Table 1. Initial parameters for BLT.
Adapted from Praschak-Rieder & Willeit, 2003, Pail et al., 2011, and “Center for Environmental Therapeutics,” 2016.
| Parameter | Description |
|---|---|
| Light source | Fluorescent light box with diffusion screen. |
| Light intensity | Standard Treatment: 10,000 lux for 30 minutes Alternative Treatment: 2,500 lux for 1–2 hours |
| Wavelengths | Full-spectrum visible light. |
| Light source position | The light box is angled ~30° from the line of gaze. The user does not stare directly into the light. As the illuminance (in lux) delivered to the cornea is dependent on distance, the user sits at a distance specified by the device (usually 12–24”). |
| Daily treatment | Morning treatment with time varying depending on intensity of light. (i.e. 30 mins for 10,000 lux, 1–2h for 2,500 lux). |
| Length of treatment | Unclear, though data suggest symptoms should begin to remit within the first week of therapy and cessation of therapy may lead to relapse. One recommendation for SAD patients: to begin in the autumn and continue through the spring. |
| Treatment variations (not as effective as traditional BLT) |
Dawn simulation: Gradual increase in bedside light in the AM after awakening. Evening treatment. For some with normal awakening: 1–2 hours in the evening ending 1 hour before bedtime. |
| Side effects | Minimal: Headache, eye strain, nausea. Patients with glaucoma, cataracts, or retinopathy should be under the supervision of an ophthalmologist. Caution is recommended with a photosensitive medical condition (e.g. SLE) or when taking photosensitizing medications (e.g. some antibiotics) Monitor for emergence of hypomania/mania |