To report the clinical, electrophysiological and the anatomical findings in a patient with Kearns-Sayre syndrome (KSS).We present the case of a 55-year-old female with KSS, who developed systemic features and ocular manifestations as ophthalmoplegia and retinal dysfunction, that were corroborated by electrophysiological test and High Definition Spectral Domain Optical Coherence Tomography (HD SD OCT) and OCT-Angiography (OCT-A).We report a patient with KSS, accompanied by some alterations of the RPE and photoreceptors observed in the external HD SD OCT and OCT-A. In the best of our knowledge, this is the first report in the literature of HD SD OCT findings in a patient with KSS.