Background The parameter of corneal diameter in myopic eyes is widely used in clinic,but there are different points of view about the correlation of corneal horizontal diameter with other parameters of the myopic eye.Objective This study was to investigate the relevance of the other parameters to the corneal horizontal diameter(CHD)of myopia.Methods A total of 310 cases(310 eyes)of myopic patients aged 6-50 years old who visited Affiliated First Hospital of Zhengzhou University were collected for the study.Measuring items included gender,age,myopia diopter and corneal topography.The relationships between the CHD of the right eyes and seven factors including age,gender,degree of myopia,corneal curvature (CC),corneal astigmatism (CS),corneal central thickness(CCT),and anterior chamber depth (ACD)were analyzed by empower stats software.Results The distribution range of CHD was from 10.8 mm to 13.5 mm,with the average value (11.7±3.8)mm.There were significant differences in the CC and ACD between male and female patients by t test(t =-1.574,P＜0.001 ;t=-1.145,P =0.034).Through the smoothing curve fitting,the threshold effect and single factor and multiple regression analysis,the CHD was negative linear relationship with CC (β =-0.085,P =0.011).The ACD positive linear relationship with CHD was found (β=0.722,P＜0.001).And the CHD was not correlated with the degree of myopia,CS,CCT and gender(β =0.000,0.084,-0.001,0.105;all at P＞0.05).There was different inflection point in the curve relationship between male patients and female patients.Conclusions The CHD is linear negatively correlated with CC and line positively associated with ACD in 6-50 years old myopic patients.There is no relationship between CHD and gender,spherical equivalent degree,CS,CCT.There is curvilinear relationship with inflection point between CHD and age.

Objective To compare the changes of diopter and axial length(AL) m 2 years after wearing orthokeratology lens,rigid gas permeable contact lens (RGPCL) and spectacles in adolescent myopia,and evaluate the control effects of different methods on adolescent myopia.Methods Prospective clinical study.The date of 99 eyes of 50 adolescent myopia cases wearing orthokeratology,95 eyes of 48 adolescent myopia cases wearing RGPCL,and 100 eyes of 50 adolescent myopia cases wearing full correction single vision spectacles were collected from June 2012 to June 2014.The follow-up time was 2 years.The status of diopter and AL before and wore mirror after 2 years and the uncorrected visual acuity (UCVA) in group of orthokeratology were recorded.The examinations were repeated after 2 years without wearing orthokeratology and RGPCL at least 30 days.Results There was no statistical difference in age,refractive status and AL among three groups before wearing the mirror.After wearing for 2 years,AL and spherical equivalent in three groups were increased (F =278.43,140.12;all P ＜ 0.01).The increase of AL and SE was as follows:orthokeratology group (0.30 ± 0.39) mm,(0.83 ±0.97) D;RGPCL group (0.55 ± 0.41) mm,(1.55 ± 0.63) D;spectacles group (0.59 ± 0.34)mm,(1.73 ± 0.62)D.The increase of orthokeratology group was the least,and there was no statistical difference between the other two groups.UCVA was significantly improved at each time point after wearing orthokeratology(F =486.38,P ＜0.01).Conclusion In the three optical correction methods of orthokeratology,RGP and spectacles,the ortho-keratology is the best on controlling adolescent myopia,and no difference between the other two.At the same time,wearing orthokeratology can also significantly improve UCVA in myooia cases.

