Objective To quantitatively evaluate the changes of choroidal biomarkers in patients with central serous chorioretinopathy (CSC) and preliminarily explore its pathogenesis. MethodsClinical cross-sectional study. From July 2021 to December 2022, 74 eyes of 65 patients with CSC (CSC group) confirmed by ophthalmic examination at the First Affiliated Hospital of Zhengzhou University were included in the study. Among them, 46 patients (51 eyes) were male, 19 patients (23 eyes) were female. The duration from the onset of symptoms to the time of treatment was less than or equal to 3 months. A control group consisted of 40 healthy volunteers (74 eyes) matched in age and gender. Among them, 26 patients (50 eyes) were male, and 14 patients (24 eyes) were female. Using VG200D from Microimaging (Henan) Technology Co., Ltd., macular scanning source light coherence tomography angiography was performed, with scanning range 6 mm × 6 mm. According to the division of the diabetes retinopathy treatment research group, the choroid within 6 mm of the macular fovea was divided into three concentric circles centered on the macular fovea, namely, the central area with a diameter of 1 mm, the macular area with a diameter of 1-3 mm, and the surrounding area of the fovea with a diameter of 3-6 mm. The device comes with software to record the three-dimensional choroidal vascular index (CVI), choroidal vascular volume (CVV), perfusion area of the choroidal capillary layer (CFA), choroidal thickness (CT), and three-dimensional CVI, CVV, and CT in the upper, temporal, lower, and subnasal quadrants within 6 mm of the fovea. Quantitative data between the two groups were compared using an independent sample t-test. Qualitative data comparison line χ2 inspection. The value of receiver operating curve (ROC) analysis in predicting the occurrence of CSC, including CVI, CVV, CFA, and CT. ResultsCompared with the control group, the CVI (t=3.133, 4.814), CVV (t=7.504, 9.248), and CT (t=10.557, 10.760) in the central and macular regions of the affected eyes in the CSC group significantly increased, while the CFA (t=－8.206, －5.065) significantly decreased, with statistically significant differences (P＜0.05); CVI (t=7.129), CVV (t=10.020), and CT (t=10.488) significantly increased within 6 mm of the central fovea, while CFA (t=－2.548) significantly decreased, with statistically significant differences (P＜0.05). The CVI (t=4.980, 4.201, 4.716, 8.491), CVV (t=9.014, 7.156, 7.719, 10.730), and CT (t=10.077, 8.700, 8.960, 11.704) in the upper, temporal, lower, and lower nasal quadrants within 6 mm of the central fovea were significantly increased, with statistically significant differences (P＜0.05). In the CSC group, the maximum CVI and CVV were (0.39±0.10)% and (1.09±0.42) mm3, respectively, on the nasal side of the affected eye. Upper CT was (476.02±100.89) μm. The nasal side CVI, CVV, and CT have the largest changes. The ROC curve analysis results showed that the area under the curve of CT, CVV, and CVI within 6 mm of the central region, macular region, and fovea was over than 0.5. Subcentral CT was the most specific for the diagnosis of CSC. ConclusionChoroidal biomarkers CVI, CVV, and CT in CSC patients increase, while CFA decreases. Central CT is the most specific for the diagnosis of CSC.
