ABSTRACT
Objective To systematically evaluate the changes in axial length and treatment zone diameter among my-opic patients wearing orthokeratology lenses with different back optic zone diameters.Methods A comprehensive litera-ture search was conducted on PubMed,Embase,the Cochrane Library,Web of Science,Wangfang Med Online and CNKI databases in both Chinese and English to identify randomized controlled trials or controlled trials investigating orthokeratol-ogy lenses with varying back optical zone diameters.The literature was thoroughly reviewed by two researchers,who ex-tracted relevant data and conducted a methodological quality evaluation.Finally,meta-analysis was performed using Rev-Man 5.3 software.In all the included studies,orthokeratology lenses with a conventional back optic zone diameter were taken as the control group,while orthokeratology lenses with a reduced back optic zone diameter were utilized as the ex-perimental group.Results Eight studies involving 437 patients(459 eyes)with myopia were included.The results of me-ta-analysis showed that the axial length changes in the experimental group were significantly lower than those of the control group after wearing orthokeratology lenses for 6 months and 12 months(6 months:MD=-0.09,95％CI:-0.10 to-0.07,Z=10.50,P＜0.05;12 months:MD=-0.11,95％CI:-0.13 to-0.09,Z=12.19,P＜0.05);significant differ-ences in treatment zone diameter were observed between the experimental and control groups at various time points follow-ing orthokeratology lens wearing(MD=-0.82,95％CI:-1.04 to-0.59,Z=7.03,P＜0.05).Conclusion Orthoker-atology lenses designed with smaller back optical zone diameters can effectively delay axial length growth in myopic pa-tients,but their long-term efficacy needs to be confirmed.
ABSTRACT
AIM:To discuss the efficacy and safety of orthokeratology with reducing back optic zone diameter(5mm-BOZD)compared with conventional back optic zone diameter(6mm-BOZD)in the treatment of adolescent myopia.METHODS: A prospective randomized controlled trial was performed. There were 100 cases with 100 eyes of adolescent myopia(all right eye data were taken)selected from April 2016 to January 2019, the spherical degree was -1.00--5.00D. Then they were randomly divided into the two groups. The experimental group wore 5mm-BOZD orthokeratology, and the control group wore 6mm-BOZD orthokeratology. Their axis length(AL), spherical equivalent(SE), relative peripheral refraction(RPR), best corrected visual acuity(BCVA), uncorrected near visual acuity(NVA), Efron grading was applied to record the anterior segment of the eyes, corneal hysteresis(CH), corneal resistance factor(CRF), corneal-compensated intraocular pressure(IOPcc), average noninvasive Keratograph tear breakup time(NIKBUTav)and higher order aberration(RMSh) were compared between the two groups during the 1a treatment period.RESULTS: After 1a of treatment, the AL in experimental group increased 0.05±0.05mm,while it increased 0.15±0.05mm(t=-8.949, P<0.001)in control group. The SE in experimental group increased -0.18±0.27D,while it increased-0.42±0.35D(t=3.609, P=0.001)in control group. There were statistical differences in RPR changes at N30°, N20° and T30°sites between the two groups(P<0.05). There were no statistical differences in BCVA,NVA,Efron grade,CH,CRF,IOPcc,NIKBUTav and RMSh between the two groups(P>0.05).CONCLUSION:Reducing back optic zone diameter orthokeratology can correct adolescent myopia safely and more effectively during the observation period.