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AIM: To investigate the alterations in corneal aberration and relative refractive power following the reduction of back optic zone diameters(BOZD)of orthokeratology lenses.METHODS: Myopic children aged 8-12 years, deemed suitable and willing to wear orthokeratology lenses, were randomly allocated to wear lenses with a 6.0 mm BOZD or a 5.0 mm BOZD. Data collection included changes in higher-order aberrations, relative refractive power and the treatment zone diameter of the two groups after wearing lenses for 1 d, 1 wk, 1, and 3 mo. The correlation of increase in corneal higher-order aberrations with refractive power was analyzed.RESULTS: The increases in total higher-order aberrations, spherical aberrations and coma aberrations varied over time following lens wear(all P0.05). A significant difference was observed in the increment of spherical aberrations in the 5 mm range between the two groups of patients, which varied over time(Ftime=40.179, Ptime

AIM: To compare the progression of myopia in children wearing orthokeratology lenses combined with low-concentration atropine before and after drug withdrawal, to determine the rebound effect of drug withdrawal in orthokeratology lens wearers, and to analyze its causes based on changes in pupil diameter.METHODS:A prospective case-control study was conducted to collect 80 children with myopia who were treated with orthokeratology lenses combined with 0.01% atropine ophthalmic gel at the Xi'an No.1 Hospital from January to June 2022. One year later, they were divided into a drug withdrawal group(Group A, 40 cases)and a continuous medication group(Group B, 40 cases)based on whether they stopped taking the medication. The progression of myopia before and after drug withdrawal was observed by analyzing changes in axial length(AL)and spherical equivalent(SE)in the group A within 1 a before and after drug withdrawal. The changes in AL, pupil diameter(PD), and SE were compared between the group A and group B within 2 a, and the correlation between PD and AL growth was analyzed.RESULTS:In the group A, the AL increased by 0.17±0.23 and 0.29±0.18 mm at 0.5 and 1 a after drug withdrawal, respectively, which were both greater than before drug withdrawal(t=5.318, 2.983, both P0.05). There were no statistically significant differences in AL and PD between the group A and group B at baseline, 0.5 and 1 a during combined medication(all P>0.05). At 1.5 a, the AL growth of the group A was greater than that of the group B(0.32±0.27 mm vs 0.26±0.20 mm, t=7.363, P

AIM: To observe the effect of orthokeratology combined with vision therapy and Clouclip(OCVTC)on myopic children with dysfunctional accommodation.METHODS: A prospective, non-randomized control study was conducted on 99 myopic children(99 eyes)with dysfunctional accommodation at the optometry center were of Langfang Aier Eye Hospital from April 2022 to January 2023. and they selected and divided into three groups: 39 children in OCVTC group, 30 in orthokeratology(Ortho-k)group, and 30 in single vision spectacle lens(SVL)group. The OCVTC group received office-based accommodative therapy for 3 mo and home reinforcement for 3 mo, and Clouclip was used in the first 3 wk to monitor and remind children of eye habits; the accommodative amplitudes and facility were measured at baseline, 3, 6, and 12 mo after treatment.RESULTS: The OCVTC group showed significantly better improvement in accommodative amplitude compared with both the Ortho-k group and the SVL group(all P

AIM:To explore the effect of the peripheral defocus spectacle lenses and orthokeratology(OK)on the control of myopia progression and the impact on vision related quality of life in children and adolescents.METHODS:Prospective study. A total of 237 children initially diagnosed with myopia in the ophthalmology department of Huzhou Central Hospital from January 2021 to January 2022 were selected and divided into two groups according to different correction methods: peripheral defocus spectacle lenses group(105 cases, 105 eyes)and OK lens group(132 cases, 132 eyes). The Vision Related Quality of Life Questionnaire for Primary and Secondary School Students was used to follow up the both groups of myopic children, and the best corrected visual acuity(BCVA), spherical equivalent(SE), and axial length(AL)were recorded at the first visit and 1 a of follow-up.RESULTS:After wearing lenses for 1 a, both the peripheral defocus spectacle lenses group and OK lens group showed an increase in SE and AL, but there was no statistical difference between two groups(P>0.05). The changes in SE and AL in the peripheral defocus spectacle lenses group were greater than those in the OK lens group(all P=0.001). After 1 a of follow-up, in the emotional dimension scores, the peripheral defocus spectacle lenses group of children's vision-related quality of life scales scored higher than in the OK lens group(P

Orthokeratology(OK lens)is considered to be one of the most effective optical treatments for myopia control. Its safety and efficiency in controlling myopia progression have been rigorously verified by numerous studies. As the materials and technology of lens have evolved, orthokeratology has demonstrated remarkable results in myopia control, particularly among children with moderate myopia. Not only does orthokeratology effectively decelerate axial length growth, but it also positively impacts regulatory function. However, it is crucial to acknowledge that there may be some compromise in visual quality. Therefore, the perfect balance between lens design and patient adaptability must be considered to maintain visual clarity and optimize myopia control. While orthokeratology has made significant strides in myopia control, there are still lingering questions about its long-term stability, the precise impact of visual quality, and the others. Furthermore, combining orthokeratology with other strategies offers better effects. Nevertheless, further clinical data is needed to estimate the rebound effects of withdrawal. This review summarizes the technology, safety, efficacy and combination therapy of orthokeratology on myopia control.

AIM: To assess the gap between the peak of the base curve to the surface of the cornea, as well as examines the correlation between the thickness of the tear film and the fitting of the orthokeratology lens through optical coherence tomography(OCT), providing an intuitive and quantitative clinical evaluation method for the fitting of the orthokeratology lens.METHODS: Myopia patients who fitted orthokeratology at our hospital from January to December 2023 were included. Examinations, including naked vision, slit lamp, non-contact intraocular pressure, ocular fundus, eye position, corneal diameter, corneal topography, tear film rupture time, optometry, etc., were performed on all patients before fitting. The trial lens parameter was selected according to the examination results, and fluorescein staining was performed to evaluate lens fitting state after patients adapted to wearing glasses. According to the performance of fluorescein staining, the inspected eyes are divided into three groups: lens loose group, lens fitting group, and lens tight group. In addition, the tear film thickness of three groups of subjects was measured by OCT, and the differences between the three groups of data were evaluated.RESULTS: A total of 49 myopic patients(77 eyes)were included. The average sphere degree was -3.10±1.25 D, the average cylinder degree was -0.43(-0.75, 0)D, the average horizontal keratometry(HK)was 42.48±0.81 D, and vertical keratometry(VK)was 42.98(42.25, 43.50)D. There were 21 cases(34 eyes)in the lens fitting group, with 13 cases of bilateral eyes, 8 cases of one eye, 14 cases(22 eyes)in the lens loose group, with 8 cases of bilateral eyes, 6 cases of one eye, and 14 cases(21 eyes)in the lens tight group, with 7 cases of bilateral eyes, 7 cases of one eye. There was no statistical difference in the main basic data of the subjects in the three groups(all P>0.05). OCT showed that the tear film thickness of the lens fitting group, the lens loose group, and the lens tight group was 231.18(219.0, 243.0), 220.41(214.0, 224.3), and 249.00(241.5, 258.0)μm, respectively, and there was statistical significance in the thickness among the three groups(P