ObjectiveTo observe the changes of chorioidal thickness (ChT) in patients with central serous chorioretinopathy (CSC) in different mode of vortic venous dilation. MethodsA prospective cross-sectional observational study. A total of 80 patients with 89 eyes (CSC group) diagnosed in Department of Ophthalmology, General Hospital of Central Theater Command from April to October 2023 were included in the study. Among them, 64 males had 71 eyes and 17 females had 18 eyes. A total of 15 healthy volunteers matched in age and sex were selected as the control group. Among them, 14 men had 26 eyes and one woman had two eyes. The macular region was examined by ultra-wide-angle scanning frequency source optical coherence tomography (OCTA) with BM400K BMizar made by TowardPi (Beijing) Medical Technology Co., LTD. Scanning rate 1 536 A scanning×1 280 B scanning, scanning range 24 mm×20 mm. The accompanying software delineated nine subfields (superotemporal, upper, superonasal, temporal, central, nasal, inferotemporal, lower, inferonasal regions) to record ChT. En-face OCTA mode was utilized to observe the anatomy and functional anastomosis of the vortex veins above and below the choroidal blood layer. Eyes in the CSC group were further categorized into upper-dominant, symmetrical, and lower-dominant groups based on the difference in vortex vein expansion shown in the choroidal layer of the en-face image, with 36, 35, and 18 eyes respectively. Statistical analysis included the use of independent samples t-test or Mann-Whitney test for comparison between two groups, one-way analysis of variance or Kruskal-Wallis H test for comparison between multiple groups, and the χ test or Fisher test for categorical variables. ResultsCompared with the control group, ChT in the CSC group was thickened in the foveal area and different areas of the macula, with the greatest difference in the fovea, and the differences were statistically significant (t=3.345, 5.018, 2.902, 4.667, 7.276, 3.307, 3.868, 4.795, 2.583; P＜0.05). Compared with the ChT of the control group, there was no statistically significant difference in the superotemporal, region of the upper-dominant group (t=1.510, P＞0.05); in other regions, the differences were statistically significant (t=3.207, 5.163, 2.526, 4.310, 6.285, 2.656, 3.812, 2.173; P＜0.05). The differences in the foveal area and other areas in the symmetrical group were statistically significant (t=4.488, 5.554, 3.457, 5.314, 7.256, 3.507, 5.584, 6.019, 2.994; P＜0.05). In the superotemporal, and superonasal, regions of the lower dominant group, the differences were not statistically significant (t=1.150, 1.465; P＜0.05); in other regions, the differences were statistically significant (t=2.278, 4.168, 5.244, 2.783, 5.040, 3.432, 2.095; P＜0.05). ConclusionThe dilated distribution of vortex veins on en-face ultra-wide-angle OCTA has a corresponding relationship with ChT. In eyes with CSC, the superior vortex vein drainage system may be the primary route for choroidal drainage.
Objective To observe the anastomotic status of the vortex veins in patients with central serous chorioretinopathy (CSC). MethodsA cross-sectional study of clinical practice. From July 2021 to July 2022, 50 cases (50 eyes) of monocular CSC patients diagnosed through ophthalmic examination at the First Affiliated Hospital of Zhengzhou University were included in the study. Among them, there were 37 males (74.0%, 37/50) and 13 females (26.0%, 13/50), with the mean age of (44.30±9.59) years old. The course of disease from the onset of symptoms to the time of treatment was less than 3 months. The affected eye and contralateral eye of CSC patients were divided into the affected eye group and contralateral eye group, respectively. Fifty healthy volunteers of the same age and gender were selected as the normal control group with 50 eyes. The macular area scanning source optical coherence tomography (OCT) vascular imaging examination was performed with Visual Microimaging (Henan) Technology Co., Ltd. VG200D. Horizontal watershed vortex veins anastomosis rate and asymmetric vortex-venous dilation rate were observed by en face OCT. The device comes with software to calculate the central foveal choroidal thickness (SFCT), mean choroidal thickness (MCT), and choroidal vascular index (CVI). One-way analysis of variance and χ2 test were used to compare the three groups. When variances were unequal between groups, nonparametric tests were performed. ResultsThe SFCT values of the affected eye group, contralateral eye group, and normal control group were (567.12±129.02), (513.26±133.17), (327.64±97.40) μm, respectively; MCT were (407.38±97.54), (388.24±94.13), (275.46±60.55) μm, respectively; CVI were 0.34±0.05, 0.32±0.04, and 0.27±0.04, respectively; anastomosis rates of vortex veins were 98% (49/50), 78% (39/50), and 40% (20/50), respectively; asymmetric dilation rates of vortex veins were 96% (48/50), 88% (44/50), and 48% (24/50), respectively. The differences of SFCT (F=53.974), MCT (Z=51.415), CVI (F=28.082), vortex vein anastomosis rate (χ2=43.056), asymmetric dilation rate of vortex veins (χ2=37.728) among three groups were statistically significant (P＜0.001). Compared with the contralateral eye group, the SFCT, MCT, CVI, vortex vein anastomosis rate, and vortex vein asymmetric dilation rate in the affected eye group were significantly higher than those in the contralateral eye group. Among them, the differences of SFCT (t=2.054), CVI (t=2.211), and vortex vein anastomosis rate (χ2=9.470) were statistically significant (P＜0.05); the differences of MCT (Z=7.490), asymmetric dilation rate of vortex veins（χ2=2.714) were not statistically significant (P=1.000, 0.140). ConclusionsSFCT, MCT, and CVI in the affected and contralateral eyes of monocular CSC patients significantly increase. The anastomotic rate and asymmetric dilation rate of the vortex vein in the opposite eye were lower than those in the affected eye.
