Determination of retinal surface area

Previous attempts at determining retinal surface area and surface area of the whole eye have been based upon mathematical calculations derived from retinal photographs, schematic eyes and retinal biopsies of donor eyes. 3-dimensional (3-D) ocular magnetic resonance imaging (MRI) allows a more direct measurement, it can be used to image the eye in vivo, and there is no risk of tissue shrinkage. The primary purpose of this study is to compare, using T2-weighted 3D MRI, retinal surface areas for superior-temporal (ST), inferior-temporal (IT), superior-nasal (SN) and inferior-nasal (IN) retinal quadrants. An ancillary aim is to examine whether inter-quadrant variations in area are concordant with reported inter-quadrant patterns of susceptibility to retinal breaks associated with posterior vitreous detachment (PVD). Seventy-three adult participants presenting without retinal pathology (mean age 26.25 ± 6.06 years) were scanned using a Siemens 3-Tesla MRI scanner to provide T2-weighted MR images that demarcate fluid-filled internal structures for the whole eye and provide high-contrast delineation of the vitreous-retina interface. Integrated MRI software generated total internal ocular surface area (TSA). The second nodal point was used to demarcate the origin of the peripheral retina in order to calculate total retinal surface area (RSA) and quadrant retinal surface areas (QRSA) for ST, IT, SN, and IN quadrants. Mean spherical error (MSE) was −2.50 ± 4.03D and mean axial length (AL) 24.51 ± 1.57 mm. Mean TSA and RSA for the RE were 2058 ± 189 and 1363 ± 160 mm2, respectively. Repeated measures anova for QRSA data indicated a significant difference within-quadrants (P < 0.01) which, contrasted with ST (365 ± 43 mm2), was significant for IT (340 ± 40 mm2 P < 0.01), SN (337 ± 40 mm2 P < 0.01) and IN (321 ± 39 mm2 P < 0.01) quadrants. For all quadrants, QRSA was significantly correlated with AL (P < 0.01) and exhibited equivalent increases in retinal area/mm increase in AL. Although the differences between QRSAs are relatively small, there was evidence of concordance with reported inter-quadrant patterns of susceptibility to retinal breaks associated with PVD. The data allow AL to be converted to QRSAs, which will assist further work on inter-quadrant structural variation

Scleral Thickness in Human Eyes

Purpose: To obtain information about scleral thickness in different ocular regions and its associations. Methods: The histomorphometric study included 238 human globes which had been enucleated because of choroidal melanomas or due to secondary angle-closure glaucoma. Using light microscopy, anterior-posterior pupil-optic nerve sections were measured. Results: In the non-axially elongated group (axial length #26 mm), scleral thickness decreased from the limbus (0.5060.11 mm) to the ora serrata (0.4360.14 mm) and the equator (0.4260.15 mm), and then increased to the midpoint between posterior pole and equator (0.6560.15 mm) and to the posterior pole (0.9460.18 mm), from where it decreased to the peri-optic nerve region (0.8660.21 mm) and finally the peripapillary scleral flange (0.3960.09 mm). Scleral thickness was significantly lower in the axially elongated group (axial length.26 mm) than in the non-axially elongated group for measurements taken at and posterior to the equator. Scleral thickness measurements of the posterior pole and of the peripapillary scleral flange were correlated with lamina cribrosa thickness measurements. Scleral thickness measurements at any location of examination were not significantly (all P.0.10) correlated with corneal thickness measurements. Scleral thickness was statistically independent of age, gender and presence of glaucoma. Conclusions: In non-axially elongated eyes, the sclera was thickest at the posterior pole, followed by the peri-optic nerv

