Prevalence and Associations of Keratoconus Among Children, Adults, and Elderly in the Population-Based Ural Eye Studies

PURPOSE

To estimate prevalence and associations of keratoconus in populations in Russia with an age from childhood to seniority.

METHODS

The study population consisted of the cohorts of 3 population-based studies performed in urban and rural areas within the same geographical region in Bashkortostan/Russia: the Ural Children Eye Study (UCES; age = 6-18 y; n = 4890), the Ural Eye and Medical Study (UEMS; age = >40 y; n = 5314), and the Ural Very Old Study (UVOS; age = >85 y; n = 651). Based on Scheimflug imaging, keratoconus was defined by a keratometric reading of ≥48 diopters (D) in any eye.

RESULTS

The mean maximal and minimal corneal refractive power increased from the UCES (43.58 ± 1.50 D and 42.70 ± 1.42 D, respectively) to the UEMS (44.26 ± 1.70 D and 43.61 ± 1.76 D, respectively) and to the UVOS (45.1 ± 1.72 D and 43.98 ± 1.68 D, respectively). Correspondingly, keratoconus prevalence increased from the UCES (42/4890; 0.086%; 95% CI = 0.060, 0.112) to the UEMS (112/5314; 2.11%; 95% CI = 1.72, 2.49) and to the UVOS (42/651; 6.45%; 95% CI = 4.56, 8.34). In the UCES, higher keratoconus prevalence was associated (multivariable analysis) with higher birth order [odds ratio (OR) = 2.34; 95% CI = 1.32, 4.15; P = 0.004], lower birth weight (OR = 0.99; 95% CI = 0.99, 0.99; P < 0.001), and shorter axial length (OR = 0.15; 95% CI = 0.08, 0.30; P < 0.001). In the UEMS, keratoconus prevalence correlated with shorter axial length (OR = 0.15; 95% CI = 0.10, 0.23; P < 0.001), larger corneal volume (OR = 1.17; 95% CI = 1.09, 1.25; P = 0.001), thicker lens (OR = 2.27; 95% CI = 1.06, 5.28; P = 0.04), cortical cataract degree (OR = 1.02; 95% CI = 1.01, 1.04; P = 0.01), and higher stage of age-related macular degeneration (OR = 1.65; 95% CI = 1.09, 2.51; P = 0.02). In the UVOS, keratoconus prevalence correlated with lower educational level (OR = 0.84; 95% CI = 0.71, 0.99; P = 0.04) and lower dynamometric handgrip force (OR = 0.92; 95% CI = 0.88, 0.97; P = 0.003).

CONCLUSIONS

In this study on multiethnic groups from Russia, keratoconus prevalence increased from the pediatric group (0.09%) to the adult group (2.11%) and seniority group (6.45%), correlated mostly with biometric ocular parameters and was in all age groups statistically independent of most systemic parameters.

Prevalence of depression, anxiety and suicidal ideas and associated factors, in particular sensory impairments, in a population of Bashkortostan in Russia

To assess prevalence and associated factors of depression, anxiety and suicidal ideas in populations from Russia, we conducted in rural and urban regions in Bashkortostan/Russia two population-based studies (Ural Eye and Medical Study (UEMS), performed from 2015 to 2017; Ural Very Old Study (UVOS), performed from 2017 to 2020) which included participants aged 40 + years and 85 + years, respectively. Depression was assessed using the questionnaire of the Center for Epidemiologic Studies Depression Scale Scoresheet, and anxiety was examined applying the State Trait Inventory Anxiety Test. Suicidal ideas were explored by the question whether suicide had previously been thought of or attempted (and if yes, for what reasons). In the statistical analysis we assessed the mean of the main outcome parameter (depression score and anxiety score) and searched for associations between these parameters and other parameters in univariable and multivariable regression analyses. In the UEMS with 5893 individuals (age: 59.0 ± 10.7 years; range 40-94 years), higher depression score and anxiety score were associated (multivariable analysis) with more marked hearing loss (beta: 0.07; P < 0.001, and beta: 0.07; P < 0.0012, respectively) and worse visual acuity (beta: 0.04; P = 0.02; and beta: 0.03; P = 0.03, resp.), in addition to female sex, Russian ethnicity, lower educational level, less alcohol consumption, weaker hand grip strength, less physical activity, and higher prevalence of dry eye disease. Attempted suicide was reported by 88 (1.5%; 95% CI 1.2, 1.8) participants. Having thought of suicide within the last 6 months was reported by 63 (1.1%) individuals. Out of 1491 UVOS participants (age: 88.2 ± 2.8 years; range 85-100 years) with a mean depression score of 20.0 ± 10.3 (median 18; range 0-58), 916 (61.4%; 95% CI 59.0, 63.9) fulfilled the definition of depression (depressions core ≥ 16). Higher depression score and higher anxiety score correlated (multivariable analysis) with higher hearing loss score (beta: 0.07; P = 0.02, and beta: 0.08; P = 0.009, resp.) and worse visual acuity (beta: 0.13; P < 0.001, and beta: 0.09; P = 0.007, resp.), in addition to female sex, urban region, less physical activity, less fruit intake, and lower cognitive function. Overall, 15 (1.0%; 95% CI 0.50, 1.50) individuals had attempted or thought of suicide. In conclusion, the findings suggest that besides female sex, lower level of education and lower cognitive function, it was sensory impairment, namely vision and hearing impairment, which belonged to the determinants of depression and anxiety in these populations from Russia.