EVALUATION OF THE SITA STANDARD AND SITA FAST PERIMETRIC ALGORITHMS IN NORMALS AND GLAUCOMA PATIENTS

Purpose To evaluate the new treshold strategies of the Humphrey Field Analyser, SITA Standard and SITA Fast, in normals and glaucoma patient s. Methods Fifty healthy volunteers and 50 glaucoma patients were test ed twice with three algorithms: Full threshold,, SITA Standard and SIT A Fast in two sessions. The second test was taken into account to elim inate learning effect. Glaucoma patients were chosen to cover a large range of deficits. Quantitative analysis of global indexes was perform ed as well as qualitative comparison of visual fields by a trained opt ometrist. Results Compaired to Full Threshold, testing time was reduce d by 51% in normals and 49% in glaucoma with SITA Standard and by 72% and 69% with SITA Fast, respectively. In glaucoma, mean testing rime d ropped from 16'01 '' with Full Threshold to 8'05 '' with SITA Standard and to 4'55 '' with SITA Fast, Quantitative comparison showed a high correlation between indexes (MD Full Threshold vs MD SITA Standard: r = 0.98, p < 0.01; PSD Full Threshold vs PSD SITA Standard: r = 0.94, p < 0.01). However SITA Standard and SITA Fast had a tendency to undere stimate visual field defects; In glaucomatous subjects, mean MD amelio rated by 1.01 dB with SITA Standard and by 1.71 dB with SITA Fast. Mea n PSD ameliorated by 0.04 dB and 0.43 dB, respectively. Qualitative an alysis confirmed these last results showing artificial slight or impor tant improvement of visual fields in 21% of the cases with SITA Standa rd and 30% with SITA Fast, compared to Full Threshold. Conclusion SITA Standard and SITA Fast strategies improve dramatically visual field t esting time, by 51% and 72% respectively. However, one should be cauti ous in comparing results obtained with different algorithms as these n ew strategies improve the mean defect and, to a lesser extent, the loc alized defect.