Comparison of Clinical Features among Children of Multicultural Families, Ethnic Koreans and Native Koreans

PURPOSE: To explore whether genetic and environmental factors influenced ophthalmic disease among children of multicultural families, ethnic Koreans, and native Koreans. METHODS: In this retrospective study, 120 patients who visited the pediatric ophthalmology clinic of a university hospital were included. They were equally divided into three groups: a multicultural group, an ethnic Korean group, and a native Korean group. Parental nationalities, age, gender, chief complaint, visual acuity, refractive error, diagnosis at the initial visit and the extent of compliance with treatment were analyzed. RESULTS: Of the multicultural group, 14 (35%) of 40 patients were Chinese immigrants, and constituted the most common subgroup. None of the age at initial visit, gender, the prevalence of refractive error, or amblyopia status differed significantly among the three groups. In the multicultural and native Korean groups, the proportions of abnormal eye positioning as the chief complaint were higher than that of the ethnic Korean group (p = 0.005). The most common diagnosis in the two former groups was strabismus. Myopia was the most common diagnosis in the ethnic Korean group. The prevalence of strabismus in the multicultural group (55%) was significantly higher than that in the native Korean group (30%) and the ethnic Korean group (20%) (p = 0.003). The prevalence of strabismus in the multicultural group was significantly higher than in the other groups (p = 0.003). However, we found no significant difference in strabismus subtype among the three groups. In the general family group, the extent of loss to follow-up was significantly higher than in the other groups (p = 0.002). CONCLUSIONS: The chief complaint, the prevalence of ophthalmic disease, and the compliance rate differed significantly among the three groups. Both genetic and environmental factors may have played a role.

Influence of Myopia on Size of Optic Nerve Head and Retinal Nerve Fiber Layer Thickness Measured by Spectral Domain Optical Coherence Tomography

PURPOSE: To investigate optic nerve head size and retinal nerve fiber layer (RNFL) thickness according to refractive status and axial length. METHODS: In a cross-sectional study, 252 eyes of 252 healthy volunteers underwent ocular biometry measurement as well as optic nerve head and RNFL imaging by spectral-domain optical coherence tomography. Correlation and linear regression analyses were performed for all subjects. The magnification effect was adjusted by the modified axial length method. RESULTS: Disc area and spherical equivalent were positively correlated (r = 0.225, r² = 0.051, p = 0.000). RNFL thickness showed significant correlations with spherical equivalent (r = 0.359, r² = 0.129, p = 0.000), axial length (r = -0.262, r² = 0.069, p = 0.000), disc radius (r = 0.359, r² = 0.129, p = 0.000), and radius of the scan circle (r = -0.262, r² = 0.069, p = 0.000). After adjustment for the magnification effect, those relationships were reversed; RNFL thickness showed negative correlation with spherical equivalent and disc radius, and positive correlation with axial length and radius of the scan circle. The distance between the disc margin and the scan circle was closely correlated with RNFL thickness (r = -0.359, r² = 0.129, p = 0.000), which showed a negative correlation with axial length (r = -0.262, r² = 0.069, p = 0.000). CONCLUSIONS: Optic disc radius and RNFL thickness decreased in more severely myopic eyes, but they increased after adjustment for magnification effect. The error due to the magnification effect and optic nerve head size difference might be factors that should be considered when interpreting optical coherence tomography results.