Introduction: Corneal transplantation is one of the most common types of transplantation surgery of any tissue type. Ocular Surface Stem Cell Transplantation (OSST) aids in the improvement of clinical visual outcomes. Two major allograft OSST procedures include keratolimbal allograft (KLAL) procedure and living related conjunctival limbal allograft (lr-CLAL) procedure are performed on patients with severe LSCD.A post-operative phenomena coined “sludging” has distinct, but also overlapping clinical features with acute rejection yet has different clinical course without the same long-term consequences. Our clinical goal is to characteristic this vascular occurrence and investigate if this post portative complication has associated risk factors that increase or decrease the incidence. Methods: This study is a retrospective chart review of 278 eyes from Cincinnati Eye Institute seen from January 2006 to December 2016. The indications for OSST were eyes with severe LSCD that led to ocular impairments such as corneal conjunctivization, scarring, and vascularization leading to decreased vision. The features that were evaluated for correlation with observed sludging were gender, LSCD etiology, and type of OSST (ie. KLAL, Ir-CLAL, combined). Quantifiable data (e.g. interval after OSST when sludging first noted, time to resolution) was collected in an ordinal fashion that categorized each duration into the following intervals: less than a week, more than 2 weeks, more than 1 month, outcomes and Fischer exact test for dichotomous outcomes will be included in the statistical portion of the project. A P