ObjectiveTo observe and analyze the changes of macular choroidal thickness in children with occult high myopia and its influencing factors.MethodsA prospective, non-randomized, contemporaneous controlled trial. From September 2019 to October 2020, 56 children (110 eyes) who first visited the ophthalmic clinic of the Affiliated Hospital of Chengde Medical College without any myopia correction training were enrolled in this study. There were 33 males (64 eyes) and 23 females (46 eyes), with the average age of 8.62±1.87 years old; the age ranged from 6 to 12 years old. According to the clinical manifestations of myopia in children, they were divided into occult high myopia group (27 cases, 52 eyes) and control group (29 cases, 58 eyes). In the 52 eyes of the occult high myopia group, the spherical equivalent refraction (SER) of －0.00 to －1.00 D, ＞－1.00 to －2.00 D, ＞－2.00 to －3.00 D were 15, 16 and 21 eyes. Among 58 eyes in the control group, the SER of －0.00 to －1.00 D, ＞－1.00 to －2.00 D, ＞－2.00 to －3.00 D were 21, 18 and 19 eyes, respectively. The macular fovea within 6 mm was divided into three concentric circles centered on the macular fovea, which included the central area with a diameter of 1 mm, the inner ring area with a diameter of 1-3 mm, and the outer ring area with a diameter of 3-6 mm, totally 9 areas. The inner ring and outer ring were divided into upper, lower, nasal and temporal areas. The changes of choroidal thickness in each macular area of children in occult high myopia group and control group were observed. The choroidal thickness in each macular area was compared between the two groups using independent sample t-test. Pearson correlation analysis was used to analyze the correlation between mean foveal choroidal thickness and gender, age, intraocular pressure, ocular axis, diopter and corneal curvature in occult high myopia group.ResultsChoroidal thickness in macular area of children in occult high myopia group was thinnest in nasal side and thickest in temporal side. Compared with the control group, the mean choroidal thickness in the 9 macular zones of children in the occult high myopia group was significantly thinner than that in the control group, and the difference was statistically significant (P＜0.05). The mean choroidal thickness in each macular region decreased with the increase of diopter in children with occult high myopia. Compared with the control group with the same spherical equivalent, there was no significant difference in the area above the inner ring and the outer ring of the macular fovea in the occult high myopia group of －0.00 to －1.00 D and the temporal side of the inner ring and the outer ring of the macular fovea in the occult high myopia group of ＞－2.00 to －3.00 D (P＞0.05), but there were significant differences among the other regions (P＜0.05). Pearson correlation analysis results showed that the average choroidal thickness of the fovea in children with occult high myopia was negatively correlated with age (r=－3.410, R2=11.630, P=0.010), eye axis (r=1.420, R2=2.016, P=0.030) and diopter (r=－2.680, R2=7.182, P=0.040), but not significantly correlated with gender (r=0.166, R2=0.028, P=0.240), intraocular pressure (r=0.330, R2=0.109, P=0.800) and corneal curvature (r=－0.260, R2=0.068, P=0.850).ConclusionsThe thickness of macular choroidal in children with occult high myopia is the thinnest on the nasal side of the macular fovea and the thickest on the temporal side of the macular fovea. The mean choroidal thickness in each region of the macular is thinner than that in the common myopia children with the same diopter. The mean choroidal thickness of fovea is negatively correlated with age, ocular axis and diopter.
ObjectiveTo observe and analyze the changes of macular retinal thickness and related factors in children with occult myopia. MethodsA prospective longitudinal control study. From February 2021 to February 2022, 120 eyes of 60 children who first visited Department of Ophthalmology of The Affiliated Hospital of Chengde Medical College without any corresponding myopia correction treatment were included in the study. There were 32 males (64 eyes) and 28 females (56 eyes), with the age of 4-6 years. Visual acuity, medical optometry, corneal topography, spectral-domain optical coherence tomography (OCT) and axial length (AL) were measured at the first visit and 3, 6, 9 and 12 months. The children were divided into occult myopia group with 60 eyes of 30 cases and control group with 60 eyes of 30 cases according to visual acuity, equivalent spherical refraction (SE), AL and corneal curvature (CC). The macular fovea retinal thickness was measured by spectral-domain OCT enhanced deep imaging technique. According to the treatment and study of diabetic retinopathy, the retina within the 6 mm of the macular center was divided into three concentric circles with the macular fovea as the center, the central fovea of 1 mm, the inner ring of 1-3 mm and the outer ring of 3-6 mm. In the inner ring and outer ring, the retina was divided into 4 areas, upper and lower, left and right, with a total of 9 regions. The four regions of the inner ring and the outer ring were superior, inferior, nasal and temporal, respectively. The differences of AL, CC, SE, macular retinal thickness and the changes of related factors with time were compared between the occult myopia group and the control group. SE, AL, CC and retinal thickness in different macular regions of the two groups were compared by repeated measurement analysis of variance. In pairwise comparison, the minimum significant difference t test was used in different measurement time points, and the independent sample t test was used between groups at the same measurement time points. ResultsAt first diagnosis and after diagnosis, there were significant differences in SE (F=783.710), AL (F=742.192), macular fovea (F=330.292), inferior and temporal (F=158.250, 108.292) side of the outer ring retinal thickness in occult myopia group (P＜0.01). In the control group, there were significant differences in the retinal thickness of SE (F=1 793.976), AL (F=457.362), macular fovea (F=31.029), inferior and temporal (F=7.405, 77.245) side of the outer ring retinal thickness (P＜0.01). In both groups, with the prolongation of the time after the first diagnosis, the SE gradually increased, the AL gradually lengthened, and the thickness of the macular fovea, inferior and temporal side of the outer ring retinal thickness gradually thinned. Independent sample t test was performed on the data with differences between groups at the same time, and the results showed that at 3, 6, 9 and 12 months after first diagnosis, there were significant differences in SE, AL and CC between the occult myopia group and the control group (t=－4.801,－11.532, 16.276,－17.145), AL (t=24.203, 26.353, 27.057, 25.552); CC (t=－23.362,－25.382,－25.890,－24.350; P＜0.01). There were significant differences in macular fovea, inferior and temporal side of the outer ring retinal thickness at 6, 9 and 12 months, macular fovea (t=－2.596,－2.542, －2.941; P＜0.05), outer ring temporal (t =－2.285, －2.610, －2.506; P＜0.05). ConclusionThe SE and AL of the occult myopia group and the control group increase with time, and the former increase more rapidly than the latter; the macular fovea, inferior and temporal side of the outer ring retinal become thinner, and the former become thinner than the latter.