The Type II Aachen-Keratoprosthesis in humans: case report of the first prolonged application.

PURPOSE: To improve the prognosis of corneal grafts in silicone-oil filled eyes of patients with severe ocular trauma by a prolonged application of the Type II Aachen-Keratoprosthesis (KPro). This application endeavors to improve post-keratoplasty prognosis by avoiding corneal endothelial dystrophy in the aphakic eye due to contact with silicone oil. PATIENT AND PROCEDURES: The Aachen-Keratoprosthesis' haptic was modified to allow tight contact with cells. The Type II Aachen-Keratoprosthesis was then implanted in an 18-year-old male, with previous management of bilateral corneal rupture. Rather than utilize the device as a temporary intraoperative tool, we extended the device's lifespan in the eye. MAIN FINDINGS: Following implantation, the patient could see hand movements up to 0.1 with best correction. After 8 weeks, vision decreased and a retroprosthetic membrane proliferated. Upon conjunctival retraction, 3 months after the initial surgery, we excised the prosthesis and performed a re-vitrectomy and corneal grafting. The silicone oil was removed. After eighteen postoperative months, the graft remained clear, the retina was completely attached, and the vision was stable: 0.1 best corrected. CONCLUSION: This case reports the prolonged implantation and prospect of the Type II Aachen-Keratoprosthesis to be utilized as a permanent device to restore vision in the near future.

Aachen keratoprosthesis as temporary implant for combined vitreoretinal surgery and keratoplasty: report on 10 clinical applications.

UNLABELLED: A new keratoprosthesis was used during pars plana vitrectomy in order to test the optical quality, watertightness, short-term biocompatibility and handling of the new device. The implantability was also tested, given that this keratoprosthesis might in future be left in place for several months. This Aachen keratoprosthesis (Aachen-KPro) is developed to be used as permanent implant to restore vision in corneal blind patients. PATIENT AND METHODS: The Aachen-KPro was used during pars plana vitrectomy in 10 patients with opaque corneas. In four cases, trauma precipitated the ocular disease. Eye burn was the cause of corneal and retinal disorders in another four cases. One patient had a history of congenital glaucoma with myopia, and one of uveitis with corneal dystrophy. After trephination of 6.5 mm in diameter, the Aachen-KPro, composed of soft silicone rubber, was temporarily placed in the trephination hole. After completion of the vitrectomy, the Aachen-KPro was replaced by a 7 mm corneal graft. RESULTS: Intraoperative use of the Aachen-KPro allowed uncomplicated intraoperative handling, smooth adaptation to the corneal rim in the trephination hole, and an undistorted view of the central and peripheral retina. Leakage, even during scleral depression, could be avoided by individual suturing of the scleral rim. After a follow-up period of 1-10 months, the retina was still attached in all cases. The corneal graft was clear after surgery in four eyes, and edema was found in three cases. Amnion or conjunctiva was placed over three patients' transplants. CONCLUSION: We report the first temporary implantations of a new keratoprosthesis in 10 patients. Its flexibility and good optical qualities allowed control of intraoperative procedures. The outcome and prognosis of the vitreoretinal surgery and keratoplasty were related to the primary diagnosis. The Aachen-KPro has shown advantages, especially in eyes where the anterior eye segment is severely damaged by eye burn or previous surgical interventions. In the future, prolonged use of the Aa-chen-KPro is planned for selected eyes.

Aachen-Keratoprosthesis as temporary implant. Case report on first clinical application.

BACKGROUND: The Aachen-Keratoprosthesis was designed to serve as a permanent keratoprosthesis, modeling natural corneal physical properties as closely as possible. Prior to permanent application in patients, keratoprostheses are commonly tested in animal models to assess biochemical and biomechanical compatibility. However, immune and inflammatory responses acquired through animal experimentation are difficult to extrapolate in order to develop a predictable and generalized outcome in humans. Therefore, this preliminary report includes results following a temporary implantation of the Aachen-Keratoprosthesis in a patient during vitreoretinal surgery to assess the long-term prospect of application as a permanent artificial cornea. PATIENT AND METHODS: A 43 year old man presented with a ruptured right eye resulting in an opaque cornea and retinal detachment. A soft silicone rubber keratoprosthesis, the Aachen-Keratoprosthesis, was temporarily implanted. Subretinal membranes were removed and the total retinal detachment was reattached. Liquid perfluorocarbon and silicone oil were used. The temporary keratoprosthesis was replaced by a 7 mm corneal graft after completion of surgery. RESULTS: The Aachen-Keratoprosthesis was securely positioned into the trephined hole. It allowed complete visualisation of vitreous, retina and thus controlled manipulations in the vitreous cavity up to the extreme periphery. Leakage across the trephination-prosthesis interface was minimal. CONCLUSION: We report the first temporary application of an innovative keratoprosthesis. Its flexibility and good optical qualities allow visualisation and control of intraoperative procedures. This temporary pilot study of the Aachen KPro encourages further investigation of the Aachen KPro as a permanent replacement for a diseased cornea.