Dysfunction of transmission in the inner retina: incidence and clinical causes of negative electroretinogram

Graefes Arch Clin Exp Ophthalmol. 2006 Nov;244(11):1467-73. doi: 10.1007/s00417-006-0319-1. Epub 2006 Apr 13.


Background: Only limited data exist on the incidence of negative electroretinograms (ERG) in clinical practice. The purpose of this study is therefore to determine the incidence and clinical causes of a negative ERG in a tertiary care centre focused on inherited and acquired retinal degenerations.

Methods: All ERGs recorded (in accordance with ISCEV standards) in our electrophysiological laboratory from 1992 to 2004 were retrospectively reviewed. The negative ERGs (criterion: ERG with b:a wave ratio<or=1 in the scotopic standard combined response in at least one eye) were analysed in the context of further clinical results. The photopic ON- and OFF-responses were recorded with long duration (200 ms) stimuli.

Results: A total of 1999 ERGs from 1644 patients were performed during the study period. 47/1644 patients (2.9%) presented with a negative ERG and were included in the study. Clinical diagnoses included inherited retinal dystrophies [X-linked congenital retinoschisis (XRS) (n=17), congenital stationary night blindness (CSNB) (n=6), retinitis pigmentosa (RP) (n=6), cone (-rod) dystrophy (n=5), choroideremia (n=1), Müller cell sheen dystrophy (MCSD) (n=1)] and acquired retinopathies (melanoma-associated retinopathy (MAR) (n=1), vigabatrin retinotoxicity (n=1)). In nine patients a definitive diagnosis could not be established. Unilateral negative ERGs were seen in 10/37 patients where ERG was bilaterally recorded. The fellow eye presented with a b:a wave ratio >1 (8 eyes) or ERG responses were not detectable (2 eyes). Photopic ON- and OFF-responses were recorded in 38 eyes of 29 patients and 32/38 eyes presented with a negative ERG. The ON-response was reduced in 25/32 eyes, whereas the OFF-response was reduced in only 11/32 eyes.

Conclusions: The incidence of a negative ERG can differ between the laboratories depending on the causes for ERG recording and was in our laboratory 2.9% in a consecutive series of patients with inherited or acquired retinal degenerations. A disorder characteristically associated with negative ERG (e.g. XRS, CSNB, MAR) was diagnosed in 53% of these patients, whereas in 47% the negative ERG indicated an unexpected post-receptoral dysfunction, e.g. in cone (-rod) dystrophy or RP. The ON-bipolar pathway was affected in most cases.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Child
  • Child, Preschool
  • Electroretinography*
  • Female
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Night Blindness / diagnosis*
  • Night Blindness / physiopathology
  • Paraneoplastic Syndromes / diagnosis*
  • Paraneoplastic Syndromes / physiopathology
  • Photoreceptor Cells, Vertebrate / pathology*
  • Retina / physiopathology
  • Retinal Degeneration / diagnosis*
  • Retinal Degeneration / physiopathology
  • Retinoschisis / diagnosis*
  • Retinoschisis / physiopathology