Abstract
Purpose:
Although corneal transplantation is one of the most common and successful organ transplants in humans, a significant number donor corneas reject every year. Cornea neovascularization (NV), opacification and increased thickness are all indicators of cornea rejection. One of the factors associated with an increased rate of cornea neovascularization and rejection is the type of suture and suturing technique used to secure the donor button. This study evaluates postkeratopasty outcomes using OCT and angiography following two suture techniques: interrupted or continuous, in a rabbit model of penetrating keratoplasty (PK).
Methods:
Twelve New Zealand White rabbits underwent allogenic PK in one eye. The donor cornea was secured with either a continuous 10/0 nylon suture (six animals) or with sixteen 10-0 nylon interrupted sutures (six animals). Transplant rejection was assessed by measuring the area of NV, the level of opacification and the cornea thickness. The area of NV from the limbus into the graft was measured by using corneal fluorescein angiography (FA) and digital measurements. Persistence of opacification was assessed by slit-lamp microscopy and graded on a 0 to 4+ scale. Cornea thickness and cornea astigmatism was measured by ocular coherence topography (OCT). At sacrifice (day 28) the cornea was fixed for histological analysis of neovascularization, inflammation, and rejection.
Results:
Corneal neovascularization, opacification, cornea thickness was significantly higher in the interrupted suture group compared to the continuous suture group. (p = 0.006 or less). All corneas in the continuous suture group exhibited minimal neovascularization and generally presented with ≤ 1 opacification at each time point studied. A single running suture results in less postoperative astigmatism compared with the interrupted sutures technique.
Conclusions:
Corneas within the interrupted suture group were associated with a significant increased level of neovascularization, opacification and astigmatism followed by a higher rate of rejection. The suturing method appears to be a factor leading to the rate of cornea rejection in a rabbit PK model and may be correlated to human surgical outcomes.
Keywords: 480 cornea: basic science •
551 imaging/image analysis: non-clinical •
609 neovascularization