Abstract
Purpose :
Retinal detachment is a common problem impacting almost 50,000 people annually in the US. If not immediately treated, loss of vision can result but the current state of the art, using synthetic “tamponades”, has serious drawbacks. We hypothesize that a refractive-index match hydrogel with tailored swelling pressure and degradation time will allow normal eye function during healing without significant behavioral changes or secondary surgeries.
Methods :
Eighteen (18) male and 18 female New Zealand White rabbits received full baseline ophthalmic exams. Following vitrectomy and subretinal injection of 0.9% NaCl to create a large inferotemporal RD, 24 animals received hydrogel and 12 animals received normal saline as controls. ERG, and OCT were measured at 1, 7, 14, 28, 49 and 84 days post-vitrectomy. IOP, slit-lamp and gross exams were performed at 1 week intervals. Eyes were collected at 14, 28, 49 and 84 days and histology was determined at each time point for one control and one test article. In addition a chromatographic analysis technique developed here was used to determine the evolution and clearance of the hydrogel components as it degraded at each timepoint.
Results :
There was no significant increase in intraocular pressure during the length of the study. Chromatographic tracking of the hydrogel components demonstrate that the gel is degrading in vivo over 2-3 weeks, and that the components clear from the eye over time. By the end of the study only trace levels of both components are detected. In addition, histology indicates only minimal differences between the control and test articles. The healing process was also tracked to allow comparison between the control (bleb only) and the test article.
Conclusions :
The development of a new hydrogel with tunable properties is demonstrated that can be designed to degrade over a period consistent with the healing process. The gel possesses properties similar to the native tissue and therefore works well as a temporary vitreous replacement. By designing a degradable hydrogel one can leverage the natural fluid flow of the eye to refill the eye after healing has occurred and avoid the need to permanently implant synthetic materials in this space. The preliminary data indicates that the material is well tolerated and the healing process in the presence of the gel is at least as good as the unsupported surgery.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.