Reproducibility of retinal circulation measurements obtained using laser speckle flowgraphy-NAVI in patients with glaucoma

Abstract

Background: Laser speckle flowgraphy (LSFG) enables noninvasive quantification of the retinal circulation in glaucoma patients. In this study, we tested the intrasession reproducibility of LSFG-NAVI, a modified LSFG technique. Methods: Sixty-five eyes from 33 subjects (male (M):female (F) = 17:16) with a mean age of 49.4 ± 11.2 years were examined in this study. Two parameters indicating reproducibility – the coefficient of variation (COV) and the intraclass correlation coefficient (ICC) – were analyzed three times on the same day that mean blur rate (MBR) was measured using LSFG-NAVI. The sites analyzed were the retinal artery and vein, the optic disk, and the choroid. Following classification according to the Glaucoma Hemifield Test (GHT; SITA-Standard 30-2 program), the COV and ICC were examined in patients with (GHT+; 38 eyes, M:F = 20:18, average age 48.9 ± 12.8 years) and without (GHT-; 27 eyes, M:F = 13:14, average age 50.1 ± 8.7 years) abnormal glaucomatous visual fields. Results: For all subjects, the intrasession reproducibility of MBR in the optic disk (COV: 3.4 ± 2.0; ICC: 0.95) and choroid (COV: 4.7 ± 3.4; ICC: 0.98) was excellent. The reproducibility for the retinal vein (COV: 8.4 ± 5.6, ICC: 0.90) and retinal artery (COV: 10.9 ± 9.9, ICC: 0.9) was moderate. MBRs in the optic disk had good reproducibility in both the GHT+ group (COV: 3.8 ± 2.0; ICC: 0.97) and the GHT− group (COV: 2.9 ± 2.1; ICC: 0.95). Local assessment of the optic disk in normal or glaucoma patients showed that the COVs of the quadrant optic disk areas were best in the temporal area of MBR (3.4%, 4.2%, respectively). Conclusion: LSFG-NAVI showed favorable reproducibility in evaluation of retinal circulation of glaucoma patients, particularly in the optic disk and choroid.