Leber Congenital Amaurosis Health Article

Treatment and management

Currently, there is no treatment for LCA, and thus, patient and family education and adaptive assistance is critical. Some people with remaining vision may benefit from vision-assistance technology such as electronic, computer-based, and optical aids, but severely visuallyimpaired individuals often utilize traditional resources such as canes and companion-guide dogs. Orientation and mobility training, adaptive training skills, job placement and income assistance are available through hospital physical and occupation therapy programs and various community resources. It should be noted that up to 20% of patients with LCA may have associated mental retardation and will require additional adaptive and vocational assistance.

Most people with LCA are unable to read print and instead utilize Braille, an alphabet represented by raised dots that can be felt with the fingertips. People with LCA often attend schools specially designed to meet the needs of visually-impaired students and may require modifications to their home and work environments in order to accommodate their low or absent vision. As almost all patients with LCA are legally blind, they will not be able to drive or operate heavy machinery. Genetic counseling may assist affected individuals with family planning.

Scientists have isolated several mutant genes that can each cause LCA. Ongoing scientific research is directed toward understanding how these genes function in the retina and toward locating the remaining genes that cause LCA. With this information, scientists can better develop a means of prevention and treatment. A dramatic example of this principle was provided in 2000, when researchers were able to restore vision in mice with LCA2. By giving oral doses of a chemical compound derived from vitamin A, the scientists were able to restore the animals' visual functions to almost normal levels after just two days. The researchers report that they will attempt the same experiments in dogs with LCA2 before trying the treatment in humans. It should be noted that LCA2 causes only 10% of the known cases of LCA, and the treatment in this experimental study does not work for other types of LCA.

Prognosis

While children born with LCA may have variable symptoms and differing levels of visual acuity, they can lead productive and healthy lives with adaptive training and assistance. In those patients who do not have associated problems with their brain, heart, or kidney, life span is approximately the same as the general population, otherwise the prognosis is variable and depends on the extent of the complication.

BOOKS

"Disorders of Vision" In Nelson Textbook of Pediatrics, edited by R. E. Behrman. Philadelphia: W. B. Saunders, 2000, pp. 1900-1928.

PERIODICALS

Dharmaraj, S. R., et al. "Mutational Analysis and Clinical Correlation in Leber Congenital Amaurosis." Ophthalmic Genetics 21 (September 2000): 135-150.

Gamm, D. M., and A.T. Thliveris. "Implications of Genetic Analysis in Leber Congenital Amaurosis." Archives of Ophthalmology 119 (March 2001): 426-427.

Lambert, S. R., A. Kriss, and D. Taylor. "Vision in Patients with Leber Congenital Amaurosis." Archives of Ophthalmology 11 (February 1997): 293-294.

Perrault, I. "Leber Congenital Amaurosis." Molecular Genetics and Metabolism 68 (October 1999): 200-208.

ORGANIZATIONS

Foundation Fighting Blindness. Executive Plaza 1, Suite 800, 11350 McCormick Rd., Hunt Valley, MD 21031-1014. (888) 394-3937. <http://www.blindness.org>.

WEBSITES

"Entry 20400: Leber Congenital Amaurosis, Type 1." OMIM—Online Mendelian Inheritance in Man. <http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=20400>.

Leber's Links: Leber's Congenital Amaurosis. <http://www.freeyellow.com/members4/leberslinks/index.html>.

Oren Traub, MD, PhD