Effect of 0.01% atropine combined with orthokeratology lens on axial elongation: a 2-year randomized, double-masked, placebo-controlled, cross-over trial.

Purpose: To evaluate the effect of 0.01% atropine combined with orthokeratology (OK) lens on axial elongation in schoolchildren with myopia. Methods: Sixty children aged 8-12 years with spherical equivalent refraction (SER) from -1.00D to -4.00D in both eyes were enrolled in this randomized, double-masked, placebo-controlled, cross-over trial. Children who had been wearing OK lenses for 2 months were randomly assigned into combination group (combination of OK lens and 0.01% atropine) for 1 year followed by control group (combination of OK lens and placebo) for another 1 year or vice versa. This trial was registered in the Chinese Clinical Trial Registry (Number: ChiCTR2000033904, 16/06/2020). The primary outcome was changes in axial length (AL). Data of right eyes were analyzed. Results: There were statistically significant differences in the changes in AL between combination and control groups after generalized estimating equation model adjusting for age and baseline SER (p = 0.001). The mean axial elongation difference between combination and control groups was 0.10 mm in the first year (0.10 ± 0.13 mm vs. 0.20 ±0.15 mm; p = 0.01), and 0.09 mm in the second year (0.22 ± 0.10 mm vs. 0.13 ± 0.14 mm; p = 0.01), respectively. The mean axial elongation difference of two groups in the first year was similar to that in the second year during the cross-over treatment. Conclusion: In central Mainland China in myopic children, the treatment of combination therapy is more effective than single OK lens in controlling axial elongation.

Comparison of 0.02% atropine eye drops, peripheral myopia defocus design spectacle lenses, and orthokeratology for myopia control.

CLINICAL RELEVANCE: There are many methods to control the progression of myopia. However, it is currently unknown which method could better control myopia progression: 0.02% atropine eye drops, peripheral myopic defocus design spectacle lenses (PMDSL), or orthokeratology (OK). BACKGROUND: To compare the efficacy of 0.02% atropine, PMDSL, and OK to control axial length (AL) elongation in children with myopia. METHODS: This study was analysed based on a previous cohort study (0.02% atropine group) and retrospective data (PMDSL and OK group). Overall, 387 children aged 6-14 years with myopia - 1.00D to - 6.00D in the three groups were divided into four subgroups according to age and spherical equivalent refraction (SER). The primary outcome was changed in AL over 1-year. RESULTS: The mean axial elongation was 0.30 ± 0.21 mm, 0.23 ± 0.16 mm, and 0.17 ± 0.19 mm in the 0.02% atropine, PMDSL, and OK groups, respectively. Multivariate linear regression analyses showed significant differences in axial elongation among the three groups, especially in children aged 6-10, but not in children aged 10.1-14; the corresponding axial elongation was 0.35 ± 0.21 mm, 0.23 ± 0.17 mm, and 0.21 ± 0.20 mm (P < 0.05 between any two groups, except between PMDSL and OK groups at P > 0.05) and 0.22 ± 0.20 mm, 0.21 ± 0.13 mm, and 0.13 ± 0.18 mm (P < 0.05 between any two groups, except between 0.02% atropine and PMDSL groups at P > 0.05) in children with SER from - 1.00D to - 3.00D and from - 3.01D to - 6.00D, respectively. CONCLUSIONS: Within the limits of this study design and using only the current brand of PMDSL, OK appeared to be the best method, followed by PMDSL and then 0.02% atropine, for controlling AL elongation over one year. However, different effects were found in the various age and SER subgroups.

Changes in axial length in anisometropic children wearing orthokeratology lenses.

