Positive and Negative Associations of Myopia with Ocular Diseases in Population-Based Studies.

OBJECTIVE: Prevalence of myopia and vision impairment due to myopic macular degeneration and myopia-related optic neuropathies have markedly increased worldwide. We evaluated whether myopia is associated with the prevalence of other ocular disorders in a positive or negative sense. DESIGN: Population-based studies conducted in Russia, China and India. PARTICIPANTS: The Russian Ural Eye and Medical Study (UEMS) and the Beijing Eye Study (BES) included 5899 individuals and 4439 individuals (all aged 40+ years), respectively, and the Central India Eye and Medical Study (CIEMS) consisted of 4711 individuals, aged 30+ years. The studies were conducted in rural and urban regions in Bashkortostan/Russia, Nagpur/India, and Beijing/China. METHODS: The participants underwent a series of ophthalmological and general medical examinations. MAIN OUTCOME MEASURES: Axial length as surrogate for myopia, and prevalence of diabetic retinopathy (DR), age-related macular degeneration (AMD), angle-closure glaucoma (ACG), and open-angle glaucoma (OAG). RESULTS: In the UEMS, DR prevalence (OR:0.73;95%CI:0.56,0.96), AMD prevalence (OR:0.85;95%CI:0.74,0.98) and ACG prevalence (OR:0.72;95%CI:0.55,0.95) decreased, and OAG prevalence (OR:1.65;95%CI:1.45,1.88) increased with longer axial length in multivariable analyses. In the CIEMS, lower AMD prevalence (OR:0.81;95%CI:0.69,0.95) and lower ACG prevalence (OR:0.55;95%CI:0.36,0.83), and higher OAG prevalence (OR:1.45;95%CI:1.15,1.83) were associated with longer axial length. DR prevalence (0.33%;95%CI:0.16,0.50) was too low for statistical analysis in the CIEMS. In the BES, prevalence (OR:0.64;95%CI:0.50,0.81) and 10-year incidence of DR (OR:0.48;95%CI:0.33,0.71) and prevalence (OR:0.83;95%CI:0.77,0.89) and 5-year incidence of AMD (OR:0.996;95%CI:0.993,0.999) decreased, and prevalence (OR:1.35;95% CI:1.17,1.56) and 10-year incidence of OAG (OR:1.40;95%CI:1.22,1.61) increased with longer axial length. In all three studies, the association between higher OAG prevalence and longer axial length was nonlinear with a slight increase for the moderate myopia range, and a steep increase in the highly myopic range. CONCLUSIONS AND RELEVANCE: Myopia is associated with a lower prevalence of DR, AMD and ACG and lower incidence of DR and AMD, while high myopia more than moderate myopia is associated with a higher prevalence and incidence of OAG. Future studies may assess whether in myopia, in particular in moderate myopia, the myopia-related advantages, i.e., lower prevalence of DR, AMD and ACG, may outweigh the increased risks for OAG and other myopia-related disorders.

Is Kidney Function Associated with Age-Related Macular Degeneration?: Findings from the Asian Eye Epidemiology Consortium.

PURPOSE: Chronic kidney disease (CKD) may elevate susceptibility to age-related macular degeneration (AMD) because of shared risk factors, pathogenic mechanisms, and genetic polymorphisms. Given the inconclusive findings in prior studies, we investigated this association using extensive datasets in the Asian Eye Epidemiology Consortium. DESIGN: Cross-sectional study. PARTICIPANTS: Fifty-one thousand two hundred fifty-three participants from 10 distinct population-based Asian studies. METHODS: Age-related macular degeneration was defined using the Wisconsin Age-Related Maculopathy Grading System, the International Age-Related Maculopathy Epidemiological Study Group Classification, or the Beckman Clinical Classification. Chronic kidney disease was defined as estimated glomerular filtration rate (eGFR) of less than 60 ml/min per 1.73 m2. A pooled analysis using individual-level participant data was performed to examine the associations between CKD and eGFR with AMD (early and late), adjusting for age, sex, hypertension, diabetes, body mass index, smoking status, total cholesterol, and study groups. MAIN OUTCOME MEASURES: Odds ratio (OR) of early and late AMD. RESULTS: Among 51 253 participants (mean age, 54.1 ± 14.5 years), 5079 had CKD (9.9%). The prevalence of early AMD was 9.0%, and that of late AMD was 0.71%. After adjusting for confounders, individuals with CKD were associated with higher odds of late AMD (OR, 1.46; 95% confidence interval [CI], 1.11-1.93; P = 0.008). Similarly, poorer kidney function (per 10-unit eGFR decrease) was associated with late AMD (OR, 1.12; 95% CI, 1.05-1.19; P = 0.001). Nevertheless, CKD and eGFR were not associated significantly with early AMD (all P ≥ 0.149). CONCLUSIONS: Pooled analysis from 10 distinct Asian population-based studies revealed that CKD and compromised kidney function are associated significantly with late AMD. This finding further underscores the importance of ocular examinations in patients with CKD. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Drusen in the macula and parapapillary region.

