Abstract
Purpose: :
To evaluate the effect of a biodegradable hyaluronic (HA) scaffold on lens regeneration in the rabbit.
Methods: :
A biodegradable HA scaffold was made by thermal degradation of a cross-linked HA gel. A non-degraded HA gel control was used for comparison. Endocapsular lens extraction by phacoemulsification and irrigation/aspiration of the lens through a 2 mm capsulorrhexis was performed in 9 New Zealand (NZ) white rabbits. Approximately 0.03-0.06 cc of the HA gel was injected to distend the capsule bag and maintain capsule tautness. The rabbits were followed for 3 months by slit lamp biomicroscopy, photography, Scheimpflug analysis and A-Scan biometry. The lens regrowth was estimated by determining the percent of lens regrowth filling the capsule bag using retroillumination photographs taken at 1 wk, 2 wk, 1 mo, 2 mo & 3 mo. The clarity of the regenerated lens was graded on a scale of 0 to 4 with 0 = opaque and 4 = a normal clear lens.
Results: :
The cross-linked HA gel had a cobblestone appearance when placed into the evacuated capsule bags. The degraded HA gel was uniformly clear with a smooth texture. Lens regeneration was first noted at Day12. By one month, the percent of lens regrowth filling the capsule bag was 42% for the degraded HA gel and 4.9 % for the crosslinked HA gel. The capsule bag was filled with lens regrowth by Day 62 in the degraded HA gel group. By the close of the study at 3 months, the retained HA in the cross-linked HA gel group occupied 36.17% of the central lens area. In the degraded HA gel group, the regenerated lenses were spherical with a clear cortex of good structure. The nucleus was slightly opaque and spheroid in 4 of the 6 lenses and filled approximately 13.7% of the central lens area. At 3 months, the regenerated axial lens thickness was 4.4±0.2 mm for the degraded HA gel Group.
Conclusions: :
Lens regeneration was facilitated by implantation of a biodegradable HA scaffold in NZ white rabbits.
Keywords: regeneration • proteoglycans/glycosaminoglycans