Cone dystrophy is an eye disorder involving the cones, the specialized structures in the eye used for color vision. A number of forms of cone dystrophy have been identified and the condition appears to be genetic in nature. Treatment options are focused on helping patients compensate for loss of visual acuity, as the damaged cones cannot be replaced and it is not possible to reverse vision loss associated with cone dystrophy. Researchers interested in genetic ocular disease are working on identifying the genes involved with the goal of developing more effective treatments.
Some people with cone dystrophy are born with missing or damaged cones, and the condition remains static throughout life. Others experience progressive damage to the eye, with the onset of vision problems in the late teens or later in life, depending on the nature of the disease. In these patients, the eye may look physically normal during an exam in the early stages of disease, but the patient will experience vision problems.
Cone dystrophy can cause poor color vision, increased sensitivity to light, and vision loss. Patients will be more comfortable in low light conditions and cannot perform tasks requiring the ability to distinguish between colors, especially when subtle color variations are involved. The level of impairment can be quite variable and some patients have other vision problems as well. When patients first go to the doctor for treatment, it can sometimes be difficult to identify cone dystrophy unless a patient mentions a family history of the disease, illustrating the importance of providing medical histories to care providers.
An ophthalmologist can examine the patient, determine the level of damage involved, and assess the patient's current visual acuity. Cone dystrophy treatment can include wearing smoked or fogged lenses to be more comfortable in bright conditions, along with using corrective lenses to improve visual acuity. Learning coping skills to compensate for poor color vision and decreased visual acuity may also be recommended for patients with this condition. Low vision aids like large print books, portable magnifiers, and so forth can be helpful for patients.
People aware of a family history of cone dystrophy should receive regular eye exams to check on eye health and visual acuity. Regular exams will allow vision problems to be identified as early as possible, providing patients with access to treatment in a timely fashion. It is important to be aware that this condition may eventually impair a person's safety behind the wheel, while operating heavy equipment, and in similar environments.