Abstract | 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.
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Authors | Agnes B Renner, Ulrich Kellner, Elke Cropp, Michael H Foerster |
Journal | Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie
(Graefes Arch Clin Exp Ophthalmol)
Vol. 244
Issue 11
Pg. 1467-73
(Nov 2006)
ISSN: 0721-832X [Print] Germany |
PMID | 16612636
(Publication Type: Case Reports, Journal Article, Research Support, Non-U.S. Gov't)
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Topics |
- Adolescent
- Adult
- Aged
- Child
- Child, Preschool
- Electroretinography
- Female
- Humans
- Incidence
- Male
- Middle Aged
- Night Blindness
(diagnosis, physiopathology)
- Paraneoplastic Syndromes
(diagnosis, physiopathology)
- Photoreceptor Cells, Vertebrate
(pathology)
- Retina
(physiopathology)
- Retinal Degeneration
(diagnosis, physiopathology)
- Retinoschisis
(diagnosis, physiopathology)
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