Ortho-k Treatment Research Articles

Assessing the efficacy of myopia control in monocular orthokeratology treated unilateral myopic children

PurposeTo investigate the efficacy of myopia control by comparing the orthokeratology (Ortho-K) treated eyes and the emmetropic contralateral eyes in unilateral myopic children, and to identify the inter-individual influence factors.MethodIn this retrospective study, 1566 medical records of children wearing Ortho-K lens were reviewed, and 62 children who received monocular Ortho-K lens for more than 1 year were analyzed. The change in axial length (AL) of the Ortho-K eyes and the emmetropic contralateral eyes was recorded. To evaluate the absolute and relative efficacy of myopia control, the intra-bilateral absolute reduction in AL growth (ibARAL) and the intra-bilateral relative reduction in AL growth (ibRRAL) were calculated as main outcomes. Association of the AL elongation, ibARAL and ibRRAL with age, sex and ocular parameters was analyzed by correlation analysis and generalized estimating equation (GEE) analysis.ResultThe average initial wearing age was 10.76 ± 1.45 (ranged 8.5 to 15.8). The average baseline SER was − 2.15 ± 1.03 (ranged − 5.25 to -1.00) D in the Ortho-K eyes and − 0.01 ± 0.40 (ranged − 0.75 to 0.75) D in the contralateral eyes. At the 1-year follow-up, the average increased AL was significantly less in the Ortho-K eyes (0.07 ± 0.18 mm) than in the fellow eyes (0.48 ± 0.24 mm) (p < 0.001). The mean ibARAL was 0.41 ± 0.30 mm, and the mean ibRRAL was 83.4%±56.3%. In the GEE model, the AL change in Ortho-K eyes (β = 0.051, p = 0.009, 95%CI: 0.012 to 0.090), the ibARAL (β= -0.153, p = 0.000, 95%CI: -0.228 to -0.078) and the ibRRAL (β= -0.196, p = 0.020, 95%CI: -0.361 to -0.030) were independently associated with the spherical equivalent refraction (SER) of the Ortho-K eyes, after adjusting for age, sex, and keratometry.ConclusionIn our study, the Ortho-K treatment was efficacious in controlling axial length growth in the monocular orthokeratology treated unilateral myopic eyes. The efficacy increased when the myopia was more severe. In the children from 8 to 16 years old, the effectiveness was independent of age and sex.

The relationship between baseline axial length and axial elongation in myopic children undergoing orthokeratology.

To investigate the correlation between the baseline axial length (AL) and axial elongation in myopes undergoing orthokeratology (ortho-k). This was a retrospective study. During the 1-year follow-up, 1176 children (aged 8-14 years) were included and divided into an ortho-k group (n=588) and a single-vision spectacle group (n=588). The ortho-k group participants (8-11 years of age) who completed the 3-year follow-up (n=150) were further divided into three subgroups stratified by their baseline AL: subgroup 1 (AL < 24.5 mm), subgroup 2 (24.5 ≤ AL < 26 mm) and subgroup 3 (AL ≥ 26 mm). AL was measured at baseline and during the annual visit. The ortho-k group exhibited slower 1-year axial elongation (39% reduction) than the spectacle group. The 1-year axial elongation was negatively correlated with initial age in both groups. A negative association between 1-year axial elongation and baseline AL was observed in the ortho-k group but not in the spectacle group. However, this relationship only existed in ortho-k participants 8-11 years of age. For the younger ortho-k participants who completed the 3-year follow-up, the annual axial elongation was significantly higher in subgroup 1 for the first and second years but not in the third year compared with subgroups 2 and 3. Axial elongation was negatively correlated with baseline AL in the ortho-k group. Children aged 8-11 years with longer baseline AL (≥24.5 mm) demonstrated slower annual axial elongation during the first 2 years of ortho-k treatment, which may provide insight into establishing individual guidelines for controlling myopia using ortho-k in children with different baseline characteristics.

Effect of atropine, orthokeratology and combined treatments for myopia control: a 2-year stratified randomised clinical trial

PurposeTo investigate the 2-year efficacy of atropine, orthokeratology (ortho-k) and combined treatment on myopia. To explore the factors influencing the efficacy.MethodsAn age-stratified randomised controlled trial. Children (n=164) aged 8–12 years...