AIM: To compare the clinical effectiveness of using multifocal defocus spectacle lenses, orthokeratology lenses, and single-vision spectacle lenses in patients with myopia and small-angle intermittent exotropia.METHODS: This retrospective study included 150 patients aged 8-15 years with basic intermittent exotropia, strabismus of -10△ to -20△ prism diopters(D)(block lenses), and spherical equivalents of -1.00 to -5.50 D, who visited our hospital from June 2021 to September 2022. They were selected and divided into three groups on a voluntary basis: the HAL group(50 patients with multifocal myopia defocus spectacle lenses), the OK lens group(50 patients with nighttime orthokeratology lenses), and the SVL group(50 patients with regular single-vision spectacle lenses). After wearing the lenses consistently, changes in axial length, prism diopters with the naked eye and lenses(prism at 33 cm), positive fusional vergence of blurred points, and near stereopsis were observed and compared among groups before intervention and after 1 a. The Newcastle control score(NCS)was used to evaluate the eye position control ability of the patients in the three groups.RESULTS: Before the intervention, the axial lengths of the HAL, OK lens, and SVL groups were 24.83±0.91, 24.93±0.97, and 24.98±0.68 mm, respectively(P>0.05). After 1 a, the axial lengths of the three groups were 25.02±0.90, 25.18±0.97, and 25.45±0.65, respectively(P0.05). After 1 year, near stereopsis in the groups were 76.00″±20.40″, 81.20″±18.91″, and 100.60″±51.41″, respectively(P0.05), and it was 17.10±2.02, 13.12±1.41, and 13.26±2.45, respectively, after 1 a(P

AIM:To investigate the effect of diquafosol sodium(SD)eye drops combined with sodium hyaluronate eye drops on improving tear film stability after wearing orthokeratology lenses.METHODS:Prospective study. A total of 82 patients(82 right eyes)who were recruited from the outpatient department of Anhui Aier Eye Hospital from March to August 2022. Participants were assigned to three groups: sodium hyaluronate(SH)group(30 eyes), SD group(24 eyes), and sodium diquafosol combined with sodium hyaluronate(CG)group(28 eyes)according to random number table method. All groups wore the same brand of orthokeratology lens. Non-invasive tear breakup time(NIBUT), non-invasive tear meniscus height(NITMH)and lipid layer thickness were examined before treatment, and after wearing orthokeratology lens for 1 d, 1 wk, and 1 mo. Corneal spot staining was also recorded.RESULTS:The NITMH and NIBUT of CG group and the SD group at 1 mo after treatment were higher than those before wearing lenses(both P0.05). The incidence of corneal staining did not differ significantly among the groups(P>0.05).CONCLUSION:The combination of diquafosol sodium and sodium hyaluronate eye drops demonstrates a superior effect in improving NIBUT and NITMH after wearing orthokeratology lenses for 1 mo, effectively enhancing tear film stability in patients wearing orthokeratology lenses.

AIM: To compare the changes in axial length of myopic patients of different ages after wearing orthokeratology lenses with increased compression factor(ICF)or conventional compression factor(CCF)for 2 a.METHODS: Retrospective study. A total of 141 myopia patients(141 right eyes)aged 8 to 15 years who fitted with orthokeratology lenses in the General Hospital of Foshan Aier Eye Hospital from July 2020 to July 2021 were continuously included. They were divided into the CCF group(70 cases, 70 eyes)and the ICF group(71 cases, 71 eyes). The patients in the CCF group were fitted with orthokeratology lens of 0.75 DS CCF, while patients in the ICF group were fitted with orthokeratology lens of 1.25 D ICF. Taking 12 years old as a boundary, these two groups were divided into 8-11 years old and 12-15 years old group. The uncorrected visual acuity(UCVA), horizontal corneal curvature(K1)and corneal staining were recorded for all subjects after wearing lenses for 1 d, 1 wk, 1, 6 mo, 1 and 2 a. The axial length(AL)was recorded after wearing lenses for 6 mo, 1 and 2 a, and the complication and corneal epithelial staining were observed during lens wearing.RESULTS:The improvement of UCVA in the ICF group was faster than that in the CCF group, which were statistical significant after wearing lenses for 1 d, 1 wk and 1 mo, respectively(all P0.05); K1 of the ICF group decreased faster than that of the CCF group, and there were statistical significance at 1 d, 1 wk, and 1 mo after wearing lenses(all P0.05). The axial length growth of patients aged 8-11 years old in the ICF group and CCF group was 0.35±0.17 and 0.48±0.26 mm, respectively(P=0.010), after wearing lenses for 2 a, and the axial length growth of patients aged 12-15 years old in the ICF group and CCF group was 0.16±0.15 and 0.31±0.29 mm, respectively(P=0.011). During the follow-up period, corneal spotting occurred in 6 eyes(8.5%)in the ICF group, and 7 eyes(10%)in the CCF group(P>0.05), all of which were grade 1 spotting.CONCLUSION:Wearing ICF orthokeratology lens is more effective than wearing CCF lenses in controlling the growth of axial length, with faster shaping and more obvious improvement in UCVA, especially for the prevention of high myopia in children under 12 years. Therefore, young children can give priority to wearing lenses that increase the compression factor, and for children over 12 years old, the compression factor of the lens can be selectively increased according to the wearer's eye habits, health status of ocular surface and visual function.

AIM: To compare the control effectiveness among orthokeratology(OK), defocus incorporated multiple segments(DIMS)and single-vision spectacles(SVS)in adolescent myopia.METHODS: Retrospective study. A total of 111 myopic patients(221 eyes)in Ningbo Aier Guangming Eye Hospital from April 2020 to March 2021 were selected, and they were grouped into OK group(42 cases, 83 eyes), DIMS group(30 cases, 60 eyes)and SVS group(39 cases, 78 eyes)according to the method in myopia correction. All patients were followed up for 24mo, and the changes of axial length and spherical equivalent before and after treatment were recorded and analyzed.RESULTS: After 6, 12, 18 and 24mo of treatment, the axial length grew in three groups of patients, and the growth of axial length in SVS group was higher than that in OK group and DIMS group(P

AIM: To observe the effect of eccentricity of the optical treatment zone on retinal defocus after wearing orthokeratology lens for 12mo.METHODS: In this case-control study, a total of 120 myopic patients(120 eyes)who completed the fitting in our hospital from March 2021 to September 2021 and insisted on wearing orthokeratology lenses for 12mo were selected. According to the eccentricity after wearing lenses for 12mo, they were divided into the low eccentricity group(

AIM: To investigate the efficacy and safety of orthokeratology combined with 0.01% atropine solution in adolescents with myopia.METHODS: A total of 100 adolescent myopic patients(100 right eyes)who received treatment at the Department of Ophthalmology, People's Hospital of Hengshui from January 2019 to January 2022 were enrolled. All patients were divided into two groups based on the patient's preferences and randomized controlled principles: control group(n=50)and experimental group(n=50). Patients in the control group received orthokeratology alone, while those in the experimental group received orthokeratology in combination with 0.01% atropine solution. Treatment data for both groups were collected at 1, 3, 6, 9 and 12mo after treatment. The observed indicators included refraction, corneal curvature, axial length(AL), central corneal thickness(CCT), pupil diameter(PD), lipid layer thickness(LLT), break-up Time(BUT), root-mean-square of higher-order aberration(RMSh), subfoveal choroidal thickness(SFCT), corneal endothelial cell density(CD), and hexagonal cell ratio(HEX). The adverse reactions experienced during follow-up period were also observed and recorded.RESULTS: After 12mo of treatment, the refraction, corneal curvature, and AL in the experimental group were -2.42±0.17D, 38.89±1.18D and 25.44±0.23mm, respectively, which were significantly better than the control group(-2.56±0.19D, 40.12±1.65D and 25.54±0.19 mm, all P0.05). The main adverse reactions of both groups during treatment period were photophobia, anaphylaxis, conjunctivitis and keratitis, but there was no significant difference between the two groups(all P>0.05).CONCLUSION: Compared to orthokeratology alone, the combination of orthokeratology and 0.01% atropine solution effectively prevents and improves the development of adolescent myopia without increasing the incidence of adverse reactions.

