Clinical Geriatrics

Even though February is the shortest month of the year, it has been designated as the time to remember two of the most important issues affecting the older individual—heart disease and visual impairment. February has been designated American Heart Month, apparently as a tribute to Valentine’s Day, and Age-related Macular Degeneration (AMD)/Low Vision Awareness Month. The importance of addressing matters of the heart is widely recognized, whereas maintenance of ophthalmic health may be marginalized and help only sought after permanent damage has already occurred. Prevention is key and early recognition and treatment may make all the difference in preserving vision and function, which can improve quality of life; therefore, I thought it would be a good idea to remind everyone of just how significant a problem visual impairment is.

The prevalence of visual impairment increases with age. One of the major causes of visual impairment, cataracts, affects 6.8% of persons aged 50 to 59 years and up to 68.3% of those over the age of 80. While AMD affects 0.7% of those aged 60 to 60 years, it can be found in as many as 2.4% in those aged 70 to 79 years and 11.8% in those 80 years and older. Intermediate AMD is more common, affecting 6.4%, 12.0%, and 23.6% of those aged 60 to 69, 70 to 79, and 80 years and older, respectively. Diabetic retinopathy can be diagnosed in 5.8% of those aged 65 to 74 and 5.0% of those age 75 and older, with AMD and diabetes mellitus being the two most common causes of blindness in the older person. Collectively, the aforementioned conditions result in 3.0% of persons between the ages of 70 and 79 and 16.7% of persons over the age of 80 having low vision, defined as the best-corrected visual acuity possible being <20/40 in the better-seeing eye. Blindness currently affects 0.8% and 7.0% of persons aged 70 to 79 years and over the age of 80, respectively. As the population continues to age, the total number of persons with these problems and who are visually impaired will continue to grow. 

Vision screening using a Snellen eye chart may give a false sense of security that a person’s vision is not significantly impaired if it is not correctly administered. Remember that macular degeneration begins with a central defect that may result in impaired visual function in one's daily activities. Many individuals may read the chart correctly by turning their heads and thus using more peripheral vision. Questions regarding one's ability to read newspapers, drive, and other activities provide important information. Periodic examination using an ophthalmoscope must also be part of one's examination and referral to an ophthalmology specialist if any abnormality is noted either on examination or by history.  Screening for glaucoma should also be part of good preventive care.

The World Health Organization (WHO) reports that 285 million people are visually impaired with 39 million of these individuals being blind. Across the globe, uncorrected refractive errors are the main cause of visual impairment, with cataracts being the leading cause of blindness in economically challenged countries. The WHO considers 80% of all visual impairment to be curable or preventable.