[Agreement and correlation between the frequency doubling perimetry and the blue-yellow perimetry in glaucoma: no...

To test the agreement and correlation between the frequency doubling technology and the short wavelength perimetry in glaucoma.

Glaucoma patients were selected from the Glaucoma Sector of CEROF - Universidade Federal de Goiás, and then underwent frequency doubling technology and short wavelength perimetry examinations in both eyes (if eligible) on the same day in a random sequence. Pearson's correlation between the global indices (mean deviation - MD e pattern standard deviation - PSD) and the agreement between the examinations (Kappa) were obtained.

Forty-three eyes from 26 patients were included in the study. Comparing the MD (-4.5 +/- 4.5 dB for the frequency doubling technology and -8.0 +/-6.8 dB for the short wavelength perimetry, p<0.001) and PSD (6.4 +/- 2.8 dB for the FDT and 5.8 +/- 2.4 dB for SWAP, p=0.1), only MD was statistically different between the groups. The global indices MD e PSD were highly correlated between the frequency doubling technology and short wavelength perimetry (r=0.644, p<0.001 and r=0.586, p<0.001, respectively). There was a high agreement between the examinations (Kappa=0.319, p<0.001).

In the present study, a high correlation between the global indices (MD and PSD) by the frequency doubling technology and short wavelength perimetry was found, as well as a high agreement between the examinations. These observations indicate either that both cell populations are similarly affected by glaucomatous damage or that both methods measure activity in the same cell populations.