Prospective Cross-Sectional Study of Repeatability of Peripapillary Capillary Density Measurement Using Optical Coherence Tomography Angiography in Eyes With Optic Nerve and Retinal Vascular Pathology

Abstract

Background:Optical coherence tomography angiography (OCTA) is a new noninvasive imaging modality that provides high resolution images of the optic nerve head and peripapillary retinal capillary vasculature which can be affected by optic nerve or retinal pathologies. High repeatability of peripapillary capillary density measurement using OCTA has been demonstrated in normal eyes and eyes with glaucoma. The purpose of our study was to quantify the repeatability of peripapillary capillary density measurement using OCTA in both normal eyes and eyes with optic atrophy, optic disc edema, and retinal vasculopathy.Methods:This prospective cross-sectional study enrolled 31 patients (59 eyes) including 16 eyes with optic nerve pathology (7 with disc edema from papilledema and 9 with optic atrophy), 35 eyes with retinal vascular disease, and 8 normal eyes. All eyes were imaged twice (30 minutes apart) with the Optovue AngioVue OCTA instrument to obtain 4.5 × 4.5 mm peripapillary scans. Scans were considered good quality if signal strength was 6 or greater. The OCTA parameters obtained include the radial peripapillary capillary (RPC) density of the whole disc, inside the disc, peripapillary region, and the 4 quadrants of the disc (superior, nasal, inferior, and temporal). A Student's t test was used to compare means. Intraclass correlation coefficient (ICC) was calculated to measure repeatability.Results:Repeatability of RPC density measurements for all regions analyzed demonstrated good to excellent repeatability for the whole cohort {ICC for the whole image was 0.915 (95% confidence interval [CI] = 0.855–0.951)}; ICC for the peripapillary region was 0.945 (95% CI = 0.905–0.969). In the subset of eyes with good image quality (i.e., signal strength ≥ 6), ICC was slightly higher for all regions, with excellent repeatability of the peripapillary region (ICC was 0.971 [95% CI = 0.943–0.986]). Conversely, for eyes with poor image quality scans (i.e., signal strength < 6), ICC was lower, corresponding to moderate to good repeatability for most parameters. For the subset of eyes with optic atrophy, disc edema from papilledema or retinal vasculopathy, all had good to excellent repeatability of the vessel density of the entire disc (ICC values were 0.954 [95% CI = 0.804–0.990], 0.921 [95% CI = 0.711–0.982], and 0.895 [95% CI = 0.788–0.951, respectively]) and of the peripapillary region (ICC values were 0.980 [95% CI = 0.904–0.996], 0.966 [95% CI = 0.854–0.993], and 0.916 [95% CI = 0.827–0.961], respectively).Conclusions:The peripapillary capillary density measurement obtained using a commercial OCTA instrument is highly repeatable in eyes with optic nerve atrophy, disc edema from papilledema, or retinal vasculopathy.

Peripapillary and macular microvasculature features of non-arteritic anterior ischemic optic neuropathy

“…Optical coherence tomography and OCTA are invaluable in the clinical setting for assessing NAION patients because they produce vital structural and vascular measurements of the optic nerve and the macula to serve as biomarkers for predicting visual outcome. OCTA is a novel, non-invasive technology that is increasingly utilized in assessing patients with optic neuropathies like glaucoma and in neuro-ophthalmic causes of optic neuropathies ( 32 – 36 ). OCTA imaging reflects blood flow changes that may reflect functional impairment prior to irreversible structural thinning.…”

Effect of Optic Disc Tilt on the Measurement of Peripapillary Vessel Density Using Optical Coherence Tomography Angiography

“…Although OCTA-measured pVD has shown excellent ability to diagnose glaucoma,19–21 its ability to detect glaucomatous progression requires that pVD have good measurement reproducibility. OCTA-measured pVD has shown good short-term and long-term reproducibility in eyes with and without glaucoma, as well as in eyes with other optic nerve diseases, such as optic nerve atrophy and disc edema 22–26. To the best of our knowledge, however, no previous studies have evaluated the effects of optic disc tilt on the reproducibility of pVD measured by OCTA.…”

“…OCTA-measured pVD has shown good short-term and long-term reproducibility in eyes with and without glaucoma, as well as in eyes with other optic nerve diseases, such as optic nerve atrophy and disc edema. [22][23][24][25][26] To the best of our knowledge, however, no previous studies have evaluated the effects of optic disc tilt on the reproducibility of pVD measured by OCTA. This study found that the long-term reproducibility of OCTA-measured pVD was lower in eyes with tilted than NTD, both overall and in most sectors of the eye.…”