A comparison of short wavelength automated perimetry with frequency doubling perimetry for the early detection of visual field loss in ocular hypertension

Background: Achromatic automated perimetry (AAP) is limited in its ability to detect very early visual field loss in ocular hypertensive patients. Tes ts targeting axons that are selectively damaged, or have low redundancy, ma y detect visual field losses before they are seen on AAP. It has been claim ed that short wavelength automated perimetry (SWAP) and frequency doubling perimetry (FDP) are two tests that provide early detection. Methods: Patients (n = 62) were selected on the basis that they had raised intraocular pressure but normal visual fields detected by AAP. A SWAP and a n FDP was performed on each of the patients and the results compared. Field s were scored as either normal or abnormal based on criteria used in previo us studies. Results: On comparing FDP with SWAP as the 'gold standard', a sensitivity o f 88.9% and a specificity of 96.2% was found, showing a high concordance be tween the two tests. Conclusion: These results suggest that as SWAP may be predictive of AAP vis ual field loss, FDP may be similarly predictive.