Retinal involvement in mitochondrial disease

Abstract

AbstractRetinal involvement in mitochondrial disease is a variable feature of mitochondrial dysfunction. The retinal pigment epithelium and photoreceptor layers can both be affected. It manifests with signs ranging from asymptomatic peripheral salt‐and‐pepper retinopathy to classic bone‐spicule pigmentary changes. The consequences can be progressive mild or severe visual field constriction and central visual acuity loss. The pathophysiological mechanisms involved in retinal dysfunction in mitochondrial disease are still being elucidated and may include a range of metabolic and bioenergetic defects.Mitochondrial conditions affecting the eye that display prominent outer retinal involvement include.(a) mitochondrial encephalomyopathy, lactic acidosis and stroke‐like episodes (MELAS) secondary to the m.3243A > G mtDNA mutation in MT‐TL1,(b) neuropathy, ataxia and retinitis pigmentosa (NARP) secondary to the m.8993 T > G mtDNA mutation in MT‐ATP6,(c) chronic progressive external ophthalmoplegia (CPEO), in particular the Kearns‐Sayre syndrome (KSS) secondary to single large‐scale mtDNA deletions, and.(d) some newer entities, such as optic neuropathy and pigmentary retinopathy seen in patients with mutations in the gene SSBP1.The features and diagnostic pathway for these conditions will be illustrated and discussed.