Rod photoreceptor processes in pediatric disorders

Abstract

Purpose: Probe rod cell function in pediatric diseases with known structural or biochemical defects using scotopic electroretinography. Methods: Rod function was studied by means of scotopic, full-field electroretinography(ERG). The conditions of ERG testing allowed derivation of the parameters of the activation and deactivation of rod phototransduction from the ERG a-wave, and post-receptoral function from b-wave and P2 stimulus-response functions. Data from children with Mitochondrial Disorders (n= 22), cholesterol deficiency due to Smith-Lemli-Opitz (SLO) syndrome (n=14), a history of Retinopathy of Prematurity, ROP (n=25), and parents (26) of children with Bardet Biedl syndrome (BBS) were compared to those of healthy control subjects (n=26). Results: The patients with SLO have significant deficits in sensitivity and saturated amplitude of the rod response. In ROP the deficits in rod sensitivity vary significantly with severity of acute phase ROP. In children with mitochondrial disorders, the recovery of the rod response is more than twice as long as normal. In the parents who are heterozygous for BBS, rod cell dysfunction appears to be proximal to the outer segments. Conclusions: These structural and biochemical defects produce various patterns of rod cell dysfunction. These results contribute to disease identification, and to understanding cellular mechanisms in these disorders.

Related Papers

• → Comparison of visual function in pigmented and albino rats by electroretinography and visual evoked potentials(2008)51 cited
• → Electrophysiological testing as a method of cone–rod and cone dystrophy diagnoses and prediction of disease progression(2015)16 cited
• Electroretinogram in cone dystrophy.(1991)
• Is general anaesthesia necessary to record reproducible electroretinograms in rabbits?(1994)
• → Skin-electroretinography patterns in early onset retinal dystrophies(2018)