Protect nearsighted eyes from myopic maculopathy: prevent further vision loss with regular eye exams by a retina specialist, and timely treatment if it's needed.
The macula is located in the center of the retina and is responsible for clear and accurate vision. Pathologic myopia is the seventh leading cause of visual impairment in the U.S. and Europe, says Szilard Kiss, MD, Director of Clinical Research and assistant professor of ophthalmology at Weill Cornell Medical College.
Regular, expert evaluation is key
"Patients who are highly myopic should be examined on a regular basis by an ophthalmologist, preferably a retina specialist," Dr. Kiss says. "The frequency should be no less than yearly, with those who are showing signs of maculopathy requiring more frequent dilated fundus examinations." Diagnosing and treating the disease early may help preserve vision. Myopic maculopathy can lead to progressively poor vision and, ultimately, blindness if left untreated.
He adds that myopic maculopathy typically affects patients who have at least -6 diopters of nearsightedness with an axial length of greater than 26 millimeters. Diopters are units of measure of the optical power of a lens, and the axial length is basically the length from the front of the eye to the back. Myopic eyes are longer than healthy or normal eyes. For example, someone with 20/40 vision might require just -1/2 diopter lens to get to 20/20, whereas a person with 20/500 vision, approximately, would need a -6 diopter lens for the same degree of correction.
Patient age, degree of myopia, axial length, and the presence of a posterior staphyloma (a protrusion of the cornea or sclera in the back of the eye) are important factors for the progression of myopic maculopathy, Dr. Kiss explains.
"Visual impairment is caused by the development of various types of myopic maculopathies," he says. "In highly myopic eyes, the elongation of the eye and the development of a posterior staphyloma result in a thinning of the retina and the underlying choroid [a vascular layer between the retina and the sclera, or the white of the eye]. This is often a bilateral, irreversible process." These changes may result in macular schisis (a splitting of the retina in the central macula region) and/or choroidal neovascularization (CNV, new blood vessels that originate in the choroid and impede vision).
Unfortunately, surgical correction of myopia, such as LASIK or PRK procedures, does not prevent the development or progression of myopic maculopathy. However, there are some treatment options, depending on the nature of the disease.
Dr. Kiss explains that treatment of macular schisis requires surgery, a procedure called pars plana vitrectomy. For CNV, there are several options. "Depending on the location of the abnormal blood vessels, treatment of the CNV can be with laser photocoagulation, photodynamic therapy, or intravitreal injection of anti-vascular endothelial growth factor drugs, which include the same medications used for age-related macular degeneration," he says. Some CNV may be treated surgically, although this option is less frequently used.
WHAT YOU CAN DO
* If you are nearsighted, have an eye exam once a year.
* Be evaluated by an ophthalmologist or a retina specialist, rather than an optometrist.
* Be prepared to have your pupils dilated; dilation is needed for the doctor to have a clear view of the inside of your eye, although it may make your eyes very sensitive to light and may prohibit you from driving for a few hours.
|Printer friendly Cite/link Email Feedback|
|Publication:||Women's Health Advisor|
|Date:||Nov 1, 2010|
|Previous Article:||A new blood test for ovarian cancer uses mass spectrometry: the test is reportedly 100 percent effective, but larger studies are needed before it's...|