AIM: To compare the control effects between toric-designed orthokeratology and spherical orthokeratology on adolescents with moderate-to-low myopia.METHODS: The clinical data of 169 adolescents(290 eyes)with moderate-to-low myopia in Jiayuan Outpatient Department of Shanghai Demu Ophthalmology from July 2020 to June 2021 were analyzed retrospectively. The patients were divided into toric group and spherical group according to the type of orthokeratology, with 81 cases(135 eyes)and 88 cases(155 eyes)respectively. The changes of visual acuity and ocular axis before and after treatment were recorded to evaluate the therapeutic effect.RESULTS: The uncorrected visual acuity of both groups significantly improved at 1a after treatment(P0.05).CONCLUSION: Both toric-designed orthokeratology and spherical orthokeratology can improve the uncorrected visual acuity of adolescents with low-to-moderate myopia, and there is no significant difference in controlling effect on myopia.

AIM: To investigate the influencing factors of punctate staining of corneal epithelium in patients wearing orthokeratology.METHOD: Data of 280 cases wearing orthokeratology were collected, including 185 cases in the group without corneal staining and 95 cases in the group with corneal staining. All patients were examined for general distant vision, intraocular pressure, slit lamp, fundus examination after mydriasis, comprehensive optometry, corneal topography, corneal thickness, corneal endothelium, axial length, Schirmer Ⅰtest(SⅠt)before wearing lenses, meibomian gland loss score before wearing lenses, eccentric distance, interleukin-2(IL-2)in tear, tumor necrosis factor-α(TNF-α)content analysis and so on. The influencing factors of corneal epithelium punctate staining were analyzed by univariate and multivariate Logistic regression.RESULTS: There were significant differences in preoperative diopter, preoperative meibomian gland deletion score, IL-2, TNF-α and lens sediment between the two groups(all P

AIM:To explore the influence factors of the treatment zone diameter(TZD)and its correlation with axial length growth(ALG)after Paragon CRT orthokeratology.METHODS: Retrospective clinical study. The data of 226 myopic patients(226 eyes)wearing Paragon CRT orthokeratology from April 2020 to September 2022 were collect. The correlated factors of TZD after wearing lens for 1mo, and the relationship between the overlapping treatment zone/ pupil area ratio and the ALG after wearing lens for 1a were analyzed.RESULTS: After wearing lens for 1mo, the TZD was negatively correlated with central corneal thickness(CCT)and positively correlated with the flat corneal eccentricity. After wearing lens for 1a, the ALG of the small TZD group(0.25±0.18mm)was significantly smaller than that of the large TZD group(0.34±0.24mm, P=0.002), and the ALG of the small area ratio group(0.24±0.19mm)was significantly smaller than that of the large area ratio group(0.35±0.23mm,P

AIM: To observe changes in fundus microcirculation of myopic adolescents after wearing orthokeratology by applying optical coherence tomography angiography(OCTA).METHODS: Prospective study. A total of 40 cases(40 eyes)of adolescents with low to moderate myopia who chose orthokeratology to correct visual acuity at our hospital from April 2021 to June 2022 were collected. The uncorrected distant visual acuity and axial length were evaluated at 1, 3 and 6mo before and after wearing orthokeratology, respectively. Furthermore, the changes in superficial vessel density(SVD), deep vessel density(DVD), central retinal thickness(CRT), foveal avascular zone area(FAZ-A), foveal avascular zone perimeter(FAZ-P), retinal nerve fiber layer(RNFL)thickness and radial peripapillary capillaries density(RPCD)were observed by applying OCTA.RESULTS: The uncorrected distant visual acuity was significantly improved at 1, 3 and 6mo after wearing orthokeratology(P0.05). Moreover, there were significant differences in both SVD of fovea quadrant and DVD of fovea and lower quadrant(P0.05).CONCLUSION: Wearing orthokeratology can significantly improve visual acuity and increase local retinal vessel density in the macula in adolescents with low to moderate myopia.

AIM:To observe the changes of choroidal thickness(CT)and axial length(AL)in adolescents with myopic anisometropia before and after orthokeratology(OK lenses)treatment.METHODS: In this retrospective case-control study, 71 myopic participants who insisted on using OK lenses more than 6mo at night from June 2020 to September 2021 in Second People's Hospital of Shenzhen were enrolled. They were divided into three groups, including group A consisted of 31 myopic participants with non-anisometropic myopia with binocular lenses(A1 group: the right eyes, A2 group: the left eyes), group B consisted of 18 bilateral myopic anisometropes(B1 group: the eyes with high degree, B2: the eyes with low degree)and group C consisted of 22 unilateral myopic anisometropes(C1: the eyes with high degree, C2: the eyes with low degree). The length of axis, the CT values of subfoveal(SF)and the superior(S0.5, S1.0, S1.5), inferior(I0.5, I1.0, I1.5), temporal(T0.5, T1.0, T1.5)and nasal(N0.5, N1.0, N1.5)at 0.5, 1.0 and 1.5mm from the fovea before and after wearing lenses at 6mo were measured.RESULTS: After wearing lenses at 6mo, CT of all sites in group A1 was all thickening compared with that before wearing lenses(all P0.05). Among them, the CT at SF, S0.5, S1.0, S1.5, I0.5, I1.0, I1.5, N0.5, N1.0 and N1.5 was thinner than before wearing lenses, but it was not statistically significant. There were differences in all sites of CT in group C1 compared with that before and after wearing lenses(all P0.05).CONCLUSION: For adolescents with myopic anisometropia patients after long-term wearing OK lenses have CT thickening in high degree eyes, but no thickening in low-degree eyes, and even thinning. At the same time, wearing OK lenses can slow axis elongation and reduce interocular anisometropia difference in axis, which is an effective clinical method to control the development of anisometropia.

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, P0.05).CONCLUSION:Reducing back optic zone diameter orthokeratology can correct adolescent myopia safely and more effectively during the observation period.