ObjectiveTo observe the effect of intravitreal injection of anti-vascular endothelial growth factor drugs on the subfoveal choroid thickness (SFCT) of patients with retinal vein occlusion (RVO) and macular edema (ME). MethodsA prospective clinical study. From January 2017 to January 2019, 59 monocular RVO-ME patients with 59 eyes diagnosed in the eye examination of The First Central Hospital of Baoding were included in the study. Among them, there were 31 males with 31 eyes and 28 females with 28 eyes; the average age was 57.4±10.3 years old. The course of the disease was 5 days to 1 month, all of whom had the first-onset disease. Branch retinal vein occlusion (BRVO) was found in 35 eyes (BRVO-ME group); non-ischemic central retinal vein occlusion (CRVO) was found in 24 eyes (CRVO-ME group). Best corrected visual acuity (BCVA) and frequency domain optical coherence tomography (OCT) were performed. The BCVA examination was carried out using the international standard visual acuity chart, which was converted into the logarithmic minimum angle of resolution (logMAR) visual acuity during statistics. The Cirrus HD-OCT 5000 instrument from Carl Zeiss company of Germany was used to measure the central macular thickness (CMT) and SFCT. All eyes were treated with intravitreal injection of anti-vascular endothelial growth factor drugs. The follow-up time after treatment was 6 months, and the changes of BCVA, CMT and SFCT of eyes before treatment and 2 weeks after treatment were compared and observed, as well as the occurrence of treatment-related complications. The comparison of BCVA, CMT, and SFCT at different times before and after treatment were adopted repeated measures analysis of variance; pairwise comparison of differences at different time points adopts the least significant difference t test. ResultsBefore treatment, the average logMAR BCVA and CMT of RVO-ME eyes were 0.92±0.46 and 604.71±169.35 μm, respectively. At 2 weeks, 1, 3, and 6 months after treatment, the average logMAR BCVA of the affected eye was significantly improved compared with that before treatment, and the CMT was significantly decreased. The difference was statistically significant (F=55.664, 59.518; P＜0.05). Before treatment, the average SFCT of the affected eye and the contralateral eye of RVO-ME patients were 306.3±65.8 and 241.3±59.8 μm, respectively. The SFCT of the affected eye was significantly thicker than that of the contralateral healthy eye, and the difference was statistically significant (t=25.772, P＜0.05). At 2 weeks, 1, 3, and 6 months after treatment, the average SFCT of the eyes were 267.7±81.4, 252.3±57.3, 239.2±46.5, 240.6±48.3 μm, respectively. Compared with before treatment, treatment SFCT decreased significantly at different times afterwards, and the difference was statistically significant (F=924.341, P＜0.001). There was no significant difference in SFCT between CRVO-ME group and BRVO-ME group at 2 weeks, 1, 3, and 6 months after treatment (P＞0.05). No complications such as endophthalmitis, cataract progression and neovascular glaucoma occurred during the follow-up period of all eyes. ConclusionThe SFCT of eyes with short course of disease and first-onset RVO-ME is thickened; anti-VEGF drug treatment can effectively reduce SFCT, improve ME, and increase BCVA.
