Lyonization in ophthalmology.

PURPOSE OF REVIEW: To describe the entity of Lyonization in ocular eye diseases, along with its clinical and counseling implications.

RECENT FINDINGS: Several X-linked ocular diseases such as choroideremia, X-linked retinitis pigmentosa, and X-linked ocular albinism may have signs of Lyonization on ocular examination and diagnostic testing. These findings may aid in the proper diagnosis of ocular disease in both female carriers and their affected male relatives.

SUMMARY: Manifestations of Lyonization in the eye may help in the diagnosis of X-linked ocular diseases which may lead to accurate diagnosis, appropriate molecular genetic testing and genetic counseling.