Five-Year Follow-Up of Parapapillary Atrophy: The Beijing Eye Study

Purpose: To assess longitudinal changes in parapapillary atrophy in the adult population of Greater Beijing. Methods: The population-based Beijing Eye Study 2006 included 3251 subjects who had participated in the Beijing Eye Study 2001 and returned for re-examination. The mean age was 60.4610.1 years. Using optic disc photographs, we measured parapapillary atrophy which was divided into alpha zone and beta zone. Results: Overall progression rate of alpha zone was seen in 0.660.1 % (95 % confidence interval (CI):0.3,0.9) of the subjects and of beta zone in 8.260.5 % (95%CI:7.2,9.1) of the subjects. In binary regression analysis, rate of progression of alpha zone was significantly associated higher age (P = 0.04) and the co-progression of zone Beta (P,0.001). Rate of progression of beta zone was significantly associated with higher age (P,0.001; odds ratio (OR):1.11;95%CI:1.10,1.14), higher intraocular pressure (P,0.001;OR:1.10;95%CI:1.05,1.14), higher myopic refractive error (P,0.001;OR:0.71; 95%CI:0.67,0.75), rural region of habitation (P = 0.002;OR: 0.58; 95%CI:0.41,0.82), presence of glaucomatous optic nerve damage (P,0.001;OR:2.89; 95%CI:1.62,5.14), co-progression of alpha zone (P,0.001;OR:7.13;95%CI:2.43,20.9), absence of arterial hypertension (P = 0.03;OR: 0.70; 95%CI:0.51,0.96), and thicker central corneal thickness (P = 0.02;OR:1.01;95%CI:1.00,1.01). Subjects with a non-glaucomatous optic nerve damage (n = 22) as compared to the remaining subjects did not vary in the progression rate of alpha zone (0.0 % versus 0.660.1%; P = 1.0) and beta zone (8.260.5 % versus 6.360.6%;P = 1.0)

Cognitive impairment in the population-based ural very old study

BackgroundDespite its marked importance in public health, the prevalence of cognitive impairment (CI) and its associated factors have only rarely been examined in old populations in general or in Russia at all.ObjectiveTo assess CI prevalence and its determinants in a very elderly population in Russia.Materials and methodsThe population-based Ural Very Old Study, conducted in rural and urban region in Bashkortostan/Russia, included 1,526 (81.1%) out of 1,882 eligible individuals aged 85+ years. A series of medical examinations including the Mini-Mental State Examination (MMSE) for the assessment of CI was performed.ResultsMini-Mental State Examination data were available for 1,442 (94.5%) individuals (mean age: 88.3 ± 2.9 years; range: 85–103 years). The median MMSE score was 24 (interquartile range: 19, 27). Prevalence of any CI (MMSE score &lt; 24 points) was 701/1,442 [48.6%; 95% confidence interval (CI): 46.0, 51.2]. Prevalence of mild, moderate and severe CI (MMSE score 19–23 points, 10–18 points, and ≤9 points, respectively) was 357/1,442 (24.8%; 95% CI: 22.5, 27.0), 246/1,442 (17.1%; 95% CI: 15.1, 19.0), and 98/1,442 (6.8%; 95% CI: 5.5, 8.1), resp. A lower MMSE score correlated (regression coefficient r2: 0.31) with older age (beta: −0.13; P &lt; 0.001), rural region of habitation (beta: 0.15; P &lt; 0.001), lower level of education (beta: 0.19; P &lt; 0.001), higher depression score (beta: −0.33; P &lt; 0.001) (or alternatively, higher prevalence of hearing loss (beta: −0.10; P = 0.001), worse visual acuity (beta: −0.10; P = 0.001), and lower physical activity (beta: 0.06; P = 0.04).ConclusionIn this elderly study population from rural and urban Russia, prevalence of any, mild, moderate and severe CI was 48.6, 24.8, 17.1, and 6.8%, resp. Besides medical and lifestyle factors, vision and hearing impairment were major factors associated with CI

Five Year Incidence of Visual Field Loss in Adult Chinese. The Beijing Eye Study.