The effect of corneal power distribution on axial elongation in children using three different orthokeratology lens designs

PurposeTo investigate the correlation between spatial corneal power distribution and one-year axial length (AL) elongation using three ortho-k lens designs by a unified mathematical method. MethodsA total of 137 subjects were included: 42 with Euclid lenses, 28 with DRL lenses, and 67 with CRT lenses. AL elongation, Xmax, Ymax and power exponent were compared among the three groups. One-year relative corneal refractive power change (RCRPC) was calculated by a polynomial function and a monomial function. Factors including age, baseline spherical equivalent refractive error (SER), Xmax, Ymax and power exponent was tested against one-year AL growth in a stepwise multiple linear regression model. ResultsThe power exponent (F = 7.29, P = 0.0012) and Xmax (F = 62.88, P < 0.0001) of the DRL group was significantly smaller than that of the other two lens groups. Ymax was not significantly different among three lens groups (F = 1.18, P = 0.31). The one-year AL elongation of the DRL group (0.09 ± 0.14 mm) was significantly slower than that of the Euclid group (0.26 ± 0.14 mm, P = 0.002) and CRT group (0.32 ± 0.18 mm, P < 0.0001). AL elongation was significantly correlated with Xmax (standardized β = 0.196, P = 0.003), power exponent (standardized β = 0.644, P < 0.001), and age (standardized β = -0.263, P < 0.001), with R2 being 0.608. ConclusionA smaller and more aspheric treatment zone may be beneficial for reducing axial elongation in children undergoing ortho-k treatment, regardless of their baseline myopic refractive error.

Photopic pupil size change in myopic orthokeratology and its influence on axial length elongation.

To explore the photopic pupil size behavior in myopic children undergoing overnight orthokeratology (ortho-k) over 1-year period and its effects on the axial elongation. A total of 202 Chinese myopic children were enrolled in this prospective clinical trial. Ninety-five subjects in ortho-k group and eighty-eight subjects in spectacle group completed the 1-year study. Axial length (AL) was measured before enrollment and every 6mo after the start of ortho-k. The photopic pupil diameter (PPD) was determined using the Pentacam AXL and measured in an examination room with lighting of 300-310 Lx. Stepwise multiple linear regression analysis was used to identify variables contribution to axial elongation. Compared with spectacle group, the average 1-year axial elongation was significantly slower in the ortho-k group (0.25±0.27 vs 0.44±0.23 mm, P<0.0001). In ortho-k group, PPDs significantly decreased from 4.21±0.62 mm to 3.94±0.53 mm after 1mo of lens wear (P=0.001, Bonferroni correction) and the change lasts for 3-month visit. No significantly change during the other follow-up visits was found (P>0.05, Bonferroni correction). The 4.81 mm PPD may be a possible cutoff point in the ortho-k group. Subjects with PPD below or equal to 4.81 mm tended to have smaller axial elongation compared to subjects with PPD above 4.81 mm after 1-year period (t=-3.09, P=0.003). In ortho-k group, univariate analyses indicated that those with older age, greater degree of myopia, longer AL, smaller baseline PPD (PPDbaseline) experienced a smaller change in AL. In multivariate analyses, older age, greater AL and smaller PPDbaseline were associated with smaller increases in AL. In spectacle group, PPD tended to be stable (P>0.05, Bonferroni correction) and did not affect axial growth. PPDs experience significantly decreases at 1-month and 3-month ortho-k treatment. Children with smaller PPD tend to experience slower axial elongation and may benefit more from ortho-k.

Weighted Zernike defocus coefficient of treatment zone is a meaningful indicator for myopia control efficacy of Ortho-K lenses

BackgroundThe goal of this study was to reproduce a three-dimensional representation of corneal defocus characteristics after orthokeratology (Ortho-K) treatment via an indicator defined as the weighted Zernike defocus coefficient of the treatment zone (Cweighted defocus). This could be used to predict the effectiveness of Ortho-K treatment quantitatively in a timely manner after the one-month visit.MethodsSeventy myopic children with axial length (AL) elongation after Ortho-K treatment (group A) and 63 myopic children with AL shortening after Ortho-K treatment (group B) were included in this one-year retrospective study. The proposed indicator was calculated by a customized MATLAB program. Multivariate binomial logistic regression and multivariate linear regression analyses were used to explore the association between AL change and the Cweighted defocus, age, sex, and other ocular biometric parameters.ResultsThe 12-month AL change, age, pupil diameter, and vertical decentration of the Ortho-K lens were significantly different between the two groups. Multivariate logistic regression analysis showed that a larger Cweighted defocus (≥ 0.35 D/mm2) (OR: 0.224; 95% CI: 0.078–0.646; P = 0.006) was correlated with the emergence of AL shortening after orthokeratology treatment. A multivariate linear regression model showed that a greater Cweighted defocus was associated with slower 12-month AL elongation (β = − 0.51, P = 0.001).ConclusionsThe Cweighted defocus is an effective predictive indicator of myopia control, and a larger Cweighted defocus may lead to slower elongation of AL. This meaningful indicator may help in the evaluation and adjustment of Ortho-K lens parameters in a timely manner and minimize the cost of clinical trial and error.