PURPOSE: To examine histological characteristics and differences between drusen beneath the retinal pigment epithelium (small hard drusen) located in the macula and located in the parapapillary region. METHODS: We histomorphometrically examined human eyes enucleated due to uveal melanomas or secondary angle-closure glaucoma. RESULTS: The study included 106 eyes (age, 62.6 ± 15.2 years) with macular drusen (n = 7 globes) or parapapillary drusen (n = 29 eyes) and 70 eyes without drusen. In all drusen, periodic-acid-Schiff-positive material was located between the RPE basal membrane and the inner collagenous layer of Bruch's membrane (BM). Macular drusen as compared with parapapillary drusen had lower height (15.2 ± 10.1 µm versus 34.3 ± 19.8 µm; P = 0.003), while both groups did not differ significantly in basal drusen width (74.0 ± 36.3 µm versus 108.7 ± 101.0 µm; P = 0.95). Eyes with macular drusen and eyes without drusen did not differ significantly in BM thickness (2.74 ± 0.44 µm versus 2.55 ± 0.88 µm; P = 0.57) or in RPE cell density (35.4 ± 10.4 cells/480 µm versus 32.8 ± 7.5 cells/480 µm; P = 0.53), neither in the drusen region nor in the drusen vicinity, while BM thickness (4.60 ± 1.490 µm; P < 0.001) and RPE cell density (56.9 ± 26.8 cells/480 µm; P = 0.005) were higher at the parapapillary drusen. Eyes with macular drusen, eyes with parapapillary drusen, and eyes without drusen did not differ significantly in choriocapillaris density (all P > 0.10) and thickness (all P > 0.35). Limitations of the study, among others, were a small number and size of drusen examined, diseases leading to enucleation, lack of serial sections, limited resolution of light microscopy, and enucleation-related and histological preparation-associated artefacts. CONCLUSIONS: The findings of this study, also taking into account its methodological limitations, suggest that macular drusen and parapapillary drusen shared the morphological feature of periodic-acid-Schiff-positive material between the RPE basal membrane and BM and that they did not vary significantly in choriocapillaris thickness and density. RPE cell density and BM thickness were higher in parapapillary drusen than in macular drusen.

Prevalence and Associations of Nonglaucomatous Optic Nerve Atrophy in High Myopia: The Ural Eye and Medical Study.

PURPOSE: To assess the prevalence of nonglaucomatous optic nerve atrophy (NGOA) in highly myopic individuals. DESIGN: Population-based study. PARTICIPANTS: The Ural Eye and Medical Study included 5899 (80.5%) of 7328 eligible individuals (80.5%). METHODS: Nonglaucomatous optic nerve atrophy, graded into 5 arbitrary stages, was characterized by decreased visibility of the retinal nerve fiber layer (RNFL) on photographs, neuroretinal rim pallor, abnormally thin retinal arteriole diameter, and abnormally thin peripapillary RNFL as measured by OCT. MAIN OUTCOME MEASURES: Nonglaucomatous optic nerve atrophy prevalence and degree. RESULTS: Of 5709 participants (96.9%) with axial length measurements, 130 individuals (2.3%) were highly myopic, of whom 116 individuals (89.2%; age, 57.8 ± 11.1 years; axial length, 27.0 ± 1.2 mm) had available fundus photographs and OCT images and were included into the study. Nonglaucomatous optic nerve atrophy prevalence was 34/116 individuals (29.3%; 95% confidence interval [CI], 21.0-38.0), and mean NGOA degree in eyes with NGOA was 1.7 ± 1.0 arbitrary units. Higher NGOA degree correlated (multivariable analysis; regression coefficient, r2 = 0.59) with longer axial length (ß, 0.22; P = 0.007), wider temporal parapapillary γ zone width (ß, 0.50; P < 0.001), higher prevalence of diabetes (ß, 0.20; P = 0.005), and higher systolic blood pressure (ß, 0.15; P = 0.03). Higher NGOA prevalence was associated with longer axial length (odds ratio [OR], 7.45; 95% CI, 2.15-25.7), wider temporal parapapillary γ zone (OR, 6.98; 95% CI, 2.61-18.7), and higher systolic blood pressure (OR, 1.05; 95% CI, 1.01-1.10). CONCLUSIONS: In this ethnically mixed population from Russia with an age of 40 years or more, high axial myopia showed a relatively high prevalence of NGOA, increasing with longer axial length and wider temporal parapapillary γ zone. For each 1 mm of axial elongation and γ zone widening, the odds for NGOA increased 7.45-fold and 6.98-fold, respectively. The axial elongation-associated and γ zone-related increase in the distance between the retinal ganglion cells and the optic disc may lead to a lengthening and stretching of the retinal ganglion cell axons and may be of importance pathogenetically. In highly myopic eyes, NGOA may be a reason for visual field and central visual acuity loss, unexplainable by myopic macular pathologic features. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Intraocular epidermal growth factor concentration, axial length, and high axial myopia.

