A 27-year-old man presents to the emergency department for sudden visual changes in his right eye that began 3 hours ago. He reports seeing brief flashes of light and new "floaters" earlier this week, but he did not seek care. Today he noticed painless loss of vision described as a "dark curtain" coming down from the superior part of his visual field. He has severe nearsightedness (contact lens prescription −8.0 diopters). He denies eye pain, headache, jaw claudication, or trauma today. Vital signs are normal. Visual acuity is decreased in the right eye. Fundoscopic exam of the right eye shows an elevated, corrugated (crinkled) retina with retinal vessels that appear to change direction as they course over the elevated area.

Which of the following is the most appropriate next step in management?