SITA-SWAP in glaucoma diagnosis

Purpose: The aim of the study is to verify the characteristics of the new algorithm SITA-SWAP in glaucoma diagnosis. Methods: 25 consecutive patients followed by the glaucoma service of the University Eye Clinic, Fondazione Policlinico San Matteo, were selected as glaucoma suspects on the basis of the outcomes of standard automated perimetry (SAP), Scanning Laser Polarimetry and Confocal Scanning Laser Ophthalmoscopy. Test duration and global indices MD (mean defect) and PSD (pattern standard deviation) of 24-2 SITA-SWAP were compared to the same data from 24-2 SITA-SAP (SS) and 24-2 Full Threshold-SWAP (FS). A questionnaire about individual tolerability, perception of test duration and fatigue connected to the different perimetric exams, was also submitted to each patient. Results: SITA-SWAP mean test duration was 3.56­±0.56, significantly less than FS (11.47±1.12) and SS (5.03±0.41). The mean MD for SITA-SWAP was -3.42±4.3, significantly different from SS (-1.31±1.4) but not from FS (-2.27±4.5), indicating the influence of lens opacities on blue light transmission. The mean PSD for SITA-SWAP was 3.33±1.02, significantly different from SS (1.70±0.37) and from CPSD provided by FS (2.25±1.17), showing a promising sensitivity of SITA-SWAP in pointing out localized defects. SITA-SWAP was evaluated as shorter, easier to perform, better tolerated as compared to FS and shorter but more challenging as compared to SS by most of the patients. Conclusions: SITA-SWAP seems to be a rapid and easy perimetric test, able to help physician in glaucoma diagnosis. The blue light transmission through optic media is constantly influenced by their opacities.