The Boston type 1 keratoprosthesis (KPro), used in patients with high risk of corneal graft failure, is increasingly being used. However, the medium- to long-term outcomes are currently unclear. We analyzed the medium- (2–5 years) and long-term (>5 years) efficacy and safety of the Boston type 1 KPro in terms of visual outcomes, device retention, and postoperative complications.
We last searched electronic databases (Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid MEDLINE Epub Ahead of Print, EMBASE, and CENTRAL) on March 31, 2018. Visual outcomes and device retention at 2 and 5 years, alongside postoperative complications, were primary outcome measures.
We identified 407 articles. Thirty studies were included in this systematic review and meta-analysis. The combined proportion of eyes with ≥6/60 vision was 62% at 2 years and 51% at 5 years. The combined retention rate was 88% at 2 years and 74% at 5 years. Retroprosthetic membrane (36.6%) and glaucoma (39.3%) were found to be the most common long-term complications. Very few studies showed visual outcomes or retention rates at 5 years, with results sparse and collectively not meaningful because of small patient numbers and ambiguous reporting of follow-up times.
The 2-year results indicate that there is a place for the Boston type 1 KPro in the management of corneal blindness. However, there is scarce evidence regarding its medium- and long-term efficacy and safety. The high rate of reported complications necessitates strict patient selection and stringent follow-up.
*Brighton & Sussex Medical School, Brighton, United Kingdom;
†Sussex Eye Hospital, Brighton and Sussex University Hospitals NHS Trust, Brighton, United Kingdom;
‡Department of Ophthalmology, Faculty of Medicine, Alexandria University, Alexandria, Egypt;
§Medical Research Institute, Alexandria University, Alexandria, Egypt; and
¶Tongdean Eye Clinic, Hove, United Kingdom.
Correspondence: Christopher Liu, OBE, FRCOphth, FRCSEd, FRCP, CertLRS, Sussex Eye Hospital, Eastern Rd, Brighton BN2 5BF, East Sussex, United Kingdom (e-mail: Christopher.Liu@bsuh.nhs.uk).
The authors have no funding or conflicts of interest to disclose.
J. Priddy and A. S. Bardan have contributed equally to this work as joint first authors.
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Received December 21, 2018
Received in revised form May 28, 2019
Accepted June 25, 2019
Online date: August 8, 2019