Prevalence and Associations of Asteroid Hyalosis: The Beijing Eye Study

Background: To determine the prevalence and associations of asteroid hyalosis (AH) in a Chinese population-based cohort.Methods: The population-based Beijing Eye Study 2011 included 3468 individuals with a mean age of 64.6 ± 9.8 years (range: 50-93 years). AH is a condition in which small yellow-white, spherical particles known as asteroid bodies (ABs) are present within the vitreous body.Results: Fundus photographs were gradable in 3419 subjects. AH was detected in 65 (0.9%, 95% CI: 0.7%, 1.2%) eyes of 53 (1.5%, 95% CI: 1.1%, 1.9%) subjects. AH was bilateral in 18.9%. Mean age of all subjects with AH was 69.2± 9.5 years (median, 71.0 years; range, 51–91 years), mean refractive error was 0.63±1.53D (median, 0.75 D; range, -4.12 to 4.00D). In multivariate analysis, prevalence of AH was associated with elder age (P=0.014, OR 1.057), thicker lens (P=0.034, OR 3.843), higher refractive error (P=0.016, OR 1.401).Conclusions: In adult Chinese in Beijing, the prevalence of AH was 0.9% for eyes or 1.5% for subjects. AH was associated with elder age, thicker lens and higher refractive error. It does not support previous observations of an association of AH with diabetes or other systemic indicators.

Change in the ophthalmoscopical optic disc size and shape in a 10-year follow-up: the Beijing Eye Study 2001–2011

BackgroundTo assess prevalence and associated factors of changes in the ophthalmoscopic optic disc size and shape.MethodsThe case–control study included all highly myopic eyes (myopic refractive error ≤−6.0 diopters) and a randomly selected group of non-highly myopic eyes, examined in the population-based Beijing Eye Study 2001 and 2011.ResultsThe study included 89 highly myopic eyes (age:65.0±9.8 years) and 86 non-highly myopic eyes. Reduction in ophthalmoscopic disc size (prevalence, high myopia: 30 (33.7%) eyes; non-high myopia: 7 (8.1%) eyes) was associated with non-circular gamma zone enlargement (OR: 19.4; 95% CI: 6.7 to 56.6; p<0.001) and disc-fovea line elongation (OR: 2.80;95% CI: 1.12 to 6.98; p=0.03). Disc size reduction was correlated with a disc diameter shortening in direction of the widest gamma zone enlargement (correlation coefficient r=34; p=0.01). The perpendicular disc diameter remained mostly unchanged, resulting in an ovalisation of the ophthalmoscopic disc shape. Enlargement of the ophthalmoscopic disc size (prevalence, high myopia: 22 (24.7%) eyes; non-high myopia: 4 (4.7%) eyes) was associated with circular gamma zone enlargement (4.99; 95% CI: 1.95 to 12.8; p=0.001) and high myopia (OR: 4.29; 95% CI: 1.34 to 13.8; p=0.01).ConclusionsMyopic axial elongation may lead first to a Bruch’s membrane (BM) opening (BMO) shift into the foveal direction leading to BM overhanging into the nasal intrapapillary compartment, development and enlargement of gamma zone at the temporal disc side, reduction in the ophthalmoscopically visible disc area and ovalisation of the ophthalmoscopic disc shape. In a second step, an axial elongation-associated BMO enlargement may lead to a circular gamma zone increase and, due to the retraction of BM at the nasal disc border, to an enlargement of the ophthalmoscopically visible optic disc.

Choroidal shift in myopic eyes in the 10-year follow-up Beijing eye study

The aim of the study was to assess longitudinal changes in the spatial relationship of the choroidal vasculature to retinal vasculature in myopic eyes. In the population-based longitudinal Beijing Eye Study in 2001/2011, we examined all highly myopic eyes with assessable fundus photographs and a randomized group of non-highly myopic. Using fundus photographs, we qualitatively assessed changes in the location of major choroidal vessels in relationship to retinal vessels. The study consisted of 85 highly myopic eyes (58 participants;age:64.8 ± 9.4 years) and 85 randomly selected non-highly myopic eyes. A choroidal shift in relationship to the retinal vessels was detected more often in the highly myopic group than the non-highly myopic group (47/85 (55%) vs 6/85 (7%); P < 0.001). In the highly myopic group, the choroidal vessel shift occurring on the disc-fovea line in 39 (44%) eyes, was similar to, or smaller than, the enlargement in gamma zone width in 26 (67%) eyes and in 11 (28%) eyes respectively. The choroidal vessel shift was larger (P = 0.002) in eyes without choroidal vessels in gamma zone than in eyes with large choroidal vessels in gamma zone. In 14 (17%) eyes, a localized centrifugal choroidal shift was observed in association with an increase in the stage of myopic maculopathy. The results suggest that highly myopic eyes show a change in the position of large choroidal vessels in relationship to retinal vessels, in association with development or enlargement of gamma zone and an increase in the stage of myopic maculopathy.

