Short-wavelength automated perimetry.

Short-wavelength automated perimetry (SWAP) is a visual field test designed to assess the short-wavelength sensitive color system by isolating the blue-yellow pathway. SWAP is a powerful clinical tool able to detect visual field deficits 3 to 5 years before standard automated perimetry (white-on-white) in most glaucoma patients, and progression of visual field defects up to 3 years earlier. SWAP deficits are predictive of the onset and location of future visual field loss, and they correlate well with structural damage associated with glaucoma. The main disadvantage of SWAP remains the longer testing time required. In the clinic, it is recommended that SWAP be performed on patients who are at higher risk for glaucoma. Although SWAP was originally developed to detect visual loss in glaucoma patients, it is also useful for patients with diabetic retinopathy and maculopathy, optic neuropathies, vision loss associated with HIV, migraine, and multiple sclerosis. More sensitive psychophysical tests of visual function, such as SWAP, can significantly shorten clinical trials and aid in the validation of new therapeutic approaches.