Long-Term Outcomes of Boston Type 1 Keratoprosthesis in Patients With Limbal Stem Cell Deficiency From Aniridia Versus Other Causes

Friday, April 17, 2015
KIOSKS (San Diego Convention Center)
Samantha Williamson, MD
Joao Crispim, MD
Jose de la Cruz, MD, MSc
Maria S. Cortina, MD

Purpose
To describe long-term outcomes of Boston Type 1 Keratoprosthesis (KPro) implantation in eyes with limbal stem cell deficiency (LSCD) from aniridia versus other causes.

Methods
Records were reviewed of 130 KPro implantations at a university-based tertiary care institution from February 2007 to July 2014. Eighteen eyes from 17 patients with aniridia underwent KPro implantation. Fourteen eyes of 13 patients with limbal stem-cell deficiency from other causes (10 chemical burn, 2 keratoconjunctivitis, 2 of unknown etiology) underwent KPro implantation. Outcome measures included preoperative and last recorded post-operative best-corrected visual acuity (BCVA), intraoperative, and post-operative complications, including retroprosthetic membrane development (RPM) and implant extrusion.

Results
Mean age at KPro implantation for aniridics was 44±18 years. BCVA preoperatively measured 20/400 or worse in all eyes. After a mean follow-up of 33±23 months, post-operative BCVA measured 20/250 or better in 10 eyes. Postoperative complications included RPM(12) in 67% and corneal melt(3) and extrusion(3) in 16.7%. Mean age at KPro implantation for non-aniridic LCSD patients was 59±15.5. Pre-operatively, BCVA measured 20/200 or worse in all eyes. After a mean follow-up of 46±16.3 months, post-operative BCVA measured 20/60 or better in 6 eyes and 20/400 or better in 9 eyes. Postoperative complications included RPM(7) in 50% and corneal melt(5) and extrusion(5) in 36%. The overall retention rate was 83% in aniridic and 64% in non-aniridic LSCD eyes, with a mean implant survival of 1635±1132 and 1022±485 days, respectively.

Conclusion
Long-term follow-up of keratoprosthesis implantation in patients with LCSD from aniridia or other causes supports Kpro as a useful therapeutic option in these challenging patients. The majority of eyes in each group demonstrated improved post-operative visual acuity. Prior studies have questioned LCSD etiology as a prognostic factor, but no statistically significant differences (p>0.05) were seen in rates of retroprosthetic membrane, sterile keratolysis, and implant extrusion.