ObjectiveTo obverse the changes of macular choroidal thickness (CT) in patients with mild to moderate Alzheimer’s disease (AD).MethodsThis was a case-control study. Twenty-one patients with mild to moderate AD confirmed by Neurology Department of Jinhua Central Hospital from November 2016 to June 2018 and 21 age-matched control subjects were concluded in the study. There was no significant difference in age (t=0.128), intraocular pressure (t=0.440) and axial length (t=1.202) between the two groups (P＞0.05). There was significant difference in mini-mental state examination score (t=8.608, P＜0.05). CT was measured by OCT with enhanced depth imaging technique in the subfoveal choroid, at 0.5 mm and 1.0 mm from the center of the fovea nasal (NCT0.5, 1.0 mm), temporal (TCT0.5, 1.0 mm), superior (SCT0.5, 1 .0 mm), and inferior (ICT0.5, 1.0 mm). Independent-samples t test was used to compare the results obtained from these two groups.ResultsSFCT (t=2.431), NCT0.5, 1.0 mm (t=3.341, 2.640), TCT0.5, 1.0 mm (t=3.340, 2.899), SCT0.5, 1.0 mm (t=3.576, 3.751) and ICT0.5, 1.0 mm (t=2.897, 2.903) were significantly thinner in AD eyes than those in control eyes.ConclusionCompared with healthy subjects, patients with mild to moderate AD showed a significant reduction in CT.
ObjectiveTo observe the center retinal thickness (CRT) and subfoveal choroidal thickness (SFCT) in eyes with central retinal artery occlusion (CRAO) before and after treatment.MethodsA total of 34 patients (34 eyes) diagnosed with CRAO by fundus fluorescence angiography (FFA) were retrospectively analyzed. There were 18 males (18 eyes) and 16 females (16 eyes). The average age was (61.42±14.09) years. The mean onset time was (2.64±3.73) days. The mean hospitalization time was (11.92±4.95) days. The mean axial length (AL) was (23.53±2.04) mm. The best-corrected visual acuity (BCVA), slit-lamp biomicroscopy, indirect ophthalmoscopy, fundus color photography, fundus fluorescein angiography, spectral domain optical coherence tomography (OCT) and AL measurement were performed. BCVA was converted to the logarithm of the minimum angle of resolution (logMAR). According to FFA, visual loss and the results of OCT, patients were divided into 3 groups: incomplete CRAO (15 eyes) , subtotal CRAO (8 eyes), total CRAO (11 eyes). SFCT and CRT in affected and the fellow eye were measured by OCT for enhanced deep imaging. Follow up lasted for 1 month after treatment, with an average follow-up of (34.71±6.82) days. The changes of SFCT, CRT, and BCVA before and after treatment were observed. The correlation between BCVA after treatment and pretreatment CRT was also analyzed.ResultsAfter 1 month of follow-up, the logMAR BCVA in incomplete group, subtotal group and total group were significantly higher than before treatment (t=3.74, 3.61, 3.26; P=0.004, 0.009, 0.017). Before treatment, the average CRT of the contralateral eyes in the total, subtotal and incomplete group were (215.00±19.85), (224.00±22.79), (214.00±8.21) μm, and the mean SFCT were (264.54±121.71), (266.50±58.17), (261.86±90.95) μm. The average CRT of the affected eyes were (353.18±60.26), (280.14±11.08), (266.63±19.65) μm, and the average SFCT were (233.72±111.35), (237.75±53.30), (259.86±98.14) mm. Compared with the fellow eyes, the average CRT in the 3 groups were thickened, and the difference were statistically significant (t=8.274, 3.694, 11.577; P＜0.001, 0.008, ＜0.001); the average SFCT in the total group was decreased, the difference was statistically significant (t=?2.138, P=0.048). The mean CRT among the 3 groups of eyes was statistically significant (F=12.02, P＜0.001). There was no significant difference in the average SFCT (F=0.178, P=0.838). After 1 month follow-up, the mean CRT in the total, subtotal and incomplete group were (231.18±49.28), (219.16±21.34), (217.86±24.98) μm, and the average SFCT were (239.81±109.57), (241.86±42.81), (260.57±91.67) μm. Compared with before treatment, the average CRT in the three groups of eyes were decreased, the difference were statistically significant (t=13.032, 3.711, 4.970; P＜0.001, 0.008, 0.003); the difference in mean SFCT were not statistically significant (t=?0.785, ?0.202, ?0.078; P=0.466, 0.845, 0.940). Correlation analysis showed that BCVA after treatment was positively correlated with pretreatment CRT (odds ratio=0.578, P=0.002).ConclusionCRAO resulted in CRT in the preliminary stage and became thinner after receiving treatments. There exists a positive correlation between visual outcome and CRT before receiving treatments.
