Posterior embryotoxon should prompt assessment for other anomalies

The presence of posterior embryotoxon should prompt a careful examination for signs of glaucoma, and children with the condition should be assessed for systemic abnormalities, English researchers suggest.

C.A. Rennie and colleagues at West Suffolk Hospital in England examined more than 700 patients in all age ranges during routine eye appointments to assess the prevalence of posterior embryotoxon and to look for pathological features associated with the condition. Embryotoxon is a congenital defect in which opacity appears at the periphery of the innermost surface of the cornea.

Of 723 patients evaluated initially, 49 were identified with posterior embryotoxon, an overall prevalence rate of 6.8%. In this group, patients ranged in age from 18 months to 95 years old.

There was a higher prevalence in patients up to 20 years old (22.5%) than in patients 21 years or older (5.9%).

Patients who were identified with posterior embryotoxon were asked to return for a more complete ocular exam that included keratometry, corneal topography and gonioscopy. In 29 patients with posterior embryotoxon who returned for further examination, six patients had glaucoma (two with Axenfeld’s anomaly and one with aniridia) and one had ocular hypertension. Twenty patients had bilateral posterior embryotoxon on slit-lamp examination, which increased to 24 patients with gonioscopy, according to the study authors. Gonioscopy showed that eight patients had associated inferior pigmentation of Schwalbe’s line.

The study is published in the April issue of Eye.