AIM: To evaluate the changes of amplitude of accommodation(AA)and axial length(AL)undergoing overnight orthokeratology treatment. And to explore the mechanism of orthokeratology on controlling the development of myopia in pre-adolescent. METHODS: Prospective study, 215 pre-adolescent myopia aged 7-14 years old were enrolled in the study from May 2018 to August 2019. Every subject was measured for comprehensive eye examination. And according to the above measurements and the compliance of children and their parents, 113 patients who matched the inclusion criteria accepted treatment of orthokeratology(ortho-k group)and the other 102 subjects were selected to wear spectacle(spectacle group). During regular follow-up visits, AA was measured respectively at pre-wear, 1, 3, 6mo and 1a after orthokeratology. AL was measured at baseline and after 1a. The changes were evaluated and compared between the orthokeratology and spectacle group.RESULTS: After 1a follow-up, 100 eyes of 100 subjects in the ortho-k group completed the follow-up, and 13 eyes of 13 subjects were withdrawn from the study. In the spectacle group, 77 eyes of 77 subjects completed the study, and 25 eyes of 25 subjects were withdrawn. At baseline, the AA of myopia was 13.57±2.47D, the AA after 1, 3 and 6mo, 1a was significantly higher than before(all P

AIM: To observe the control effects of low concentration atropines, orthokeratology, and spectacles on children with myopia in Baotou, and to analyze change rules of myopia-related regulatory parameters for providing bases for myopia preventions and controls.METHODS: We selected 120 children with myopia aged 8-14 years old(240 eyes), treated in Ophthalmology Clinic of the First Affiliated Hospital of Baotou Medical College from June 2018 to December 2018. They were divided into three groups as follows: low concentration atropine group, orthokeratology group, and spectacles group. The accommodative lag, positive relative accommodation, negative relative accommodation, and diopter were followed up at 1, 3, 6, 12mo.RESULTS:During the follow ups of 3, 6, and 12mo. We observed a statistically significant difference in the accommodative lag between the orthokeratology group and low concentration atropine group spectacles group(P

AIM: To investigate the dynamic changes of corneal hysteresis(CH)and corneal resistance factor(CRF)before and after orthokeratology(OK)in children with different degrees of myopia.METHODS: Totally 40 cases(80 eyes)of myopic children treated in our hospital from January 2019 to January 2020 were retrospectively analyzed. The subjects were divided into low-grade group and medium-grade group according to the spherical equivalent(SE)level. They were all treated with night wearing OK glasses. The LogMAR naked eye vision of the children was detected and recorded before and 1wk, 1, 6mo and 1a after wearing glasses. The levels of central corneal thickness(CCT)and axial length(AL)were monitored by ocular a-ultrasound, the SE level was measured by comprehensive optometry, the corneal curvature(K)was measured by corneal topography, the corneal compensated intraocular pressure(IOPcc)level was measured by ORA analyzer, and the values of CH and CRF were calculated at the same time.RESULTS:The naked visual acuity of LogMAR at 1wk, 1, 6mo and 1a after wearing glasses was significantly lower than that before wearing glasses(all P

AIM:To observe the near stereoscopic visual function of adolescents with different degrees of myopic anisometropia after being corrected by spectacles and orthokeratology.METHODS:In this prospective clinical research,220 patients aged 10-20 years old with myopic anisometropia were recruited between March 2017 and December 2018. All the patients were divided into four groups according to the difference of cycloplegic spherical equivalent refractive(SER)error between the two eyes: group of 76 cases without anisometropia(SER error difference less than 1.00D), group of 60 cases with mild anisometropia(SER error difference of 1.00-

AIM: To observe the changes of tear film osmolarity(TFO)and inflammatory cytokines after wearing orthokeratology lens.METHODS: Prospective randomized controlled trial. Totally 79 cases of adolescent myopia(-1.00D to -5.00D)were selected from May 2016 to February 2019. Then they were randomly divided into the experimental group(39 cases)and the control group(40 cases). The experimental group wore orthokeratology lens, and the control group wore frame glasses. Their average noninvasive Keratograph tear breakup time(NIKBUTav), TFO, concentrations of IL-1β, IL-6, TNFα in tear samples were observed for 1a.RESULTS: NIKBUTav and TNFα after wearing orthokeratology lens for 6mo, 1a and stopping wearing for 4wk were different from that pre-wearing orthokeratology lens(P

AIM: To investigate the influence of orthokeratology combined with 0.01% Atropine Sulfate Eye Gel on the recovery of myopia in children and the factors influencing the curative effect of children. METHODS: Totally 200 children with myopia admitted to our hospital in 2017-03/2019-03 were selected. According to the requirements of children and guardians, the observation group(orthokeratology combined with 0.01% Atropine Sulfate Eye Gel)and the control group(only wearing orthokeratology)were selected. Totally 108 cases in the observation group were included in the study, 8 cases were abandoned after 6mo, and 100 cases were finally included to complete the follow-up. 92 cases in the control group were included in the study, 5 cases abandoned after 6mo, and 87 cases completed the follow-up. The patients' best corrected far vision, best corrected near vision, naked eye vision, intraocular pressure, pupil diameter and adjustment amplitude and discomfort symptoms after treatment were collected before and after 6mo.RESULTS: The uncorrected visual acuity of the observation group after treatment was 0.12±0.05, and that of the control group was 0.19±0.07, which were significantly higher than those before treatment(P0.05); the pupil diameter of the observation group after treatment was(7.01±0.66)mm, which was significantly higher than(6.09±0.69)mm before treatment(P0.05). Pearson correlation analysis showed that good myopia control was negatively correlated with age, uncorrected visual acuity and astigmatism before treatment(P

AIM: To observe the changes of relative peripheral refraction(RPR)after wearing orthokeratology(OK)lens, and to explore the relationship between the changes of RPR and the axial length(AL).METHODS: Totally 104 cases of adolescent myopia(-1.00D to -6.00D)were selected from May 2016 to Nov. 2018. Then they were randomly divided into the experimental group and the control group. The experimental group wore OK lens, and the control group wore frame glasses. Their AL, RPR(N30°-T30°)were observed for 1a.RESULTS:The RPR of the experimental group showed myopic drift at each time point after wearing OK lens(P0.05). The RPR of the control group showed an increase in hyperopia. One year later, there were statistical differences in the changes of AL and RPR between the two groups(P

AIM: To investigate the efficacy and safety of orthokeratology combined with 0.01% atropine in controlling low to moderate myopia in adolescents.METHODS: A prospective non-randomized controlled study was conducted among 120 eyes of 120 adolescents with low to moderate myopia. 60 eyes in the control group were treated with orthokeratology, and 60 eyes in the combined group were treated with orthokeratology combined with 0.01% atropine. The best corrected distant visual acuity(BCDVA), best corrected near visual acuity(BCNVA), refraction, axial length, accommodative amplitude, photopic pupil diameter, mesopic pupil diameter, lipid layer thickness(LLT), tear film break up time(BUT)and complications were determined before treatment and at 1a after treatment. RESULTS: There were no significant differences in BCDVA and BCNVA within and between the two groups before and after treatment(P>0.05). After treatment, the spherical equivalents of both groups progressed significantly(P0.05). After treatment, the accommodative amplitude of the combined group decreased significantly, while the photopic and mesopic pupil diameters significantly increased, respectively(P0.05). During the treatment period, there was no difference in the incidence of total adverse reactions between the combined group and the control group(26.7% vs 15.0%, P>0.05). CONCLUSION: Combined treatment with 0.01% atropine and orthokeratology would be a safe and more effective choice of treatment to control the development of myopia in adolescents.