Purpose: There is a particular anisometropia occurring in one eye with myopia, while the other eye has very low myopia, emmetropia, or very low hyperopia. It is unclear how the binocular axial length changes when these children wear unilateral OK lenses only in the more myopic eyes. This study investigates the changes in the axial elongation of both eyes. Methods: This is a 1-year retrospective study. In total, 148 children with myopic anisometropia were included. The more myopic eyes were wearing orthokeratology lenses (treated eyes), whereas the contralateral eyes were not indicated for visual correction (untreated eyes). The untreated eyes were classified into three subgroups based on the spherical equivalent refraction (SER): low myopia (≤ -0.50 D, n = 37), emmetropia (+0.49 to -0.49 D, n = 76), and low hyperopia (≥0.50 D, n = 35). Changes in the axial length (AL) were compared between the untreated and treated eyes and among the three subgroups. Results: The axial elongation was 0.14 ± 0.18 mm and 0.39 ± 0.27 mm in all treated and untreated eyes, respectively (p < 0.001). The interocular AL difference decreased significantly from 1.09 ± 0.45 mm at the baseline to 0.84 ± 0.52 mm at 1 year (p < 0.001). The baseline median (Q1, Q3) SER of the untreated eyes were -0.75 D (-0.56, -0.88 D), 0.00 D (0.00, -0.25 D), and +0.75 D (+1.00, +0.62 D) in low myopia, emmetropia, and low hyperopia subgroups, respectively. The axial elongation was 0.14 ± 0.18 mm, 0.15 ± 0.17 mm, and 0.13 ± 0.21 mm (p = 0.92) in the treated eyes and 0.44 ± 0.25 mm, 0.35 ± 0.24 mm, and 0.41 ± 0.33 mm in the untreated eyes (p = 0.11) after 1 year. Multivariate linear regression analyses only showed significant differences in axial elongation between the emmetropia and low myopia subgroups of untreated eyes (p = 0.04; p > 0.05 between other subgroups). Conclusion: Unilateral orthokeratology lenses effectively reduced axial elongation in the more myopic eyes and reduced interocular AL differences in children with myopic anisometropia. The refractive state of the untreated eyes did not affect the axial elongation of the more myopic eye wearing the orthokeratology lens. In the untreated eyes, AL increased faster in the low myopia subgroup than in the emmetropia subgroup.

Prevention of myopia shift and myopia onset using 0.01% atropine in premyopic children - a prospective, randomized, double-masked, and crossover trial.

This study aims to evaluate the efficacy of 0.01% atropine eye drops in preventing myopia shift and myopia onset in premyopic children. A prospective, randomized, double-masked, placebo-controlled, and crossover trial was conducted over 13 months. Sixty premyopic children aged 6-12 years with cycloplegic spherical equivalent refraction (SER) > - 0.75 D and ≤ + 0.50 D in both eyes were assigned in a 1:1 ratio to receive one drop of 0.01% atropine or placebo once nightly for 6 months (period 1), followed by a 1-month recovery period. Then, the 0.01% atropine group was crossed over to the placebo group, and the latter was crossed over to the 0.01% atropine group for another 6 months (period 2). The primary outcomes were changes in SER and axial length (AL), and the secondary outcomes were the proportion of myopia onset (SER ≤ - 0.75D) and fast myopic shift (change in SER ≤ - 0.25D) in the two periods. Generalized estimating equation (GEE) model performed a statistically significant treatment effect of 0.01% atropine compared with placebo (pSER = 0.02, pAL < 0.001), with a mean SER and AL difference of 0.20D (- 0.15 ± 0.26D vs. - 0.34 ± 0.34D) and 0.11 mm (0.17 ± 0.11 mm vs. 0.28 ± 0.14 mm) in period 1, and 0.17D (- 0.18 ± 0.24D vs. - 0.34 ± 0.31D) and 0.10 mm (0.15 ± 0.15 mm vs. 0.24 ± 0.11 mm) in period 2. The GEE model showed that the proportion of myopia onset (p = 0.004) and fast myopic shift (p = 0.009) was significantly lower in the 0.01% atropine group than that in the placebo group. The period effect was not statistically significant (all p > 0.05). A total of 0.01% atropine significantly prevented myopic shift, axial elongation, and myopia onset in premyopic schoolchildren in central Mainland China. CONCLUSION: Within the limits of only two consecutive 6-month observation period, 0.01% atropine eye drops effectively prevented myopic shift, axial elongation, and myopia onset in premyopic children. TRIAL REGISTRATION: This trial was registered in the Chinese Clinical Trial Registry (Registration number: ChiCTR2000034760). Registered 18 July 2020. WHAT IS KNOWN: • Minimal studies on interventions for pre-myopia, despite the International Myopia Institute stating that preventing myopia is an "even more valuable target" for science and practice than reducing progression after onset. WHAT IS NEW: • A total of 0.01% atropine eye drops may safely and effectively reduce the proportion of myopia onset and fast myopic shift in premyopic schoolchildren.

