Although recent developments in endothelial keratoplasty techniques have provided faster and more predictable visual rehabilitation, these procedures are still invasive and can cause unwanted side effects, such as an early surge of endothelial cell loss and less than ideal corneal shape.1 Looking at an alternative approach, a new study published online in Ophthalmology reports that a novel cell injection therapy using cultured human corneal endothelial cells (hCECs) for patients with endothelial failure is safe and effective up to five-years postoperatively.

A team of researchers from Japan enrolled 11 eyes of 11 patients with pseudophakic endothelial failure conditions who underwent hCEC injection therapy between 2013 and 2014.

All patients had follow-up exams at weeks one, four, 12 and 24, in addition to annual visits up to year five postoperatively. The study considered specific corneal endothelial cell parameters including corneal endothelial cell density (ECD), coefficient of variation of area and percentage of hexagonal cells, in addition to central corneal thickness, best-corrected visual acuity (BCVA) and intraocular pressure (IOP).

At five years post-op, the researchers found normal corneal endothelial function was restored in 10 of the 11 eyes, and corneal and epithelial and stromal edema completely disappeared. The hCECs were successfully repopulated on the Descemet’s membrane and/or the bare posterior-surface of the corneal stroma, indicating they were biologically functional with good longevity, the researchers noted.

Additionally, contact specular microscopy imaging performed at five years revealed a relatively high corneal ECD at the center of the posterior corneal surface in 10 eyes, a decrease of coefficient of variation and an increase of the hexagonality of the cells, suggesting CECs at the posterior surface at the study’s end tended to be more stable than those at the early postoperative period, the investigators suggested.

BCVA also significantly improved in 10 of the treated eyes, with a mean logMAR visual acuity change of 0.046 from 0.876 pre-surgery. In addition, the researchers observed no major adverse reactions directly related to the hCEC injection therapy.

The findings in this ‘first-in-man’ clinical trial suggest this minimally invasive intervention is a safe and effective treatment for patients with severe corneal endothelial failure conditions, researchers wrote in their paper.

Numa K, Imai K, Ueno M, et al. Five-year follow-up of first eleven cases undergoing injection of cultured corneal endothelial cells for corneal endothelial failure. Ophthalmology. September 6, 2020. [Epub ahead of print].