AIM: To study the effect of ocular surface and meibomian gland dysfunction of adolescents before and after wearing overnight orthokeratology, and to explore its effects on adolescent tear film. METHODS: A prospective clinical study was conducted. 55 cases of 8 to 16-year-old adolescents who met the selection criteria from January 2017 to November 2017 were selected for orthokeratology. Before lens wear and after lens wear 1wk, 1mo, 3mo, 6mo, and 12mo were followed up for Ocular Surface Disease Index(OSDI)questionnaire, slit-lamp examination, and Keratograph 5M.RESULTS: During the study period, no patients developed infectious keratitis. The OSDI scores were 7.38±1.71 points, 9.21±1.39 points, 10.19±1.02 points, 10.28±1.18 points, 10.29±1.85 points after wearing at 1wk, 1, 3, 6, and 12mo respectively, which were higher than those before wearing(4.80±1.63 points)were increased, and the difference was statistically significant at different times before and after wearing(PPPP>0.05).There was no significant change in TMH at 1wk, 1, 3, 6, 12mo after wearing, and the difference was not statistically significant(F=2.168, P>0.05). Corneal fluorescein staining scores were 3.51±1.67 points, 3.54±1.62 points, 4.05±1.52 points, 4.14±1.32 points, 4.50±1.43 points, respectively, 1wk after wearing, 1, 3, 6, and 12mo, which were higher than those before wearing(PP>0.05).CONCLUSION: The tear film function in the early period of wearing the orthokeratology is reduced, but it gradually returns to the level before wearing the lens after 6mo, and tends to increase steadily. After wearing the orthokerato-scope, the symptoms of eye discomfort increase and corneal fluorescein stain increased after wearing, no effect on meibomian gland function.

AIM: To observe the changes of binocular eye accommodation function in correcting anisometropia by monocular orthokeratology in anisometropic children, and to explore the mechanism of regulation in the progression of myopia control by orthokeratology.METHODS: It was a prospective self-control study. A total of 22 anisometropic children(44 eyes), aged 8-13 years, who wore an orthokeratology lens in only one eye were enrolled in the outpatient clinic of Hainan Provincial Eye Hospital from September 2016 to September 2018. The eyes with an orthokeratology lens had a mean spherical equivalent refraction of -2.751±1.16 diopter(D), and fellow eyes without a lens had a refraction of -0.10±0.32D. The eyes wearing orthokeratology lens were used as the lens wearing group, and the fellow eyes without a lens were used as non-wearing lens group. During the follow-up period,we measured changes of diopter difference, monocular accommodative amplitude(MAA), monocular accommodative facility(MAF)and accommodative response(AR)before wearing the lens and wearing the lens for 12mo.RESULTS: The monocular accommodative amplitude and monocular accommodative facility of the wearing group before wearing the lens were lower than those of the non-wear group(PPt=3.63, Pt=0.75, P=0.46)compared with the non-wearing group. The monocular accommodative facility 14.63±1.58 cyc/min after wearing the lens for 12mo was higher than that before wearing the lens 9.25±3.38cyc/min(t=2.83, P=0.01), and the difference was not statistically significant(t=0.38, P=0.71)compared with the non-wearing group. The accommodative lag 0.62±0.29D of the wearing group after 12mo was reduced compared with that before wearing the lens 1.35±0.26D(t=2.57, P=0.02),and compared with the non-wearing group, the difference was not statistical significance(t=0.61, P=0.55). The mean equivalent diopter of the non-lens group was -0.75±0.35D after 12mo, and the number of diopter group increased by -0.65±0.39D(t=4.24, Pt=2.90, Pt=5.30, PP>0.05).CONCLUSION: The accommodation function of anisometropic children in correcting anisometropia by monocular orthokeratology was significantly improved compared with that before wearing the lens and was consistent with the contralateral eyes without lens group. The refractive state of the group wearing orthokeratology lens was more stable, and the contralateral eyes without lens gradually showed mild myopia refractive state, but the accommodation did not change significantly.

AIM: To observe the efficacy and safety of low-dose atropine eye drops combined with orthokeratology in the treatment of low and moderate myopia in adolescents.METHODS: Totally 126 cases of low and moderate myopia in adolescents(all right eye data, 126 eyes)who all wore orthokeratology lens for 1mo were selected from May 2016 to Aug 2018. Then they were randomly divided into the experimental group and the control group. The experimental group(63 eyes)was combined with low-dose(0.01%)atropine eye drops once a night, and the control group(63 eyes)was combined with polyethyleneglycol eye drops once a night. Their AL,SE, BCNVA,PD,AMP,BUT and IOP were observed. RESULTS: After 1y of treatment, the AL in the low myopia experimental group increased(0.13±0.03mm), while the low myopia control group increased(0.22±0.05mm). The AL in the moderate myopia experimental group increased(0.12±0.03mm),while the moderate myopia control group increased(0.20±0.05mm). The SE in the low myopia experimental group increased(0.16±0.07D), while the low myopia control group increased(0.21±0.08D). The SE in the moderate myopia experimental group increased(0.16±0.05D), while the moderate myopia control group increased(0.20±0.09D). There was statistical difference in AL and SE between the two groups(PP>0.05). But the pupil diameter of the experimental group was significantly larger than that of the control group. The accommodation amplitude of the experimental group was lower than that of the control group(PCONCLUSION: 0.01% atropine eye drops combined with orthokeratology can control the progression of myopia in adolescents more effectively, which is safe and effective.

AIM: To observe the influence of the overnight orthokeratology(OK)on the ocular surface and tear film, and to assess the discomfort caused by OK wearing in adolescent myopic patients.METHODS: This is a prospective study included 69 myopic adolescents(138 eyes)aged 12-18 years old. 31 subjects were fitted with spectacles and 38 underwent OK treatment for 12mo. All subjects were measured with the ocular surface disease index(OSDI), the corneal and conjunctival fluorescein staining(the Oxford Scheme), tear film breakup time(TBUT), noninvasive tear break-up time(NIBUT)and the Schirmer I test before wearing and at 1, 3, 6, and 12mo after wearing.RESULTS: Compared with the spectacle group and baseline, the OSDI scores were significantly higher at all recording time, the Oxford scores were significantly higher at 6 and 12mo, and TBUT and NIBUT were significantly lower at all recording time in the OK group(all PP>0.05)while no statistically differences were observed in the Schirmer I test comparing the two groups(P>0.05).CONCLUSION: OK wearing may increase the OSDI and the Oxford scores mildly, and decrease the stability of tear film. Special attention must be paid to the OK wearers with baseline and follow-up ocular surface, tear film condition, and discomfort symptoms.

AIM: To observe the adolescents with different degrees of myopia who wore orthokeratology lens for 1a were visited and discuss the influence and safety of orthokeratology for curing the adolescent myopia.METHODS: Totally 158 cases of adolescent myopia(-1.00D to -8.00D)who all wore the same brand orthokeratology lens were selected from September 2016 to December 2017. Their visual quality, including aberration detection, subjective discomfort and visual quality questionnaire was observed for 1a. RESULTS: After wearing orthokeratology, the patients' total RMS decreased, while the RMSh, the RMS3(including coma)and the RMS4(including spherical aberration)increased. The higher of baseline degree, the higher incidence of subjective visual discomfort, and the difference between pre-wearing and after was not statistically significant in subjective visual quality score(P>0.05).CONCLUSION: The patients' objective visual quality decreased after wearing orthokeratology lens. However, the long-term observation revealed that the overall visual quality had no significant impact on lifelihood and learning, which indicates orthokeratology is a safe and effective mean of myopia curing.

