Does the Presence of a Disc Hemorrhage Affect OCT-Measured Vessel Density and Retinal Nerve Fiber Layer Thickness?

Purpose: To determine if the presence of disc hemorrhage (DH) causes any artifactual change in peripapillary vessel density (VD) and retinal nerve fiber layer (RNFL) thickness as measured by OCT.Design: Cohort study.Participants: Glaucoma patients having a single peripapillary DH.Methods: Fifteen glaucoma patients having a single peripapillary DH underwent OCT and OCT angiography. Patients were reviewed every 2 months and scans were repeated on disappearance of the DH. Peripapillary VD and RNFL thickness were evaluated at these 2 time points in the DH sector to determine whether the presence of a DH affects these measurements. The mirror-image sector (e.g., superotemporal sector if DH is inferotemporal) was used as a control. Statistical analysis was carried out using the paired t test. Additionally, the analysis of covariance test was used to determine if there was any difference in the measurements between the visits after controlling for signal strength index (SSI).Main Outcome Measures: Peripapillary VD and RNFL thickness were measured in the presence of a DH, and then after DH resolution.Results: The mean +/- standard deviation (SD) interval between scans was 4.0 +/- 0.4 months. The inferotemporal sector was the most common site of DH (66.6%). The mean +/- SD intraocular pressure was reduced medically from 16.1 +/- 4.7 mmHg at the time of DH to 13.4 +/- 4.2 mmHg at the time of DH resolution (P = 0.001). The mean +/- SD VD in the DH sector was 52.5 +/- 9.7% at the time of DH and 51.1 +/- 8.7% on DH resolution (P = 0.30). The mean +/- SD RNFL thickness in the DH quadrant was 91 +/- 20 mu m in the presence of DH and 92 +/- 21 mu m after DH resolution (P = 0.26). There was no significant difference between the mean VD or the mean RNFL thickness in the DH and control quadrants at these 2 time points after controlling for change in SSI (P > 0.05).Conclusions: The presence of a DH does not artifactually alter the VD or RNFL thickness measurements. Therefore, OCT scans obtained in the presence of a DH may be included in series used for studying progression. (C) 2018 by the American Academy of Ophthalmology