In Vivo Observation of Lens Regeneration in Rat Using Ultra-Long Scan Depth Optical Coherence Tomography

To evaluate morphologic changes of lens regeneration in rats in vivo after extracapsular lens extraction (ECLE) by ultra-long scan depth optical coherence tomography (UL-OCT).

A total of 42 Sprague-Dawley rats were used in this study. We performed ECLE on the right eyes of animals in the surgery group (n = 34). Biomicroscopy and UL-OCT scans were carried out for the surgery group immediately (within 1 hour postoperatively) and at days 1 and 3, weeks 1 and 2, and months 1, 2, and 3 postoperatively. After in vivo examination, three animals of the surgery group were euthanized at each time point for histology study, while the other 10 animals were examined continuously at those time points. The regenerated lens was evaluated in OCT images at 2 and 3 months postoperatively. The control group consisted of eight untreated rats that had OCT examination at the age of 5 months.

Lens regeneration could be observed from 2 weeks postoperatively. Regeneration was mainly at the peripheral capsular bag in the first month and central region thereafter. The average thickness of regenerated lenses was 2222 ± 309 and 2324 ± 352 μm at 2 and 3 months, respectively. Regeneration was faster in the first 2 months and slowed down thereafter. Although anterior capsule opening and posterior capsule adhesion and wrinkling existed, the regenerated lens still could form a relatively regular shape, however, the size was much smaller than that of the normal lenses from rats with the same age.

Ultra-long OCT provides longitudinal data of the process of lens regeneration on a single individual rat in vivo, which may allow one to follow and compare the lens regenerative process under different interventions or therapy after ECLE in rats.