Five- to Twelve-Year Outcomes of Autologous Simple Limbal Epithelial Transplantation: Long-Term Corneal Epithelial Imaging and Phenotypic Analysis

PURPOSE: To objectively assess the long-term corneal epithelial recovery after autologous simple limbal epithelial transplantation (SLET) for ocular chemical burn (OCB)-induced unilateral limbal stem cell deficiency (LSCD). DESIGN: Prospective, fellow-eye controlled, cross-sectional imaging and diagnostic study. SUBJECTS: The study included 47 patients, who were 5 to 12 years postautologous SLET done for OCB-induced unilateral LSCD. METHODS: The donor and recipient eyes of all patients were assessed at a single follow-up visit with slit-lamp biomicroscopy (SLB), in vivo confocal microscopy (IVCM), impression cytology (IC), anterior segment optical coherence tomography (ASOCT), and Scheimpflug imaging (SI). The objective parameters that were assessed were corneal epithelial phenotype (CEP), thickness (CET), reflectivity (CER), and densitometry (CED). Median values with inter-quartile ranges were assessed for all parameters and analyzed using non-parametric tests. MAIN OUTCOME MEASURES: The primary outcome measure was successful restoration of normal CEP on SLB, IVCM, and IC. Secondary outcome measures were comparison of CET and CER on ASOCT, and CED on SI between the eyes with successful and failed CEP restoration, and donor eyes. RESULTS: The study analyzed 94 eyes of 47 patients, with a median follow-up of 5.75 years post-SLET. Successful restoration of CEP on SLB, IVCM, and IC was observed in 32 (68%) recipient eyes, while failure was seen in 15 (32%) eyes. The CEP was normal in all 47 (100%) donor eyes. The median CET was similar in healthy donor eyes, eyes with successful CEP restoration (55.9 microns, 50.3-59.2 vs. 57.8, 49.9-63.1; P = .47) and eyes with failure (57.7 microns, 50.9-66.2; P ≥ .59). Although, the median CER (100.72, 89.9-111.2 vs. 121.6, 109.7-139.8; P = .001) and CED (14.7, 13.4-17.1 vs. 26.5, 20.1-30.2; P = .02) values were significantly lower in eyes with successful CEP restoration as compared to eyes with failure, they were still significantly greater than corresponding values in the healthy donor eyes for CER (90.33, 84.9-96.9; P = .02), and CED (13.5, 11.4-15.1; P = .03), respectively. CONCLUSIONS: Long-term 5-12 year successful restoration of the corneal epithelial phenotype was seen in two-thirds of eyes postautologous SLET. While corneal epithelial reflectivity, and densitometry were relatively better in eyes with successful outcomes, corneal epithelial thickness was similar in all eyes.