Pattern electroretinogram optimized for glaucoma screening (PERGLA) can be used to detect early destruction of retinal ganglion cells (RGCs). This allows patients to undergo glaucoma surgery while damage is still reversible, according to a study in the December issue of Ophthalmology.

PERGLA is a non-invasive test that requires the placement of electrodes on a patient’s forehead, temples and lower eyelids.

In this study, researchers from the Bascom Palmer Eye Institute analyzed data from 47 patients with uncontrolled intraocular pressure or progressive glaucomatous optic neuropathy.

Patients underwent trabeculectomy or aqueous drainage device implantation; they had an ocular examination and PERGLA before surgery as well as three months post-op.

At the end of the study, the researchers found that mean postoperative intraocular pressure was significantly lower than values before surgery, which suggested a statistically significant recovery in RGC function. Additionally, the researchers noted that mean PERGLA amplitude was significantly increased and PERGLA phase was decreased following surgery.

“An increase in PERGLA amplitude implies that viable RGCs were able to generate a stronger electrical signal after surgery. Similarly, the reduced PERGLA phase after surgery suggests a reduction in latency, which is consistent with RGC functional recovery,” wrote lead author Mitra Sehi, Ph.D., and associates. “It remains to be established whether the observed changes in PERGLA amplitude and phase in the early postoperative period are maintained with extended follow-up.”

Sehi M, Grewal DS, Goodkin ML, Greenfield DS. Reversal of retinal ganglion cell dysfunction after surgical reduction of intraocular pressure. Ophthalmology. 2010 Oct 6. [Epub ahead of print]