Objective:To compare the clinical effect of 0.02% atropine eye drops once every two days and 0.01% atropine eye drops once every day in myopia control and adverse reactions in children.Methods:A randomized controlled study was performed.The 231 Han nationality myopic children wearing full-corrected single-vision spectacle lenses enrolled from June 2016 to June 2017 in The First Affiliated Hospital of Zhengzhou University and Henan Eye Hospital were divided into two groups by random number table, with 110 children in the 0.02% atropine group and 121 children in the 0.01% atropine group.The subjects were treated with 0.02% atropine eye drops once every two days or 0.01% atropine eye drops once every day to each eye before bedtime for one year.Ninety-two cases and 101 cases were followed up for one year in the 0.02% and 0.01% atropine group, respectively.The right eyes were selected as experimental eyes, and the spherical equivalent refraction (SER), axial length (AL), amplitude of accommodation (AMP), pupil diameter (PD), anterior chamber depth (ACD), and corneal curvature were recorded at baseline and 12 months after treatment.Discomfort symptoms were also observed during the 1-year follow-up.The study protocol was approved by an Ethics Committee of The First Affiliated Hospital of Zhengzhou University (No.2016-35). Written informed consent was obtained from guardians prior to any treatment.Results:After 1 year of treatment, the mean SER change was (-0.46±0.49)D and (-0.48±0.46)D, and the mean AL change was (0.38±0.21)mm and (0.39±0.19)mm, and the mean AMP change was (-1.49±0.29)D and (-1.61±0.26)D, and the mean PD change was (0.72±0.44)mm and (0.70±0.40)mm in the 0.02% atropine group and 0.01% atropine group, respectively.There was no significant difference in the change of SER, AL, AMP, PD between the two groups (all at P>0.05). There were 21 cases (19.1%) in the 0.02% atropine group and 25 cases (20.7%) in the 0.01% atropine group that represented mild photophobia in bright sunlight, which disappeared in 12 and 13 cases during 1-6 months respectively.The photophobia symptoms of the remaining children were alleviated.There existed 5 cases (4.5%) and 6 cases (5.0%) in the two groups that developed mild near blurred vision that lasted no more than 1 month. Conclusions:Compared with 0.01% atropine eye drops once a day, 0.02% atropine once every two days has the same efficacy on controlling myopia progression in children with no more adverse reactions.

Objective To evaluate the effects of 0.0％ and 0.02％ atropine on pupil diameter (PD) and accommodation amplitude (AMP) in myopic children and analyze its relation factors.Methods A prospective randomized controlled trial design was adopted.One hundred and ninety-three myopia children were included from June to October,2016 in the First Affiliated Hospital of Zhengzhou University,all the children completed one-year follow-up.All the children were divided into three groups randomly,with 72,74 and 80 myopic children in 0.01％ atropine group,0.02％ atropine group and control group,respectively.The myopic children in 0.01％ atropine group and 0.02％ atropine group wore single-vision spectacle lenses and were treated with 0.01％ and 0.02％ atropine eye drops nightly,respectively.The myopic children in the control group wore spectacle lenses only.The PD and AMP were measured at baseline,and 4,8 and 12 months after treatment.Results There were no significant difference of baselinePD and AMP among the three groups (F=9.321,P=0.820;F=13.209,P=0.220).Compared with basline,after 12 months,the PD increased by 0.75,0.84 and 0.02 mm in 0.01％ atropine group,0.02％ atropine group and control group,respectively.There were statistically significant differences of PD among three groups at different time points (Fgroup =2.168,P=0.013;Ftime =2.139,P=0.015;Finteraction =2.148,P=0.001).Compared with baseline,the PD of 0.01％ atropine group and 0.02％ atropine group were increased 4,8 and 12 months after treatment,and the difference was statistically significant (all at P＜0.001).The PD was stable in control group.After 12 months,the AMP were reduced by 1.25,1.12 and 0.28 D in 0.01％ atropine group,0.02％ atropine group and control group,respectively.There were statistically significant differences of AMP among the three groups at the different time points (Fgroup =18.346,P =0.034;Ftime =1.823,P =0.002;Fintercation =3.239,P =0.023).Compared with baseline,the AMP of 0.01％ atropine group and 0.02％ atropine group were increased 4,8 and 12 months after treatment,and the differences were statistically significant (all at P＜0.05).The AMP remained stable in control group.The change of PD in 0.01％ atropine group and 0.02％ atropine group was correlated with age,baseline PD and baseline eye axis length,respectively (β =0.060,P =0.019;β =-0.440,P＜0.001;β =-0.37,P =0.045).The change in AMP of the atropine group was significantly correlated with the baseline adjustment range (β =-0.71,P＜0.001).Conclusions 0.01％ and 0.02％ atropine show similar effects on pupil diameter and accommodation amplitude after 12 months of treatment in myopic children.

