Glaucoma Specialty

Visual electrophysiology can:

  • Establish baseline measurements once high intraocular pressure is detected
  • Provide objective functional testing to complement structural imaging
  • Provide additional information to help diagnose, manage, and track treatment efficacy of glaucoma

Objective monitoring of optic nerve function using PERG and PhNR

Glaucoma primarily affects the retinal ganglion cells (RGCs) whose function can be assessed with visual electrophysiological tests that measure timing and amplitudes of electroretinography (ERG) responses. These objective measurements can provide valuable data for tracking functional changes over time, without the subjective variability of visual field tests.  

Pattern electroretinography (PERG) test administered to a patient

Pattern ERG (PERG)

A sensitive measure for early diagnosis, the PERG test targets macular and central RGC function, providing early functional biomarkers for subclinical detection of RGC dysfunction.  

You can perform PERGs using isoluminant monitors such as the Diagnosys LI-LCD monitor or the Envoy OLED. Both of these stimulators can be added to either desktop or cart-based clinical systems.  

CPT Code for PERG: 0509T  

Photopic negative response (PhNR)

The PhNR test measures global function of RGCs and is well-suited for general monitoring of RGC health across the retina. Learn about the recent developments in PhNR. 

Perform the PhNR test using the ColorDome stimulator on any of our clinical systems.  

CPT Code for PhNR (ERG): 92273 

A patient is undergoing electroretinography (ERG) using a Ganzfeld stimulator.

You can order clinical accessories directly from Diagnosys.  

For support with running tests and understanding applications, please contact our support department or visit our Help Center.