Descemet Endothelial Thickness Comparison Trial II

Inclusion Criteria:

* Dysfunctional endothelium from FECD with few guttata extending beyond 4.5 mm
* Peripheral endothelial cell count \>1000 cells/mm2 in at least one quadrant
* Good surgical candidate for either procedure as determined by the surgeon
* Willingness to participate
* Age greater than 18 years

Exclusion Criteria:

* Aphakia, anterior chamber IOL or scleral fixated IOL in study eye prior to or anticipated during EK
* Pre-operative central sub-epithelial or stromal scarring that the investigator believes is visually significant and could impact post-operative stromal clarity assessment
* Other primary endothelial dysfunction such as PPMD
* Visually significant optic nerve or macular pathology
* Hypotony (Intraocular pressure \<10mmHg)
* Any prior intraocular surgery other than cataract surgery
* \>3 clock hours of ANY anterior or posterior synechiae
* \>1 quadrant of stromal corneal vascularization
* Inability to comply with post-operative instructions (i.e. unable to position)
* Pregnancy