ObjectiveTo compare the clinical and imaging characteristics of eyes with idiopathic focal choroidal excavation (FCE) and acquired FCE, and to preliminarily analyze the association of FCE with different fundus diseases. MethodsA retrospective clinical study. A total of 90 patients (93 eyes) diagnosed with FCE at the Ophthalmology Department of The First Affiliated Hospital of Zhengzhou University from March 2021 to May 2024 were included in the study. All affected eyes underwent best-corrected visual acuity (BCVA) testing, intraocular pressure (IOP) measurement, ophthalmoscope, fundus color photography, and swept-source optical coherence tomography (SS-OCT). SS-OCT was used to measure subfoveal choroidal thickness (SFCT), choroidal thickness at the temporal, nasal, and inferior margins of the FCE, as well as the maximum width and depth of the FCE. Based on the presence of concomitant fundus diseases, FCE cases were divided into an idiopathic FCE group (51 eyes) and an acquired FCE group (42 eyes). Clinical characteristics at the initial and final visits were compared between the two groups. Clinical features were also analyzed for acquired FCE eyes with different associated fundus diseases. A logistic regression model was used to identify potential risk factors for FCE coexisting with other fundus diseases. ResultsCompared to the idiopathic FCE group, the acquired FCE group had significantly decreased BCVA (Z=?8.290), significantly increased FCE width (Z=?2.762), and significantly higher incidence rates of saucer-shaped FCE (χ2=8.352) and ellipsoid zone disruption (χ2=7.999). These differences were all statistically significant (P＜0.05). No significant differences were found between the two groups in age, gender distribution, IOP, foveal involvement, proportion of conforming FCE, retinal pigment epithelium-Bruch’s membrane rupture, presence of hyperreflective material under the excavation, presence of surrounding thick vessels, FCE depth, SFCT, or choroidal thickness at the inferior, temporal, and nasal margins of the FCE (P＞0.05). Logistic regression analysis revealed that FCE width (odds ratio=1.002, 95% confidence interval: 1.001-1.004, P=0.005) was the sole risk factor for FCE coexisting with other fundus complications. In both the idiopathic and acquired FCE groups, FCE depth and width remained relatively stable during follow-up. BCVA improved in the acquired FCE group after treatment. ConclusionsFCE can coexist with various fundus diseases. FCE width is the only risk factor for the development of other fundus complications in FCE-affected eyes. Treating retinal or choroidal diseases associated with acquired FCE can provide visual benefits to patients.
