Abstract
Purpose: :
To evaluate nanoscale dendritic polymers as in situ polymerizable adhesives for repairing corneal lacerations, cataract incisions, and corneal transplants.
Methods: :
In our study, we evaluated the efficacy of dendritic polymer hydrogel adhesives in sealing corneal lacerations, cataract incisions, and corneal buttons in enucleated porcine and human eyes. A series of dendrimers of various sizes, shapes, and crosslinking chemistries were investigated. For the central corneal laceration study, a keratome blade was used to create a full thickness 4.1 mm wound. A 3.0 mm dual beveled, angled slit knife was used to make the 3.0 mm clear corneal linear incision. In the corneal transplant studies, the entire thickness of the cornea was removed as a button using an 8 mm trephine and this button was autographed back onto the existing eye. For all the studies, one group of eyes were treated with the dendritic adhesive and the other group was treated with sutures or left untreated according to the standard of care for each wound model. The eyes were placed under an operating microscope and then pumped with saline solution. The leak pressure, or intraocular pressure at which fluid leaked from the wound, was measured for each group (untreated, suture, adhesive; N>=4/group). In vivo studies are on going.
Results: :
The leak pressure for eyes with the untreated central laceration was less than 5 mm Hg, but for the eyes treated with the dendritic adhesives the leak pressure varied from 70 to greater than 250 mmHg depending on the formulation. For the cataract incision study, the mean leak pressure for the self-sealed eyes and suture treated eyes were 25 and 50 mm Hg, respectively, while for the eyes treated with the dendritic adhesive it was greater than 150 mmHg. In the corneal transplant model, the leak pressure for eyes with the autografts receiving 16 interrupted 10-0 nylon sutures was 15 mm Hg. When the hydrogel sealant was applied to the sutured wound with 16 interrupted sutures, the leak pressure was found to increase to 101 mmHg.
Conclusions: :
This study demonstrates the ability of these new biocompatible dendritic hydrogel adhesives to successfully repair a variety of corneal wounds. The relationships between polymer structure/composition and performance will be discussed along with the in vivo results.
Keywords: cornea: clinical science • cornea: basic science • wound healing