Abstract
Purpose: :
To assess Pulsar Perimetry (PP) learning effect (LE) and test-retest variability (TRV) in normal subjects (NORM) and patients with ocular hypertension (OHT), glaucomatous optic neuropathy (GON) and primary open-angle glaucoma (POAG).
Methods: :
This multicentre prospective study included 4 groups of subjects: 46 NORM; 36 OHT; 31 GON; and, 33 POAG patients. All subjects underwent standard automated perimetry (SAP) and PP CP-T30W test. PP uses a 5° circular sinusoidal stimulus having a counterphase flickering temporal frequency of 30 Hz and duration of 500 msec. Spatial resolution and contrast are simultaneously modified during the test, which uses a Tendency Oriented Perimetry (TOP) threshold strategy. The stimulus is presented in 66 test locations within the central 30° visual field (VF). One eye per patient was evaluated. LE and TRV for PP were assessed for test results repeated three times (minimum of 30 min between tests). LE was evaluated by comparing results from the first session with the other two (Wilcoxon test). TRV was assessed by the differences between retests for each combination of single tests. TRV was calculated for: PP global indices (Mean Sensitivity [MS], Mean Defect [MD] and Loss Variance square root [sLV]); and, single MS for each of the 66 test areas [sMS]. The influence of age, visual field (VF) eccentricity and VF loss severity on TRV were also assessed (linear regression and Wilcoxon test).
Results: :
LE was not significant for the global indices in the four groups (Wilcoxon test, p>0.05). TRV was significantly lower for sLV compared to MS and MD in all groups (Friedman test, p<0.001). TRV for all global indices did not show significant differences between groups (Kruskal-Wallis test, p>0.05). In the control group, TRV for the global indices was not dependent on subject age; mean TRV for sMS was not related to eccentricity (Wilcoxon test; p= .24). In the POAG-group, TRV for sMS significantly increased with increasing VF loss severity (linear regression analysis, R2=0.13; p<0.01).
Conclusions: :
PP did not show a significant LE. TRV for global indices was similar between groups and was not influenced by age. TRV for sMS was not influenced by eccentricity but significantly increased with VF loss severity. Further studies are needed to determine PP reproducibility and reliability in determining the topography and threshold sensitivity of VF defects.
Keywords: visual fields • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)