Better imaging detects glaucoma progression earlier

Seattle-It may be possible to view early changes in the eye before the clinical symptoms of glaucoma become apparent. A better understanding of the structural changes in glaucoma could potentially allow for a better diagnosis of the disease, said Kevin M. Ivers, a PhD candidate at the College of Optometry, University of Houston.

Using the adaptive optics scanning laser ophthalmoscope (AOSLO), which takes sharper and higher-resolution images of the eye than current clinical instruments, Ivers and his team were able to view very early changes in the eye.

Speaking at the annual meeting of the American Academy of Optometry, Ivers discussed the results of a study involving non-human primates.

“The initial damage of glaucoma likely occurs in a tissue called the lamina cribosa, which lies in the optic nerve at the back of the eye,” Ivers said. “It is sponge-like tissue that provides structural and functional support to nerve fibers, which pass visual information to the brain.”

In 7 subjects, a change was seen in the lamina structure. In 4 subjects, increases in the anterior lamina cribosa surface depth (ALCSD) and mean pore parameters occurred prior to a change in the retinal nerve fiber layer (RNFL) thickness.

These changes thus occurred prior to clinical changes, Ivers said.

“To summarize,” he said, “We can see these changes in the lamina prior to changes in the RNFL thickness, and we can use high-resolution instruments to provide images of the lamina. We can track changes in disease progression during glaucoma.”

This will ultimately provide a better understanding of the disease mechanism along with the possibility of earlier diagnosis, Ivers concluded.