[Transient visual loss in morning glory syndrome].

The causes of monocular transient visual loss (TVL) are diverse, necessitating a careful approach to diagnosis and differential evaluation of multiple conditions. In rare cases, TVL may occur in association with optic disc anomalies such as morning glory syndrome (MGS), coloboma, or optic disc drusen. The purpose of this article is to present a clinical case of TVL in a patient with MGS. A 25-year-old patient reported experiencing TVL in the left eye over the past 3-4 years, triggered by physical exertion, straining, or visual tasks requiring concentration. Ophthalmoscopy revealed MGS in the left eye, as well as exercise-induced contractile movements of the optic disc accompanied by TVL. Ultrasonography revealed an avascular hyperechoic structure displacing the central retinal artery and vein laterally, which likely contributed to compromised blood flow in the posterior segment of the eye and the occurrence of TVL. The optic nerve changes causing TVD were found to be local and unrelated to systemic status.