Premacular Subhyaloid Hemorrhage in a Young Adult After Cannabis Consumption: A Case Report.

Premacular subhyaloid hemorrhage is an uncommon cause of acute visual impairment and is most frequently associated with Valsalva, trauma, hypertension, retinal vascular disease, or hematologic disorders. However, idiopathic cases have been described, suggesting the possibility of additional contributing factors. We describe the case of a 25-year-old man who presented with sudden unilateral visual loss two hours after cannabis consumption. Clinical examination and multimodal imaging confirmed a large premacular subhyaloid hemorrhage in the absence of trauma, Valsalva maneuver, systemic disease, or underlying retinal vascular abnormalities. Given the macular location and large size of the hemorrhage, Nd:YAG laser hyaloidotomy was performed to facilitate drainage of blood into the vitreous cavity and accelerate visual recovery. Laser energy was progressively increased from low initial settings until successful perforation of the posterior hyaloid was achieved at 10 mJ, resulting in immediate drainage of the hemorrhage. The procedure was well tolerated without complications, and best-corrected visual acuity returned to 20/20 (Snellen) one week after treatment. This case highlights the value of Nd:YAG laser hyaloidotomy for selected large premacular hemorrhages and emphasizes technical considerations when performing the procedure in young patients, in whom greater posterior hyaloid thickness and adherence may require higher laser energy. It also describes a premacular hemorrhage occurring in temporal proximity to cannabis use. Although causality cannot be established, the observation raises the hypothesis that cannabis-related vascular effects could potentially contribute to retinal hemorrhagic events.