Effect of 0.02% and 0.01% atropine on ocular biometrics: A two-year clinical trial.

Background: Several studies have shown that various concentrations of low-concentration atropine can reduce myopia progression and control axial elongation safely and efficiently in children. The aim of this study was to evaluate the effects of 0.02% and 0.01% atropine on ocular biometrics. Methods: Cohort study. 138 and 142 children were randomized to use either 0.02% or 0.01% atropine eye drops, respectively. They wore single-vision (SV) spectacles, with one drop of atropine applied to both eyes nightly. Controls (N = 120) wore only SV spectacles. Ocular and corneal astigmatism were calculated using Thibos vector analysis and split into J0 and J45. Results: The changes in cycloplegic spherical equivalent refraction (SER) and axial length (AL) were -0.81 ± 0.52D, -0.94 ± 0.59D, and -1.33 ± 0.72D; and 0.62 ± 0.29 mm, 0.72 ± 0.31 mm, and 0.89 ± 0.35 mm in the 0.02% and 0.01% atropine and control groups, respectively (all P < 0.05). Both anterior chamber depth (ACD) and ocular astigmatism (including J0) increased, and lens power decreased in the three groups (all P < 0.05). However, there were no differences in the changes in ACD, ocular astigmatism, and lens power among the three groups (all P > 0.05). Intraocular pressure (IOP), corneal curvature, ocular astigmatism J45, and corneal astigmatism (including J0 and J45) remained stable over time in the three groups (all P > 0.05). The contributions to SER progression from the changes in AL, lens and corneal power of the three groups were similar (P > 0.05). The contribution of AL change alone to the change in SER was 56.3%, 63.4% and 78.2% in the above corresponding three groups. Conclusions: After 2 years, 0.02% and 0.01% atropine had no clinical effects on corneal and lens power, ocular and corneal astigmatism, ACD or IOP compared to the control group. 0.02% and 0.01% atropine helped to control myopia progression mainly by reducing AL elongation.

Combination of orthokeratology lens with 0.01% atropine in slowing axial elongation in children with myopia: a randomized double-blinded clinical trial.

BACKGROUND: To evaluate the additive effects of orthokeratology (OK) lenses and 0.01% atropine on slowing axial elongation in myopic children. METHODS: A prospective, randomized, double-blinded, placebo-controlled trial was conducted over a 12-month period. Sixty children aged 8 to 12 years with spherical equivalent refraction from - 1.00 to -4.00 D who had been wearing OK lenses successfully for 2 months (as baseline) were randomly assigned in a 1:1 ratio to combination group (combination of OK lens and 0.01% atropine eye drops) and control group (combination of OK lens and placebo). The primary outcome was change in axial length, along with secondary outcomes including change in pupil diameter (PD) and accommodative amplitude (AMP) at 12 months (measured at 4-month intervals). RESULTS: After 12 months, the overall axial elongation was 0.10 ± 0.14 mm and 0.20 ± 0.15 mm (p = 0.01) in the combination and control groups, respectively. The change in axial length in the two groups showed significant differences only in the first four months (median [Q1, Q3] (95% CI), -0.01 mm [-0.07, 0.05] (-0.06, 0.04) vs. 0.04 mm [0.00, 0.10] (0.02, 0.09); p = 0.04), but no difference thereafter. Multivariate linear regression analysis showed that the axial elongation was significantly slower in the combination group than in the control group (standard ß = -0.10, p = 0.02). PD significantly increased by 0.45 mm [0.20, 0.68] at the 4th month visit (p < 0.001) and then remained stable in the combination group. The PD in the control group and AMP in the two groups remained stable from baseline to 12 months (all p > 0.05). CONCLUSION: The combination therapy was more effective than the OK lens alone in slowing axial elongation after 12 months of treatment, and mainly in the first 4 months. TRIAL REGISTRATION: The First Affiliated Hospital of Zhengzhou University, ChiCTR2000033904. Registered 16/06/2020, http://www.chictr.org.cn/login.aspx?referurl=%2flistbycreater.aspx.