PURPOSE: Various molecules such as dopamine have been found to be associated with axial elongation in experimental studies. Here, we examined whether intraocular EGF is associated with axial length in myopic patients. METHODS: The hospital-based investigation included patients of European descent without optic nerve, retinal, or macular diseases except for myopic maculopathy. Using aqueous humor samples collected during surgery, the EGF concentration was examined applying a cytometric bead array. High myopia was defined by an axial length of ≥ 27.0 mm. RESULTS: The study included a non-highly myopic group of 11 patients (mean age, 72.9 ± 10.8 years; mean axial length, 24.3 ± 1.1 mm) and a highly myopic group of three patients (age, 81.11 ± 12.3 years; axial length, 29.5 ± 1.3 mm), with one of them having pathologic myopic maculopathy. In multivariable linear regression analysis, higher EGF concentration was correlated with the highly myopic versus non-highly myopic group (beta, 1.24; non-standardized correlation coefficient B, 6.24; 95% confidence interval (CI), 0.10,12.4;P = 0.047) after adjusting for axial length. The amount of intraocular EGF was significantly higher in the highly myopic group than in the non-highly myopic group (89.1 ± 40.8 pg versus 34.1 ± 13.2 pg; P = 0.005), and it was highest in the eye with myopic maculopathy (135 pg). CONCLUSIONS: The intraocular amount of EGF is higher in highly myopic versus non-highly myopic eyes.

Prevalence and Pattern of Geographic Atrophy in Asia: The Asian Eye Epidemiology Consortium.

PURPOSE: Although there have been many population-based studies of age-related macular degeneration (AMD), only limited information is available in Asia on the epidemiology of geographic atrophy (GA). We aimed to determine the prevalence and patterns of GA through an analysis of multiple studies conducted within the Asian Eye Epidemiology Consortium (AEEC). DESIGN: Cross-sectional meta-analyses. PARTICIPANTS: A total of 97 213 individuals aged 40 years and older. METHODS: Data from 22 population-based studies from countries belonging to the AEEC were included. In all studies, AMD was defined on the basis of standardized grading systems. Geographic atrophy was defined as an area of pallor in the fundus with visibility of the underlying choroidal blood vessels and sharply defined borders. Random-effects meta-analysis was performed to estimate overall and age-, gender-, and region-specific pooled prevalence of GA. MAIN OUTCOME MEASURES: Prevalence of GA per 1000 persons. RESULTS: The mean age was 60.8 ± 10.0 years, and 42 673 (43.9%) were male. Overall, a total of 223 individuals (0.2%) had GA. The pooled overall prevalence of GA was 1.57 per 1000 persons (95% confidence interval [CI], 1.04-2.10), which was 3 times less than that of neovascular AMD of 5.20 per 1000 persons (95% CI, 3.97-6.43). Compared with those aged 50 to 59 years, the prevalence of GA increased from 0.34 per 1000 persons (95% CI, 0.07-0.62) to 2.90 per 1000 persons (95% CI, 1.55-4.25) in those aged ≥70 years. The GA prevalence per 1000 persons was similar between urban (2.22; 95% CI, 1.22-3.23) and rural residents (1.33; 95% CI, 0.70-1.96). Geographic atrophy was more prevalent in South Asia (based on studies from India and Nepal, 3.82 per 1000 persons; 95% CI, 1.72-5.93) compared with East Asia (based on studies from China, Korea, Hong Kong, Taiwan, and Japan, and the Singapore Chinese Eye Study, 0.76 per 1000 persons; 95% CI, 0.31-1.22, P = 0.005). CONCLUSIONS: Geographic atrophy is uncommon in Asian populations compared with those of European ancestry. Even within Asia, geographic differences in GA prevalence were seen. The findings of this meta-analysis suggest that better dissection of risk factors in the Asian population for GA may provide insights into the biological pathways that drive these late-stage manifestations, thus suggesting better targets for prevention.

Chronic kidney disease in Russia: the Ural eye and medical study.

BACKGROUND: To examine the prevalence of chronic kidney disease (CKD) and its associations in a Russian population. METHODS: Out of 7328 eligible individuals, the population-based cross-sectional Ural Eye and Medical Study included 5899 (80.5%) individuals aged 40+ years and undergoing a detailed medical examination. The estimated glomerular filtration rate (eGFR) was calculated using the Chronic-Kidney-Disease-Epidemiology-Collaboration (CKD-EPI) equation. RESULTS: The mean eGFR was 72.3 ± 19.1 mL/min/1.73m2 (median:70.3 mL/min/1.73m2). Prevalence of CKD stage 3a (eGFR< 60 mL/min/1.73m2 and > 45 mL/min/1.73m2), CKD stage 3b (eGFR< 45 mL/min/1.73m2 and > 30 mL/min/1.73m2) and CKD stage 4+ (eGFR< 30 mL/min/1.73m2) were 1351/5841 (23.1%;95% confidence interval (CI):22.1,24.2), 294/5841 (5.0%;95%CI:4.5,5.6), and 29/5841 (0.5%;95%CI:0.3,0.7), respectively. The CKD stage 3+ prevalence increased (P < 0.001) from 11.1% (95%CI:8.4,13.9) in 40-44-year-olds to 56.8% (95%CI:52.8,60.8) in 75 + year-olds. In univariate analysis, CKD stage 3a + prevalence increased with higher systolic blood pressure (P < 0.001). In multivariable analysis, higher prevalence of CKD stage 3a + was associated with older age (P < 0.001;odds ratio (OR):1.06;95%CI:1.05,1.07), female sex (P < 0.001;OR:2.29;95%CI:1.94,2.69), rural region of habitation (P = 0.001;OR:1.29;95%CI:1.11,1.50), higher body mass index (P = 0.03;OR:1.02;95%CI:1.002,1.03), lower prevalence of house ownership (P = 0.02;OR:0.57;95%CI:0.35,0.92), higher prevalence of mostly sitting or standing during work (P < 0.001;OR:1.40;95%CI:1.20,1.64), higher serum concentration of triglycerides (P < 0.001;OR:1.23;95%CI:1.12,1.35) and blood urea nitrogen (P < 0.001;OR:1.33;95%CI:1.27,1.40), lower serum concentration of hemoglobin (P = 0.03;OR:0.99;95%CI:0.99,0.999), and lower prevalence of chronic obstructive pulmonary disease (P < 0.001;OR:0.57;95%CI:0.42,0.78). CONCLUSIONS: In this population from Russia aged 40+ years, prevalence of CKD stage 3+ (28.7%;95%CI:27.5,29.8) was relatively high as compared to populations from other countries. Associated factors were older age, female sex, rural region, higher body mass index, a sedentary lifestyle, and lower socioeconomic background.

