PHILADELPHIA — Permanent keratoprosthesis is becoming a viable and popular alternative to corneal transplantation, according to two specialists speaking here at the 2007 Wills Eye Hospital Annual Alumni Conference.
Sadeer B. Hannush, MD, and Brandon Ayres, MD, discussed surgical techniques and case studies. In particular, the addition of a new indication for keratoprosthesis use — repeat graft failure — represents a “paradigm shift,” Dr. Hannush said.
Other indications include cicatricial pemphigoid, chemical burns, bullous keratopathy, dystrophy, ectasia and trauma. Contraindications include lack of light perception, an unstable posterior segment and uncontrolled IOP, functional vision in the contralateral eye or a successful keratoprosthesis in the fellow eye.
More than 1,000 Boston Keratoprostheses have been implanted, Dr. Hannush said, noting that the first 861 keratoprostheses implanted since January 2003 had a 95% retention rate and a 100% rate in patients with previous graft failure.
In those 861 cases, pharmacologic measures included use of fluoroquinolones and vancomycin, perioperative and postoperative steroids, anticollagenase and a bandage contact lens. A tube shunt was also used to prevent glaucoma, Dr. Hannush said.
In one case study, a 22-year-old man underwent a repeat graft with a Boston Keratoprosthesis combined with extracapsular cataract extraction with implantation of an IOL and a tube shunt. At 1 week postop, the eye had visual acuity of 20/50 with no infection. IOP was controlled without medication, Dr. Ayres said.
A second case involved a 56-year-old man who suffered an alkali burn in an auto accident. The patient had poor vision and photophobia, which was worse in his left eye. At 6 months after undergoing keratoprosthesis surgery, vision had improved to 20/40, he said.
Dr. Ayers noted that keratoprosthesis surgery requires careful patient selection. More long-term data are needed to determine whether the procedure could become a standard treatment for multi-graft rejection, he said.
