By Zack Steele
I’m asked almost daily if eye problems can be inherited. Scientific evidence and genetic evidence are often controversial on this subject because for every study that suggests a genetic component, there’s another that states the opposite. Some severe diseases we can definitely attribute to heredity. My clinical experience supports that there is a genetic component in many cases.
I’m most commonly asked about nearsightedness or farsightedness and if a child is destined to follow the same road of diminished eyesight as his or her parents.
A recent study strongly indicates that the primary cause of nearsightedness is, in fact, heredity. Interestingly, the study also suggests the amount of time a child spends studying or reading plays a minor role in the development of myopia, or nearsightedness.
The researchers also found that, per week, myopic children spent more time studying and reading for pleasure and less time playing sports than non-myopic children. Myopic children also scored higher on a test of basic reading and language skills than did children with normal vision. The study suggests that nearsighted children my have an academic advantage and that myopic children scored about 10 percentile points higher than did non-myopic children on a test of basic reading and language skills.
Eye care professionals have known for some time that if you have glaucoma, there’s a good chance that someone else in your family also may have it. For primary open-angle glaucoma, the most common form of glaucoma in which the pressure in the eye is too high, there’s approximately a one-in-five chance that a close relative also has the disease. For some less common forms of glaucoma, such as Reiger’s syndrome and glaucoma of childhood, the risk of brothers or sisters and children developing the disease is close to 50 percent.
Less is known about the hereditary component of other eye diseases such as macular degeneration. Most doctors and patients believe there’s some genetic component to the different forms of macular degeneration, just based on a family’s history.
How will this type of research help patients with debilitating eye disease? If scientists can find the defective gene or genes that cause a disorder like glaucoma, we should be able to identify the precise substances responsible for causing it. This knowledge will allow us to better understand the mechanisms that cause glaucoma.
This understanding might dramatically change the way we treat glaucoma. In the distant future, it may be possible to replace a glaucoma-causing gene and either prevent glaucoma or more effectively treat it. We might even envision a day when a patient would take a specific medication to treat the underlying cause of his or her glaucoma, rather than just lowering eye pressure.
Obviously, more genetic research will bring more concrete answers to these questions that most people have about family history and eye disease. My suggestion is as always, if you’re concerned about any of these problems, talk to your eye care professional.
Dr. Zack Steele is a 2003 graduate of UAB School of Optometry. His practice, Trussville Vision Care, is located on Chalkville Road in downtown Trussville.