Diagnostic Capability of Peripapillary Retinal Volume Measurements in Glaucoma

Abstract

Purpose To determine the diagnostic capability of spectral domain optical coherence tomography (SD-OCT) peripapillary retinal volume (RV) measurements. Materials and Methods A total of 156 patients, 89 primary open angle (POAG) and 67 normal subjects, were recruited. SD-OCT peripapillary RV was calculated for four quadrants using 3 annuli of varying scan circle diameters: outer circumpapillary annuli of circular grids 1, 2, and 3 (OCA1, OCA2, OCA3). Area under the receiver operating characteristic (AUROC) curves and pairwise comparisons of receiver operating characteristic (ROC) curves were performed to determine which quadrants were best for diagnosing POAG. The pairwise comparisons of the best ROC curves for RV and RNFL were performed. The artifact rates were analyzed. Results Pairwise comparisons showed that the smaller annuli OCA1 and OCA2 had better diagnostic performance than the largest annulus OCA3 (p<0.05 for all quadrants). OCA1 and OCA2 had similar diagnostic performance, except for the inferior quadrant which was better for OCA1 (p=0.0033).The pairwise comparisons of the best ROC curves for RV and RNFL were not statistically significant. Retinal volume measurements had lower rates of artifacts at 7.4% while RNFL measurements had higher rates at 42.9%. Conclusion Peripapillary RV measurements have excellent ability for diagnosing not only glaucoma patients but also a subset of early glaucoma patients. The inferior quadrant of peripapillary annulus OCA1 demonstrated the best diagnostic capability for both glaucoma and early glaucoma. The diagnostic ability of RV is comparable to that of RNFL parameters in glaucoma but with lower artifact rates.

Effects of Age, Race, and Ethnicity on the Optic Nerve and Peripapillary Region Using Spectral-Domain OCT 3D Volume Scans

“…Study subjects were prospectively recruited between 2009 and 2015 from the Glaucoma Service of the Massachusetts Eye and Ear Infirmary (MEEI) as a part of the prospective Spectral Domain Optical Coherence Tomography in Glaucoma (SIG) study. 7 , 11 , 16 , 20 – 23 Informed consents were obtained from all study patients. The study methods were approved by the MEEI Institutional Review Board, adhered to the tenets of the Declaration of Helsinki, and was compliant with the Health Insurance Portability and Accountability Act.…”

“… 19 This paper, however, focuses on other, newer parameters, which can be generated from a three-dimensional (3D) volume scan of the optic nerve and its peripapillary region. These 3D optic nerve volume scan parameters include the following: peripapillary RT within an annular region, 20 peripapillary retinal volume (RV) within an annular region, 21 neuroretinal rim minimum distance band (MDB) thickness, 1 , 22 , 23 and neuroretinal rim MDB area. 23 …”

“…For glaucoma diagnosis, OCT parameters that can be derived from a 3D optic nerve volume scan have been shown to have similar or better diagnostic capability compared to RNFL thickness measurements while sometimes having fewer artifacts. 20 – 23 For example, peripapillary RT and RV have diagnostic performance that is comparable to or better than RNFL thickness. 20 , 21 Furthermore, peripapillary RT and RV may have an advantage over RNFL thickness because retinal measurements may have fewer segmentation difficulties, as can be seen with glaucomatous RNFL reflectivity loss and peripapillary atrophy (PPA).…”

“… 20 – 23 For example, peripapillary RT and RV have diagnostic performance that is comparable to or better than RNFL thickness. 20 , 21 Furthermore, peripapillary RT and RV may have an advantage over RNFL thickness because retinal measurements may have fewer segmentation difficulties, as can be seen with glaucomatous RNFL reflectivity loss and peripapillary atrophy (PPA). 20 , 21 Similar to the BMO-MRW, the MDB is a 3D neuroretinal rim parameter that quantifies the amount of tissue in the neuroretinal rim band, which is delimited internally by the retinal surface and externally by the OCT-derived disc border, based on the termination of the retinal pigment epithelium/Bruch's membrane (RPE/BM) complex.…”

“… 20 , 21 Furthermore, peripapillary RT and RV may have an advantage over RNFL thickness because retinal measurements may have fewer segmentation difficulties, as can be seen with glaucomatous RNFL reflectivity loss and peripapillary atrophy (PPA). 20 , 21 Similar to the BMO-MRW, the MDB is a 3D neuroretinal rim parameter that quantifies the amount of tissue in the neuroretinal rim band, which is delimited internally by the retinal surface and externally by the OCT-derived disc border, based on the termination of the retinal pigment epithelium/Bruch's membrane (RPE/BM) complex. 1 , 22 , 23 The MDB thickness has similar or better diagnostic capability compared to RNFL thickness for glaucoma and performs significantly better in the nasal region, 22 , 23 which is a region where the RNFL parameter typically yields poorer diagnostic performance.…”