Purpose: To evaluate the capacity of Frequency Doubling Perimetry (FDP) to classify normal subjects and patients with glaucoma.
Type of study: cross sectional. 54 glaucoma patients (mean age 65 S.D. 9.3 years) and 54 normal subjects matched in age (64.2 S.D. 9.8 years) were examined. Normal subjects showed an intra-ocular pressure (IOP) of </= 21 mmHg, a normal optic disc appearance (disc stereophotos) and normal standard perimetry (Humphrey II, 24-2 full threshold or SITA standard programs). Glaucoma subjects presented an IOP>21 mmHg, a glaucomatous optic nerve and a glaucomatous standard perimetry. One eye per patient was selected at random. All were examined using FDP C-20-5 and N-30 programs. Sensitivity, specificity and receiver operating feature curves (ROC) for N-30 parameters were calculated. A quantitative correlation with standard perimetry (Pearson) was calculated as well.
Results: Sensitivity and specificity for C-20-5 resulted in 74% and 96% respectively and 88% and 92% respectively for N-30. ROC area for mean deviation was 0.85 and 0.93 for the standard pattern deviation. Standard deviation in the FDP pattern showed a strong linear correlation with the Humphrey 24-2 standard deviation pattern (r(2)= 0.76, P<0.001).
Conclusions: The FDP N-30 could classify normal and glaucoma subjects with a high sensitivity and specificity. There was strong correlation between FDP and standard perimetry parameters.