Five Rs enable thorough optic nerve exam, documentation

The “five Rs” help ophthalmologists improve the quality and documentation of optic nerve examination, said Anne L. Coleman, MD, PhD, The Frances and Ray Stark Professor of Ophthalmology, Jules Stein Eye Institute, UCLA David Geffen School of Medicine, Los Angeles.

“Examining the optic nerve is critical for diagnosing glaucoma and following patients for disease progression,” Dr. Coleman said. “I find this mnemonic useful in my clinical practice and for resident training because it offers a systematic approach to the optic nerve examination that enables a thorough evaluation and proper documentation.”

The “five Rs” were developed by Robert Weinreb, MD; Felipe Medeiros, MD, PhD; and Remo Susanna Jr., MD, and represent five rules for performing the clinical evaluation:

• Observe the scleral Ring to identify the limits of the optic disc and its size.
• Identify the size of the Rim.
• Examine the Retinal nerve fiber layer.
• Examine the Region of parapapillary atrophy.
• Look for Retinal and optic disc hemorrhages.

Dr. Coleman explained it is important to look at the optic disc and determine its size because the size of the cup varies with the size of the disc. Therefore, knowing if the disc is small or large is helpful in interpreting cupping. 

Evaluation of the rim focuses in part on whether the size findings obey the “ISNT” rule (inferior > superior > nasal > temporal rim) and also looks for notching and thinning. Retinal nerve fiber layer evaluation is easier with red-free photographs; increased visibility of retinal vessel borders is a sign of diffuse nerve fiber layer loss.

Examining the region of parapapillary atrophy focuses on the beta zone where there can be glaucoma-associated retinal pigment epithelium and choriocapillaris atrophy. Looking for retinal and optic disc hemorrhage is important because those findings are missed easily but crucial to identify since they are prognostic indicators for glaucoma progression.