G W Cibis1, K M Fitzgerald. 1. Sections of Ophthalmology and Rehabilitative Medicine, University of Missouri, Kansas City, USA.
Abstract
PURPOSE: To provide electroretinographic differentiation between 4 genetically distinct conditions associated with a negative. Schubert Bornschein type electroretinogram (ERG): Complete congenital stationary night blindness (cCSNB), incomplete CSNB (incCSNB), Duchenne muscular dystrophy, and a family with an autosomal dominantly inherited negative ERG. METHODS: ERGs were recorded in all subjects according to the ISCEV standards. Additionally, a long-duration flash was used under photopic testing conditions to separate depolarizing (ON) and hyperpolarizing (OFF) bipolar cell contributions. Dark adaptometry was obtained in cooperative adult subjects. RESULTS: We were unable to differentiate between these 4 genetically distinct conditions using the scotopic ERG response to the bright white flash only. The photopic, cone-derived ERG to both short- and long-duration flashes was more informative in making distinctions between these 4 disorders and understanding the possible mechanisms behind the abnormal ERG. CONCLUSION: None of these disorders are progressive or a result of abnormal photoreceptor phototransduction. We suggest that they each represent a signal transmission error at the photoreceptor to depolarizing bipolar cell synapse that affects both rod and cone output. We propose that vision is spared in the latter 2 conditions because of timing errors in transmission as opposed to a complete signaling block, as seen in cCSNB.
PURPOSE: To provide electroretinographic differentiation between 4 genetically distinct conditions associated with a negative. Schubert Bornschein type electroretinogram (ERG): Complete congenital stationary night blindness (cCSNB), incomplete CSNB (incCSNB), Duchenne muscular dystrophy, and a family with an autosomal dominantly inherited negative ERG. METHODS: ERGs were recorded in all subjects according to the ISCEV standards. Additionally, a long-duration flash was used under photopic testing conditions to separate depolarizing (ON) and hyperpolarizing (OFF) bipolar cell contributions. Dark adaptometry was obtained in cooperative adult subjects. RESULTS: We were unable to differentiate between these 4 genetically distinct conditions using the scotopic ERG response to the bright white flash only. The photopic, cone-derived ERG to both short- and long-duration flashes was more informative in making distinctions between these 4 disorders and understanding the possible mechanisms behind the abnormal ERG. CONCLUSION: None of these disorders are progressive or a result of abnormal photoreceptor phototransduction. We suggest that they each represent a signal transmission error at the photoreceptor to depolarizing bipolar cell synapse that affects both rod and cone output. We propose that vision is spared in the latter 2 conditions because of timing errors in transmission as opposed to a complete signaling block, as seen in cCSNB.
Authors: N T Bech-Hansen; M J Naylor; T A Maybaum; R L Sparkes; B Koop; D G Birch; A A Bergen; C F Prinsen; R C Polomeno; A Gal; A V Drack; M A Musarella; S G Jacobson; R S Young; R G Weleber Journal: Nat Genet Date: 2000-11 Impact factor: 38.330
Authors: Joseph G Laird; Sarah H Gardner; Ariel J Kopel; Vasily Kerov; Amy Lee; Sheila A Baker Journal: Invest Ophthalmol Vis Sci Date: 2019-07-01 Impact factor: 4.799
Authors: Maja Sustar; Graham E Holder; Jan Kremers; Claire S Barnes; Bo Lei; Naheed W Khan; Anthony G Robson Journal: Doc Ophthalmol Date: 2018-06-22 Impact factor: 2.379