under-test is obtained L/f= (1+M)(1+1/M). As the focal distance of the lens-under-test is small (± 8 mm), a high resolution CMOS sensor was used (Basler ace - acA2000-165uc, 2040 x 1086 pixels and pixel size 5.5 µm) in combination with a fixed focal length imaging lens (25mm/F1.4 59871 Edmund optics, New Jersey). The object consisted of a periodic pattern of dark and white lines. Reference image was taken without the lens-under-test by placing the camera at the position with the image in focus. The lens-under-test was placed at random position from the object and the distance of the camera was repositioned such that the image of the object is in focus. Measurement method was verified by a known aspheric lens with focal distance 4.03 mm (Thorlabs C340TMD-A) resulting in an error of less than 1% on the focal length.
Results :
Lens power at baseline was 17 ±0.95 D and did not change when treated with saline. Lens power was measured in air and converted to lens power in water (refractive index of lens in air is 1.5, refractive index of lens in water is 1.13). Lens power increased after 2 hours of FAOD treatment with 0.45 ± 0.35 D, after 3 hours of FAOD treatment with 0.96 ± 0.96 D and after 5 hours (maximum) with 2.11 ± 0.67. FAOD treatment of human lenses thus results in increased lens power.
Conclusions :
FAOD treatment, but not PBS treatment, leads to gain of human lens power after 5-hours of incubation.These results indicate that FAOD could potentially be used to reverse presbyopia by deglycating lens proteins.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.