Prevalence of and factors associated with low Back pain, thoracic spine pain and neck pain in Bashkortostan, Russia: the Ural Eye and Medical Study.

BACKGROUND: Back pain and neck pain are leading causes of the burden of disease worldwide, while information about their prevalence in Russia is missing. METHODS: The population-based Ural Eye and Medical Study was conducted in a rural and urban region in Bashkortostan/Russia. As part of a detailed systematic examination, we assessed the prevalence of low back pain, thoracic spine pain and neck pain in an interview with standardized questions in 5397 study participants (mean age:58.6 ± 10.6 years;range:40-94 years). RESULTS: The mean prevalence of low back pain, thoracic spine pain and neck pain was 2912/5397 (54.0%;95% confidence interval (CI):52.6,55.3), 1271/5397 (23.6%;95%CI:22.4,24.7), and 1570/5397 (29.1%;95%CI:27.9,30.3), respectively. A higher prevalence of low back pain was associated with females (P = 0.04;odds ratio (OR):1.14;95%CI:1.004,1.30), younger age (P < 0.001;OR:0.99;95%CI:0.98,0.99), higher body mass index (P = 0.002;OR:1.02;95%CI:1.01,1.03), lower frequency of vigorous activities during leisure time (P = 0.001;OR:0.79;95%CI:0.69,0.90), more time spent sitting and reclining (P = 0.03;OR:1.00;95%CI:1.00,1.00), higher serum concentration of high-density lipoproteins (P = 0.004;OR:1.10;95%CI:1.03,1.18), higher prothrombin index (P = 0.003;OR:1.01;95%CI:1.003,1.01), higher prevalence of a history of cardiovascular disease (P = 0.004;OR:1.23;95%CI:1.07,1.42), falls (P < 0.004;OR:1.71;95%CI:1.45,2.00), bone fractures (P = 0.01;OR:1.18;95% CI:1.03,1.34), unconsciousness (P < 0.001;OR:1.78;95%CI:1.40,2.25), osteoarthritis (P < 0.001;OR:2.76;95%CI:2.34,3.26), iron-deficiency anemia (P < 0.001;OR:1.87;95%CI:1.41,2.50), and thyroid disorder (P = 0.004;OR:1.37;95%CI:1.10,1.70), fewer days of vegetable intake (P < 0.001;OR:0.89;95%CI:0.85,0.93), smaller amounts of salt intake (P = 0.008;OR:0.97;95%CI:0.94,0.99), higher anxiety score (P < 0.001;OR:1.05;95%CI:1.03,1.06), and in women, history of menopause (P = 0.02;OR:1.36;95%CI:1.05,1.75). The prevalence of thoracic spine pain and neck pain showed similar associations. CONCLUSIONS: In a Russian population, the prevalence of low back pain, thoracic spine pain and neck pain (54.0, 23.6 and 29.1%, respectively) were correlated with parameters such as the female sex, younger age, higher body mass index, higher anxiety score, higher prevalence of a history of cardiovascular disease, lower frequency of vigorous activities and more time spent sitting or reclining. These data may be of interest for assessing the burden of back and neck pain in Russia as part of the global burden of disease.

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 < 140 g/L in men,< 130 g/L in women; definition #2:hemoglobin concentration < 130 g/L in men,< 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 < 0.001; standardized regression coefficient beta:-0.20), higher waist-hip circumference ratio (P < 0.001;beta:0.05), higher prevalence of car ownership (P < 0.001;beta:0.05), higher blood concentrations of bilirubin (P < 0.001;beta:0.05) and triglycerides (P < 0.001;beta:0.06), lower erythrocyte sedimentation rate (P < 0.001;beta:-0.32), and shorter blood clotting time (P < 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 < 0.001;OR:2.52;95%CI:1.47,4.33), higher erythrocyte sedimentation rate (P < 0.001;OR:1.08;95%CI:1.06,1.09), longer blood clotting time (P < 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 < 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.

Glaucoma.

