Abstract
Abstract: :
Purpose: To investigate the use of the multifocal electroretinogram (mfERG) in a Neuro-ophthalmology practice. Methods: Between March, 1999 and November 2001, 71 patients were referred from a single Neuro-ophthalmology practice for mfERG testing. Each patient had a mfERG recorded with a bipolar Burian-Allen contact lens electrode or a DTL electrode after the pupil was dilated with 1% tropicamide. The mfERGs were recorded using equipment and software from EDI. The display, 44° in diameter, consisted of 103-scaled hexagons. One 7-min. run was recorded from each eye. Amplitudes and latencies were examined with the VERIS software and programs written in MATLAB. Results: Sixty-one of the patients were tested for diagnostic purposes: to rule out the retina as the site of disease (ROR, n=39); to distinguish between diseases (2D, n=9); to rule out functional or non-organic causes (F, n=7); and to follow progression of a retinal disease (P, n=6). The remaining 10 were part of ongoing studies (e.g. the effects of ION and of the papillorenal syndrome on the mfERG). In 3 of the 61 patients seen to aid in the diagnosis, we were unable to obtain usable records due to poor fixation, technical problems or the patient's inability to tolerate the test. Of the remaining 58 patients, the mfERG was abnormal in 14 of the 37 ROR patients, 6 of 9 the 2D patients, and none of the 7 F patients. Five of the 6 progression patients could be followed with the mfERG. (The sixth progression patient was unable to stay awake.) Of the 14 ROR patients with retinal problems, the most likely cause was paraneoplastic syndrome (n=4), a vascular insult (n=3), AZOOR (n=2), cone dystrophy (n=2), trauma (n=1), ARMD (n=1), and unknown (n=1). Of the 23 ROR patients without retinopathy, the most likely cause was unknown (n=6), ION (n=5), glaucoma (n=4), optic neuropathy (n=3), contact lens overwear (n=1), amblyopia (n=1), drug toxicity (n=1), tilted disk (n=1), and meningioma (n=1). Conclusion: The mfERG aided in the diagnosis and the planning of treatment for most of patients. Of particular importance was the mfERG's ability to distinguish diseases of the retina (pre-ganglion cells) from diseases of the ganglion cells and the optic nerve.
Keywords: 395 electroretinography: clinical • 487 neuro-ophthalmology: optic nerve • 486 neuro-ophthalmology: diagnosis