The prevalence of tropia, phoria and their types in a student population in Iran.

Purpose: The aim of this study is to determine the prevalence of tropia, phoria, and their types in Islamic Azad University students in Shahrekord, Iran.Methods: Of 826 students that were invited, 752 participated in this cross-sectional study (response rate = 91.04%). After applying exclusion criteria, statistical analyses were performed on the data of 726 individuals. All participants underwent optometric tests including measurement of visual acuity, objective and subjective refraction, as well as binocular vision and ocular health examinations. The unilateral and alternate cover tests were done to detect the tropia and phoria at 6 m and 40 cm, respectively.Results: The overall prevalence and 95% confidence interval (CI) of tropia, exotropia, and esotropia were 1.5% (0.8 to 2.7), 1.2% (0.6 to 2.4), and 0.3% (0.1 to 1.1), respectively. The prevalence of esotropia was significantly higher in older age groups (24 years old) (p = .040) . The prevalence of exotropia was significantly higher in females (0.039) and in myopic individuals (p = .001). The overall prevalence and 95% CI of phoria, exophoria, and esophoria were 12.9% (10.7 to 15.6), 11.7% (9.6 to 14.3), and 1.2% (0.6 to 2.3), respectively. There was a significant difference in the overall prevalence of exophoria according to the age (0.021). The prevalence of esophoria was significantly higher in females (p = .039). The prevalence of exophoria was significantly higher in myopic participants (p = .003). Exophoria and exotropia were the most common types of phoria and tropia, respectively.Conclusion: The prevalence of strabismus in university students was similar to the Iranian general population but lower than other countries. One in every 10 students had phoria, which was much lower than similar reports on Iranian populations; however, due to near-work activity, these students are prone to asthenopia, early visual fatigue, and decreased productivity. Therefore, it is suggested that university students also undergo screening programs to detect the cases of tropia and phoria.

Accommodative insufficiency in a student population in Iran / Insuficiencia acomodativa en una población estudiantil de Irán

Purpose: To determine the prevalence of accommodative insufficiency (AI) and its relation with age, gender, and refractive errors in a college-age student population in Iran. Methods: The present study was conducted cross-sectionally in 2017. All students had optometric tests including measurement of visual acuity, objective and subjective refraction, as well as binocular vision and accommodative examinations. Amplitude of accommodation was measured with the Donders¡' push-up method using the Royal Air Force (RAF) rule. Monocular accommodative facility was measured with ±2.00 diopter flipper lenses. The accommodative response was tested using dynamic retinoscopy with the monocular estimation method (MEM). Results: The prevalence of AI in the studied population was 4.07% (95% CI: 2.61-5.52). The rate was 6.04% (95% CI: 3.58-8.50) in females and 2.01% (95% CI: 0.53-3.48) in males, and logistic regression showed a significantly higher odds of AI in females (OR = 3.14, 95% CI: 1.33-7.45, p-value = 0.009). The prevalence of AI was 2.59% (95% CI: 0.55-7.56) in the 18-19-year-old age group and 4.08% (95% CI: 0.09-8.07) in the 24-25-year-old group (p-value = 0.848). The prevalence of AI among emmetropic, myopic, and hyperopic individuals was 3.74% (95% CI: 1.88-5.61), 4.44% (95% CI: 2.07-6.81), and 5.26% (95% CI: 4.79-16.32), respectively (p-value = 0.869). In the multiple regression model, only gender showed significant relationship with AI (Odds ratio = 3.14, 95% CI: 1.33-7.45; p-values = 0.009). Conclusion: The prevalence of AI in the present study is lower than the most prevalence rates reported in previous studies. In the present study, gender and AI showed a strong association, such that AI prevalence was significantly higher in females than males

Objetivo: Determinar la prevalencia de la insuficiencia acomodativa (IA) y su relación con la edad, sexo, y errores refractivos en una población universitaria de Irán. Métodos: El presente estudio se realizó de forma transversal en 2017. Se realizaron pruebas optométricas a todos los estudiantes, incluyendo medición de la agudeza visual, refracción objetiva y subjetiva, visión binocular y pruebas de acomodación. La amplitud de acomodación se midió con el método de Donders (push-up) utilizando la regla de la RAF (Royal Air Force). La flexibilidad acomodativa monocular se midió con flippers de ± 2 dioptrías. La respuesta acomodativa se evaluó mediante retinoscopía dinámica utilizando el método de estimación monocular (MEM). Resultados: La prevalencia de IA en la población de estudiantes fue de 4,07% (95%ICI: 2,61-5,52). La tasa fue de 6,04% (95%IC: 3,58-8,5) en mujeres y 2,01% (95%IC: 0,53-3,48) en varones, y la regresión logística reflejó un odds ratio significativamente superior de IA en mujeres (OR= 3,14, 95%IC: 1,33-7,45, valor p = 0,009). La prevalencia de IA fue de 2,59% (95%IC: 0,55-7,56) en el grupo de edad de 18-19 años, y de 4,08% (95%IC: 0,09-8,07) en el grupo de 24-25 años (valor p = 0,848). La prevalencia de IA entre los individuos emetrópicos, miopes e hipermétropes fue de 3,74% (95%IC: 1,88-5,61), 4,44% (95%IC: 2,07-6,81), y 5,26% (95%IC: 4,79-16,32), respectivamente (valor p=0,869). En el modelo de regresión múltiple, únicamente el sexo reflejó una relación con IA (Odds ratio = 3,14 95%IC: 1,33-7,45; valor p= 0,009). Conclusión: La prevalencia de IA en el presente estudio es inferior a la mayoría de las tasas de prevalencia reportadas en estudios previos. En el presente estudio, sexo e IA reflejaron una fuerte asociación, en el sentido de que la prevalencia de IA fue significativamente superior en las mujeres con respecto a los varones