2020–2021 BCSC Basic and Clinical Science Course™
12 Retina and Vitreous
Part II: Disorders of the Retina and Vitreous
Chapter 14: Retinal Degenerations Associated With Systemic Disease
Retinal Degeneration With Systemic Involvement
Neuromuscular Disorders
Pigmentary retinopathy associated with neuromuscular pathology is present in a variety of disorders (see Table 14-1). ERG abnormalities found in these neurologic disorders confirm the presence of retinopathy but are not diagnostic for any one disorder.
Although Duchenne muscular dystrophy does not cause a pigmentary retinopathy, it deserves mention because the ERG signal shows a negative waveform similar to that found in patients with congenital stationary night blindness (CSNB)—specifically, a normal a-wave but a reduced b-wave (see Chapters 3 and 12). This ERG response suggests a defective “on-response” pathway, but patients with this disorder do not have night blindness. Interestingly, Duchenne muscular dystrophy is caused by mutations in the gene for dystrophin, a protein that is abundant in muscle but also found in neural synaptic regions and in the retina.
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Barboni MT, Nagy BV, de Araújo Moura AL, et al. ON and OFF electroretinography and contrast sensitivity in Duchenne muscular dystrophy. Invest Ophthalmol Vis Sci. 2013;54(5):3195–3204.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.