Short-term effect of Ortho-K on axial length and choroidal thickness

Purpose. To investigate the short-term effect of orthokerato- logy (ortho-k) on choroidal thickness (CHT), anterior chamber depth (ACD), central corneal thickness (CCT), and its rela- tionship to the change in axial length (AL). Material and Methods. Sixteen eyes of sixteen adult (age 25 - 54 years) ortho-k lens wearers discontinued treatment for one month. Measurements were taken before discontinua- tion, at the end of the break, and 2 - 4 weeks after resuming ortho-k lens wear. CHT was measured subfoveally and then nasally, as well as temporally of the fovea at 4 locations. Meas- urements were taken between 2 and 6 pm. Results. No significant change in subfoveal CHT was found. The CHT decreased significantly only 1 and 1.5 mm nasally after discontinuation (-12 ± 21 µm p = 0.035 and -13 ± 17 µm p = 0.006) and increased 0.5 mm temporally after resuming the lens wear (+11 ± 17 µm p = 0.025). Both CCT and ACD increased significantly after discontinuation of ortho-k lens wear (+8 ± 11.0 µm p = 0.01 and +0.04 ± 0.05 mm p = 0.005) and then decreased again after resuming ortho-k lens wear (-7 ± 11 µm p = 0.03 and -0.05 ± 0.07 mm p = 0.009). AL did not change significantly between any of the study phases and correlated significantly negatively with CHT, but with no other parameters. Conclusion. Subfoveal CHT did not change significantly due to short-term ortho-k lens treatment in adults. AL was not affected by the treatment either, despite the increase in ACD after discontinuation. Thus, ortho-k does not seem to have a short-term influence on AL. Keywords orthokeratology, choroidal thickness, myopia, myopia control, axial length, OCT

Effect of overnight orthokeratology lenses on tear film stability in children

PurposeTo assess the tear film surface quality after orthokeratology using an automated Medmont E300 corneal topographer. MethodsChildren who wore orthokeratology lenses for more than one year were selected in this retrospective study. Tear film disruption (TFD) and central tear film disruption (cTFD) were measured with Medmont E300 corneal topographer at initial and each follow-up visit after fitting with orthokeratology lenses, providing a nominal value from 0 (perfect) to 1 (poor). Tear film surface quality before and after ortho-k treatment was compared. Results145 children using orthokeratology lenses were observed. TFD and cTFD significantly increased at 1-day follow up (TFD, t = -17.3, P < 0.001; cTFD, t = -10.4, P < 0.001). This change remained consistent through to 12-months visit (TFD, F = 51.1, P < 0.001; cTFD, F = 28.0, P < 0.001). A sub-group of n = 11 children were discontinued for 1-month before being refit with OrthoK lenses of a different design. Similarly, there was a significant increase in TFD compared to pre-orthoK scans (0.172 ± 0.161), but this returned to baseline levels after ceasing lens wear (0.084 ± 0.059). A sub-group of monocular OrthoK wearers (n = 23) found that TFD and cTFD values increased in eyes with monocular lens-wearing but remained stable in the lateral eyes. ConclusionsObjective measurements of tear-film quality are reduced in children after fitting with orthokeratology lenses, but return to baseline after 1-month of lens cessation. It is of importance to ensure tear film surface quality is continuously monitored throughout use of orthoK lenses.

