Purpose: To investigate alterations of corneal layers in eyes treated for acute postoperative endophthalmitis. Methods: In this retrospective, nonrandomized comparative study, eyes treated with 25 gauge pars plana vitrectomy (PPV) for acute post-cataract endophthalmitis (group A) were compared to eyes receiving uneventful cataract surgery (group B) and uneventful 25 gauge PPV for epiretinal membrane (group C). After a minimum follow-up of 8 months from last surgical procedure, laser scanning in vivo confocal microscopy (IVCM) was performed. Results: Twelve eyes for each group were recruited. Comparing study eyes with control eyes of group B and C, no statistical difference was found in corneal epithelial cell density (p = n.s.), in density of nerve fibers (p = n.s.), mean grade of nerve reflectivity (p = n.s.), mean grade of nerve tortuosity (p = n.s.), mean grade of anterior keratocyte activation (p = n.s.), and corneal endothelium cell density (p = n.s.), whereas a statistically higher mean grade of posterior keratocyte activation was found in group A (p < 0.01). Epithelial and endothelial corneal morphologies were graded as regular in all groups. Langerhans cells and corneal dendritic-shaped hyper-reflective endothelial deposits were found in group A. Both findings were absent in group B and C, and the difference was statistically significant (p < 0.01). Conclusions: IVCM was a useful tool in the detection of microscopic chronic corneal abnormalities caused by postoperative endophthalmitis. These findings confirmed the presence of a subclinical chronic corneal inflammation localized to the posterior stroma that should be related to the infectious process. Future studies might clarify pathological processes in the acute phase of postoperative endophthalmitis
