Purpose <p>To evaluate the quantitative changes in the number and spatial distribution of corneal guttae in subjects with Fuchs endothelial corneal dystrophy (FECD) following a single intracameral injection of allogeneic magnetic human corneal endothelial cells (EO2002).</p> Methods <p>This prospective analysis included participants from a Phase 1 U.S. multicenter study who received an intracameral injection of EO2002 without concurrent endothelial polishing (endobrushing) or Descemet membrane stripping. High-resolution retroillumination images of the central cornea were captured at pre-injection (baseline), 3 months, and 6 months post-treatment. Corneal guttae were meticulously quantified by two independent, masked graders using a standardized protocol involving a 7-zone concentric circular grid overlaid on the images. Inter-grader reliability was assessed.</p> Results <p>Four participants who met the inclusion criteria were analyzed. A significant reduction in central corneal guttae was observed. The mean percentage decrease in guttae count compared to pre-injection in the central analytical zones was 53% ± 28% (standard deviation) at 3 months, progressing to 70% ± 16% at 6 months. The reduction was most pronounced in the central and paracentral zones, corresponding to the primary targeted delivery area of the magnetically guided cells, with a diminishing effect towards the periphery.</p> Conclusions <p>This study provides the first quantitative evidence of visible guttae reduction per retroillumination photography in FECD following endothelial cell therapy, without endo-polishing, Descemet membrane stripping or surgical manipulation. Our findings suggest that magnetically guided allogeneic CEC therapy may alter the Descemet membrane-endothelial complex in FECD.</p>