Objective:To evaluate the clinical efficacy of 0.01% atropine eye drops in the control of myopia progression in Chinese children with myopia.Methods:A prospective non-randomized controlled study was performed.The 152 myopic children aged 6 to 14 years were enrolled from June to October in 2016 in the First Affiliated Hospital of Zhengzhou University, the subjects wore single-vision spectacle lenses (SV) to correct refractive errors and were divided into two groups: the eyes in the atropine group ( n=72) were treated with one drop of 0.01% atropine eye drops before sleep; the eyes in the simple SV group ( n=80) only wore SV.Repeated measurements of refractive power and axial length were performed at baseline, 4, 8 and 12 months after treatment.Discomfort symptoms were also observed.Informed consent was provided according to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University. Results:After 12 months of treatment, the progression of myopia in the atropine group was (0.46±0.42)D, which was significantly lower than (0.70±0.42)D in the simple SV group ( t=5.479, P<0.001). The increase of axial length in the atropine group was (0.36±0.21)mm, which was significantly lower than (0.46±0.41)mm in the simple SV group ( t=9.883, P=0.004). The proportions of myopia progressed more than 0.50 D per year were 45%(28/70)and 28%(19/80) in the atropine group and simple SV group, respectively, with a significant difference between the two groups ( χ2=7.582, P=0.035). In the atropine group, photophobia appeared in 16 cases (22.9%), and was gradually relieved.Allergy was observed in 1 case and disappeared after atropine withdrawal. Conclusions:Application of 0.01% atropine eye drops can effectively control the progression of myopia and have few discomfort symptom in Chinese myopic children.

Objective To observe the adverse effects of 0.01％ atropine sulfate eye drops on myopic children.Methods A prospective non-randomized controlled trial was conducted.Ninety-nine myopic children (99 right eyes) were randomly assigned to experimental group(55 cases) and control group(44 cases).Myopic children of experimental group wore completely corrected frame glasses,while 0.01％ atropine sulfate eye drop was dropped into each eye once a day before going to bed.Myopic children in control group only wore completely corrected frame glasses.The follow-up time was 4 months.Best corrected visual acuity (BCVA),intraocular pressure (IOP),change of pupil diameter (PD) and amplitude of accommodation,symptoms of discomfort after medication were observed.This study followed the Helsinki declaration and was approved by Ethic Committee of the First Affiliated Hospital of Zhengzhou University.Informed consent was signed by the parents of each patient.Results No significant differences were found in best corrected distance visual acuity (BCDVA),best corrected near visual acuity(BCNVA) and IOP between the two groups before and 4 months after treatment (BCDVA:Fgroup =3.880,P =0.112;Ftime =27.220,P =0.413;BCNVA:Fgroup =5.200,P =0.311;Ftime =38.200,P =0.116,IOP:Fgroup =12.350,P=0.214;Ftime =22.300,P =0.146).After 4 months treatment,the PD was (6.99 ±0.64) mm in the experimental group,which was significantly higher than that before treatment(P＜0.001).The PD of the experimental group was higher than that of the control group after 4 months treatment,and the difference was statistically significant (P＜0.01).The amplitude of accommodation in the experimental group was 14.01 ±3.98 after 4 months treatment.which was 1.20 D lower than that before treatment,the difference was statistically significant (P＜0.01).The amplitude of accommodation of the experimental group was lower than that of the control group after 4 months treatment,the difference was statistically significant (P ＜ 0.01).Four cases (8％) appeared photophobia symptoms.Two cases and 2 cases appeared photophobia for 1 week or 2 weeks,respectively.However this symptom would relieve after wear sunglasses or sunshade caps in outdoor activities.One case (2％) appeared ocular itching and swelling after 1 month treatment,but disappeared after withdrawal.There were no other uncomfortable symptoms such as near sight blurring.Conclusions In mainland of China,the BCDVA,BCNVA and IOP of myopic children are stable;the PD is dilated and the amplitude of accommodation is decreased slightly after 4 months treatment of 0.01％ atropine,and 10％ children appear photophobia,but do not affect their study and life.

