Abstract
Abstract: :
Purpose: To assess outcomes and identify risk factors for penetrating keratoplasty using a synthetic cornea, AlphaCorTM. Methods: A multicentre prospective clinical trial was established with Ethics committee approvals to establish the safety and efficacy of a novel synthetic cornea in patients too high risk for donor corneal grafts. Pre-operative visual acuities ranged from PL to 20/200. Risk factor and outcome data was collected to allow comparison of outcomes with matched controls (ie same patient, previous graft); unmatched controls (ie same surgeon, standard donor graft performed previous to each synthetic graft) and with summarized graft outcome data (Australian Corneal Graft Registry). Results: To 28/11/01, 40 devices have been implanted. Follow-up 0.5 to 36 months, mean 9.2 months. Device retention is 87.5%. There were no extrusions but 3 devices (7.5%) were removed due to stromal melts adjacent to the device and were replaced with donor grafts. 2 devices (5%) were removed because of depositions, (one a diffuse deposition attributed to drug deposition , one due to opacities due to recurrent infection of host tissue) and were replaced with new devices. Postoperative acuities range PL to 20/30, mean improvement of over 2 lines. The single most significant risk factor for melt-related complications after AlphaCor implantation is a history of herpes simplex. Risk factors for loss of optic clarity have also been identified and include certain topical medications and smoking. Conclusion: Early outcomes with AlphaCor (previously known as the Chirila KPro) suggest that the device is a promising alternative to donor tissue in high risk cases. In particular, acuity outcomes for patients with a history of prior graft failure compare favourably with controls. The device also demonstrates a high degree of safety, due to its relatively non-invasive, repeatable method of implantation. Case selection is important for good outcomes and herpetic patients are now excluded pending further clinical trials. Further, avoidance of risk factors that cause deposition within hydrogels is important for sustained good outcomes. Clinical evaluation continues.
Keywords: 451 keratoprostheses • 353 clinical (human) or epidemiologic studies: outcomes/complications