A 67-year-old Caucasian male complains of progressive visual loss in his right eye over the past several months. He has a history of hypertension and type 2 diabetes mellitus. Current medications include a daily baby aspirin, hydrochlorothiazide, lisinopril, and metformin. There is no family history of visual problems. He has a 35 pack year smoking history and admits to occasional alcohol use. He is afebrile with a blood pressure of 137/82 mmHg and pulse of 73/min. Cardiac and pulmonary examinations are unremarkable. A neurologic examination demonstrates no focal motor or sensory abnormalities. The patient is asked to cover his left eye and to look at a small spot on a grid made of parallel vertical and horizontal lines. He describes the vertical lines as being bent and wavy. Which of the following is the most likely cause of this patient's complaints?

Question

A 67-year-old Caucasian male complains of progressive visual loss in his right eye over the past several months.  He has a history of hypertension and type 2 diabetes mellitus.  Current medications include a daily baby aspirin, hydrochlorothiazide, lisinopril, and metformin.  There is no family history of visual problems.  He has a 35 pack year smoking history and admits to occasional alcohol use.  He is afebrile with a blood pressure of 137/82 mmHg and pulse of 73/min.  Cardiac and pulmonary examinations are unremarkable.  A neurologic examination demonstrates no focal motor or sensory abnormalities.  The patient is asked to cover his left eye and to look at a small spot on a grid made of parallel vertical and horizontal lines.  He describes the vertical lines as being bent and wavy.  Which of the following is the most likely cause of this patient's complaints?

Quizplus · Accepted Answer

The most likely diagnosis in this case is macular degeneration, which is the leading cause of blindness in industrialized countries. One of the earliest findings in macular degeneration is distortion of straight lines such that they appear wavy. The grid test described above is frequently used to screen for patients with macular degeneration. The primary risk factor for macular degeneration is increasing age, although smoking can increase the risk as well. Patients may be asymptomatic, but others complain of visual problems in either one or both eyes. Driving and reading are often some of the first activities that are affected since they require fine visual acuity, which is provided primarily by the macula. In addition to the grid test described above, ophthalmologic examination can identify drusen deposits in the macula, which are common lesions seen with this disorder. (Choice A) Lens opacification is the cause of visual loss from cataracts. Cataracts, however, should not cause straight lines to appear wavy. (Choice B) An enlarged blind spot may be seen with papilledema, but this patient has no evidence of increased intracranial pressure to result in papilledema. (Choice C) Increased intraocular pressure is the cause of glaucoma, which does not typically present with distortion of straight lines. (Choice E) Visualization of straight lines is a task that requires fine visual acuity, which is controlled primarily by the centrally-located macula as opposed to the more peripheral retina. Educational objective: Macular degeneration is the most common cause of blindness in industrialized nations. Activities that require fine visual acuity are usually the first affected, and patients with this condition may report that straight grid lines appear curved.

A 67-Year-Old Caucasian Male Complains of Progressive Visual Loss in His