What cognitive side effects can topiramate cause, and what ocular risk exists?

• A. Sedation and blurred vision due to dried eyes.
• B. Memory enhancement; risk of cataracts.
• C. Cognitive slowing or word-finding difficulties; risk of acute myopia and secondary angle-closure glaucoma.
• D. No cognitive effects; no ocular risks.

Answer: (C)

Topiramate can affect both thinking processes and the eye. Cognitively, it can cause slowing in thought and difficulties with retrieving words, reflecting a mild CNS depressant effect that some people notice after starting or increasing the dose. Ocularly, it carries a risk of acute myopia and secondary angle-closure glaucoma. This happens when the drug promotes forward movement of the lens-iris diaphragm due to cilio-choroidal changes, leading to a sudden decrease in vision and potentially very high eye pressure. If these eye symptoms appear—sudden blurry vision, eye pain, halos around lights, or headaches—stopping the medication and seeking urgent eye care is important.