Glaucoma is a heterogeneous group of diseases characterised by cupping of the optic nerve head and visual-field damage. It is the most frequent cause of irreversible blindness worldwide. Progression usually stops if the intraocular pressure is lowered by 30-50% from baseline. Its worldwide age-standardised prevalence in the population aged 40 years or older is about 3·5%. Chronic forms of glaucoma are painless and symptomatic visual-field defects occur late. Early detection by ophthalmological examination is mandatory. Risk factors for primary open-angle glaucoma-the most common form of glaucoma-include older age, elevated intraocular pressure, sub-Saharan African ethnic origin, positive family history, and high myopia. Older age, hyperopia, and east Asian ethnic origin are the main risk factors for primary angle-closure glaucoma. Glaucoma is diagnosed using ophthalmoscopy, tonometry, and perimetry. Treatment to lower intraocular pressure is based on topical drugs, laser therapy, and surgical intervention if other therapeutic modalities fail to prevent progression.

Association between axial length and horizontal and vertical globe diameters.

PURPOSE: To assess relationships between axial length and the horizontal and vertical globe diameters. MATERIAL AND METHODS: The study consisted of enucleated human eyes. The horizontal, vertical, and sagittal diameters were measured. RESULTS: The study included 135 globes removed because of malignant uveal melanoma (111 globes) or end-stage painful glaucoma (n = 24 eyes). Mean axial, horizontal, and vertical diameters were 24.6 ± 2.6 mm (range: 20-35 mm), 23.7 ± 1.4 mm (range: 21-29 mm) and 23.7 ± 1.4 mm (range: 20-29 mm) respectively. The horizontal diameter and vertical diameter did not differ significantly (P = 0.92), while both were significantly (P < 0.001) shorter than the axial diameter. The horizontal diameter was significantly and linearly correlated with the vertical globe diameter (P < 0.001; regression line: vertical globe diameter = 0.84 × horizontal globe diameter + 3.69). The axial diameter was significantly (P < 0.001) associated with the horizontal diameter and vertical diameters in a bipartite manner. In eyes with an axial length ≤24 mm, horizontal and vertical diameters increased by 0.44 and 0.51 mm, respectively, for each mm increase in axial diameter, while in eyes with an axial length >24 mm, the horizontal and vertical globe diameter increased by a lower amount of 0.19 and 0.21 mm, respectively, for each mm increase in axial diameter. CONCLUSIONS: Myopic enlargement of the globe beyond an axial length of 24 mm takes place predominantly in the sagittal axis, leading to a change in the globe form from a sphere to an elongated form. It fits with the notion that myopic elongation may occur by an elongation of the eye walls in regions close to the globe's equator.

BRUCH MEMBRANE AND THE MECHANISM OF MYOPIZATION: A New Theory.

BACKGROUND: The process of emmetropization is the adjustment of the length of the optical axis to the given optical properties of the cornea and lens after the end of the second year of life. Since its underlying mechanisms have not been fully explored yet, we reviewed findings available in the literature to discuss its potential etiology and the mechanism of myopization as an overshooting of emmetropization. METHODS: Literature review. RESULTS: The process of emmetropization occurs by axial elongation. Up to the end of the second year of life, the eye grows spherically by active increase in scleral volume. Axial elongation in the process of emmetropization is associated with thinning of the retina and reduced density of retinal pigment epithelium cells (RPE) in the retro-equatorial region, and with thinning more of the choroid than of the sclera, starting at the equator and being most marked at the posterior pole. In contrast, retinal thickness and RPE density in the macular region and thickness of Bruch's membrane (BM) in any region are independent of axial length. CONCLUSIONS: It led to the hypothesis that axial elongation occurs by production of BM in the retro-equatorial region leading to a decreased RPE density and retinal thinning in that region and a more tube-like than spherical enlargement of the globe, without compromise in the density of the macular RPE cells and in macular retinal thickness. The increased disc-fovea distance in axially myopic eyes is caused by the development and enlargement of parapapillary, BM free, gamma zone while the length of macular BM, and indirectly macular RPE cell density and macular retinal thickness, remain constant. The target tissue for medical modification of emmetropization/myopization may be the RPE, producing and elongating BM in the retro-equatorial region.

Parapapillary drusen of the retinal pigment epithelium.