AIM: To analyze the control effect of orthokeratology(OK)combined with atropine of low concentration on moderate to low myopia in adolescents.METHODS: Totally 76(152 eyes)adolescents with moderate to low myopia who were admitted to the department from January 2016 were enrolled. According to the voluntary principle, they were divided into orthokeratology group(OK group, n=36 cases, 72 eyes)and orthokeratology combined with atropine of low concentration group(combination group, n=40 cases, 80 eyes). The OK glasses were given for the two groups. The combination group was additionally given 0.1g/L atropine eye drops. All were followed up for 1a. The changes of uncorrected visual acuity, diopter, axial length, intraocular pressure, tear film function and corneal parameters were measured before and after wearing glasses. The incidence of complications was statistically analyzed.RESULTS: There were no significant differences in uncorrected visual acuity, diopter, axial length and intraocular pressure between the two groups before wearing glasses and at 1a of wearing glasses(P>0.05). The change of uncorrected visual acuity before wearing glasses and at 1a of wearing glasses of combination group was higher than that of OK group while the differences in diopter and axial length were lower than those of OK group(PP>0.05). At 1a of wearing glasses, LLT and BUT of combination group were higher than those of OK group while OSI was lower than that of OK group(PP>0.05). At 1a of wearing glasses, the changes of above indexes of combination group were lower than those of OK group(PP>0.05).CONCLUSION:OK glasses combined with atropine of low concentration can improve the uncorrected visual acuity of adolescents with moderate to low myopia, control the increase of diopter and axial length. And there is significant negative influence on corneal morphology and tear film function, and with high safety.

AIM: To systematically evaluate changes in dioptre, keratometry results, uncorrected visual acuity, and ocular axis in teenage patients with myopia using orthokeratology lens for different durations. To understand and determine the duration for using orthokeratology lens more accurately in these patients and to provide correct and reliable treatment guidance for these patients.METHODS: Computerised search was conducted to retrieve studies from PubMed, CBM, WanFang Data, VIP, and CNKI databases, from the establishment of the databases to April 2019. The search yieldedrelevant studies on the use of orthokeratology to control the development of myopia in teenage patients. After two researchers independently conducted literature screening, data extraction, and methodological quality evaluation, a Meta-analysis was performed using RevMan 5.3 software.RESULTS: Finally, 8 relevant studies were selected, which included 1 136 teenage patients with myopia. The Meta-analysis revealed that after wearing orthokeratology lens for 1wk, keratometry results changed without statistical significance \〖1wk: MD=0.91, 95% CI(-0.01-1.83), P=0.05\〗. However, after using orthokeratology lens for 1, 3, 6, and 12mo, keratometry results decreased \〖1mo: MD=0.82, 95% CI(0.12-1.53), P=0.02; 3mo: MD=1.31, 95% CI(0.63-2.00), PMD=1.35, 95% CI(0.62-2.09), PMD=1.41, 95% CI(0.68-2.41), PMD=2.61, 95% CI(1.52-3.71), PMD=-0.81, 95% CI(-0.84--0.79), PMD=-0.06, 95% CI(-0.21-0.09), P=0.44\〗. CONCLUSION: The use of orthokeratology lens cannot only reducekeratometry values, but also control the growth of the ocular axis. However, these results can be achieved only after long-term wear.

AIM:To study the effect of orthokeratology on accommodation function in myopic children.METHODS: This was a retrospective clinical study. The clinical data of myopia children in our hospital from September 2015 to December 2018, who wore orthokeratology contact lens(Ortho-k)or single vision lens(SVL)to control myopia were analyzed. 27 cases(54 eyes)with Ortho-k were all selected as the study group, the control group was matched from 108 cases(216 eyes)of the SVL group with the Propensity Score-matching(PSM)function of SPSS software. After matching, 27 cases treated with Ortho-k were compared to 27 cases treated with SVL. Accommodation function were assessed by accommodative amplitude(AA), accommodative sensitivity(AS), accommodative lag(LAG), negative relative accommodation(NRA), and positive relative accommodation(PRA)before and 1, 3, 6 and 12mo after treatment.RESULTS: There was no statistical significance in the differences of the accommodative parameters between groups(all P>0.05); Wearing time had a significant effect on AA, AS, LAG, NRA and PRA of myopic children in two groups(FAA=4.7, FAS=5.6, FLAG=10.2,FNRA=7.06, FPRA=8.8, all PFAA=5.3, FAS=4.6, FLAG=11.4, FNRA=3.4, FPRA=11.1, all P<0.05).CONCLUSION: Wearing orthokeratology can improve the accommodation function of myopic children, which may be one of the mechanisms by which they control myopia.

AIM: To investigate the related factors of orthokeraology(ortho-K)decentration.METHODS: Within a prospective study, 88 eyes of 88 patients who visited to our center between July 2014 and December 2016 were enrolled. To verify the possible role of the spherical equivalent(SE), the corneal astigmatism(CA), e value, steep K, flat K, front curvature asymmetry index(SIf)and age in the ortho-K location prediction.RESULTS: This study included 24 eyes of grade Ⅰ decentration, 26 eyes with grade Ⅱ, 25 eyes with grade Ⅲ, and 13 eyes with grade Ⅳ, by which based on the decentration system that published by our team. One-way ANOVA showed that there was statically significant difference of SE, Ks and Kf in different grading groups(PPCONCLUSION: The SE might be the main factor which lead to the ortho-K decentration.

AIM: To investigate the related factors influencing the myopia control effect in adolescents with orthokeratology.METHODS: This study selected 102 adolescents who wearing ortho-k lens in the First Affiliation Hospital of Xi'an Jiaotong University during July 2014-October 2017.Their axial elongation, refraction, wearing time were observed.RESULTS: After 3a treatment, the axial elongation of 102 adolescents increased 0.42±0.37mm. Among the low myopia, the middle and high myopia groups, the axial elongation increased 0.65±0.35mm, 0.32±0.37mm and 0.30±0.29mm, respectively. The axial elongation in the high myopia groups was the most slowest(the combination of orthokeratology and spectacles); There was an interaction between the wearing time and the initial refraction, the wearing time and the initial age(all PF=0.292, P=0.695). The axial elongation has no difference between male and female.CONCLUSION: The initial refraction and the initial age of myopic adolescents were important factors influencing axial elongation. The combination of orthokeratology and spectacles has effection in controlling axial elongation.

AIM:To study the effects of long-term wearing monocular orthokeratology on ocular surface.METHODS: A retrospective study was conducted in patients with unilateral myopia(The contralateral eye of each patient was emmetropic.)who used orthokeratology lens for more than half a year. The patients were recruited from January 2013 to December 2015, in ophthalmological clinic, 101 Hospital of PLA, Wuxi. The tear break-up time(BUT), basal tear secretion, central corneal thickness, corneal endothelial cell density, conjunctival congestion and corneal epithelium fluorescein staining were observed before wearing orthokeratology and at different time points during wearing orthokeratology.RESULTS: Fifty-three young patients(53 eyes)with long-term wearing a monocular orthokeratology lens were observed, whose ages were 10.43±1.70 years old and their spherical equivalents(SEs)were -3.37±1.50D. For the myopic eyes, after 1-week treatment of monocular orthokeratology, the BUT was shortened, but there was no significant difference compared with those after 1-month, 3-month, 6-month treatment of monocular orthokeratology(P>0.05). For the emmetropic eyes, there was no significant difference in changing the BUT at above different time points(P>0.05). There was no significant difference in the value of basal tear secretion at those time points between two different kinds of eyes(The myopic eyes with orthokeratology and the emmetropic eyes without orthokeratology)(P>0.05). Compared with before wearing orthokeratology lens, there was no significant difference in both corneal center thickness and corneal endothelial cell density at those time points after wearing orthokeratology lens(P>0.05). After wearing orthokeratology lens, the corneal epithelial stain was mostly Ⅰ dyed. After 1wk, 1, 3 and 6mo respectively, the Ⅰ dyed amounts were 10 eyes(19%), 6 eyes(11%), 8 eyes(15%), 6 eyes(11%),the Ⅱ dyed amounts were 1 eye(2%), 0, 0, 1 eye(2%). The conjunctival congestion(score 1)showed up on 10 patients after wearing the orthokeratology lens. After all the 10 cases stopping wearing orthokeratology lens, but taking some antibiotics and corneal repair agents, the corneal epithelium stain disappeared and the conjunctival congestion faded away. For the emmetropic eyes, no obvious conjunctival congestion was observed during the observation period, and the corneal epithelial stain was 0.CONCLUSION: Continuous wearing orthokeratology can cause the decrease of the stability of tear film. And it also affects the conjunctiva and corneal epithelium by degrees. But it has no significant effect on tear secretion, corneal thickness and corneal endothelial cells. There will be no apparent ocular surface damage on non-wearing eyes.

