Synthetic Cannabinoid Use Linked to Severe Vision Loss and Unusual Eye Damage in Case Report

The patient presented with severely decreased vision in both eyes. His optic discs were covered with black pigment overlying atrophic nerve tissue, with blood vessels appearing to disappear below the pigmentation. Vision loss began gradually after he started using bonsai (a synthetic cannabinoid) two years prior. No similar case had been previously reported.

Single case report of a 32-year-old male presenting with decreased vision. Ophthalmological examination included optic disc evaluation. Patient history included tobacco, alcohol, and cannabis use, with vision decline temporally linked to synthetic cannabinoid (bonsai) use onset.

Synthetic cannabinoids are poorly understood in terms of their long-term effects on specific organs. This case documents a previously unreported type of eye damage that may represent a unique toxicity of these substances.

Synthetic cannabinoids continue to cause unexpected and severe health effects that differ from natural cannabis. As new synthetic compounds appear on the market, novel toxicities like this optic neuropathy may become more common, and clinicians need to be aware of them.

Single case report cannot establish causation. The patient also used tobacco, alcohol, and cannabis, making it difficult to attribute the optic neuropathy solely to bonsai. No toxicological confirmation of specific synthetic cannabinoid compounds used. The pigmentation pattern is unprecedented and not yet confirmed by other cases.