Photo Rounds

Loss of central vision

A 78-year-old white woman sought care for problems she was having with her vision. She had a loss of central vision that had gradually worsened over the previous 6 months. Fully independent before, she could no longer drive and was having difficulty with activities of daily living. Her peripheral vision was normal.

What's your diagnosis?


 

The physician referred the patient to an ophthalmologist, who noted macular depigmentation and drusen (yellowish-colored subretinal deposits on the macula) during the fundoscopic exam. The ophthalmologist diagnosed dry, age-related macular degeneration (AMD).

AMD causes central vision loss in elderly patients. The pathophysiology of AMD is not completely understood, but it involves chronic changes in the retina and retinal pigment epithelium mediated by environmental and genetic factors. AMD is diagnosed by ophthalmoscopic detection of drusen. A healthy lifestyle decreases the risk of development and progression of AMD.

AMD is the leading cause of irreversible vision loss in the industrialized world. Prevalence of advanced AMD is 1.4% in patients older than 40 years of age and 15% in white women older than 80 years of age. AMD that causes significant vision loss is more common in whites than blacks or Hispanics. Smoking increases the risk in women.

If you are caring for a patient with AMD, it’s wise to refer him or her to an ophthalmologist to evaluate for treatments such as intravitreal injections, laser photocoagulation, photodynamic therapy, or surgery.

Intraocular injections of pegaptanib and ranibizumab (anti-VEGFs) reduce the risk of visual acuity loss in patients with advanced neovascular AMD. Bevacizumab performs similarly to ranibizumab. Consider antioxidants (vitamin C, 500 mg; vitamin E, 400 IU; and beta-carotene, 15 mg) plus 80 mg zinc per day to decrease the risk of worsening vision loss in patients with intermediate to advanced AMD.

It is best, however, to avoid beta-carotene for smokers or people who have smoked in the last 10 years because in this population, the beta-carotene might increase the risk of lung and prostate cancer.

Text for Photo Rounds Friday courtesy of Richard P. Usatine, MD. Photo courtesy of Paul D. Comeau. This case was adapted from: Chumley H. Age-related macular degeneration. In: Usatine R, Smith M, Mayeaux EJ, et al, eds. Color Atlas of Family Medicine. 2nd ed. New York, NY: McGraw-Hill; 2013:155-157.

To learn more about the Color Atlas of Family Medicine, see:

• http://www.amazon.com/Color-Family-Medicine-Richard-Usatine/dp/0071769641/ref=dp_ob_title_bk

You can get the second edition of the Color Atlas of Family Medicine as an app for mobile devices by clicking this link: • http://usatinemedia.com/

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