AIM: To explore the correlation between eccentricity in the optical treatment area and tear film function and corneal morphology after orthokeratology. METHODS:Eighty patients(80 eyes)with myopia who were treated with orthokeratology were selected as subjects. The eccentric distance, tear film function and corneal morphology of the patient's optical treatment area were detected at different time points before and after wearing the lens. According to the median eccentric distance, the patients were divided into low eccentricity group and high eccentricity group. The differences of tear film function and corneal morphology at different time points before and after wearing were compared between the two groups. Pearson correlation coefficient was used to analyze the correlation between total eccentricity and tear film function and corneal morphological parameters at 12mo after wearing glasses. RESULTS:Compared with before wearing lenses, the corneal surface asymmetry index and corneal surface regularity index of the two groups were significantly increased at 1wk, 3, 6 and 12mo after wearing lenses(PPPPPP>0.05). The difference was statistically significant at 6mo and 12mo after wearing lenses(Pr=0.869, 0.815; Pr=-0.865, -0.745, -0.912, -0.713; all Pr=0.185, P=0.199). CONCLUSION:The eccentricity of the optical treatment area occurs at the beginning of wearing lenses. And the total eccentric distance has a significant correlation with the changes of tear film function and corneal morphology after keratoplasty.

AIM: To explore whether there was a difference in clinical efficacy of toric design orthokeratology and regular spherical orthokeratology in myopia patients with high difference in corneal surface. METHODS: A retrospective analysis of 48 moderate myopia patients(94 eyes), who went to the optometry center of Ruikang Hospital Affiliated to Guangxi University of Chinese Medical form July 2016 to December 2017. The height difference between the horizontal axis and the vertical axis away from the central cornea at 4mm was ≥30μm calculated in all patients with corneal topography. In Group A, 25 cases(48 eyes)with toric design orthokeratology, Group B(23 cases, 46 eyes)with regular spherical. After wearing orthokeratology 1wk, 1, 3mo, the uncorrected visual acuity(UCVA), the changes of corneal astigmatism in 3mm corneal center, the eccentricity of corneal treatment area were observed. RESULTS: The UCVA was improved of both groups after operation, while was not significantly different between the two groups(P>0.05). The corneal regular astigmatism in 3mm corneal center were decreased after wearing orthokeratology 1wk, 1, 3mo, the changes were more obvious in Group A than Group B(PPCONCLUSION: For myopic patients with height difference between the horizontal axis and the vertical axis from the central cornea, the toric design orthokeratology is superior to regular spherical design orthokeratology in reducing astigmatism and stability of treatment area.

AIM: To observe the effectiveness of AC custom-made orthokeratology(Ortho-K)lens in overnight orthokeratology fitting.METHODS: A prospective study was conducted for 84 patients(165 eyes)with myopia who wore overnight Ortho-K lens for the first time. All patients were randomly divided into two groups with 38 patients(76 eyes)in observation group wearing AC custom-made Ortho-K lens and 46 patients(89 eyes)in control group wearing standard Ortho-K lens. Three items including the uncorrected visual acuity(UCVA), corneal topography, and the complications of corneal epithelium were observed and quantized to be evaluated at 1mo after Ortho-K lens wearing. RESULTS: The assessment of 156 eyes(94.5%, including 73 eyes in observation group and 83 eyes in control group)in Ortho-K lens fitting were fine or acceptable at 1mo. Only 9 eyes(5.5%, including 3 eyes in observation group and 6 eyes in control group)were not good or unacceptable at that time, so that their Ortho-K lens had to be followed-up ulteriorly or changed instead. In all examination of this study, the UCVA of 159 eyes(96.4%, including 74 eyes in observation group and 85 eyes in control group)could reach one line lower to the BVCA or better in standard logarithmic visual acuity chart. The assessment of 157 eyes(95.2%, including 73 eyes in observation group and 84 eyes in control group)in corneal topography were fine or acceptable and there were no patients that had any serious complications in corneal epithelium. The observation group wearing AC custom-made Ortho-K lens performed better than the control group wearing standard Ortho-K lens in the result of UCVA, corneal topography, and the complications in corneal epithelium(PCONCLUSION: The overnight orthokeratology was effective and satisfying. AC custom-made Ortho-K lens performed better than standard Ortho-K lens in the assessment after wearing for 1mo.

AIM: To measure the tear film thickness when with a good fitted night wear orthokeratology lens in youth, and observe the change of corneal parameters. METHODS: From July 2015 to August 2016, 51 eyes of 26 teenagers with myopia who would wear orthokeratology and accept regular follow-up were enrolled. The mean spherical equivalent refraction of teenagers was -2.78D±1.53D(-1.00D to-6.00D)before wearing orthokeratology, and the mean astigmatism was 1.29D±0.61D(0 to -2.68D). The tear film thickness were measured by optical coherence tomography(OCT)when the eyes wearing orthokeratology for 1mo. The surface regularity index(SRI)value was measured by corneal topography to compare its relationship with the tear film thickness and the changes of corneal anterior surface parameters during the period of wearing lens were observed. RESULTS: At 1mo after wearing orthokeratology, the mean tear film thickness of right eyes was 230.09±10.40μm, and that was 224.38±10.57μm of left eyes. The mean tear film thickness was 228.75±9.66μm in male eyes and that was 224.80±6.74μm in female eyes. The mean tear film thickness of all eyes was 227.05±10.29μm, and the mean SRI value was 0.16±0.14. There was no correlation between tear film thickness and SRI value(P>0.05). The FK value, SK value and average K value from before wearing to after wearing for 2d and 1wk gradually decreased, the difference was statistically significant(PP>0.05). CONCLUSION: OCT can be used as a safe and reliable method for measuring the thickness of the tear film space during the wearing of orthokeratology, which may be of certain value for the safety assessment of the long term wearing of orthokeratology. Orthokeratology works very quickly, corneal curvature decreases rapidly 2d after wearing and stabilizes during the period.

AIM:To study the effects of orthokeratology, low concentration atropine and frame glasses on juvenile myopia prevention and control. METHODS: A total of 120 juvenile patients(240 eyes)with mild to moderate myopia were chosen in our hospital from January 2016 to July 2016. They were divided into 3 groups voluntarily. Children in orthokeratology group(40 cases, 80 eyes)were treated with orthokeratology; children in low concentration atropine group(40 cases, 80 eyes)were treated with low concentration atropine; children in frame glasses group(40 cases, 80 eyes)were treated with frame glasses. After 18mo follow-up, refractive degree and ocular axial length of three groups were statistically analyzed. RESULTS: After 18mo, diopters of children in orthokeratology group and atropine group were lower than those of children in frame glasses group(PPP>0.05). The axial growth of children in orthokeratology group and atropine group were lower than those of children in frame glasses group(PPP>0.05). CONCLUSION: Both orthokeratology and low concentration atropine can effectively control the progress of diopter and axial length in juvenile myopia, and their curative effects were better than frame glasses. During the 18mo observation period, the curative effects of orthokeratology and atropine have no significant differences.