PURPOSE: To describe the occurrence, morphology and associations of parapapillary drusen of the retinal pigment epithelium (RPE-drusen). METHODS: Using light microscopy, we histomorphometrically examined enucleated human eyes. RESULTS: The study included 83 eyes (axial length: 25.9 ± 3.2 mm; range: 20.0-35.0 mm). Eyes with parapapillary RPE-drusen (n = 29 (35%) eyes) as compared to those without drusen had a significantly shorter axial length (24.0 ± 1.8 mm vs 27.0 ± 3.3 mm; p < 0.001), higher prevalence (27/29 vs 12/54; p < 0.001) and longer width (213 ± 125 µm vs 96 ± 282 µm; p < 0.0001) of parapapillary alpha zone, and thicker BM in parapapillary beta zone (8.4 ± 2.7 µm vs 3.9 ± 2.0 µm; p < 0.001) and alpha zone (6.6 ± 3.9 µm vs 4.4 ± 1.5 µm; p = 0.02). Prevalence of parapapillary RPE-drusen was 27 (69%) out of 39 eyes with alpha zone. Beneath the RPE-drusen and in total alpha zone, choriocapillaris was open, while it was closed in the central part of parapapillary beta zone. BM thickness was thicker (p = 0.001) in alpha zone than beta zone, where it was thicker (p < 0.001) than in the region outside of alpha/beta zone. BM thickness outside of alpha/beta zone was not correlated with prevalence of parapapillary RPE-drusen (p = 0.47) or axial length (p = 0.31). RPE cell density was higher in alpha zone than in the region adjacent to alpha zone (22.7 ± 7.3 cells/240 µm vs 18.3 ± 4.1 cells/240 µm; p < 0.001). In the parapapillary RPE-drusen, RPE cells were connected with a PAS-positive basal membrane. CONCLUSIONS: Parapapillary RPE-drusen as fibrous pseudo-metaplasia of the RPE were associated with shorter axial length, higher prevalence and larger size of alpha zone, and thicker BM in alpha zone and beta zone. The RPE-drusen may be helpful to differentiate glaucomatous parapapillary beta zone from myopic beta zone.

Bruch's membrane and Brücke's muscle in the pars plana region.

PURPOSE: To examine Bruch's membrane (BM) in association with the longitudinal part of the ciliary muscle (LPCM) in the pars plana region. METHODS: Using light microscopy, we histomorphometrically assessed BM and the LPCM in the pars plana region. RESULTS: The histomorphometric study included 51 eyes (51 patients; mean age: 60.8 ± 15.0 years; axial length: 26.0 ± 3.3 mm; range: 21.0-36.0 mm). The LPCM (total length: 4.60 ± 1.10 mm) ended 1.15 ± 0.56 mm anterior to the ora serrata. Within the pars plana region, the LPCM (length: 2.58 ± 0.98 mm) had direct contact with BM for 1.95 ± 0.99 mm (71.1 ± 18.4% of the BM undersurface), while a capillary layer was interposed between the BM and the LPCM for 0.70 ± 0.40 mm (29.0 ± 18.4%). In the pars plana region free of LPCM close to the ora serrata, the percentage of BM covered by the capillary layer was higher than in the pars plana region containing the LPCM (63.0 ± 42.1% vs. 29.0 ± 18.4%; p < 0.001). At the LPCM end, BM was in direct contact with a collagenous tissue from the LPCM and was focally thickened as compared to BM with an underlying capillary layer (9.5 ± 5.3 µm vs. 4.3 ± 1.2 µm; p < 0.001). CONCLUSIONS: The direct contact of BM with the LPCM in the pars plana in association with focal BM thickening at the LPCM end suggests an insertion of LPCM on the BM. Taking into account the biomechanical strength of BM, it may imply a functional unit of the LPCM with BM in the process of accommodation with a secondary movement of the posterior BM and tertiary thickening of the subfoveal choroidal space.

Prevalence of Myopic Maculopathy Among the Very Old: The Ural Very Old Study.

Purpose: To assess the prevalence of myopic macular degeneration (MMD) in very old individuals. Methods: The population-based Ural Very Old Study (UVOS) included 1526 (81.1%) of 1882 eligible inhabitants aged ≥85 years. Assessable fundus images were available for 930 (60.9%) individuals (mean age, 88.6 ± 2.7 years). MMD was defined by macular patchy atrophies (i.e., MMD stage 3 and 4 as defined by the Pathologic Myopia Study Group). Results: MMD prevalence was 21 of 930 (2.3%; 95% CI, 1.3-3.3), with 10 individuals (1.1%; 95% CI, 0.4-1.7) having MMD stage 3 and 11 participants (1.2%; 95% CI, 0.5-1.9) MMD stage 4 disease. Within MMD stage 3 and 4, prevalence of binocular moderate to severe vision impairment was 4 of 10 (40%; 95% CI, 31-77) and 7 of 11 (64%; 95% CI, 30-98), respectively, and the prevalence of binocular blindness was 2 of 10 (20%; 95% CI, 0-50) and 3 of 11 (27%; 95% CI, 0-59), respectively. In minor myopia (axial length, 24.0 to <24.5 mm), moderate myopia (axial length, 24.5 to <26.5 mm), and high myopia (axial length, ≥26.5 mm), MMD prevalence in the right eyes was 0 of 46 eyes (0%), 3 of 40 eyes (8%; 95% CI, 0-16), and 7 of 9 (78%; 95% CI, 44-100), respectively; MMD prevalence in the left eyes was 1 in 48 eyes (2%; 95% CI, 0-6), 4 of 36 eyes (11%; 95% CI, 0-22), and 3 of 4 eyes (75%; 95% CI, 0-100), respectively. In multivariable analysis, a higher MMD prevalence (odds ratio, 8.89; 95% CI, 3.43-23.0; P < 0.001) and higher MMD stage (beta, 0.45; B, 19; 95% CI, 0.16-0.22; P < 0.001) were correlated with longer axial length but not with any other ocular or systemic parameter. Conclusions: MMD prevalence (stages 3 and 4) in very old individuals increased 8.89-fold for each mm axial length increase, with a prevalence of ≥75% in highly myopic eyes. In old age, highly myopic individuals have a high risk of eventually developing MMD with marked vision impairment.