Objective:To compare the effect of delaying progression of myopia in children between defocus incorporated multiple segments (DIMS) spectacle lens and orthokeratology.Methods:A nonrandomized controlled clinical study was conducted.A total of 390 children (390 eyes) with myopia who were treated in the First Affiliated Hospital of Zhengzhou University from January 2018 to December 2020 were included, with the spherical equivalent (SER) of -0.75 to -6.00 D. According to the willingness of patients and patients' guardians, the subjects were divided into DIMS group, orthokeratology group and single-vision spectacle lens group, with 130 cases (130 eyes) in each group, wearing DIMS spectacle lenses, standard or astigmatic design orthokeratology and conventional single-vision full-correction aspheric spectacle lenses, respectively.The SER of the eyes was measured using an automatic computerized refractometer in combination with subjective refraction before and one year after lens wear, and the axial length (AL) of the eyes was measured using IOLMaster.A total of 327 patients in the three groups met the inclusion and exclusion criteria, including 107 in the DIMS group, 112 in the orthokeratology group, and 104 in the single-vision spectacle lens group.All the right eyes were included in this study.The changes in SER and AL before and after wearing lenses for 1 year were compared among the three groups.The relationship between AL and SER changes and baseline data in the DIMS group was evaluated by Pearson linear correlation analysis.The study followed the Declaration of Helsinki, and the study protocol was reviewed and approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University (No.2023-KY-0174-002). The subjects and their guardians were fully aware of the purpose and methodology of the study, and voluntarily signed an informed consent form.Results:There were statistically significant overall differences in SER and AL at different time points among the three groups (SER: Fgroup=7.065, P=0.009; Ftime=183.730, P<0.001.AL: Fgroup=6.151, P=0.014; Ftime=175.290, P<0.001). One year later, the differences in SER and AL changes among the three groups were statistically significant ( F=7.065, P=0.009; F=6.151, P=0.014). The SER and AL of each group after 1 year was greater than the baseline, with the SER and AL and their changes significantly smaller in orthokeratology group and DIMS group than in single-vision spectacle lens group and greater in DIMS group than in orthokeratology group, showing statistically significant differences (all at P<0.05). Compared with single-vision spectacle lenses, wearing orthokeratology for 1 year can inhibit SER and AL progression by 58.3% and 59.0%, and wearing DIMS frame glasses for 1 year can inhibit SER and AL progression by 46.9% and 43.6%.The percentage of eyes with no change in SER was 5.77%(6/104), 24.11%(27/112) and 17.76%(19/107) in the single-vision spectacle lens group, orthokeratology group and DIMS group, respectively, and the percentage of AL was 0.00%(0/104), 8.93%(10/112) and 7.48%(8/107), respectively, showing statistically significant differences among the three groups ( χ2=9.316, 8.676; both at P<0.001). The AL change in the DIMS group was weakly negatively correlated with age ( r=-0.252, P=0.006). Conclusions:Wearing DIMS spectacle lenses is not as effective as orthokeratology in delaying myopia in children, but it is significantly better than wearing conventional single-vision spectacle lenses.