Effect of 0.02% and 0.01% atropine on astigmatism: a two-year clinical trial.

BACKGROUND: To evaluate the effects of 0.02% and 0.01% atropine eye drops on ocular and corneal astigmatism over 2 years. METHODS: A prospective clinic-controlled trail. The cohort study assessed 400 myopic children and divided them into three groups: 138 and 142 children were randomized to use either 0.02% or 0.01% atropine eye drops, respectively. They wore single-vision (SV) spectacles, with one drop of atropine applied to both eyes once nightly. Control children (n = 120) only wore SV spectacles. Spherical equivalent refractive errors (SER) and corneal curvature were measured every 4 months. The SER and corneal curvature were assessed by cycloplegic autorefraction and IOLMaster. Ocular and corneal astigmatism were calculated by Thibos vector analysis and then split into its power vector components, J0 (with-the-rule astigmatism) and J45 (oblique). RESULTS: After 2 years, the ocular astigmatism increased by -0.38 ± 0.29 D, -0.47 ± 0.38 D, -0.41 ± 0.35 D in the 0.02%, 0.01% atropine groups and control group, respectively (p = 0.15). The corresponding corneal astigmatism increased by -0.20 ± 0.34 D, -0.28 ± 0.35 D and -0.26 ± 0.26 D (p = 0.18). The ocular astigmatism J0 increased by 0.19 ± 0.28 D, 0.22 ± 0.36 D, 0.18 ± 0.31 D in the 0.02% atropine, 0.01% atropine and control groups, respectively (p = 0.65). The corresponding corneal astigmatism J0 increased by -0.05 ± 0.34 D, -0.11 ± 0.37 D and -0.13 ± 0.30 D (p = 0.23). There was a small but significant increase in ocular astigmatism (including J0) (all P < 0.05), but there were no changes in the ocular astigmatism J45 and corneal astigmatism (including J0 and J45) in the three groups over time (all p > 0.05). However, there were no significant differences in the changes in ocular astigmatism (including J0) among the three groups. CONCLUSIONS: Treatment with 0.02% and 0.01% atropine had no clinically significant effect on ocular and corneal astigmatism over 2 years. TRIAL REGISTRATION: The First Affiliated Hospital of Zhengzhou University, ChiCTR-IPD-16008844 . Registered 14/07/2016.

Orthokeratology Lenses Versus Administration of 0.01% Atropine Eye Drops for Axial Length Elongation in Children With Myopic Anisometropia.

OBJECTIVE: To investigate the effect of orthokeratology (OK) lenses and that of 0.01% atropine eye drops on axial length (AL) elongation in children with myopic anisometropia. METHODS: Ninety-five children with myopic anisometropia who used OK lenses (N=49) or 0.01% atropine eye drops (N=46) were enrolled in this retrospective 1-year study. For all children, the eyes with higher spherical equivalent refractive error (SER) were assigned to the H-eye subgroup, whereas the fellow eyes with lower SER were assigned to the L-eye subgroup. RESULTS: After 1-year treatment, the mean change in the AL of H eyes and L eyes in the OK lenses group was 0.18±0.16 mm and 0.24±0.15 mm, respectively (P=0.15), and 0.28±0.20 mm and 0.25±0.18 mm, respectively (P=0.48), in the 0.01% atropine group. Multivariate regression analyses showed significant differences in AL change between H and L eyes after treatment with OK lens (P=0.03), whereas no significant difference in the 0.01% atropine (P=0.22). The change in the AL in the H-eye group was less with OK lenses than with 0.01% atropine (P=0.04), whereas there was no significant difference between the change in AL in the L-eye group between treatment with OK lens and 0.01% atropine (P=0.89). CONCLUSIONS: In myopic anisometropic children, AL differences between 2 eyes decrease by wearing OK lenses but do not change after administration of 0.01% atropine eye drops. The increased effect of OK lenses, but not 0.01% atropine, in reducing axial elongation at 1 year in the eye with higher SER in anisometropic children warrants further investigation.

