Purchase this article with an account.
M. K. Menz, E. E. Sutter, J. Alvarado; Distinguishing Glaucomatous and Retinal Dysfunction Using the mfERG. Invest. Ophthalmol. Vis. Sci. 2010;51(13):3265.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To differentiate retinal from optic nerve dysfunction using the mfERG techniques in patients with abnormal retinal pathology who also showed structural abnormalities typical for glaucoma.
Testing was performed on 4 glaucoma patients, 2 patients had diabetic retinopathy and 2 patients with myopic retinal degeneration. Their visual field tests were atypical for glaucoma. One patient with diabetic retinopathy also was on hydroxychloroquine (HCQ) and was suspected of having HCQ induced retinopathy. Outer retinal function was evaluated by means of the standard mfERG protocol. To test inner retinal and ganglion cell contributions to the mfERG, we employed a stimulation mode called the global flash paradigm. It enhances inner retinal response contributions and exhibits a contribution from optic nerve fibers (Optic Nerve Head Component, ONHC). The ONHC was used to evaluate nerve conduction.
In all 4 patients we could separately identify retinal and optic nerve abnormalities with the mfERG. Example: The patient suspected of having HCQ induced retinopathy showed a central scotoma in the visual field. However the retinal mfERG in this area was within normal range while the ONHC was abnormal. This suggests local optic nerve dysfunction rather than HCQ toxicity as the cause of scotoma.
Diagnosis of complicated cases that could include both retinal and optic nerve dysfunction can be facilitated with the mfERG. Our stimulation and analysis techniques allow us to locally differentiate between retinal and optic nerve dysfunction.
This PDF is available to Subscribers Only