Keratolimbal allograft for limbal stem cell deficiency after severe corneal chemical injury: a systematic review.

PURPOSE: To review the published literature on outcomes of keratolimbal allograft (KLAL) for the surgical treatment of limbal stem cell deficiency (LSCD) and corneal blindness after severe corneal chemical injury.

METHODS: Literature searches were conducted in the following electronic databases: MEDLINE, EMBASE, Science Citation Index, CINAHL, LILACS and the Cochrane Library. Standard systematic review methodology was applied. The main outcome measure was the proportion of eyes with best-corrected visual acuity (BCVA) ≥20/200 at last follow-up. Other measures of allograft success were also collected.

RESULTS: We identified six reports in which KLAL outcomes in the eyes after chemical injury could be distinguished. There were no randomised controlled studies. The outcomes of KLAL in 36 eyes of 33 patients were analysed. One study with seven eyes did not specify KLAL follow-up specific to chemical injury. Median postoperative follow-up for the other 29 eyes in 26 patients was 42 months (range 6.2-114 months). In the same 29 eyes, 69% (20/29) had BCVA ≥20/200 at the last follow-up examination. Eighty-nine per cent of all eyes (32/36) underwent penetrating keratoplasty simultaneous or subsequent to KLAL.

CONCLUSIONS: The number of studies where outcomes of KLAL in eyes with severe corneal chemical injury could be discerned was limited, and variability was observed in outcome reporting. The quality of evidence to support the use of KLAL in LSCD in severe chemical corneal burns was low. Standardisation and longer follow-up are needed to better define evidence-based best practice when contemplating surgical intervention for blindness after corneal chemical injury.

PROSPERO REGISTRATION NUMBER: CRD42017054733.