Outcomes of the keratoprosthesis in pediatric patients 5 years after implantation

A study of the 5-year outcomes of a keratoprosthesis (KPro, Massachusetts Eye and Ear) in pediatric patients showed that most eyes had improvements in vision, but device retention and complications remain challenging, according to Michael Bednar and colleagues who presented their findings at the 51^st annual American Association for Pediatric Ophthalmology and Strabismus in Boston from March 18-22.

Bednar is a medical student associated with the Cornea Service, Massachusetts Eye and Ear (MMEI), Department of Ophthalmology, Harvard Medical School, Boston.

The KPro device is an alternative to standard corneal transplantation for use in patients who may not be good candidates for transplantation because of the potential for a poor prognosis.

Implantation of the device in pediatric patients is uncommon but may have a place in specific cases, the investigators explained, to “support visual development during critical periods and reduce the risk of amblyopia.”

Bednar and colleagues undertook this single-center retrospective review to evaluate the clinical outcomes of KPro devices after implantation into pediatric eyes and determine device retention, complication rates, and visual acuity.

A total of 525 eyes had undergone implantation of the KPro device. Of those, 11 eyes of nine children younger than 18 years were included; 10 of the 11 patients were female (mean age, 6.3 years; range, 6 months to 17 years). Six eyes had preexisting glaucoma.

The underlying diseases of the study patients were corneal opacity in four patients, Stevens-Johnson syndrome in three patients, and chemical burns and a congenital disorder in two patients each.

The indications for KPro implantation were graft failure in seven eyes, primary corneal procedure in four eyes, and corneal opacity and corneal edema/neovascularication in two eyes each.

What the KPro evaluation found

The investigators reported the outcomes associated with the KPro: a retention rare of 36.4%, development of a retroprosthetic membrane 72.7%, corneal melt 68.9%, retinal detachment 29.9%, de novo glaucoma 35.7%, and endophthalmitis 20.0%. No infectious keratitis, sterile vitritis, or glaucoma progression occurred in any eyes.

Regarding visual acuity, two patients achieved 20/40 or better, three 10/150 to 20/800, one counting fingers, and two patients each hand motions vision and fix and follow vision. The Visual acuity was unavailable for one patient.

The investigators concluded, “Most pediatric eyes achieved an improvement in vision. with KPro implantation, and 46% of eyes achieved a postoperative best-corrected visual acuity of 20/800 or better.”

Retention of the device and complications, especially development of a retroprosthetic membrane and corneal melts, continue to be challenges.

He was joined in this study by Leyla Yavuz Saricay, MD, and Thomas H. Dohlman, MD, both from the Cornea Service, MEI, and Boston Children’s Hospital, Department of Ophthalmology, Harvard Medical School.