A patient presents with visual disturbances and normal vision in one eye with a swollen disc. Which condition is primarily suspected?

In this scenario, the presentation of visual disturbances along with a swollen optic disc and normal vision in one eye is highly indicative of central retinal vein occlusion. This condition arises from the blockage of the central retinal vein, leading to increased venous pressure and subsequent edema of the optic disc. Patients often report blurry vision or other visual disturbances and may have an abrupt loss of vision in severe cases.

The key aspects of the situation align with central retinal vein occlusion: the swollen disc manifests due to retinal hypoxia and edema, while normal vision may still be preserved if there is no significant impact on the macula or surrounding retinal area.

Other conditions such as closed-angle glaucoma, giant cell arteritis, and optic neuritis present with different symptoms or findings. For example, closed-angle glaucoma typically results in acute ocular pain, headache, nausea, vomiting, and a clearly reduced vision due to increased intraocular pressure, which contrasts with the normal vision noted here. Giant cell arteritis would likely involve visual symptoms accompanied by systemic signs such as scalp tenderness or jaw claudication, and would also present more acutely. Lastly, optic neuritis typically produces pain with eye movement and a specific pattern of vision loss, often associated with inflammatory conditions like multiple sclerosis