Orthokeratology and high myopia

The aim of this study is to review the current literature on ortho-K lenses use in myopia with a particular focus on the efficacy and safety of orthokeratology in myopia, and its effects in the case of high myopia, as well as the impact of COVID-19 pandemic on myopia and orthokeratology. COVID-19 pandemic influenced the incident of myopia as well as progression of myopia. Ortho-K lenses have been shown to be safe and effective in reducing the axial elongation and decreasing myopia progression in low to moderate myopia and with some limitations in high myopia patients. During the COVID-19 pandemic, ortho-K treatment was not affected, and the pandemic had no effect on the axial elongation in myopia children undergoing treatment with ortho-K lenses. Myopia is becoming a major health problem worldwide that is increasing to an alarming rate. The progression of myopia can lead to serious irreversible complications. There is sufficient evidence proving that orthokeratology lenses are effective and safe in myopia. More studies need to be done in high myopia. Long term success of the use of ortho-k lenses increases with the proper lens fitting.

The effect of orthokeratology treatment zone decentration on myopia progression

BackgroundThis study aimed to compare the changes in the axial length (AL) in myopic children that wear centered and decentered orthokeratology (Ortho-K).MethodsThis retrospective study included 217 subjects who were treated with an Ortho-K lens for >12 months. The subjects were divided into three groups based on the magnitude of the Ortho-K lens treatment zone decentration: mildly, moderately, and severely decentered groups. Distance and direction of treatment zone decentration were calculated using software that was developed in-house. The AL changes in different groups were compared.ResultsBased on the distance of the treatment zone decentration, 65 children (65 eyes) were included in the mildly decentered group, 114 children (114 eyes) in the moderately decentered group, and 38 children (38 eyes) in the severely decentered group. The mean decentration distance in the three groups was 0.35 ± 0.11 mm, 0.71 ± 0.13 mm, and 1.21 ± 0.22 mm, respectively. The mean AL increase in the three groups after 12 months of Ortho-K lens wear was 0.24 ± 0.21 mm, 0.23 ± 0.18 mm, and 0.19 ± 0.20 mm, respectively. There were no significant differences in AL changes among the three groups.ConclusionsOrtho-K lens decentration is common in clinical practice. The AL change after Ortho-K lens wear was not significantly different in subjects with different magnitudes of Ortho-K lens decentration. Fitting the Ortho-K lens in the properly centered zone is recommended to ensure the safety of Ortho-K lens wear and to maintain visual quality.

Change in Corneal Power Distribution in Orthokeratology: A Predictor for the Change in Axial Length.

PurposeTo investigate the correlation between the change in spatial corneal power distribution and axial length (AL) elongation during orthokeratology (Ortho-k) treatment using mathematical methods.MethodsSeventy-six subjects aged from eight to 13 years were fitted with Paragon CRT ortho-k lenses. Manifest refraction and corneal topography were checked at baseline and one day, one week, two weeks, one month, three months, six months, nine months, and one year after lens wear. AL was measured at baseline and the six-month and one-year follow-up visits. Relative corneal refractive power change (RCRPC) was calculated by a polynomial function and a monomial function. Factors including age, baseline spherical equivalent refractive error (SER), power exponent and RCRPC were tested against one-year AL growth in a stepwise multiple linear regression model.ResultsA total of 67 subjects completed the one-year study, with nine dropouts. The SER significantly reduced after the first month of lens wear (P < 0.001). AL significantly changed over time (P = 0.0003) with the annual growth being 0.32 ± 0.18 mm. Power exponent and RCRPC were stable throughout the follow-up visits (all P > 0.05). Change of AL was significantly correlated with baseline age (standardized β = −0.292, P < 0.001) and power exponent (standardized β = 0.691, P < 0.001), but not with the other factors being analyzed. The regression equation using baseline age (X1) and power exponent (X2) as functions for 1-year AL change (Y) was Y = 0.438-0.034X1 + 0.309X2, with R2 being 0.752.ConclusionsThe asphericity of the treatment zone may affect axial elongation in children undergoing ortho-k therapy.Translational RelevanceBecause the ortho-k lens design may affect myopia control effect in children undergoing ortho-k therapy, future ortho-k lenses should consider applying these designs to obtain a better myopia control effect in children.

