Differential Diagnosis
The patient presents with difficulty in near vision, but distant vision is intact. Pupils are 3 mm and constrict with convergence, but not to light. Based on these symptoms, the differential diagnosis can be categorized as follows:
Single Most Likely Diagnosis
- Convergence Insufficiency: This condition is characterized by difficulty in converging the eyes, which is necessary for near vision. The pupils constricting with convergence but not to light suggests an issue with the near response, which is consistent with convergence insufficiency.
Other Likely Diagnoses
- Presbyopia: A common age-related condition that affects near vision, typically starting in the early to mid-40s. The symptoms of difficulty with near vision but intact distant vision align with presbyopia.
- Accommodative Insufficiency: Similar to convergence insufficiency, this condition affects the eye's ability to focus on near objects due to a problem with the accommodation reflex.
Do Not Miss Diagnoses
- Glaucoma: Although less likely given the specific symptoms, glaucoma can cause issues with vision and should always be considered, especially if there are any signs of increased intraocular pressure or optic nerve damage.
- Hydrocephalus: Can cause problems with vision, including issues with near vision, due to increased intracranial pressure affecting the optic nerves or other parts of the brain involved in vision.
Rare Diagnoses
- Neurosyphilis: A rare condition that can affect various parts of the body, including the eyes and brain, potentially causing vision problems.
- Pancoast Tumor: A type of lung cancer that can affect the nerves controlling eye movements and vision, but it would be an uncommon cause of the specific symptoms described.
- Optic Neuritis: Inflammation of the optic nerve, which can cause vision loss, but typically affects one eye and can involve both near and distant vision.