| Part I Comparison retarding effect of the 4 most commonly used optical correction methods in clinical practice for juvenile myopia ObjectiveTo study the changes of diopter and axial length of myopia in adolescents after two years of wearing orthokeratology,rigid gas-permeable contact lenses(RGP),gradient changing multi-focus frame glasses?and single light full-correction frame glasses,at the same time related factors of the changes were analyzed,and to evaluate the retarding effect of different lenses on juvenile myopia progression.MethodsProspective clinical contrast study.188 patients with myopia who underwent ophthalmoscopy in the Optometry Department of the First Affiliated Hospital of Zhengzhou University were collected from January 2013 to December 2015.According to the wishes of the guardian and the patient,give 50 cases(99 eyes)with orthokeratology,47 cases(92 eyes)with RGP,41 cases(82 eyes)with gradual multi-focus frame glasses and 50 cases(100 eyes)with monocular corrective frame glasses respectively.ALL subjects were followed up for 2 years.The spherical degree(SD),cylindrical degree(CD),spherical equivalent(SE)and axial length(AL)of four groups of myopic patients were recorded before and 2 years after wearing glasses.In order to measure myopic diopter and axial length more accurately,the orthokeratology group and the RGP group were required to stop wearing glassess for at least 30 days after 2 years for re-examination.Variance analysis,SNK-q test,paired t test,chi-square test and Person level linear correlation analysis were used to analyze the data.ResultsBefore wearing glasses,there were no significant differences in age,refractive status and axial length among the groups(all P > 0.05).49 cases(97 eyes)in orthokeratology group,46 cases(91 eyes)in RGP group,41 cases(82 eyes)in gradient group and 48 cases(96 eyes)in frame group were followed up for one year.AL in all four groups increased(F = 201.021,P < 0.01),they were as follows: orthokeratology group:(0.17±0.21)mm,RGP group(0.29±0.19)mm,gradient lens group(0.24±0.30)mm,frame lens group(0.28±0.22)mm.Orthokeratology group had the least increase(q = 16.072,16.541,17.650,all P < 0.01),and the other three groups had no significant difference in AL changing.Forty-three cases(86 eyes)in orthokeratology group,40 cases(79 eyes)in RGP group,40 cases(80 eyes)in gradient group and 45 cases(90 eyes)in frame group were followed up for 2 years.After 2 years of wearing,the AL and SE of the four groups increased(F = 295.371,161.211,P < 0.01).The increase of AL and SE were(0.35±0.10)mm and(-0.79±0.63)D in orthokeratology group,(0.56±0.37)mm and(-1.60±0.58)D in RGP group,(0.46±0.22)mm and(-1.21±0.61)D in gradient lens group,(0.58±0.13)mm and(-1.70±0.62)D in frame lens group,respectively.The addition of orthokeratology group was the least,followed by gradual mirror group.There was no significant difference in the other two groups.The increase of SE in orthokeratology group was negatively correlated with basal SE and SD(r=-0.406,-0.424,all P < 0.01).After wearing glasses,the UCVA of the orthokeratology group increased significantly compared with that before wearing(F = 453.221,P < 0.01).ConclusionsIn the 4 most commonly used optical correction methods in clinical practice for juvenile myopia,The retarding effect of orthokeratology is the best,followed by gradual multi-focus frame glasses.There was no significant difference between RGP and single focus full-correction frame glasses.Orthokeratology is more effective to higher degree of myopia in retarding effort.At the same time,wearing orthokeratology can significantly improve the uncorrected visual acuity of myopia patients.Part II Study on reversibility and safety of orthokeratologyObjective To study on reversibility of orthokeratology and complications at different stages of wearing.Methods Prospective clinical contrast study.Ninety patients(179 eyes)wearing orthokeratology glasses in the Optometry Department of the First Affiliated Hospital of Zhengzhou University from January 2012 to December 2015 were selected according to the selection criteria.All the patients underwent routine ophthalmology examination and special examination of wearing orthokeratology glasses before wearing them.ALL subjects were followed up for 2 years.After wearing 2 years,ALL subjects were required to stop wearing glassess for at least 30 days for re-examination.Myopic spherical degree(SD),cylindrical degree(CD),spherical equivalent(SE),corneal mean astigmatism(Sim K),corneal flat axis and steep axis diopter,thinnest central corneal thickness(CCT),corneal endothelial cell density,corneal endothelial hexagonal cell ratio,intraocular pressure(IOP)and corneal conjunctival complications were recorded before and 2 years after wearing.Paired t test,Pearson and linear regression analysis were used to analyze the data.Results A total of 78 cases(86.7%)were followed up for 2 years.The values of CD and Sim K before wearing were(-0.71±0.59)D and(-1.29±0.50)D,respectively,and(-1.02±0.46)D and(-1.56±0.48)D after 2 years,there was a slight increase compare to the initial wearing time,which was-0.31 D and-0.27 D,respectively.The difference was statistically significant(t = 5.904,5.541,P < 0.05).The flat K value of cornea was(42.96 ± 1.14)D,2 years later(42.66 ± 1.52)D,which was slightly lower than that before wearing(t = 2.401,P < 0.05).The steep K value of cornea was(44.30 ± 1.61)D,2 