You are answering a USMLE-style medical question. Question: A 40-year-old man is referred to an optometrist. He complains of mild vision impairment over the last 6 months. His vision has continued to slowly deteriorate and his condition is now affecting his night driving. Past medical history is significant for well-controlled schizophrenia. He takes a low-potency typical antipsychotics and a multivitamin every day. He has been compliant with his medication and has regular follow-up visits. What is the best first step in the management of this patient’s symptoms? Options: A) Decrease medication dosage B) Reassurance C) Ocular examination under anesthesia D) Slit-lamp examination Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.