ObjectiveTo investigate the changes of choroid thickness in adolescents with different types of non-pathological high myopia (HM). MethodsA retrospective observational study. From January 2021 to April 2022, 179 eyes of 101 adolescents with myopia in Liaocheng Aier Eye Hospital were collected and analyzed. According to the spherical equivalent (SE) and corneal curvature, subjects were divided into mild myopia or emmetical eye group (control group), HM group, occult HM group (OHM group) and super HM group (SHM group). There were 52 eyes in 30 cases, 47 eyes in 26 cases, 42 eyes in 24 cases and 38 eyes in 21 cases, respectively. Medical optometry, intraocular pressure, optical coherence tomography (OCT), axial length (AL) and corneal curvature were measured. The macular foveal choroidal thickness was analyzed by using spectral-domain OCT. The diopter was expressed in SE. The thickness of choroid in the fovea of macular region was measured by enhanced deep imaging with frequency domain OCT. The thickness of choroid was measured in 9 regions within 1 mm, 3 mm from the fovea, including the upper, lower, nasal and temporal regions. Generalized estimating equation was used to compare the data among groups, and the least significant difference t-test was used to compare the data among groups. The correlation between AL, corneal curvature, intraocular pressure and choroidal thickness was analyzed by Pearson correlation. ResultsThe choroidal thickness in the foveal macula and the areas 1 mm and 3 mm away from the fovea were compared among the control group, HM group, OHM group and SHM group, the difference were significant (χ2=76.646, 36.715, 27.660, 35.301, 24.346, 38.093, 36.275, 33.584, 36.050; P＜0.05). Compared with the control group, the choroidal thickness of the fovea and the choroidal thickness in each area within 1 and 3 mm from the fovea in the HM group, the OHM group and the SHM group were significantly thinner than those in the control group, and the difference was statistically significant (P＜0.05). There were statistically significant differences in choroidal thickness in each region between the group and the SHM group, and between the OHM group and the SHM group (P＜0.05). The results of correlation analysis showed that AL was negatively correlated with choroidal thickness in various regions (P＜0.05); SE was positively correlated with choroidal thickness in various regions (P＜0.05); corneal curvature and intraocular pressure had no significant correlation with choroidal thickness in various regions (P＞0.05). ConclusionsThe choroidal thickness of SHM is significantly lower than that of OHM and HM; OHM patients have lower SE. However, the choroidal thickness is significantly thinner. AL and SE are the influencing factors of choroidal thickness.
ObjectiveTo compare and observe the fundus imaging characteristics of eyes with glucocorticoid-related central serous chorioretinopathy (CSC). MethodsA retrospective clinical study. A total of 149 CSC patients with 166 eyes diagnosed at Department of Ophthalmology of The First Affiliated Hospital of Zhengzhou University from March 2021 to October 2024 were included in the study. The duration of the disease from the appearance of symptoms to treatment was less than 3 months. All affected eyes underwent best-corrected visual acuity (BCVA), fundus color photography, swept-source optical coherence tomography (SS-OCT), and fundus fluorescein angiography (FFA) examinations. BCVA was tested using an international standard vision chart and converted into logarithm of the minimum angle of resolution (logMAR) visual acuity for statistical analysis. The SS-OCT instrument measured subfoveal choroidal thickness (SFCT), central macular thickness (CMT), choroidal vascular volume (CVV), and the width and height of flat irregular pigment epithelial detachment (FIPED). FIPED, subretinal fibrin, and choroidal layer strong reflective spots were identified from SS-OCTA B-scan images; multiple leakages (leak points >3) were identified from FFA images. Based on the presence or absence of a clear history of glucocorticoid administration before the onset, patients were divided into glucocorticoid-related and non-glucocorticoid-related groups, comprising 41 patients with 53 eyes and 108 patients with 113 eyes, respectively. Clinical and fundus imaging characteristics of the two groups were compared. The comparison of quantitative data between the two groups was performed using independent samples t test or non-parametric independent samples Wilcoxon test; the comparison of qualitative data was performed using χ2 test. ResultsCompared with