Safety and efficacy of 0.02% and 0.01% atropine on controlling myopia progression: a 2-year clinical trial.

Four hundred myopic children randomly received atropine 0.02% (n = 138) or 0.01% (n = 142) in both eyes once-nightly or only wore single-vision spectacles (control group) (n = 120) for 2 years. Spherical equivalent refractive error (SER), axial length (AL), pupil diameter (PD), and amplitude of accommodation (AMP) were measured every 4 months. After 2 years, the SER changes were - 0.80 (0.52) D, - 0.93 (0.59) D and - 1.33 (0.72) D and the AL changes were 0.62 (0.29) mm, 0.72 (0.31) mm and 0.88 (0.35) mm in the 0.02% and 0.01% atropine groups and control group, respectively. There were significant differences between changes in SER and AL in the three groups (all P < 0.001). The changes in SER and AL in the 2nd year were similar to the changes in the 1st year in the three groups (all P > 0.05). From baseline to 2 years, the overall decrease in AMP and increase in PD were not significantly different in the two atropine groups, whereas the AMP and PD in the control group remained stable (all P > 0.05). 0.02% atropine had a better effect on myopia control than 0.01% atropine, and its effects on PD and AMP were similar to 0.01% atropine. 0.02% or 0.01% atropine controlled myopia progression and AL elongation synchronously and had similar effects on myopia control each year.

Risk factors for rapid axial length elongation with low concentration atropine for myopia control.

Three hundred and twenty-eight myopic children, randomized to use either 0.01% (N = 166) or 0.02% (N = 162) atropine were enrolled in this study. Gender, age, body mass index(BMI), parental myopia status, atropine concentration used, pupil diameter, amplitude of accommodation, spherical equivalent refractive error (SER), anterior chamber depth (ACD) and axial length (AL) were collected at baseline and 1 year after using atropine. Rapid AL elongation was defined as > 0.36 mm growth per year. Univariate analyses showed that children with rapid AL elongation tend to be younger, have a smaller BMI, use of 0.01% atropine, narrow ACD, lower SER, shorter AL, smaller change in pupil diameter between 1 year and baseline (all P < 0.05). Multivariate logistic regression analyses confirmed that rapid AL elongation was associated with children that were younger at baseline (P < 0.0001), use of 0.01% atropine (P = 0.04), a shorter baseline AL (P = 0.03) and a smaller change in pupil diameter between 1 year and baseline (P = 0.04). Younger children with shorter AL at baseline, less change in their pupil diameter with atropine treatment and using the lower of the two atropine concentrations may undergo rapid AL elongation over a 12 months myopia control treatment period.

Comparison of Administration of 0.02% Atropine and Orthokeratology for Myopia Control.

OBJECTIVE: To compare the efficacies of 0.02% atropine eye drops and orthokeratology to control axial length (AL) elongation in children with myopia. METHODS: In this historical control study, 247 children with myopia whose administration of 0.02% atropine (n=142) or underwent orthokeratology from an earlier study (n=105, control group) were enrolled. Data on AL and other baseline parameters were recorded at baseline and after 1 and 2 years of treatment. RESULTS: The mean changes in AL in the first and second years of treatment were 0.30±0.21 and 0.28±0.20 mm, respectively, in the 0.02% atropine group and 0.16±0.20 and 0.20±0.16 mm, respectively, in the orthokeratology group. Axial length elongations after 2 years of treatment were 0.58±0.35 and 0.36±0.30 mm (P=0.007) in the 0.02% atropine and orthokeratology groups, respectively. Multivariate regression analyses showed that the AL elongation was significantly faster in the 0.02% atropine group than in the orthokeratology group (ß=0.18, P=0.009). In multivariate regression analyses, younger age and shorter baseline AL were associated with a rapid AL elongation in the 0.02% atropine group (ßage=-0.04, P=0.01; ßAL=-0.17, P=0.03), while younger age, lower baseline spherical equivalent refractive error (SER), and shorter baseline AL were associated with a greater increase in AL in the orthokeratology group (ßage=-0.03, P=0.04; ßSER=0.06, P=0.03; ßAL=-0.11, P=0.009). Faster AL elongation was found in the 0.02% atropine group compared with the orthokeratology group at higher baseline SER (P=0.04, interaction test). CONCLUSION: Within the limits of this study design, orthokeratology seems to be a better method for controlling AL elongation compared with administration of 0.02% atropine in children with higher myopia over a treatment period of 2 years.

