Quantification of Retinal Ganglion Cell Morphology in Human Glaucomatous Eyes

Abstract

Purpose To characterize retinal ganglion cell morphological changes in patients with primary open-angle glaucoma associated with hemifield defect (HD) using adaptive optics–optical coherence tomography (AO-OCT). Methods Six patients with early to moderate primary open-angle glaucoma with an average age of 58 years associated with HD and six age-matched healthy controls with an average age of 61 years were included. All participants underwent in vivo retinal ganglion cell (RGC) imaging at six primary locations across the macula with AO-OCT. Ganglion cell layer (GCL) somas were manually counted, and morphological parameters of GCL soma density, size, and symmetry were calculated. RGC cellular characteristics were correlated with functional visual field measurements. Results GCL soma density was 12,799 ± 7747 cells/mm 2 , 9370 ± 5572 cells/mm 2 , and 2134 ± 1494 cells/mm 2 at 3°, 6°, and 12°, respectively, in glaucoma patients compared with 25,058 ± 4649 cells/mm 2 , 15,551 ± 2301 cells/mm 2 , and 3891 ± 1105 cells/mm 2 ( P < 0.05 for all locations) at the corresponding retinal locations in healthy participants. Mean soma diameter was significantly larger in glaucoma patients (14.20 ± 2.30 µm) compared with the health controls (12.32 ± 1.94 µm, P < 0.05 for all locations); symmetry was 0.36 ± 0.32 and 0.86 ± 0.13 in glaucoma and control cohorts, respectively. Conclusions Glaucoma patients had lower GCL soma density and symmetry, greater soma size, and increased variation of GCL soma reflectance compared with age-matched control subjects. The morphological changes corresponded with HD, and the cellular level structural loss correlated with visual function loss in glaucoma. AO-based morphological parameters could be potential sensitive biomarkers for glaucoma.

Reflective mirror-based line-scan adaptive optics OCT

“…Application of AO-OCT to high-resolution imaging of retinal structure and function in patients with eye disease is rapidly evolving [54][55][56] and will fuel a surge in our understanding of underlying disease mechanisms on a cellular scale. The common notion that the function of cells degrades earlier than does the structure can now be confirmed with optoretinography.…”

Novel Application of Long Short-Term Memory Network for 3D to 2D Retinal Vessel Segmentation in Adaptive Optics—Optical Coherence Tomography Volumes

“…The data from both glaucoma and control subjects were combined for this study and no analysis differentiated the disease state. The full details of subject clinical assessment and AO imaging are found in previously published papers [8,22]. Pupillary dilation and cycloplegia were achieved with 1% tropicamide in subjects, who were subsequently imaged using the FDA multimodal adaptive optics (mAO) device previously described [8,30].…”

“…The full details of subject clinical assessment and AO imaging are found in previously published papers [8,22]. Pupillary dilation and cycloplegia were achieved with 1% tropicamide in subjects, who were subsequently imaged using the FDA multimodal adaptive optics (mAO) device previously described [8,30]. We examined 1.5 • × 1.5 • regions located symmetrically 2.5 • superior and inferior about the horizontal midline at eccentricities 3 • , 6 • , and 12 • in the temporal retina (Figure 1A).…”

“…Adaptive optics optical coherence tomography (AO-OCT) imaging is a non-invasive technique that provides improved lateral resolution compared to traditional optical coherence tomography (OCT) by using adaptive optics (AO) to correct for ocular aberrations. With AO-OCT, it is now possible to obtain three-dimensional (3D), cellular-level resolution of the retina and optic nerve head to study ocular physiology and diseases [1][2][3][4][5][6][7][8]. As an example of cellular resolution capabilities, AO-OCT based methods can reliably quantify retinal ganglion cell (RGC) soma morphology [8][9][10][11] and distinguish individual retinal vessels [12][13][14].…”

“…With AO-OCT, it is now possible to obtain three-dimensional (3D), cellular-level resolution of the retina and optic nerve head to study ocular physiology and diseases [1][2][3][4][5][6][7][8]. As an example of cellular resolution capabilities, AO-OCT based methods can reliably quantify retinal ganglion cell (RGC) soma morphology [8][9][10][11] and distinguish individual retinal vessels [12][13][14]. OCT and AO-OCT collect and register cross-sectional scans of the retina in sequence that are combined to form 3D volumes.…”