Abstract
Purpose :
Total limbal stem cell deficiency (TLSCD) is mostly caused by ocular surface burns and leads to severe visual impairment in addition to other symptoms. We are conducting a prospective phase 2 clinical trial for the treatment of 23 patients with unilateral TLSCD with ex vivo expanded ALSCT to restore their corneal epithelium. These patients can then undergo a penetrating keratoplasty (PKP) to restore their sight if required. We aim to evaluate the outcomes of PKP in this group of patients
Methods :
Consecutive patients involved in our ALSCT clinical trial were included (n=23). All patients underwent previous ALSCT as per our published methods and were followed up for up to 3 years. Patients underwent PKP at least 1 year post-ALSCT. Post-operative treatment included a reducing regimen of gutta prednisolone 1%. Post-operative BCVA and refraction were recorded at least every 3 months. Corneal impression cytology was taken at 6-monthly intervals throughout our ALSCT clinical trial, and the trephined corneal button was sent for histological examination, immunohistochemistry (CK12, CK13, p63, ABCG2, Ki67) and EM. PKP complications, including rejection and failures were reported. PKP survival was estimated by Kaplan-Meier survival probability estimates
Results :
Corneal impression cytology prior to PKP confirmed complete restoration of corneal epithelium in all patients. Thirteen patients (12 males, 1 female; 6 right eyes; mean age 40 years, range 22-77, SD 16) underwent PKP post-ALSCT (mean time from ALSCT to PKP 16.9 months, range 11.9-23.5, SD 3.5); 8 further patients are awaiting PKP and 2 patients will not require PKP due to good BCVA. Two patients developed endothelial rejection, both leading to graft failure. There were no other graft failures or post-op complications; 12-month graft survival is 90% (95%CI 50.8-98.7%). Pre-op mean BCVA (logMAR) was 1.18 (range 0.48-1.7, SD 0.47), significantly improving to a post-op mean BCVA of 0.35 (range 0-0.78, SD 0.25, p<0.0001) with a mean follow-up of 11.4 months post-PKP (range 3-19, SD 5.3)
Conclusions :
Most patients (21/23) with unilateral TLSCD treated with ALSCT require a PKP for visual rehabilitation. Despite this cohort being "high risk" for PKP (i.e. pre-op inflammation and neovascularization), visual outcomes as well as rejection rates and graft failure rates are similar to that reported in the literature for routine PKP
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.