Summary: Purpose: Photosensitivity can represent a serious problem in epilepsy patients, also because pharmacologic treatment is often ineffective. Nonpharmacologic treatment using blue sunglasses is effective and safe in controlling photosensitivity, but large series of patients have never been studied.

Methods: This multicenter study was conducted in 12 epilepsy centers in northern, central, southern, and insular Italy. A commercially available lens, named Z1, obtained in a previous trial, was used to test consecutively enrolled pediatric and adult epilepsy patients with photosensitivity. Only type 4 photosensitivity (photoparoxysmal response, PPR) was considered in the study. A standardized method was used for photostimulation.

Results: Six hundred ten epilepsy patients were tested. Four hundred (66%) were female patients; 396 (65%) were youndger than 14 years. Three hundred eighty-one (62%) subjects were pharmacologically treated at the time of investigation. Z1 lenses made PPR disappear in 463 (75.9%) patients, and PPR was considerably reduced in an additional 109 (17.9%) of them. PPR remained unchanged only in the remaining 38 (6.2%) patients. The response of PPR to Z1 lenses was not significantly influenced by the patients' age, sex, or type of epilepsy. No difference was found between pharmacologically treated and untreated patients.

Conclusions: The Z1 lens is highly effective in controlling PPR in a very large number of photosensitive epilepsy patients irrespective of their epilepsy or antiepileptic drug treatment. The lens might become a valid resource in the daily activity of any clinician who cares for patients with epilepsy.

Key Words: Photosensitive epilepsy—Photosensitivity—Blue glasses—Nonpharmacologic treatment—Photoparoxysmal response—PPR.

The spectrum of the BPI^® dye called Therapeutic Blue-Z™ has been found in our experiments to be virtually the same as that of the Z1 lens specified in the above article when tinted to an appropriate density.