The outermost layer of the eye, the cornea, “is made of cells but is as transparent as glass,” says Arnaud Lacoste, an investigator in Ophthalmology at the Novartis Institutes for BioMedical Research. “And any defect in the cornea that affects the transparency reduces vision; severe defects lead toward blindness.”
The transparency depends on a layer of cells called the corneal endothelium, which supplies just enough fluid to the cornea to ensure that it receives a steady source of nutrients. “In diseases where this thin layer of cells is disrupted, water accumulates in the cornea, which makes it cloudy,” Lacoste notes. “As a result, patients lose vision and often must receive a corneal transplant.”
Understanding the corneal endothelium might help researchers to design a new generation of therapies that spare patients from surgery. This image shows a 10-micron-thick en face slice of the layer. Proteins involved in the maintenance of cell-to-cell interactions are labeled in green and red, while cell nuclei appear in blue. The green protein is more abundant in the outer part of the cells, while the red protein is more abundant in deeper parts of the cells that are closer to cell nuclei.