Factors Influencing Optical Coherence Tomography Peripapillary Choroidal Thickness: A Multicenter Study

Abstract

Purpose To quantify peripapillary choroidal thickness (PCT) and the factors that influence it in healthy participants who represent the racial and ethnic composition of the U.S. population. Methods A total of 362 healthy participants underwent optical coherence tomography (OCT) enhanced depth imaging of the optic nerve head with a 24 radial B-scan pattern aligned to the fovea to Bruch's membrane opening axis. Bruch's membrane, anterior scleral canal opening (ASCO), and the anterior scleral surface were manually segmented. PCT was measured at 100, 300, 500, 700, 900, and 1100 μm from the ASCO globally and within 12 clock-hour sectors. The effects of age, axial length, intraocular pressure, ethnicity, sex, sector, and ASCO area on PCT were assessed by ANOVA and univariable and multivariable regressions. Results Globally, PCT was thicker further from the ASCO border and thinner with older age, longer axial length, larger ASCO area, European descent, and female sex. Among these effectors, age and axial length explained the greatest proportion of variance. The rate of age-related decline increased further from the ASCO border. Sectorally, the inferior-temporal sectors were thinnest (10.7%–20.0% thinner than the thickest sector) and demonstrated a higher rate of age-related loss (from 15.6% to 20.7% faster) at each ASCO distance. Conclusions In healthy eyes, PCT was thinnest in the inferior temporal sectors and thinner PCT was associated with older age, European descent, longer axial length, larger ASCO area, and female sex. Among these associations, age had the strongest influence, and its effect was greatest within the inferior temporal sectors.

OCT-Detected Optic Nerve Head Neural Canal Direction, Obliqueness, and Minimum Cross-Sectional Area in Healthy Eyes

“…our methods of data acquisition have been published. [28][29][30] We use the term ONH to refer to the tissues that are contained within the scleral canal and those immediately adjacent to it (ie, the peripapillary sclera, choroid, and retina as well as the immediate retrolaminar optic nerve).…”

“…PARTICIPANTS: A total of 362 healthy individuals were recruited from 8 centers (5 in the United States, 2 in Germany, and 1 in Canada). [28][29][30] Among these, 246 selfidentified as European descent, 30 47 as Hispanic ethnicity, 47 as African descent, 19 as Asian descent, and 3 as Native American descent participants. Inclusion criteria included age 18 to 90 years; no history of glaucoma; intraocular pressure (IOP) < _ 21 mm Hg; best corrected visual acuity > _ 20/40; refraction less than 66.00 diopter (D) sphere and 62.00 D cylinder; Glaucoma Hemifield Test and mean deviation within normal limits.…”

“…Our strategy for OCT ONH image manual segmentation has been described previously (Figure 1). 28,29 Raw OCT volumes were exported from the device and imported into custom 3D visualization and segmentation software (ATL 3D Suite). 35 ONH and peripapillary landmarks were manually segmented in each radial B-scan, and the ONH was reconstructed 3-dimensionally.…”

“…Segmented landmarks included the internal limiting membrane, posterior surface of the RNFL, posterior surface of Bruch's membrane/retinal pigment epithelium complex, BMO, neural canal wall, anterior scleral surface, and the ASCO (segmented on each side of the canal by visually projecting the plane of the peripapillary anterior scleral surface through the neural canal wall and marking their intersection). 28,29 All manual segmentations were performed by observers at the Optic Nerve Head Research Laboratory, Devers Eye Institute.…”

The connective tissue phenotype of glaucomatous cupping in the monkey eye - Clinical and research implications

“…Strong connective tissues, a robust blood supply and stable astrocytes and glia increase the chance of “normal” ONH aging. While the existence of a neuropathy of aging is controversial, the pattern of “normal” age-related axon loss and the development of glaucomatous damage are similar (Chauhan et al, 2015; See et al, 2009; Yang et al, 2017). We propose that age-related ON axon loss and glaucoma are both influenced by IOP, at all levels of IOP, and share the same non-IOP-related risk-factors and mechanisms (Figure 7).…”