Elongation of the disc-fovea distance and retinal vessel straightening in high myopia in a 10-year follow-up of the Beijing eye study

To assess changes in the disc-fovea distance (DFD) in highly myopic eyes in a 10-year population-based follow-up study. The case control study included all highly myopic eyes (myopic refractive error ≥ − 6.0 diopters or axial length ≥ 26.0 mm) and a randomized group of non-highly myopic eyes examined in the population-based Beijing Eye Study 2001 and 2011. Using fundus photographs and optical coherence tomographic images, we assessed changes in DFD, parapapillary gamma zone, angle kappa (angle between the temporal arterial arcades), and course of papillo-macular retinal vessels. The study included 89 highly myopic eyes and 86 non-highly myopic eyes. DFD elongation, gamma zone widening, angle kappa decrease and straightening of papillo-macular retinal vessels were detected more often (all P < 0.001) in the highly myopic group than in the non-highly myopic group (63/89 versus 9/86;75/89 versus 18/86;61/89 versus 9/86; and 58/89 versus 7/86,respectively). Gamma zone enlargement, angle kappa reduction and papillo-macular retinal vessel straightening were significantly (all P < 0.001) associated with DFD elongation. The length of macular Bruch’s membrane on the disc-fovea line and the vertical distance between the temporal arterial arcade did not change during follow-up. DFD elongation (10-year incidence 70.8% in highly myopic eyes) was associated with gamma zone enlargement, while macular Bruch’s membrane length remained unchanged. It supports the notion of a temporal shift of an otherwise stable posterior Bruch’s membrane in axially elongated eyes. Straightening of the papillo-macular vessels with increasing gamma zone width suggests a coincident stretching of the papillo-macular retinal nerve fibers and inner limiting membrane.

Peaks ofcircumpapillary retinal nerve fibre layer and associations in healthy eyes: the Beijing Eye Study 2011

AimsTo investigate the distribution and associations of the circumpapillary retinal nerve fibre layer thickness (RNFLT) profile, characterised as peak height and peak position, in healthy eyes.Methods667 healthy participants (294 male) were randomly selected from the Beijing Eye Study 2011. RNFLT was measured at 768 points at 3.4 mm circumpapillary position using spectral-domain optical coherence tomography (OCT). The location and height of the superior temporally peak (PeakST), superior nasal peak (PeakSN) and inferior temporal peak (PeakIT) were assessed.ResultsThe RNFLT was thickest at PeakIT (194±25 µm; location: 288±12°), followed by PeakST (182±25 µm; 73±10°) and PeakSN (125±23 µm; 135°±13°). In multivariable analysis, peak RNFLT decreased with longer axial length (p<0.001; correlation coefficient beta: −0.18 to −0.15; all peaks), older age (all p<0.01, beta: −0.10; PeakST and PeakIT), female gender (p=0.026, beta: −0.09; PeakST), and larger parapapillary gamma zone and beta zone width (p≤0.004, beta: −0.16 to−0.11; PeakSN). The temporal peaks were located more closely to the horizontal line in women (p≤0.020, beta: 0.09–0.11) and with longer axial length (p<0.001, beta: 0.27–0.31), while they were located more inferiorly in eyes with larger Bruch’s membrane openings (BMOs) (p≤0.01, beta:0.10~0.11).ConclusionsPeak RNFLT decreased by 0.34 µm for each increase of year in age (PeakST and PeakIT), by 3.2–3.5 µm for each 1 mm increase in axial length (all three peaks), and was 4.5 µm thinner in women than in men. The position of temporal peaks depended on gender, axial length and BMO diameter. These associations should be taken into count in OCT-based RNFLT assessment for disease finding, especially in glaucoma evaluation.