Dark Adaptometry Tests
Dark adaptometry (or, scotopic sensitivty) testing is useful in the diagnosis and management of retinal degenerations, senile miosis, high myopia, vitamin-A deficiency, and other night blinding conditions. The two major parameters that are measured are the dark adaptometry curve and the final dark-adapted threshold.
Whole-field scotopic sensitivity testing was recently developed by clinicians at the prestigious Wilmer Eye Institute. This test measures the dark-adapted threshold to a 1 Hz flickering light presented in Ganzfeld. Glovinsky et al. showed that glaucoma suspects with an abnormal whole-field scotopic sensitivity are more likely to have other signs of early optic nerve injury, including a higher proportion of borderline visual field defects, defects of the nerve fiber layer, or glaucomatous fellow eyes. LKC uses technology to measure scotopic sensitivity where the accuracy is not affected by poor refractive error correction or erratic fixation. The technology is also relatively insensitive to mild cataract because the entire visual field is stimulated.
In the whole-field scotopic sensitivity test, one eye is dark adapted for 30 minutes. The luminance threshold to 1 Hz sine wave flicker is determined by adjusting the brightness of the stimulus until it is just visible to the patient. The time for the entire procedure (excluding time for the patient to dark adapt) is 1 to 2 minutes.
- Inherited Retinal Disorders
- Rod-Cone Dystrophy (Retinitis Pigmentosa or RP)
- Stationary Night Blinding Disorder
- Chorioretinal Dystrophies
- UTAS Visual Diagnostic System