Browsing by Author "Fotouhi, Akbar"
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- Longitudinal changes in crystalline lens thickness and power in children aged 6-12 years oldPublication . Hashemi, Hassan; Khabazkhoob, Mehdi; Azizi, Elham; Iribarren, Rafael; Lança, Carla; Grzybowski, Andrzej; Rozema, Jos J.; Emamian, Mohammad Hassan; Fotouhi, AkbarObjectives: To determine the three-year changes in crystalline lens power (LP) and thickness (LT) in children and their associated factors. Methods: Schoolchildren aged 6-12 years living in Shahroud, northeast Iran were examined in 2015 and 2018. The Bennett formula was used to calculate LP. Multiple generalized estimating equations (GEE) analysis was used for data analysis. Results: Among the 8089 examined eyes, the mean LP in Phase 1 and 2, and the three-year change were 21.61 ± 1.47D, 21.00 ± 1.42D, and -0.61 ± 0.52D, respectively. The GEE model showed that negative shifts in LP were less pronounced with increasing age (β = 0.176; p < 0.001), and were also less noticeable in hyperopes compared to emmetropes (β = 0.120; p < 0.001). The changes in LP decreased when outdoor activity increased among urban residents (β = 0.013; p = 0.039), while it increased in rural areas (β = -0.020; p = 0.047). The mean three-year change in LT was 0.002 ± 0.13 mm. Female sex and aging by one year increased the LT by 0.022 mm (P < 0.001). However, LT decreased in 6-8-year-olds, while it increased in 10-12-year-old children, both in a linear fashion. The change in LT was less in myopes than in emmetropes (β = -0.018, P-value = 0.010). Conclusion: LP decreases after three years in 6 to 12-year-old children. LT increases slightly after three years in 6 to 12-year-old children. The changes in LP and LT were associated with refractive errors, place of residence, age and gender, and outdoor activity time.
- Prevalence of anisometropia and its associated factors in school-age childrenPublication . Hashemi, Hassan; Khabazkhoob, Mehdi; Lança, Carla; Emamian, Mohammad Hassan; Fotouhi, AkbarPurpose: To determine the prevalence of anisometropia and the associated demographic and biometric risk factors in children. Methods: This cross-sectional study was conducted on the elementary school children of Shahroud, east of Iran, in 2015. All rural students were recruited, while multistage cluster sampling was used to select the students in urban areas. All children underwent optometric examinations including the measurement of uncorrected and corrected visual acuity, autorefraction, and subjective refraction with cycloplegia. Biometric components were measured using the Allegro Biograph. Myopia and hyperopia were defined as a spherical equivalent ≤-0.5 and ≥ +2.00 diopter, respectively. Students with a history of ocular trauma or lack of cycloplegic refraction at least in one eye were excluded from the study. Results: Of 6624 selected children, 5620 participated in the study. After applying the exclusion criteria, the data of 5357 students (boys: 52.8%, n = 2834) were analyzed. The mean age of the subjects was 9.2 ± 1.7 years (range: 6-12 years). The prevalence of anisometropia ≥ 1 D was 1.1% (95% CI: 0.8 to 1.4) in all children, 1.0% (95% CI: 0.7-1.3) in boys, 1.3% (95% CI: 0.8-1.7) in girls, 1.1% (95% CI: 0.8-1.4) in urban children, and 1.4% (95% CI: 0.5-2.3) in rural children. The prevalence of anisometropia was 8.8% (95% CI: 5.3-12.2) in myopic and 5.7% (95% CI: 2.8-8.5) in hyperopic children. Axial length asymmetry (OR = 40.9; 95%CI: 10.2-164.1), myopia (OR = 17.9; 95% CI: 9.4-33.9), and hyperopia (OR = 10.1; 95% CI: (5.1-19.7) were associated with anisometropia in multiple logistic regression model. More anisometropia was associated with more severe amblyopia. The odds of amblyopia (OR = 82.3: 38.2-177-3) and strabismus (OR = 17.6: 5.5-56.4) were significantly higher in anisometropic children. The prevalence of amblyopia was 21.7% in children with myopic anisometropia ≥ 3D, 66.7% in children with hyperopic anisometropia ≥ 3D, and 100% in cases with antimetropia ≥ 3D. Conclusion: The prevalence of anisometropia was low in Iranian schoolchildren. However, a high percentage of anisometropic students had amblyopia and strabismus. Axial length was the most important biometric component associated with anisometropia.
- Three-year change in refractive error and its risk factors: results from the Shahroud School Children Eye Cohort studyPublication . Lança, Carla; Emamian, Mohammad Hassan; Wong, Yee Ling; Hashemi, Hassan; Khabazkhoob, Mehdi; Grzybowski, Andrzej; Saw, Seang Mei; Fotouhi, AkbarObjectives: To determine spherical equivalent (SE) progression among children in the Shahroud School Children's Eye Cohort Study. Methods: A prospective cohort study recruited children aged 6 to 12 years in 2015 (baseline) with a follow-up in 2018. Cycloplegic autorefraction and axial length (AL) measurements were included. SE progression over 3 years was analysed in non-myopic (SE ≥ + 0.76 D), pre-myopic (PM; SE between +0.75 D and –0.49 D), low myopic (LM; SE between −0.5 D and −5.99 D), and high myopic (HM; SE ≤ − 6 D) eyes. Age, sex, near work, outdoor time, living place, parental myopia, mother’s education, and baseline SE were evaluated as risk factors for SE progression (≤ −0.50 D). Results: Data were available for 3989 children (7945 eyes). At baseline, 40.3% (n = 3205), 3.4% (n = 274) and 0.1% (n = 7) eyes had PM, LM and HM, respectively. At the 3-year follow-up, 40.5% (n = 3216), 7.5% (n = 599) and 0.2% (n = 15) eyes had PM, LM, and HM, respectively. SE progression in eyes with LM and HM was −1.08 ± 0.76 D and −1.60 ± 1.19 D, respectively. SE progression was associated with age at baseline (Odds Ratio [OR] = 1.14; 95% confidence interval [CI], 1.08–1.21), female sex (OR = 1.80; 95% CI: 1.48–2.18), near work (OR = 1.08; 95% CI: 1.02–1.14), parental myopia (OR = 1.20; 95% CI: 1.01–1.42) and baseline SE (OR = 2.28; 95% CI: 1.88–2.78). Conclusion: A myopic shift was associated with older age, female sex, near work, parental myopia, and greater myopic baseline SE. These results help identify children at risk of progression that may benefit from treatment and lifestyle counseling.