A 64-year-old man comes to the office for a preventive visit. The patient has type 2 diabetes mellitus, which is being managed with lifestyle modification. He has had no polyuria, polydipsia, or changes in weight but states that he has had trouble seeing distant objects for the past several months. He has never had vision problems before and reports normal near vision. Two weeks ago the patient saw an optometrist who prescribed glasses with −2.5 diopter lens on the right and −0.75 diopter lens on the left that have improved his vision. Dilated eye examination 6 months ago was unremarkable. His glycated hemoglobin level is 6.8%.
Which of the following is the most likely cause of this patient's visual symptoms?

Question

A 64-year-old man comes to the office for a preventive visit.  The patient has type 2 diabetes mellitus, which is being managed with lifestyle modification.  He has had no polyuria, polydipsia, or changes in weight but states that he has had trouble seeing distant objects for the past several months.  He has never had vision problems before and reports normal near vision.  Two weeks ago the patient saw an optometrist who prescribed glasses with −2.5 diopter lens on the right and −0.75 diopter lens on the left that have improved his vision.  Dilated eye examination 6 months ago was unremarkable.  His glycated hemoglobin level is 6.8%.
Which of the following is the most likely cause of this patient's visual symptoms?

Quizplus · Accepted Answer

The most common age-related vision disorder is presbyopia, which is impairment of near vision due to loss of distensibility of the lens (Choice E). This patient, however, has reduced distance vision, often termed myopic shift, which is a common early effect of nuclear cataract formation due to increased thickness at the center of the lens and a change in dioptric power. Myopic shift typically occurs before visible opacification of the lens or other clinical findings (eg, glare, halos around lights, loss of the red reflex), which explains this patient's normal dilated eye examination 6 months ago. red reflex Oxidative damage of the lens occurs with aging and leads to cataract formation. Age-related cataract is typically slowly progressive, bilateral, and asymmetric. In addition to age, smoking, chronic sunlight exposure, diabetes mellitus, and glucocorticoid use may also contribute to cataract formation. Cataract surgery is indicated when vision declines to the point that the patient is unable to perform activities of daily living despite correction with glasses. (Choice A) Proliferative diabetic retinopathy may present with blurry vision, flashing lights, or black spots, and occurs most commonly in patients with uncontrolled diabetes. Symptoms usually develop in patients with advanced disease. This patient had no signs of retinopathy on recent examination. (Choice B) Age-related macular degeneration (AMD) causes a slow, progressive loss of vision. However, patients commonly experience impaired reading or difficulty with close-up, fine work. Also, AMD is typically associated with distortions of vision or scotoma rather than gradual blurring, and patients usually have visible signs on retinal examination. signs (Choice D) Open-angle glaucoma is characterized by painless loss of peripheral vision associated with increased intraocular pressure. Distance vision is not affected. Educational objective: Nuclear cataract is typically slowly progressive, bilateral, and asymmetric. Patients frequently experience a worsening of distance vision (myopic shift) initially, which may occur before opacification becomes evident. __________ References: Aging and age-related diseases of the ocular lens and vitreous body. (http://www.ncbi.nlm.nih.gov/pubmed/24335070)

A 64-Year-Old Man Comes to the Office for a Preventive