Efficacy, predictability and safety of long-term orthokeratology: An 18-year follow-up study

PurposeTo determine the efficacy, predictability and safety of long-term orthokeratology in children and adults. MethodsCase histories of 300 orthokeratology patients (596 eyes; 34.3% children; 65.7% adults) were reviewed to collect information on demographics, corneal and refractive parameters, visual acuity, residual refraction and adverse effects. Predictability was defined as the percentage of eyes with absolute values of spherical equivalent refraction ≤ 0.5 D of emmetropia, and efficacy as the ratio of post-orthokeratology uncorrected and pre-orthokeratology corrected distance visual acuity. ResultsMedian duration of treatment was 37 and 28.5 months in children and adults, respectively (p = 0.022). During the first year, 17.2% of children and 33% of adults ceased lens wear (p < 0.001). For children and adults with a successful ortho-k treatment of at least one year of duration, 88.7% and 95.9% of eyes had a predictable refractive outcome, and efficacy was 0.98 and 1.01, respectively. A larger percentage of children (65.7%) were free of complications than of adults (55.4%) (p = 0.015). One event of microbial keratitis occurred in adults (6.8 cases per 10,000 patient-years) and none in children. Corneal staining was the most frequent complication, with a higher incidence in adults (p = 0.007) and in higher myopia (p < 0.001), higher anterior corneal eccentricity (p = 0.019) and smaller anterior horizontal radius (p = 0.027). ConclusionOrthokeratology is a safe and predictable long-term procedure in children and adults, with a low incidence of serious adverse effects. Corneal staining episodes are relatively frequent throughout the course of the treatment, thus highlighting the relevance of education of experienced users.

The relationship between myopia progression and axial elongation in children wearing orthokeratology contact lenses

PurposeTo investigate the relationship between myopia progression and axial length (AL) elongation in orthokeratology (ortho-k) patients. MethodsThis study investigated 184 patients (baseline age 9.0 ± 1.6 years), who underwent overnight ortho-k treatment for 12 to 72 months, and stopped lens wear for 1 to 2 months. Refractive sphere and cylinder after cycloplegia, corneal curvatures along both meridians, and AL were compared before the commencement and after discontinuation of ortho-k treatment. The effects of AL change, baseline AL, corneal curvature change, baseline age, and duration of ortho-k treatment on the change in spherical equivalent refractive error (SER) were analysed. ResultsMyopia significantly progressed and AL increased following 32.8 ± 13.0 months of ortho-k lens wear and 1 to 2 months washout period, as compared to baseline (all P < 0.001). Corneal curvature along the flat meridian (FK) became significantly flatter (P < 0.001) and corneal curvature along the steep meridian (SK) became steeper (P = 0.036). In the first stepwise multiple linear regression model (R2 = 0.696), the change in SER over time (ΔSER) is significantly correlated to the change in AL (ΔAL, P < 0.001), baseline AL (P < 0.001), baseline age (P = 0.028), change in SK (P = 0.002), and the duration of ortho-k lens treatment before discontinuation (P = 0.010). In a more simplified model (R2 = 0.628), the regression equation using ΔAL to predict ΔSER is: ΔSER = -0.094–1.608*ΔAL. ConclusionsThe change in SER was significantly correlated to the change in AL, change in SK, baseline AL, baseline age, and the duration of treatment among children undergoing ortho-k therapy. The ratio of axial elongation to myopia progression was approximately 1:1.6 between the ages of 6 to 14 years. A simplified equation was derived for clinical use to estimate myopia progression from repeated AL measurement in ortho-k patients.

Repeatability and reproducibility of manual choroidal thickness measurement using Lenstar images in children before and after orthokeratology treatment

PurposeTo investigate the repeatability and reproducibility of choroidal thickness measurements using Lenstar images in young myopic children before and after one-month orthokeratology (ortho-k) treatment. MethodOcular biometry of 39 subjects were performed using the Lenstar 900. The first five measurements with maximum differences of 0.02 mm in axial length in the right eyes were saved and used for measurement of choroidal thickness. Subfoveal choroidal thickness were manually measured by identifying the signals from the retinal pigmented epithelium layer and chorioscleral interface. Repeatability was determined by comparing measurements of the same images made by the same observer on two separate occasions (four weeks apart), while reproducibility was calculated by comparing measurements of the same images made by two independent observers. Data was analysed using intra-class correlation coefficients (ICC) and non-parametric Bland and Altman plots. ResultsThe choroidal peaks could not be identified in all five measurements in all subjects. On average, only 71% subjects had at least four definable images. Compared with the use of fewer than four images, reliability using an average of four definable images improved statistically, but remained clinically unacceptable (>10 µm), although pre- and post-ortho-k ICC values were good to excellent for repeatability (0.867 and 0.975, respectively) and excellent and good for reproducibility (0.959 and 0.868, respectively). Non-parametric pre- and post-ortho-k limits of agreement (2.5% and 97.5% percentiles) obtained were −45.8 to 79.3 µm and −30.3 to 9.5 µm, respectively for repeatability, and −29.0 to 33.5 µm and −21.8 to 70.0 µm, respectively for reproducibility. ConclusionChoroidal thickness measurements using the Lenstar did not show good reliability, despite the high ICC values, non-parametric Bland and Altman plots demonstrated a wide variability of measurement errors. Any changes in subfoveal choroidal thickness, measured by Lenstar, of <80 µm may not represent real changes.