Objective:To observe the correlation between retinal capillary density and retinal thickness in the macula and spherical equivalent (SE) in school-age children.Methods:A cross-sectional study. From May to December 2022, 182 school-age children who visited the ophthalmology department of the First Affiliated Hospital of Zhengzhou University were included. There were 95 males and 87 females. The age ranged from 6 to 12 years, and the spherical equivalent (SE) was +0.50 to -6.00 D. They were divided into three groups based on the SE of the right eyes: 54 eyes in emmetropia group (+0.50≤SE<-0.50 D), 71 eyes in low myopia group (-0.50≤SE<-3.00 D), and 57 eyes in moderate myopia group (-3.00≤SE≤-6.00 D). The macular area of 6 mm×6 mm was scanned using swept-source optical coherence tomography angiography and was divided into three concentric rings centered on the fovea, including the macular central fovea (0-1 mm diameter), inner ring (1-3 mm diameter) and outer ring (3-6 mm diameter). The retinal thickness and blood flow density of superficial vascular plexus (SVP) and deep vascular plexus (DVP) in different zones within 6 mm of the macular area were measured. The relationships between SE and SVP, DVP and retinal thickness in each ring region were investigated by univariate and multivariate linear regression analyses, smooth curve fitting, and threshold effects.Results:There were significant differences in the SVP ( F=6.64, 26.06, 22.69) and DVP ( F=7.97, 25.01, 5.09) of macular central fovea, inner ring and outer ring among the emmetropia, low myopia and moderate myopia groups ( P<0.05). Univariate linear regression analysis showed that the SVP ( β=-0.56,-1.17, -0.79) and DVP ( β=-1.03, -0.93, -0.45) of the three regions were positively correlated with SE ( P<0.05). After smooth curve fitting, threshold effect analysis and multivariate linear regression analysis, the SVP and DVP in the macular central fovea were linearly positively correlated with SE ( β=-0.91, -1.40; P<0.05), and SVP and DVP in the inner ring and outer ring showed an inverted U-shaped curve relationship with SE with the inflection (<3.00 D). When the SE was less than <3.00 D, the SVP and DVP in the inner ring and outer ring were positively correlated with SE ( P<0.05). When the SE was higher than -3.00 D, except for the DVP in the inner ring region, the other parameters were negatively correlated with SE ( P<0.05). There were significant differences in retinal thickness of the inner ring and outer ring ( F=5.47, 16.36; P<0.05), and no significant difference in the macular central fovea among the emmetropia, low and moderate myopia groups ( F=2.16, P>0.05). By using univariate and multivariate linear regression analyses, the retinal thickness in the inner ring and outer ring were negatively correlated with SE ( β =1.99, 3.05; P<0.05). However, no correlation was found between retinal thickness and SE in the macular central fovea ( β=-1.65, P>0.05). Conclusions:In school-age children with SE between +0.50 D and -6.00 D, the retinal capillaries density of the macular central fovea gradually increase, and increase first and then decrease in the inner ring and outer ring with increasing SE. The retinal thickness of inner ring and outer ring gradually decrease and not change significantly in the macular central fovea.

Objective:To compare the clinical efficacy and safety of 0.01% and 0.02% atropine eye drops on myopia development in adolescents.Methods:A randomized controlled double-blind study was carried out.Two hundred and eighty myopic adolescents (280 eyes) with spherical equivalent (SE) from -1.25 to -6.0 D were enrolled in The First Affiliated Hospital of Zhengzhou University from June 2016 to June 2017.All the subjects wore full-correction single vision spectacle lenses before topical administration of atropine eye drops.The subjects were randomly divided into 0.01% atropine group (142 eyes) and 0.02% atropine group (138 eyes) according to the random number table method.Atropine 0.01% or 0.02% eye drops was topically used in the test eye once per night according to grouping, and the related parameters of the right eyes were collected for data analysis.The subjects were followed up at the 1st, 4th, 8th and 12th month following administration.The SE was measured with an autorefractor to evaluate the refractive change.The anterior chamber depth, corneal curvature and axial length (AL) were measured with an IOLMaster.The adverse responses of atropine eye drops were investigated via a questionnaire.This study protocol adhered to the Declaration of Helsinki and was approved by an Ethics Committee of The First Affiliated Hospital of Zhengzhou University (No.2016-35). Written informed consent was obtained from subjects and their guardian prior to entering the cohort.Results:The follow-up rate of 0.01% atropine group was 83.8%, and the follow-up rate of 0.02% atropine group was 84.8% at the end of following-up.SE and AL increased by (-0.47±0.32)D and (0.37±0.20)mm in 0.01% atropine group, and (-0.38±0.35)D and (0.30±0.17)mm in 0.02% atropine groups during the following-up, respectively, showing statistically significant differences between two groups ( P=0.040, 0.004). After adjusting age, body mass index and baseline SE, the analysis by generalized additive mixed model showed that the increase rate of SE was -0.039 D/month and -0.032 D/month in 0.01% and 0.02% atropine group, respectively ( Pinteraction=0.041). After adjusting age, body mass index and baseline AL, the analysis of mixed effect model showed that the increase rate of AL was 0.031 mm/month and 0.025 mm/month in 0.01% and 0.02% atropine group, respectively ( Pinteraction=0.032). In 0.01% and 0.02% atropine groups, 32 cases (26.9%) and 33 cases (28.2%) occurred photophobia from 1st to 4th week during administration, and 7 cases (5.9%) and 7 cases (6.0%) appeared near-vision blur from 2nd to 4th week.Allergic response occurred in 0.01% atropine group at 1 month of treatment, and the symptom disappeared after interruption of the medication for two days. Conclusions:The incidence of adverse resoponses of 0.01% and 0.02% atropine eye drops is similar.Atropine 0.02% eye drops is more effective in controlling myopia progression.

