The evaluation of light sensitivity in benign essential blepharospasm.

PURPOSE: To test light sensitivity thresholds rigorously in patients with benign essential blepharospasm (BEB) compared with patients who have known light sensitivity (migraineurs) and to normal control subjects.

DESIGN: Prospective, observational, case control study.

METHODS: We recruited a total of 87 subjects into each of three groups: BEB, migraine, and normal control subjects. A modified slit-lamp chin rest, heat shield, light meter, and halogen light that was modulated by a rheostat were used to measure light sensitivity thresholds. Participants were tested without spectacles, with gray-tinted spectacles, and with FL-41-tinted spectacles.

RESULTS: Light discomfort thresholds for subjects with BEB were significantly lower compared with normal control subjects (P < or = .009) and similar to the migraine group. Both gray and FL-41-tinted lenses improved light sensitivity thresholds in all groups (P < or = .0005). There was no observed difference in the improvement in light sensitivity when the gray and FL-41-tinted lenses were compared.

CONCLUSION: Patients with BEB are considerably more sensitive to light than control subjects and as sensitive to light as patients with migraine. Physicians who care for patients with BEB should consider using tinted lenses to help ameliorate symptoms.