Volumetric Measurement of Optic Nerve Head Drusen Using Swept-Source Optical Coherence Tomography

Abstract

Purpose: To describe new software tools for quantifying optic nerve head drusen volume using 3-dimensional (3D) swept-source optical coherence tomography (SS-OCT) volumetric scans. Materials and Methods: SS-OCT was used to acquire raster volume scans of 8 eyes of 4 patients with bilateral optic nerve head drusen. The scans were manually segmented by 3 graders to identify the drusen borders, and thereafter total drusen volumes were calculated. Linear regression was performed to study the relationships between drusen volume, retinal nerve fiber layer thickness, and Humphrey visual field mean deviation. Results: In the 8 study eyes, drusen volumes ranged between 0.24 to 1.05 mm3. Visual field mean deviation decreased by ∼20 dB per cubic millimeter increase in drusen volume, and the coefficient of correlation of the linear regression was 0.92. In this small patient series, visual field defects were detected when drusen volume was larger than about 0.2 mm3. Conclusions: Software tools have been developed to quantify the size of OHND using SS-OCT volume scans.

Short-term progression of optic disc and macular changes in optic nerve head drusen

“…New methods have recently been developed to determine the shape, location, and volume of buried ONHD using spectral-domain OCT [ 42 ]. Swept-source OCT also now provides the opportunity of enhanced depth imaging and more rapid acquisitions [ 43 ]. The development of the robust protocols with the use of newest OCT advancements could use these methods and technologies to track longitudinal change in ONHD with time.…”

Optic Nerve Head Drusen: An Update

“…2,29,46,47,88 There was association between ONHD volume, RNFL thinning, and visual field loss. 89,90 This structure-function correlation is less clear with buried than visible drusen. 47,88 Additional measures of macular ganglion cell layer thickness have been sensitive to early damage in cases with buried ONHD, as in some cases of early glaucoma.…”

Advances in swept-source optical coherence tomography and optical coherence tomography angiography

“…However, a larger area anterior surface of the lamina cribrosa was visible on SS-OCT. 167 In contrast, SS-OCT enabled calculation of optic nerve head drusen volume for all eyes, compared with SD-OCT fully visualizing the anterior and posterior drusen borders of no patient. 168 Using 3D-reconstructions and co-registered high-definition en face images extracted from a single densely sampled SS-OCT dataset, different patterns of optic disc pits were visualized in patients for the first time. 169 In preperimetric and early glaucoma, the retinal nerve fiber layer thickness map obtained from wide-field SS-OCT showed comparable sensitivity for distinguishing them from healthy eyes with conventional SD-OCT. 170 …”