ABSTRACT Purpose To compare corneal endothelial changes in patients with Fuchs Uveitis Syndrome (FUS) undergoing phacoemulsification surgery using confocal and specular microscopy. Methods We included 14 patients with unilateral FUS and cataracts who underwent phacoemulsification surgery in a Mexican referral center for inflammatory eye diseases. Preoperative confocal and specular microscopies were conducted, establishing baseline images for subsequent analyses. Surgery on the FUS eye was performed by a single surgeon and an intraocular lens was implanted in all cases. Both specular and confocal microscopy were repeated 6 months after FUS eye surgery and compared with baseline images. We used Image J to do a manual segmentation of KP and determine their density for further analysis hence developing a new tool for confocal microscopy image analysis. Results All patients underwent uneventful phacoemulsification surgery in the FUS eye. There was no significant change in endothelial cell density (ECD) from 2257 (±508.2) cells/mm2 preoperatively to 2214 (±535.1) cells/mm2 postoperatively (p = 0.809). Confocal microscopy revealed a decrease in Keratic Precipitate Density (KPD) from a median of 1413 (±2809.7) KPs/mm2 preoperatively to a median of 685.5 (1527.9) KPs/mm2 postoperatively (p = 0.036). Conclusions Phacoemulsification surgery in patients with FUS produces no significant loss of endothelial cells and morphological changes that can be detected by confocal and specular microscopy. We found a reduction in KPD 6 months after surgery on confocal microscopy. Additionally, our manual segmentation technique for KPs utilizing Image J offers a novel and practical approach for confocal microscopy image analysis.