AIM: To compare intervention effects on myopic children between three groups including orthokeratology combined with visual training(OCVT), orthokeratology(ortho-k), and single vision spectacle lense(SVL). METHODS: A prospective, non-randomized, case-control study was performed from September to October 2016. One hundred and twenty myopic children were enrolled from the Shaanxi Eye Research Institute and divided into three groups, which consists of 37 in OCVT group, 43 in ortho-k group and 40 in SVL group. The changes of uncorrected visual acuity(UCVA), axial length(AL)and spherical equivalent refractive error(SER)before and after 1a intervention were compared between the three groups. RESULTS: A total of 103 children completed the study, 31 in OCVT group, 37 in ortho-k group, 35 in SVL group. The changes before and after intervention of UCVA, AL, SER were significant differences between the three groups separately(PP (P>0.05). After 1a intervention, UCVA was greatly improved(PPP>0.05)in the OCVT group. In ortho-k group, UCVA was improved, SER was reduced, and AL increased significantly(all P PCONCLUSION: Orthokeratology combined with visual training has a good control effect on myopic children, but the timing, method, time length and frequency of visual training still need further study.

With the increasingly higher prevalence of myopia in children, more and more attention has been paid on the prevention and control of childhood myopia. As a non-surgical method for correcting myopia and meanwhile slowing its progression, orthokeratology is now widely used around the world. Multiple clinical studies have revealed that orthokeratology is an effective and crucial way in controlling childhood myopic progression. However, the myopia controlling efficacy differs greatly among individuals. Many factors have been reported to have potential influences in the process of myopia control of orthokeratology in children and these factors were reviewed in this article.

AIM: To assess the efficacy and safety of orthokeratology for reducing the progression of myopia in Asia children. METHODS: Seven databases, including the Cochrane Library, Medline, EMbase, CBM, CNKI, VIP, and WanFang Data, were searched. The published languages were limited to English and Chinese. The risk bias tool provided by Cochrance cooperation and methodological index for non-randomized studies(MINORS)scale were used to assess the risk bias of included studies(randomized controlled trials and controlled trials). The published biases of included studies were assessed with funnel plot. Meta-analysis was performed with Review Manager 5.3. RESULTS: Seven eligible studies, including 478 children, were included, 250 cases in ortho-k group, 228 cases in control group. The Meta-analysis indicated that change in axial length of ortho-k group was significantly less than the control group \〖WMD=-0.31, 95%CI(-0.35, -0.26), PCONCLUSION: The overall findings suggested that orthokeratology might slow the progression of myopia in children of Asia.

AIM:To evaluate the changes of the corneal surface morphology undergoing overnight orthokeratology treatment and assess the effect of optical center deviation in controlling the development of myopia. METHODS: This was a retrospective clinical study. One hundred and thirty-four children(134 eyes)with myopia aged 10.66±1.79 years were treated with overnight orthokeratology lenses. The examinations of visual acuity, axial length and corneal topography were performed before and 3, 6, 12, 18 and 24mo after wearing orthokeratology. The results of right eye were taken as the object of this study, SPSS19.0 for statistical analysis. RESULTS: The distance of decentration about 134 children at 3, 6, 12, 18 and 24mo after wearing orthokeratology were 0.84±0.45mm, 0.77±0.40mm, 0.79±0.41mm, 0.78±0.41mm, and 0.79±0.42mm respectively. The difference between these groups were not statistically significant(F=1.187,P=0.319). The mean distance of decentration after orthokeratology treatment was 0.79±0.35mm, the growth of axial length after 24mo was 0.32±0.30mm, the mean distance of decentration divided into 3 groups, mild(1.0mm)28 eyes, the growth of axial length frow 3 groups after 24mo were 0.45±0.34mm, 0.32±0.28mm, 0.23±0.29mm, were statistically significant difference between each groups(F=3.825, P=0.024). By linear-regression analysis, the growth of axial length and the mean distance of decentration after 24mo was statistically significant difference(F=7.246, P=0.008), equation of linear regression was Y=0.478-0.194X. At 24mo after wearing orthokeratology, the mean distance of decentration about 18 eyes with monocular diplopia was 1.18±0.36mm, and 116 eyes without monocular was 0.73±0.31mm, the distance of decentration were statistically significant difference(t=5.59, PCONCLUSION: The degree of decentration tended to be stable after 3mo of orthokeratology treatment and influenced the effect of myopia control and visual quality.

Orthokeratology is a kind of rigid contact lens which have reverse geometric desi, with higher oxygen permeability and security. Overnight wearing of orthokeratology can decrease the central corneal curvature and increase peripheral corneal curvature by flatting the central department of corneal, thus reduce the refraction of myopia. Through a period of time of wearing orthokeratology lens, patients can obtain good eyesight without frame glasses. Insisting on wearing orthokeratology lens can control the development of myopia. Orthokeratology is widely applied in the control of juvenile myopia, so we need scientific evaluation system to measure the visual quality after wearing orthokeratology lens. Here are the methods that used to evaluate the visual quality after wearing orthokeratology lens.

AIM: To observe the change of axial length in anisometropia myopia with simple eye receiving orthokeratology treated.METHODS: Totally 56 cases(112 eyes)with anisometropia myopia receiving monocular orthokeratology treated were divided into two groups. For every case, eye wearing orthokeratology was assigned to the experimental group and another eye to the control group. The refraction, corneal curvature and axial length were measured at pre-wear and 1mo discontinuation after wearing orthokeratology 1y.RESULTS: The statistically significant changes(t=2.8631, Pt=0.8204, P>0.05). The increase of axial length was(0.14±0.10)mm and(0.32±0.14)mm for the experimental and control group, respectively, and the increase was statistically significant(t=2.7518,PCONCLUSION: Orthokeratology can slow down myopia progression by reducing axial length to control myopia increase.

As the morbidity of myopia increasing gradually, the prevention-control of myopia has been given more attentions. Orthokeratology(OK-lens), is now widely approved and used in clinical treatment as a non-surgical measure. The OK-lens directly contact the corneal anterior surface, therefore having some effects on the morphology and biological characteristics of the cornea. The purpose of this paper is to put forward suggestions and advices for clinic, by reviewing the influence of OK-lens on the corneal sub-basal nerve plexus in the current studies.

AIM:To investigate the effect of orthokeratology on stereopsis, accommodation parameters and ocular biological parameters in myopic patients. METHODS: The clinical data of 65 patients(130 eyes)with myopia in our hospital from January 2016 to May 2017 were analyzed and they were divided into high myopia group, moderate myopia group and slight myopia group. The changes of stereopsis, accommodation parameters and ocular biological parameters were compared between the myopic patients before and after the operation. RESULTS: The difference of distant vision, stereo acuity, accommodation range and accommodation sensitivity between the three groups were statistically significant(PPP>0.05). After treatment, the corneal curvature was lower and axial length were higher than those before treatment, the difference was statistically significant(PCONCLUSION: Orthokeratology can obviously improve the distance and near vision and stereoscopic vision function of myopic patients, which may slow the increase of axis and reduce the corneal curvature.