pterygium refers to a patch of hypertrophied bulbar subconjunctival tissue.
This tissue may anchor the eyelid to the sclera, thus preventing the opening
of the eye. Ocular pterygium will be noticeable during quiet wakefulness
when both eyes are supposed to be wide open (Figure 173.1). The diagnosis
is established by direct observation of the affected eye. Ocular pterygium
may occur as an isolated finding or as a component of a syndrome. Ocular
pterygium often occurs with linear nevus sebaceous syndrome. The treatment
of ocular pterygium is surgical.
Figure 173.1.— Neonate with linear nevus sebaceous
syndrome. [A] Facial asymmetry is hardly noticeable when both eyes are
closed. [B] Facial asymmetry becomes very noticeable when attempting to
open the eyes.