Prevalence of myopia among disadvantaged Australian schoolchildren: A 5-year cross-sectional study.

PURPOSE: Myopia prevalence is influenced by environmental factors including heritability and social disadvantage. The current prevalence of myopia among disadvantaged school children in Australia has not been reported. Therefore, this study analyses refractive data for children from rural and outer suburban areas. METHODS: The records of 4,365 children aged 6-15 visiting a city-based government-school respite care center during the years 2014/2016/2018 were analyzed for right eye non-cycloplegic spherical equivalent refraction (SER). The prevalence of myopia (SER≤-0.50D) was compared with historical data. RESULTS: The prevalence of myopia was 3.5%, 4.4% and 4.3% in 2014, 2016 and 2018, respectively. The prevalence of myopia increased with age (P<0.0001), but was not related to sex or year of testing (all P >0.05). The overall mean SER was 0.89±0.86D, 0.62±0.89D and 0.56±0.95 in 2014, 2016 and 2018, respectively. Mean SER was associated with year of testing, age (all P <0.0001) and sex (P = 0.03). Mean SER decreased slightly from 2014 to 2018 and demonstrated a significant shift towards less hyperopia with increasing age. Mean SER of females was higher than that of males and decreased faster than in males with age (P interaction = 0.03). CONCLUSIONS: Myopia prevalence increased with age. The mean SER decreased slightly from 2014 to 2018. Sex differences in the rate of change with age was observed. Compared with 40 years ago, the prevalence of myopia has doubled, but it remains significantly lower than in school children of a similar age living in established urban areas that are regarded as having a higher socioeconomic status.

Effect of low-dose atropine on myopia progression, pupil diameter and accommodative amplitude: low-dose atropine and myopia progression.

PURPOSE: To evaluate the effects of 0.01% and 0.02% atropine eye drops on myopia progression, pupil diameter and accommodative amplitude in myopic children. METHODS: A cohort study assessed 400 myopic children divided into three groups: 138 and 142 children were randomised to use either 0.02% or 0.01% atropine eye drops, respectively. They wore single-vision (SV) spectacles, with one drop of atropine eye drop applied to both eyes once nightly. Control children (n=120) only wore SV spectacles. Repeated measurements of spherical equivalent refractive errors (SERs), axial length (AL), pupil diameter and accommodative amplitude were performed at baseline, and 4, 8 and 12 months after treatment. RESULTS: After 12 months, the SER change was -0.38±0.35D, -0.47±0.45D, -0.70±0.60D and AL change was 0.30±0.21 mm, 0.37±0.22 mm, 0.46±0.35 mm in the 0.02%, 0.01% atropine and control groups, respectively. There were significant differences in the change in AL and SER between three groups (all p<0.001). Between baseline and the 12-month visit, the overall change in accommodative amplitude was 1.50±0.25D, 1.61±0.31D and change in pupil diameter was 0.78±0.42 mm, 0.69±0.39 mm, with 0.02% and 0.01% atropine, respectively. Accommodative amplitude significantly decreased and pupil diameter significantly increased in two atropine groups (all p<0.001). Moreover, there was no statistical difference in the change difference in accommodative amplitude and pupil diameter between two atropine groups (p=0.24, p=0.38), whereas the accommodative amplitude (p=0.45) and pupil diameter (p=0.39) in the control group remained stable. CONCLUSIONS: 0.02% atropine eye drops had a better effect on myopia progression than 0.01% atropine, but 0.02% and 0.01% atropine showed similar effects on pupil diameter and accommodative amplitude after 12 months of treatment. TRIAL REGISTRATION NUMBER: ChiCTR-IPD-16008844.

Effects of orthokeratology lens on axial length elongation in unilateral myopia and bilateral myopia with anisometropia children.

