Corneal endothelial cell (CEC) disorders, such as Fuchs’s endothelial corneal dystrophy, induce abnormal corneal hydration and result in corneal haziness and vision loss known as bullous keratopathy. We investigated whether injection of cultured human CECs supplemented with a rho-associated protein kinase (ROCK) inhibitor into the anterior chamber could increase CEC density.

We performed an uncontrolled, single-group study involving 11 persons who had received a diagnosis of bullous keratopathy and had no detectable CECs. Human CECs were cultured from a donor cornea; a total of 1×10⁶ passaged cells were supplemented with a ROCK inhibitor (final volume, 300 μl) and injected into the anterior chamber of the eye that was selected for treatment. After the procedure, patients were placed in a prone position for 3 hours. The primary outcome was restoration of corneal transparency, with a CEC density of more than 500 cells per square millimeter at the central cornea at 24 weeks after cell injection. Secondary outcomes were a corneal thickness of less than 630 μm and an improvement in best corrected visual acuity equivalent to two lines or more on a Landolt C eye chart at 24 weeks after cell injection.

At 24 weeks after cell injection, we recorded a CEC density of more than 500 cells per square millimeter (range, 947 to 2833) in 11 of the 11 treated eyes (100%; 95% confidence interval [CI], 72 to 100), of which 10 had a CEC density exceeding 1000 cells per square millimeter. A corneal thickness of less than 630 μm (range, 489 to 640) was attained in 10 of the 11 treated eyes (91%; 95% CI, 59 to 100), and an improvement in best corrected visual acuity of two lines or more was recorded in 9 of the 11 treated eyes (82%; 95% CI, 48 to 98).

Injection of human CECs supplemented with a ROCK inhibitor was followed by an increase in CEC density after 24 weeks in 11 persons with bullous keratopathy. (Funded by the Japan Agency for Medical Research and Development and others; UMIN number, UMIN000012534.)