years later(44.26 + 1.35)D,which had no significant difference(t = 0.161 P > 0.05).The thinnest CCT was(549.26±29.04)um,2 years later(544.41±32.27)um,and there was no significant difference between the two(t = 0.794,P > 0.05).The density of corneal endothelial cells was(3252.26±312.34)mm2,2 years later(3243.11±287.41)mm2,and there was no significant difference between the two(t = 0.290,P > 0.05).The ratio of hexagonal cells in corneal endothelial cells was(66.13±13.21)%,2 years later(66.01±10.92)%,there was no significant difference between the two(t=0.087,P>0.05).The IOP before wearing was(15.06±3.61)mm Hg,and after 2 years was(15.28±2.01)mm Hg,there was no significant difference between the two(t = 0.126,P > 0.05).Complications of cornea and conjunctiva: of the 90 wearers,89(98.9%)had a sense of foreign body,14(15.6%)had reactive conjunctival congestion,4(4.4%)had double glare,and the symptoms disappeared after 1-2 weeks of adaptation.During follow-up,corneal staining was the most common,25 cases(27.8%)in this study were found,including 23 cases of mild staining below grade II(92%)and only 2 cases of grade III(8%),without one case of grade IV.Followed by mild chronic conjunctival congestion,16 cases(17.8%).There were 5 cases(5.6%)with duplication,2 cases(2.2%)with corneal indentation,and 1 case with aseptic corneal infiltration.No serious complications such as corneal infection were found during the 2-year follow-up.Conclusions Even stop wearing for at least 30 days,after wearing orthokeratology for 2 years,the changes of corneal flat K were still slightly flattened and the astigmatism were slightly increased,indicating that the effect of wearing orthokeratology on the cornea did not disappear completely for stoping at least 30 days,suggesting that it may take a longer time for the effect to disappear completely,or it may also be that the effect of long-term wearing orthokeratology is not completely reversible on the cornea.In this study,no significant statistical changes were observed except for a slight flattening of the cornea K and a slight increase in astigmatism.At the same time,no serious corneal and conjunctival complications occurred after wearing orthokeratology for 2 years,indicating that the safety of wearing orthokeratology in adolescents is relatively high.Part III The retarding effect and safety of night wearing orthokeratology combined with daytime frame glasses for high myopiaObjective To investigate the retarding effect and safety of night-wearing orthokeratology combined with daytime frame glasses for high myopiaon in adolescents.Methods 30 patients(aged 8-15 years)with high myopia(equivalent sphericity?-7.0D)and myopic sphericity?-6.0D)in the Optometry Department of the First Affiliated Hospital of Zhengzhou University were collected from January 2013 to December 2015.After full communication with the guardian and patient and signing informed consent form,the patients were given night orthokeratology(-6.00D)combined with daytime residual diopter frame lens correction(combined group).At the same time,30 cases(60 eyes)of the same age,myopia degree and sex composition were collected as the control group.The daytime frame lens were given to the combined group when the residual diopter was stable after one month of wearing orthokeratology.All subjects were followed up for 2 years,and after 2 years all subjects were required to stop wearing glassess for at least 30 days for re-examination.The spherical degree(SD),cylindrical degree(CD),spherical equivalent(SE)and axial length(AL)were recorded before and 2 years after wearing.Various conjunctival complications occurred during the initial wearing and wearing process were aslo recorded.Results 25 cases(83.3%)of the combined group and 27 cases(90%)of the control group fishnished the 1 year following-up.The increment of axial AL in the two groups was(0.10± 0.41)mm and(0.25± 0.36)mm respectively.The difference was statistically significant(t =-5.01,P < 0.01).24 cases(80%)of the combined group and 25 cases(83.3%)of the control group fishnished the 2 year following-up.There was no statistically significant difference between the two groups in basic data of whom completed 2 years follow-up(table 3-2,P > 0.05).Before wearing,the equivalent sphericity(SE)and axial length(AL)of myopia in the combined group were(-7.70±1.83)D and(26.11 ± 0.49)mm,and the SE and AL of the control group were(-7.55±2.16)D and(26.06 ± 0.73)mm respectively.After wearing for 2 years,SE and AL in the combined group were(-8.25±2.04)D and(26.32 ± 0.62)mm,while SE and AL in the control group were(-9.08±1.69)D and(26.53 ± 1.04)mm,respectively.The increments of SE and AL in the combined group were(-0.55±0.84)D and((0.21±0.57)mm,and those in the control group were(-1.53±1.18)D and((0.47±0.50)mm,respectively.There was significant difference in the increase of SE and AL between the two groups(t =-4.68,-3.97,all P<0.01).No severe keratoconjunctival complications were found in the combined group during the 2 year follow-up.Conclusions The retarding effect of night wearing orthokeratology combined with daytime frame glasses for high myopia of adolescents was very effective,wearing two years effectively delayed myopia degree increased by 64%,effectively delayed axial length growth by 55%.No serious complications were found in the combined group during the 2 year follow-up. |
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