PURPOSE: To investigate the effect of orthokeratology (OK) lens on axial length (AL) elongation in unilateral myopia and bilateral myopia with anisometropia children. METHODS: Twenty-seven unilateral myopia (group 1) and 25 bilateral myopia with anisometropia children (group 2) were involved in this 1-year retrospective study. The eyes with higher spherical equivalent refractive error (SER) were assigned to the H eyes subgroup and the fellow eyes with lower SER to the L eyes subgroup in the two groups. RESULTS: The mean change in AL of H eyes and L eyes were 0.11 ± 0.19 mm, 0.30 ± 0.28 mm in group 1 (P = 0.04) and 0.09± 0.14mm, 0.13± 0.16mm in group 2 (P = 0.36), respectively. Multivariate regression analyses showed that significant difference of change in AL was found between H eyes and L eyes in group1 (ß=0.25, P = 0.03), but no difference in group 2 (ß=0.09, P = 0.12). The AL of H eyes in group 1 and group 2, H eyes in group 1 and L eyes in group 2 had the same increased rate (ß= -0.04, P = 0.43; ß = 0.02, P = 0.56). CONCLUSIONS: Monocular OK lens is effective on suppression AL elongation of the myopic eyes and reduce anisometropia value in unilateral myopic children. The OK lens can control the AL elongation in both eyes at the same rate, but it cannot reduce anisometropia value in bilateral myopia with anisometropia children after 1-year follow-up.

Higher spherical equivalent refractive errors is associated with slower axial elongation wearing orthokeratology.

PURPOSE: To investigate the relationship between axial length (AL) increase and baseline spherical equivalent refractive errors (SER) in myopic children wearing orthokeratology contact lenses (OK). METHODS: One hundred fifteen Chinese (115 right eyes) children wearing OK were enrolled in this cohort study. Gender, age, baseline SER, corneal power, corneal astigmatism, and AL at baseline and 2 years after wearing OK were collected. Univariate analysis and trend test were used to estimate the relationship between change in AL and baseline SER. RESULTS: After univariate analysis, a statistically significant relationship was found between change in AL and baseline SER (ß=0.061, 95% CI: 0.015-0.111, P=0.015). In the trend test, after adjusting for potential confounders, higher SER was associated with smaller increases in AL (P trend=0.041). CONCLUSIONS: The SER at baseline was associated with AL growth in myopic children wearing OK. The higher SER was associated with slower AL growth and control the development of myopia.

Clinical investigation of off-flap epi-LASIK for moderate to high myopia.

PURPOSE: To compare the clinical outcome of on-flap and off-flap epi-LASIK for moderate to high myopia. METHODS: This prospective, observer-masked, randomized study included 62 eyes of 31 patients with myopia who underwent off-flap epi-LASIK (epikeratome; Moria, Antony, France) in one eye (off-flap group) and on-flap epi-LASIK in the contralateral eye (on-flap group). Corneal ablation was performed with a commercially available laser (Mel-80; Carl Zeiss Meditec, Oberkochen, Germany). Patients were seen at 3, 5, and 12 days and 1 and 3 months after surgery. Clinical outcomes were compared between groups. RESULTS: No significant between-group differences in the mean preoperative spherical equivalent (-6.18 +/- 1.29 D vs. -6.47 +/- 1.70 D), the change in lines of best corrected visual acuity at 3 months after surgery, and postoperative pain were found. Compared with the on-flap group, outcomes of better uncorrected visual acuity at 3 and 5 days after surgery (P < 0.001), rapider reepithelialization (P < 0.001), and lower level of haze at 1 and 3 months after surgery (P = 0.04, 0.04) were found in the off-flap group. Three months after surgery, contrast sensitivity function (CSF), with and without glare, did not differ from before surgery in both groups (P > 0.05) except CSF at 18 cpd with glare increased significantly in the off-flap group 3 months after surgery (P = 0.04). Wavefront aberration increased significantly from baseline in both groups 3 months after surgery (P < 0.05). The on-flap group revealed greater but insignificant increasing amplitude in wavefront aberration compared with the off-flap group. CONCLUSIONS: In comparison with on-flap epi-LASIK, off-flap epi-LASIK offers comparable postoperative pain, a lower level of haze formation, a rapider visual recovery, and better visual quality. Further investigations of a larger number of subjects and longer follow-up periods are warranted.