Short-wavelength automated perimetry and retinal nerve fiber layer evaluation in suspected cases of glaucoma

To determine if short-wavelength automated perimetry (SWAP) provides evidence that indicates early functional losses in ocular hypertensive subjects and to establish a direct comparison with early structural abnormalities in the retinal nerve fiber layer (RNFL).

A total of 160 eyes belonging to 83 patients with ocular hypertension (intraocular pressure >21 mm Hg and normal results on standard automated perimetry evaluation), on which a SWAP and RNFL study were performed, were examined. One hundred twenty-eight age-matched subjects without ocular hypertension were evaluated to establish the 95% and 99% confidence intervals at each of the 76 exploration points of the SWAP test.

The RNFL study results were normal in 83 cases (51.8%) and pathologic in 77 cases (48.1%). The SWAP results were pathologic in 57 cases (35.6%). Significant differences (P<.001) were observed when comparing the distribution of normal and pathologic SWAP results among the types of defects in the RNFL (focal wedge, diffuse atrophy, and mixed atrophy).

Short-wavelength automated perimetry is a useful test for the early detection of visual field losses. It is more sensitive than standard automated perimetry and provides a high association with RNFL assessment, which has proved capable of detecting signs of glaucomatous damage several years before the onset of the typical visual field defects.