Summary: Strabismus is a disorder in which the two eyes are not correctly aligned. If untreated it can lead to amblyopia – also called ‘lazy eye’ – a condition in which the vision in one eye deteriorates. Strabismus and amblyopia are together the most common causes of visual impairment in children.
Current treatments for strabismus and amblyopia include: surgically realigning the eyes, patching one eye or performing eye exercises to strengthen the coordination of the two eyes. Although many children with strabismus or amblyopia can be effectively treated, a better understanding of the causes of these disorders would permit a more accurate assessment of which treatment plan is most likely to succeed for each child.
UC San Diego Shiley Eye Center & Johns Hopkins Genetics of Strabismus Study
Doctors Kang Zhang (UC San Diego Shiley Eye Center) and Jeremy Nathans (Johns Hopkins University School of Medicine) are conducting a study to identify the role of inheritance in strabismus. It has long been known that strabismus tends to run in families, but the precise role that genes play in making some people more likely to develop strabismus is still unknown. If the mechanism of this genetic predisposition can be clarified, it is very likely to lead to improved treatment for future generations of strabismus patients.
The goal of this study is to identify the genes that predispose some individuals to have a misalignment of the eyes, referred to as strabismus. A related disorder called amblyopia (“lazy-eye”) results in the loss of vision in one eye due to the preferential use of the other eye. Some people who have strabismus will eventually suffer from amblyopia, whereas others will not. Both of these disorders tend to run in families, and are likely to arise from the same basic problem with coordinating vision in the two eyes. If the genes responsible for a predisposition to strabismus or amblyopia can be identified, the knowledge gained will help identify children who are at higher risk for these problems and it will also help to improve decisions regarding which therapeutic approach is most likely to help each child.
The study involves collecting information on eye alignment and function from family members to determine the pattern of inheritance of strabismus and amblyopia, and then analyzing the genetic material (DNA) obtained from a standard-size blood sample. The identities of all participants and any information pertaining to the participants will be stored in coded form to maintain confidentiality.
Further information regarding strabismus
Strabismus, commonly known as crossed or lazy eye, is a condition in which both eyes cannot be aligned simultaneously under normal conditions. One or both eyes may turn in different directions. One eye may turn all of the time or only some of the time, usually under stressful situations or during illness.
It is currently thought that up to five percent of children have some degree of strabismus. Children with strabismus may initially experience double vision due to the misalignment of the eyes in relation to one another. To avoid double vision the brain will eventually ignore or suppress the image of one eye.
The Online Mendelian Inheritance in Man (OMIM) database is a catalog of human genes and genetic disorders authored and edited by Dr. Victor A. McKusick and his colleagues at Johns Hopkins and elsewhere, and developed for the World Wide Web by NCBI, the National Center for Biotechnology Information.