Atrial fibrillation and flutter and ocular diseases. The Ural eye and medical study and the Ural very old study.

PURPOSE: To assess associations between atrial fibrillation/atrial flutter (AF) and ocular parameters and diseases. METHODS: The population-based Ural Eye and Medical Study (UEMS) and the Ural Very Old Study (UVOS) included 4894 individuals (age: 40+ years) and 835 individuals (age: 85+ years), respectively. RESULTS: In the UEMS, AF prevalence (80/4894; 1.6%; 95% CI: 1.3, 2.0) increased from 1/1029 (0.1%) in the age group of 40 to <50 years to 29/619 (4.7%) and 12/159 (7.5%) in the age groups of 70 to <80 years and 80+ years, respectively. Higher AF prevalence correlated with older age (OR: 1.08; 95% CI: 1.04, 1.12; p < 0.001), urban region of habitation (OR: 1.08; 95% CI: 1.04, 1.12; p < 0.001), higher prevalence of cardiovascular disease/stroke (OR: 2.50; 95% CI: 1.32, 4.72; p < 0.001) and lower prevalence of neck pain (OR: 0.35; 95% CI: 0.14, 0.85; p = 0.02), higher serum concentration of bilirubin (OR: 1.03; 95% CI: 1.02, 1.05; p < 0.001) and lower prothrombin index (OR: 0.96; 95% CI: 0.93, 0.99; p = 0.003), higher stage of arterial hypertension (OR: 1.52; 95% CI: 1.01, 2.28; p = 0.04) and higher ankle-brachial index (OR: 22.1; 95% CI: 4.45, 1.10; p < 0.001). In that model, AF prevalence was not associated with ocular parameters such as intraocular pressure (p = 0.52), retinal nerve fibre layer thickness (p = 0.70), refractive error (p = 0.13), axial length (p = 0.14), nuclear cataract degree (p = 0.50) and prevalence (p = 0.40), cortical cataract degree (p = 0.43) and presence (p = 0.17), lens pseudoexfoliation (p = 0.58), status after cataract surgery (p = 0.38), age-related macular degeneration prevalence (p = 0.63), open-angle glaucoma presence (p = 0.90) and stage (p = 0.55), angle-closure glaucoma prevalence (p = 0.99) and stage (p = 0.99), diabetic retinopathy prevalence presence (p = 0.37) and stage (p = 0.32), and myopic macular degeneration (p = 0.98). In the UVOS, similar results were obtained. CONCLUSIONS: In these multi-ethnic populations from Russia, AF prevalence was not associated with any major ocular disease and may not play a major role in the pathogenesis of these disorders.

Intraocular pressure and its determinants in a very old population. The ural very old study.

Purpose: To explore intraocular pressure (IOP) and its associated parameters in an aged population. Methods: The epidemiologic Ural Very Old Study (UVOS) conducted in Bashkortostan/Russia included 1526 participants with an age of ≥85 years. Besides a whole series of ocular and systemic examinations, IOP was determined applying non-contact tonometry. Body mass index, diastolic blood pressure and age were the factors used to estimate the cerebrospinal fluid pressure (CSFP). Results: The study consisted of 904 participants (age: 88.6 ± 2.7 years) with available IOP readings and without anti-glaucomatous therapy. Mean IOP was 14.5 ± 5.1 mmHg (median: 14 mm Hg; Q1:11; Q3:16; 95%CI:8,25) and 14.8 ± 4.6 mmHg (median: 14 mm Hg; Q1:12; Q3:17; 95%CI:8,28) in the right and left eyes, respectively. Higher IOP correlated (multivariable analysis; correlation coefficient r2:0.32) with female sex (P < 0.001), more sedentary lifestyle (P = 0.006), higher estimated CSFP (P < 0.001), higher total protein serum concentration (P < 0.001), stronger hand grip force (P = 0.01), thicker central cornea (P < 0.001), longer axial length (P = 0.01), absence of previous cataract surgery (P = 0.001), higher degree of pseudoexfoliation (P = 0.02, and thinner peripapillary retinal nerve fiber layer thickness (P = 0.004). Using this that model, IOP reading enlarged by 0.22 mmHg (95% CI: 0.09, 0.35) for each increase in estimated CSFP by 1 mm Hg, by 0.03 mm Hg (95% CI: 0.02,0.05) for each thickening in central corneal thickness by 1 µm, by 0.56 mm Hg (95%CI: 0.13,1.00) for each axial elongation by 1 mm, and by 0.40 mmHg (95% CI: 0.06,0.74) for each increase in the degree of pseudoexfoliation, and it decreased by 0.40 mmHg (95% CI: 0.06,0.74) by cataract surgery. Conclusions: In this study population aged 85+years, IOP readings showed similar relationships as in younger study populations, including positive associations with higher estimated CSFP and longer axial length and a negative association with cataract surgery.

Prevalence and associated factors of myopia in children and adolescents in Russia: the Ural Children Eye Study.