PURPOSE: To describe the cumulative 5 year incidence of visual field loss in adult Chinese in Greater Beijing. METHODS: The Beijing Eye Study 2006 included 3251 subjects (mean age 60.4±10.1 years) who had participated in the Beijing Eye Study 2001 and returned for re-examination. All participants underwent a comprehensive eye examination, including visual field test by frequency doubling threshold perimetry. An abnormal visual field was defined as reduced sensitivity in at least one test location. Incident visual field loss was defined as a change in visual field from normal at baseline to abnormal at follow-up. RESULTS: An incident visual field loss was detected in 273 eyes (4.3±0.5%)/235 subjects (7.3±0.5%). It was significantly associated with higher age (P = 0.001), higher intraocular pressure (P<0.001), and higher fasting blood glucose concentration (P = 0.019). Considering only eyes (n = 140) with a detected cause for visual field loss, the most frequent causes were cataract (68 (48.6%) eyes) followed by glaucoma (23 (16.4%) eyes), diabetic retinopathy (13 (9.3%) eyes), age-related macular degeneration (10 (7.1%) eyes), and myopic degenerative retinopathy (9 (6.4%) eyes). For 133 (48.7%) eyes with a visual field loss, the cause for the VFL remained unclear. CONCLUSIONS: The 5-year incidence of visual field loss was 4.3±0.5% per eye or 7.3±0.5% per subject. It increased significantly with age, intraocular pressure, and fasting blood glucose level. Major causes for the incidence of visual field loss were cataract, glaucoma and diabetic retinopathy

Anatomy and Pathology/Oncology Retinal Thickness and Axial Length

PURPOSE. To examine the relationships between axial length and foveal and peripheral retinal thickness. METHODS. Using optical coherence tomography, foveal retinal thickness was measured in participants of the population-based Beijing Eye Study without optic nerve or macula diseases. Inner and outer nuclear layer thickness as surrogate for retinal thickness was assessed in the fundus periphery in human globes enucleated due to malignant uveal melanoma or painful glaucoma. RESULTS. The study included 1117 individuals with a mean age of 64.2 6 9.7 years (range: 50-93 years) and mean axial length of 23.4 6 1.04 mm (range: 20.29-28.68 mm). In multivariate analysis, thicker central foveal thickness was associated with male sex (P &lt; 0.001; standardized regression coefficient beta: À0.13; nonstandardized regression coefficient B: À5.84; 95% confidence interval (CI): À8.56, À3.13); urban region of habitation (P ¼ 0.02; beta: 0.07; B: 3.56; 95% CI: 0.55, 6.57); thinner lens thickness (P ¼ 0.01; beta: À0.08; B: À5.11; 95% CI: À9.01, À1.21); thinner subfoveal choroidal thickness (P ¼ 0.04; beta: À0.07; B: À0.01; 95% CI: À0.03, À0.001); and longer axial length (P &lt; 0.001; beta: 0.18; B: 3.79; 95% CI: 2.41, 5.17). In the same multivariate model, superior, inferior, and temporal foveal thickness was not significantly associated with axial length (P ¼ 0.26, P ¼ 0.19, P ¼ 0.08, respectively), while thicker nasal foveal thickness was associated with longer axial length (P ¼ 0.009; beta: 0.09; B: 1.50; 95% CI: 0.37, 2.62). In the histomorphometric part of the study including 32 eyes (sagittal diameter: 27.0 6 4.2 mm; range: 22-37 mm), mean thickness of the inner and outer nuclear layers at the equator and at the midpoint equator/posterior pole decreased with longer axial length (P ¼ 0.004; beta: À0.48; and P ¼ 0.02; beta: À0.44, respectively). CONCLUSIONS. Myopic axial globe elongation was associated with retinal thinning in the equatorial and pre-equatorial region, while foveal retinal thickness was mostly unaffected by axial length. It suggests that axial elongation takes place predominantly in the equatorial and pre-equatorial region of the eye

Death by color: differential cone loss in the aging mouse retina

Differential cell death is a common feature of aging and age-related disease. In the retina, 30% of rod photoreceptors are lost over life in humans and rodents. However, studies have failed to show age-related cell death in mouse cone photoreceptors, which is surprising because cone physiological function declines with age. Moreover in human, differential loss of short wavelength cone function is an aspect of age-related retinal disease. Here, cones are examined in young (3-month-old) and aged (12-month-old) C57 mice and also in complement factor H knock out mice (CFH-/-) that have been proposed as a murine model of age-related macular degeneration. In vivo imaging showed significant age-related reductions in outer retinal thickness in both groups over this period. Immunostaining for opsins revealed a specific significant decline of >20% for the medium/long (M/L)-wavelength cones but only in the periphery. S cones numbers were not significantly affected by age. This differential cell loss was backed up with quantitative real-time polymerase chain reaction for the 2 opsins, again showing S opsin was unaffected, but that M/L opsin was reduced particularly in CFH-/- mice. These results demonstrate aged cone loss, but surprisingly, in both genotypes, it is only significant in the peripheral ventral retina and focused on the M/L population and not S cones. We speculate that there may be fundamental differences in differential cone loss between human and mouse that may question the validity of mouse models of human outer retinal aging and pathology

