A 32-year-old woman comes to the physician because of a 2-day history of "poor vision" and "flashing lights" in her left eye. She is unusually tall, with long limbs and slender fingers. Physical examination is remarkable for pectus excavatum, kyphoscoliosis, a midsystolic click, and a pansystolic murmur. Ophthalmologic examination reveals a retinal detachment and dislocation of the lens. This patient is at greatest risk for which of the following conditions?