Objective:To observe the safety and efficacy of 0.01% atropine eye drops in the prevention of myopia onset in schoolchildren.Methods:A randomized double-blind controlled study was conducted.Sixty Chinese Han children (60 eyes) with binocular spherical equivalent (SE) between + 0.50 D and -0.75 D (pre-myopia) by cycloplegic autorefraction treated in The First Affiliated Hospital of Zhengzhou University were enrolled from July to October 2020.Aged 6-12 years old, the children were divided into 0.01% atropine group and control group according to a random number table, with 30 cases (30 eyes) in each group.The children were given one drop of 0.01% atropine or placebo eye drops in both eyes once a night.The SE, axial length (AL), accommodative amplitude and pupil diameter were compared before and after 3-month, 6-month of treatment between the two groups.Discomforts were recorded.This study adhered to the Declaration of Helsinki.The study protocol was approved by an Ethics Committee of The First Affiliated Hospital of Zhengzhou University (No.2020-KY-286). Written informed consent was obtained from guardian of each subject.Results:After treatment, 26 and 25 subjects completed the 6-month follow-up in 0.01% atropine group and control group, respectively, among which 3 subjects in 0.01% atropine group accounting for 11.5% and 9 in control group accounting for 36.0% developed myopia, showing a statistically significant difference ( χ2=4.238, P=0.040). There were significant differences in the overall comparison of SE and AL at different time points between before and after treatment ( Ftime=10.981, 81.854; both at P<0.001). At 3 and 6 months after treatment, there were significant increases in the SE and AL of control group and AL of 0.01% atropine group compared with respective baseline values (all at P<0.05). There was no significant difference in SE at 3 and 6 months after treatment compared with baseline SE in 0.01% atropine group (both at P>0.05). At 6 months after treatment, the change in SE in 0.01% atropine group was (-0.15±0.26)D, which was significantly less than (-0.34±0.35)D in control group, and the change in AL in 0.01% atropine group was (0.17±0.11)mm, Which was significantly shorter than (0.28±0.14)mm in control group, with significant differences between them ( t=2.207, P=0.032; t=3.127, P=0.003). There were significant differences in pupil diameter at different time points between before and after treatment ( Ftime=2.263, P=0.032). At 3 and 6 months after treatment, the pupil diameter was increased in comparison with baseline in 0.01% atropine group (both at P<0.05). There were significant differences in accommodative amplitude at different time points between before and after treatment in the two groups ( Fgroup=0.882, P=0.042; Ftime=0.337, P=0.033). The accommodative amplitude at 3 and 6 months after treatment were decreased in comparison with baseline in 0.01% atropine group and control group at corresponding time points (all at P<0.05). Within a month after treatment, photophobia in bright sunlight occurred in 5 cases in 0.01% atropine group, accounting for 16.7%(5/30), and 2 cases in control group, accounting for 6.7%(2/30), showing no significant difference ( χ2=0.647, P=0.421). No near-vision blur and other uncomfortable symptoms was found in the two groups. Conclusions:After 6-month application of 0.01% atropine eye drops, the prevalence of myopia in pre-myopia schoolchildren decreases and the changing rate of SE and AL slows down.The accommodative amplitude is slightly reduced and pupil diameter is slightly increased, with no obvious effects on study and life.