Anne B Fulton1, Ronald M Hansen, Anne Moskowitz. 1. Department of Ophthalmology, Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA. anne.fulton@childrens.harvard.edu
Abstract
PURPOSE: To provide an overview of some of our electroretinographic (ERG) and psychophysical studies of normal development of rod function and their application to retinopathy of prematurity (ROP). METHODS: ERG responses to full-field stimuli were recorded from dark adapted subjects. Rod photoreceptor sensitivity (SROD) was calculated by fit of a biochemical model of the activation of phototransduction to the ERG a-wave. Dark adapted psychophysical thresholds for detecting 2 degrees spots in parafoveal (10 degrees eccentric) and peripheral (30 degrees eccentric) retina were measured and the difference between the thresholds, Delta10-30, was examined as a function of age. SROD and Delta10-30 in term born and former preterm subjects were compared. RESULTS: In term born infants, (1) the normal developmental increase in SROD changes proportionately with the amount of rod visual pigment, rhodopsin, and (2) rod-mediated function in central retina is immature compared with that in peripheral retina. In subjects born prematurely, deficits in SROD persist long after active ROP has resolved. Maturation of rod-mediated thresholds in the central retina is prolonged by mild ROP. CONCLUSIONS: Characterization of the development of normal rod and rod-mediated function provides a foundation for understanding ROP.
PURPOSE: To provide an overview of some of our electroretinographic (ERG) and psychophysical studies of normal development of rod function and their application to retinopathy of prematurity (ROP). METHODS: ERG responses to full-field stimuli were recorded from dark adapted subjects. Rod photoreceptor sensitivity (SROD) was calculated by fit of a biochemical model of the activation of phototransduction to the ERG a-wave. Dark adapted psychophysical thresholds for detecting 2 degrees spots in parafoveal (10 degrees eccentric) and peripheral (30 degrees eccentric) retina were measured and the difference between the thresholds, Delta10-30, was examined as a function of age. SROD and Delta10-30 in term born and former preterm subjects were compared. RESULTS: In term born infants, (1) the normal developmental increase in SROD changes proportionately with the amount of rod visual pigment, rhodopsin, and (2) rod-mediated function in central retina is immature compared with that in peripheral retina. In subjects born prematurely, deficits in SROD persist long after active ROP has resolved. Maturation of rod-mediated thresholds in the central retina is prolonged by mild ROP. CONCLUSIONS: Characterization of the development of normal rod and rod-mediated function provides a foundation for understanding ROP.
Authors: Linda L Cooper; Ronald M Hansen; Basil T Darras; Mark Korson; Frances E Dougherty; John M Shoffner; Anne B Fulton Journal: Arch Ophthalmol Date: 2002-08
Authors: Juan P Fernandez de Castro; Patrick A Scott; James W Fransen; James Demas; Paul J DeMarco; Henry J Kaplan; Maureen A McCall Journal: Invest Ophthalmol Vis Sci Date: 2014-04-17 Impact factor: 4.799