BACKGROUND: To assess the prevalence of myopia and the distribution of ocular axial length as surrogate for myopic refractive error in school children in a population in Russia. METHODS: The Ural Children Eye Study, a school-based case-control study, was conducted in Ufa/Bashkortostan/Russia from 2019 to 2022 and included 4933 children (age: 9.7±2.6 years; range: 6.2-18.8 years). The parents underwent a detailed interview and the children an ophthalmological and general examination. RESULTS: Prevalence of any myopia (≤-0.50 dioptres (D)), minor myopia (-0.50 D to -1.0 D), moderate myopia (-1.01 D to -5.99 D) and high myopia (≤-6.0D) was 2187/3737 (46.2%; 95% CI 44.8% to 48.6%), 693/4737 (14.6%; 95% CI 13.6% to 15.6%), 1430/4737 (30.2%; 95% CI 28.9% to 31.5%) and 64/4737 (1.4%; 95% CI 1.0% to 1.7%), respectively. In the children aged 17+ years, prevalence of any, minor, moderate and high myopia was 170/259 (65.6%; 95% CI 59.8% to 71.5%), 130/259 (50.2%; 95% CI 44.1% to 56.3%), 28/259 (10.8%; 95% CI 7.0% to 14.6%) and 12/259 (4.6%; 95% CI 2.1% to 7.2%), respectively. After adjusting for corneal refractive power (beta: 0.09) and lens thickness (beta: -0.08), larger myopic refractive error was associated (r2=0.19) with older age (beta: 0.33), female sex (beta: 0.04), higher prevalence of maternal (beta: 0.15) and paternal (beta: 0.12) myopia, more time spent in school, with reading books or playing with the cell phone (beta: 0.05) and less total time spent outdoors (beta: 0.05). Axial length and myopic refractive error increased by 0.12 mm (95% CI 0.11 to 0.13) and -0.18 D (95% CI 0.17 to 0.20), respectively, per year of age. CONCLUSIONS: In this ethnically mixed urban school children population from Russia, prevalence of any myopia (65.6%) and high myopia (4.6%) in children aged 17+ years was higher than in adult populations in the same region and it was lower than in East Asian school children, with similar associated factors.

Associations between axial length, corneal refractive power and lens thickness in children and adolescents: The Ural Children Eye Study.

PURPOSE: To assess relationships between ocular biometric parameters in dependence of age and sex in children and adolescents. METHODS: In the Ural Children Eye Study, a school-based cohort study, 4933 children underwent an ophthalmological and general examination. RESULTS: Complete biometric measurements were available for 4406 (89.3%) children. Cycloplegic refractive error (mean: -0.87 ± 1.73 diopters (D); median: -0.38 D; range: -19.75 D to +11.25 D) increased (multivariable analysis; r2 = 0.73) with shorter axial length (ß: -0.99; non-standardized regression coefficient B: -1.64; 95% CI: -1.68, -1.59) and lower corneal refractive power (ß: -0.55; B: -0.67; 95% CI: -0.70, -0.64), in addition to higher cylindrical refractive error (ß: 0.10; B: 0.34; 95% CI: 0.27, 0.41), thinner lens (ß: -0.11; -0.85; 95% CI: -1.02, -0.69) and male sex (ß: 0.15; B: 0.50; 95% CI: 0.42, 0.57). In univariate analysis, decrease in refractive error with older age was more significant (ß: -0.38 vs. ß: -0.25) and steeper (B: -0.22 (95% CI: -0.24, -0.20) vs. B: -0.13 (95% CI: -0.15, -0.11)) in girls than boys, particularly for an age of 11+ years. Axial length increased with older age (steeper for age <11 years) (B: 0.22 (95% CI: 0.18, 0.25) vs. 0.07 (95% CI: 0.05, 0.09)). In multivariable analysis, axial length increased with lower refractive error (ß: -0.77; B: -0.42; 95% CI: -0.43, -0.40) and lower corneal refractive power (ß: -0.54; B: -0.39; 95% CI: -0.41, -0.38), in addition to older age (ß: 0.04; B: 0.02; 95% CI: 0.01, 0.03), male sex (ß: 0.13; B: 0.23; 95% CI: 0.21, 0.32), higher cylindrical refractive error (ß: 0.05; B: 0.09; 95% CI: 0.05, 0.14) and thinner lens (ß: -0.14; B: -0.62; 95% CI: -0.72, -0.51). The axial length/corneal curvature (AL/CR) ratio increased until the age of 14 years (ß: 0.34; B: 0.017; 95% CI: 0.016, 0.019; p < 0001), and then became independent of age. The AL/CR ratio increased (r2 = 0.78) mostly with higher corneal refractive power (ß: 0.25; B: 0.02; 95% CI: 0.02, 0.02; p < 0.001), lower refractive error (ß: -0.75; B: -0.05; 95% CI: -0.05, -0.05; p < 0.001), thinner lens thickness (ß: -01.6; B: -0.09; 95% CI: -0.10, -0.08; p < 0.001) and older age (ß: 0.16; B: 0.006; 95% CI: 0.005, 0.007; p < 0.001). CONCLUSIONS: In this multiethnic group of school children in Russia, the age-related increase in myopic refractive error was more significant and steeper in girls, particularly for the age group of 11+ years. Determinants of higher myopic refractive error were longer axial length, higher corneal refractive power, lower cylindrical refractive error, thicker lens and female sex.