the non-glucocorticoid-related group, the glucocorticoid-related group had a smaller male-to-female ratio and a higher bilateral incidence, and the differences were statistically significant (χ2=4.925, 17.849; P＜0.05). The logMAR BCVA for the glucocorticoid-related and non-glucocorticoid-related groups were 0.45±0.33 and 0.21±0.21, respectively; SFCT were (644.43±131.91) and (507.26±121.79) μm; CMT were (389.51±233.45) and (362.59±140.85) μm; CVV were (4.44±1.07) and (3.67±0.82) mm3; FIPED incidence were 58.49% (31/58) and 20.35% (23/113), respectively; FIPED width and height were (1 122.01±533.98) and (742.90±388.79) μm, and (99.13±92.17) and (33.01±15.99) μm; subretinal fibrin were observed in 24 (45.28%, 24/53) and 15 (13.27%, 15/113) eyes; choroidal strong reflections were found in 38 (71.70%, 38/53) and 45 (39.82%, 45/113) eyes; multiple leak points were identified in 35 (66.03%, 35/53) and 40 (35.40%, 40/113) eyes, respectively. Compared with the non-glucocorticoid-related group, the glucocorticoid-related group had worse BCVA (Z=?4.984), thicker SFCT (t=6.586), larger CVV (t=5.160), higher incidence of FIPED (χ2=23.908), and greater width and height of FIPED (t=2.895, Z=?3.703). The glucocorticoid-related group also had a significantly increased incidence of subretinal fibrin, choroidal strong reflections, and multiple leak points, with all differences being statistically significant (χ2=20.565, 14.663, 13.675; P＜0.05); however, the comparison of CMT showed no statistically significant difference (Z=?0.651, P＞0.05). ConclusionCompared with non-glucocorticoid-related CSC, glucocorticoid-related CSC patients have poorer vision, are more likely to affect both eyes, show no gender bias; choroidal vascular dilation is more significant, and damage to the outer retina and retinal pigment epithelium is more severe.
ObjectiveTo explore the distribution of choroidal thickness and its influence factors in university students.MethodsA cross-sectional study. A total of 896 eyes of 896 college students were included in the study. Among them, there were 350 males (350 eyes) and 546 females (546 eyes). All the eyes were right eyes. The average age was 19.18 ± 1.36 years old. According to the spherical equivalent refraction (SER), the eyes were divided into non-myopia group, low myopia group, moderate myopia group and high myopia group, which were 59, 251, 356 and 230 eyes, respectively. The subfoveal ChT (SFCT) was measured using a swept-frequency source optical coherence tomography scanner. According to the ETDRS, the choroid within 6 mm of the fovea was divided into three concentric circles centered on the fovea of the macula, which were the central area with a diameter of 1 mm, the inner ring area of 1-3 mm and the outer ring area of 3-6 mm. The outer ring area of 3-6 mm has a total of 9 zones. The inner ring and outer ring 4 regions were superior, inferior, nasal and temporal, respectively. The distribution characteristics of ChT in different regions, genders and diopter groups were observed. Bivariate correlation analysis were used to analyze the correlation of ChT and SER, axial length (AL).ResultsThe average SFCT of 896 eyes was 221.28±67.35 μm. The mean SFCT of males and females were 227.20±69.38 and 217.50±65.80 μm, respectively. The difference of SFCT between different genders was statistically significant (t=2.075, P=0.038). Compared with the central region ChT, there was no significant difference in ChT between the outer ring and the outer region (t=0.086, P=0.932). The difference of ChT in other regions was statistically significant (t=-21.973, -5.818, 36.328, -3.065, -18.017, -10.595, 57.007; P＜0.001, ＜0.001, ＜0.001, ＜0.002, ＜0.001, ＜0.001, ＜0.001). In the horizontal direction, ChT gradually thickens from nasal to temporal (F=2 251.558, P＜0.001); in the vertical direction, ChT gradually decreases from superior to the central, but have a little increased from central to inner inferior, then decreased to outer inferior again (F=45.425, P＜0.05). Correlation analysis showed that SFCT was negatively correlated with AL (r=0.478, P＜0.01) and a negative correlation with axial length (r=?0.395, P＜0.01), and positively correlated with SER (r=0.478, P＜0.01). SFCT decreased by 12.29 μm for every in myopic refractive error of 1 D, or by 20.14 μm for every increase in AL of 1 mm.ConclusionsChT is changed by different location. The horizontal direction is gradually thickened from nasal to temporal. The vertical direction is thicker than the center. The inferior inner ring area is thicker than the outer ring area. Gender, SER and AL are the influencing factors of SFCT.