Blur Detection Sensitivity Increases in Children Using Orthokeratology.

PurposeTo investigate changes in blur detection sensitivity in children using orthokeratology (Ortho-K) and explore the relationships between blur detection thresholds (BDTs) and aberrations and accommodative function.MethodsThirty-two children aged 8–14 years old who underwent Ortho-K treatment participated in and completed this study. Their BDTs, aberrations, and accommodative responses (ARs) were measured before and after a month of Ortho-K treatment. A two forced-choice double-staircase procedure with varying extents of blur in three images (Tumbling Es, Lena, and Street View) was used to measure the BDTs. The participants were required to judge whether the images looked blurry. The BDT of each of the images (BDT_Es, BDT_Lena, and BDT_Street) was the average value of the last three reversals. The accommodative lag was quantified by the difference between the AR and the accommodative demand (AD). Changes in the BDTs, aberrations, and accommodative lags and their relationships were analyzed.ResultsAfter a month of wearing Ortho-K lenses, the children’s BDT_Es and BDT_Lena values decreased, the aberrations increased significantly (for all, P ≤0.050), and the accommodative lag decreased to a certain extent [T(31) = 2.029, P = 0.051]. Before Ortho-K treatment, higher-order aberrations (HOAs) were related to BDT_Lena (r = 0.463, P = 0.008) and the accommodative lag was related to BDT_Es (r = −0.356, P = −0.046). After one month, no significant correlations were found between the BDTs and aberrations or accommodative lags, as well as between the variations of them (for all, P ≥ 0.069).ConclusionOrtho-K treatment increased the children’s level of blur detection sensitivity, which may have contributed to their good visual acuity.

Two-year add-on effect of using low concentration atropine in poor responders of orthokeratology in myopic children

MethodsAxial elongation in 73 eyes of 73 subjects who completed 3 years of orthokeratology (ortho-k) treatment was retrospectively reviewed. During their first year of ortho-k treatment (phase 1), they all...

Categorisation of myopia progression by change in refractive error and axial elongation and their impact on benefit of myopia control using orthokeratology.

AimsTo compare the value of pre-treatment axial elongation (AE) and changes in refractive sphere (M change) for predicting the success in orthokeratology (ortho-k), in order to better identify suitable candidates for myopia control.MethodsThis study further analysed the data of 66 subjects receiving 7-month ortho-k treatment, following a 7-month observation period, during which single-vision spectacles were worn. Rate of myopia progression was determined by AE and M change and subjects categorised as slow, moderate, or rapid progressors based on these changes. Outcomes of myopia control, based on the AE reduction after ortho-k, were classified as ‘ineffectual’, ‘clinically insignificant’, or ‘beneficial’.ResultsOf the 20 subjects, initially categorised as slow by AE and, of whom 95% were similarly categorised by M change, none benefitted from ortho-k. In contrast, of the 22 subjects with moderate AE, 77% and 23% displaying slow and moderate M change, respectively, the majority (73%) benefitted from ortho-k lens wear. The 24 subjects with rapid AE were poorly identified by M change, with only 21% correctly categorised. The vast majority of rapid progressors showed significant benefit after ortho-k.ConclusionProgression of AE is a good indicator of subsequent success of ortho-k treatment. Delaying commencement of therapy is prudent for children with slow progression as results indicate that they would be unlikely to benefit from this intervention. As change in refractive error frequently underestimates rapid progression of AE, its value for identifying appropriate candidates for myopia control is poor.

Analysis of parental decisions to use orthokeratology for myopia control in successful wearers.

