The purpose of this study is to assess the safety of a fixed dose of human corneal endothelial cells when administered with varying concentrations of Rho kinase inhibitor (Y-27632) in patients with corneal edema secondary to endothelial dysfunction.

Key Inclusion Criteria:

1. Must have given written informed consent (signed and dated by subject or legal guardian), and any authorizations required by local law and be able to comply with all study requirements
2. Clinical diagnosis of corneal edema secondary to endothelial dysfunction
3. Best Corrected Visual Acuity (BCVA) no worse than 20/800 ETDRS (1.6 LogMAR) or better than 20/63 (0.5 LogMAR) in the study eye

Key Exclusion Criteria:

1. Keratoconus or other conditions of corneal thinning/ectasia
2. Progressive stromal or anterior corneal dystrophies
3. Pre-operative corneal epithelial, sub-epithelial or stromal staining, scarring or other opacity that is paracentral/central and visually significant, but not suspected to be secondary to corneal endothelial disease with the potential to improve from treatment with HCEC-1
4. Prior ophthalmic surgery including cataract surgery except as noted above in Inclusion Criterion #4, corneal transplantation, glaucoma (MIGS, iridectomy, trabeculectomy, valve), or vitreo-retinal surgery, aphakia, anterior chamber-IOL or iris claw IOL, multifocal IOL.
5. Relative Afferent Pupillary Defect (RAPD) in the study eye
6. Uncontrolled glaucoma or an IOP greater than 24 mmHg that is not controlled with topical beta blockers alone at the time of the Screening Visit.

The study plan and protocol will be shared with the study center and other researchers per request.

Within the treated groups, the sponsor, investigator, assessor, and subject will be masked to the assigned dose.