Effects of ascorbic acid on mechanical and optical properties of cultured porcine lenses

Abstract

Purpose : Mechanical and optical properties of patient’s lenses are known to change after vitrectomy, potentially contributing to diseases such as cataract and posterior capsule opacification. Ascorbic acid (AA) is highly concentrated in the vitreous. This study evaluated whether AA protected cultured lenses against changes in mechanical and optical properties.

Methods : Pairs of fresh porcine eyes were acquired then intact, encapsulated lenses removed. Lenses were cultured in one of four environments consisting of (1) M199 cell culture media alone (control), as well as M199 supplemented with (2) vitreous humor, (3) 365 mg/mL ascorbic acid (AA), or (4) AA and vitreous humor. Media was changed every 24 hours. Paired lenses were cultured in similar conditions except one lens was cultured with supplementary AA while the other was not. Whole lenses were removed from culture after incubation periods of 12 hours to 8 days. Optical transmission and elastic modulus were estimated using photography and a spinning test, respectively. The nucleus of each lens was also analyzed with Raman spectroscopy and shear rheometry.

Results : Rheologic data from some lens pairs showed decreased lens stiffening over time in the presence of vitreous when compared to control lenses. Optical transmittance from shorter incubation times were improved with vitreous , AA, and vitreous with added AA. Lenses cultured for longer times were always stiffer in rheologic analysis.

Conclusions : We previously found that inclusion of vitreous in lens tissue culture experiments improved lens viability over time. These findings suggest that AA may be the active ingredient in the vitreous preserving the lens’ viability and material properties during culture.

This is a 2021 ARVO Annual Meeting abstract.

 

Measured fold change in transmittance with and without added AA.

 

Measured fold change in storage modulus with and without added AA.