To investigate factors that influence parental decisions to use orthokeratology (ortho-k) as a myopia control method for their children, and parents' perspectives during children's ortho-k treatment in a hospital setting. Parents/guardians of children wearing ortho-k lenses for at least six months were required to complete a face-to-face survey to investigate the reasons for choosing ortho-k and their experience of the treatment. Parents/guardians of 128 ortho-k wearers were recruited from the West China Hospital, Sichuan, China. The majority of the participants (74%) were mothers. Wearers' mean age at the time of the survey was 12.0±2.0years, with a mean history of ortho-k lens wear of 20.3±8.0months. Most participants had learned about ortho-k through word of mouth (56%) or from ophthalmologists (40%); in China, only ophthalmologists may prescribe ortho-k. The highest ranked motivation was the rapid progression of their children's myopia (54%), followed by ophthalmologists' advice (17%) or participants' who felt they had obtained enough knowledge (17%) of ortho-k (Kruskal-Wallis test, p=0.002). 'Effectiveness' was the most common reason that participants decided to use ortho-k (81%), and potential injury was their major concern (75%). Itchy/sore eye was the most common initial adverse effect experienced with lens wear (22%), while a lost or broken ortho-k lens was the most frequently reported problem (34%). Parents of older lens wearers were significantly less involved in all procedures (Spearman rank correlation test, all p<0.001). Most wearers, according to either the participants or the wearers themselves, were willing to wear ortho-k lenses at treatment commencement (80%), and the most common reason was 'to avoid having to wear spectacles in the daytime'. The most powerful motivation for parents to enrol their children in ortho-k treatment was the rapid progression of myopia. The main reason why participants chose ortho-k, which most participants learned of by word of mouth, was the effectiveness of the treatment. During use, the most common symptom reported was itchy or sore eyes, but only initially. Children's willingness to participate is very important for successful ortho-k treatment; however, their motivation can be quite different from that of their parents. Ortho-k is a well-accepted option for myopia control in children.

Trajectories of myopia control and orthokeratology compliance among parents with myopic children

SignificanceThis study set out to illustrate the trajectories of myopia control in time sequence and explore orthokeratology compliance for parents with myopic children in the first fitting within one year. Profiling these results is crucial to improving myopia control and orthokeratology care. PurposeTo obtain a better understanding of myopia control and orthokeratology care that could promote compliance with orthokeratology (ortho-K) lenses for parents with myopic children. MethodsWe conducted semi-structured qualitative interviews and pre-interview questionnaire surveys of the parent who is mainly responsible for complying to ortho-K lens care for their myopic children aged 7–12 years, including 16 mothers and 4 fathers. A framework analytical approach that involved gaining familiarity with the data to identify a thematic framework was used for data analysis. It was written in line with the COREQ (Consolidated Criteria for Reporting Qualitative Research) checklist. ResultsFive themes and twelve subthemes depicted the parents’ trajectory during myopia diagnosis, treatment, and compliance with ortho- K for their children in the first fitting within one year. Myopia control and the convenience of outdoor activities were important reasons for parents to actively ask for ortho-K lenses for their children. Parents have non-compliance behaviors after the children wore the lenses for three months, including not scheduling follow-up visits, simplifying cleaning procedures, not replacing accessories. The degree of parents’ non-compliance differed based on the uncomfortable feelings of their child’s eyes. In general, clear, unaided vision (visual acuity > 0.9) during the day was an indicator of ortho-K’s effectiveness, according to parents. ConclusionsAlthough parents play a passive role when a child is diagnosed with myopia, they take on a proactive role when deciding on ortho-K treatment. Myopia treatment for children is a long-term process. Understanding the course of treatment and non-compliance helps eye care professionals provide parents with the necessary assistance and resources, and enables myopia treatment to yield maximum effects.

A comparative study of orthokeratology and low-dose atropine for the treatment of anisomyopia in children

Myopic anisometropia (anisomyopia) is a specific type of refractive error that may cause fusion impairment, asthenopia, and aniseikonia. It is sometimes severe enough to reduce the quality of life. Several studies have investigated the treatment effects of orthokeratology (Ortho-K) and topical atropine on anisomyopia control. However, no study has compared these two interventions simultaneously until now. The cohort of this retrospective study included 124 children with anisomyopia who were treated with binocular Ortho-K lenses, 0.01% atropine, or 0.05% atropine. After a 2-year follow-up, the inter-eye difference in axial length (AL) significantly decreased in the Ortho-K group (P = 0.015) and remained stable in the two atropine groups. When comparing the myopia control effect, the use of Ortho-K lenses resulted in an obviously smaller change in AL than the use of 0.01% and 0.05% atropine (P < 0.01). Ortho-K treatment may reduce the degree of anisomyopia and stabilise the progression of myopia. Hence, Ortho-K might be a better choice for anisomyopic children.