Prevalence and associated factors of anemia in a Russian population: the Ural eye and medical study

Background: Although anemia is one of the leading causes of the global burden of disease, information about its prevalence in Russia is mostly missing. We therefore assessed its prevalence and associated factors in a Russian population. Methods: The population-based Ural Eye and Medical Study included 5899 (80.5%) out of 7328 eligible individuals (mean age:59.0 ± 10.7 years;range:40–94 years) who underwent a standardized interview and detailed general examination. The definition of anemia was based on the hemoglobin concentration (definition #1:hemoglobin concentration &lt; 140 g/L in men,&lt; 130 g/L in women; definition #2:hemoglobin concentration &lt; 130 g/L in men,&lt; 120 g/L in women [World Health Organization definition]). Results: Higher hemoglobin concentration (mean:142.6 ± 14.8 g/L; range:80-171 g/L) was associated (multivariable analysis) with male gender (P &lt; 0.001; standardized regression coefficient beta:-0.20), higher waist-hip circumference ratio (P &lt; 0.001;beta:0.05), higher prevalence of car ownership (P &lt; 0.001;beta:0.05), higher blood concentrations of bilirubin (P &lt; 0.001;beta:0.05) and triglycerides (P &lt; 0.001;beta:0.06), lower erythrocyte sedimentation rate (P &lt; 0.001;beta:-0.32), and shorter blood clotting time (P &lt; 0.001;beta:-0.39). Using definition #1 and #2, anemia was detected in 1385 individuals (23.6%;95% confidence interval CI)CI:22.5,24.7) and in 453 individuals (7.7%;95%CI:7.0,8.4), respectively. Prevalence of moderate anemia (hemoglobin concenttration:110 g/L-80 g/L), detected in 165 individuals (2.8%;95%CI:2.4,3.2), increased with younger age (P = 0.008;odds ratio (OR):0.98;95%CI:0.96,0.99), female gender (P &lt; 0.001;OR:2.52;95%CI:1.47,4.33), higher erythrocyte sedimentation rate (P &lt; 0.001;OR:1.08;95%CI:1.06,1.09), longer blood clotting time (P &lt; 0.001;OR:8.56;95%CI:5.68,12.9), and marginally significantly, with a lower waist-hip circumference ratio (P = 0.058;OR:0.13;95%CI:0.02,1.07). In women, it was significantly (P &lt; 0.001) higher before menopause (8.8%;95%CI:6.4,11.1) than after menopause (3.5%;95%CI:2.8,4.3). Conclusions: In this Russian population as compared to populations from countries with a similar socio-demographic index, anemia prevalence was relatively low. As in other populations, higher anemia prevalence was strongly and inversely associated with menopause, and to a minor degree, with lower waist-hip circumference ratio and lower socio-economic background

Human iPSC-Derived Retinal Pigment Epithelium: A Model System for Prioritizing and Functionally Characterizing Causal Variants at AMD Risk Loci

We evaluate whether human induced pluripotent stem cell-derived retinal pigment epithelium (iPSC-RPE) cells can be used to prioritize and functionally characterize causal variants at age-related macular degeneration (AMD) risk loci. We generated iPSC-RPE from six subjects and show that they have morphological and molecular characteristics similar to those of native RPE. We generated RNA-seq, ATAC-seq, and H3K27ac ChIP-seq data and observed high similarity in gene expression and enriched transcription factor motif profiles between iPSC-RPE and human fetal RPE. We performed fine mapping of AMD risk loci by integrating molecular data from the iPSC-RPE, adult retina, and adult RPE, which identified rs943080 as the probable causal variant at VEGFA. We show that rs943080 is associated with altered chromatin accessibility of a distal ATAC-seq peak, decreased overall gene expression of VEGFA, and allele-specific expression of a non-coding transcript. Our study thus provides a potential mechanism underlying the association of the VEGFA locus with AMD