PURPOSE:To compare the two-year efficacy of spectacle lenses with highly aspherical lenslets (HAL) and orthokeratology (OK) lenses in managing myopia in children. METHODS:This retrospective study examined medical records from the Affiliated Eye Hospital of Wenzhou Medical University, involving 1683 HAL users and 1192 OK users. Participants were children aged 8-13 with a refractive error of -0.50 to -6.00 D. They were divided by age into younger (8-10 years) and older (11-13 years) groups and further divided into low myopia (-0.50 to -3.00 D) and moderate myopia (<-3.00 to -6.00 D) subgroups. The participants were included in either the 1-year or 2-year follow-up group based on the length of their follow-up records. The change in axial length (AL) was compared between the HAL and OK groups using t-tests and multiple linear regression analysis. RESULTS:In the younger group, HALs yielded significantly slower AL elongation than did the OK lenses at both the 1-year (HAL: 0.16 ± 0.19 mm; OK: 0.22 ± 0.17 mm; p < 0.001) and 2-year follow-ups (HAL: 0.32 ± 0.27 mm; OK: 0.37 ± 0.24 mm; p = 0.009). In the older group, the AL changes did not significantly differ by lens at the 1-year (p = 0.782) or 2-year (p = 0.239) follow-up. Among the low myopia subgroup, the HAL users consistently exhibited smaller AL changes than did the OK users across all follow-ups (p < 0.05), except at the 2-year follow-up in the olders (p = 0.414). For the moderate myopia subgroup, the OK lenses yielded significantly slower AL changes at the 2-year follow-up (younger: p = 0.013; older: p = 0.01), although no significant differences were found at the 1-year follow-up (younger: p = 0.635; older: adjusted: p = 0.143). CONCLUSIONS:HALs are significantly more effective than OK lenses in controlling AL elongation in younger children with low myopia, while both treatments show similar effectiveness in older children. For moderate myopia, OK lenses are preferred for superior long-term control.

To explore the distribution characteristics of peripheral retinal defocus in children and adolescents. This cross-sectional study included 500 individuals aged 3 to 18 years, who visited the People's Hospital of Lincang, the First Affiliated Hospital of Dali University and Dali Ophthalmology Hospital between January and December 2021. Data of the right eye of each participant was analyzed. There were 226 males (45.20%) and 274 females (54.80%), with an average age of (10.79±3.79) years. All participants underwent post-cycloplegic refraction, optical biometry, and intraocular pressure measurement to obtain spherical equivalent, average corneal curvature, axial length, and intraocular pressure. Multispectral refraction topography was performed to obtain topographic maps and values at various field angles and orientations of peripheral retinal defocus. Based on multispectral refraction topography, peripheral retinal defocus values were categorized as crater type, hemilateral upturn type, saddle type, and relatively flat type. The distribution of different refractive states was analyzed. The spherical equivalent of the 500 participants was(-1.51±2.61) D, axial length was (24.10±1.28) mm, and average corneal curvature was (43.20±1.22) D. Among the 500 eyes, 382 exhibited hyperopic peripheral retinal defocus values, with 316 eyes (82.72%) being myopic. Myopic peripheral retinal defocus values were observed in 118 eyes, with 15 eyes (12.72%) being myopic. Among different types of peripheral retinal defocus values, 112 eyes (22.4%) exhibited a crater type, 153 eyes (30.6%) exhibited a hemilateral upturn type, 107 eyes (21.4%) exhibited a saddle type, and 128 eyes (25.6%) exhibited a flat type. The proportion of myopia was 82.14% (92 eyes), 69.28% (106 eyes), 60.75% (65 eyes), and 3.90% (5 eyes), respectively. The peripheral retinal defocus values at 15°, 30°, and 45° were (0.01±0.08) D, (0.06±0.21) D, and (0.20±0.37) D, respectively. The peripheral retinal defocus values at temporal, inferior, nasal, and superior locations were (0.58±0.69) D, (0.52±0.63) D, (0.21±0.64) D, and (-0.26±0.67) D, respectively. Notably, the superior primarily manifested as myopic, while the others were predominantly hyperopic. Approximately three-fourths of children and adolescents exhibit hyperopic peripheral retinal defocus values, with a higher prevalence of myopia in this subgroup. The hyperopia peripheral retinal defocus value increases with the distance from the retina to the macula. The peripheral retinal defocus values between superior and inferior, nasal and temporal locations are asymmetrical, with the temporal hyperopic peripheral retinal defocus value being most prominent and the superior myopic peripheral retinal defocus value being most evident.

AIM:To evaluate the refraction difference value (RDV) variations in children and adolescents with different refractive errors and analyze its correlation with refractive development. METHODS:Participants aged 4-16y with different refractive statuses (hyperopia, emmetropia, myopia) underwent comprehensive eye examinations, including spherical equivalent (SE) refraction, axial length (AL), total RDV (TRDV), and RDVs at various eccentricities (0°-15°, 15°-30°, 30°-45°) and quadrants (inferior, superior, nasal, temporal). Statistical analysis involved one-way ANOVA for group comparisons and Pearson correlation for examining relationships between SE/AL and RDVs. Paired -tests compared quadrant-specific RDVs within groups. RESULTS:Significant difference was found in TRDV (<0.001), RDV15°-30° (=0.033), RDV30°-45° (<0.001), RDV-inferior (RDV-I, <0.001) and RDV-temporal (RDV-T, <0.001) among hyperopia, emmetropia and myopia group. Pearson correlation analysis revealed a negative correlation of SE with TRDV (=0.001), RDV30°-45° (=0.004), RDV-I (=0.047), and RDV-T (<0.001). The differences between RDV-superior (RDV-S) and RDV-I were statistically significant in all groups (<0.001 for all) and between RDV-T and RDV-nasal (RDV-N) were statistically significant in hyperopia group (<0.001). Within the pre-myopic group, the analysis revealed a negative correlation of SE with RDV-I (=0.009). Pearson correlation analysis revealed a positive correlation of AL with TRDV (=0.036), RDV15°-30° (=0.004), RDV30°-45° (<0.001), RDV-S (=0.003), RDV-I (<0.001), RDV-T (<0.001), RDV-N (=0.022), while revealed a negative correlation of AL with RDV0-15° (=0.018). CONCLUSION:Our study indicates TRDV, RDV30°-45°, RDV-I, RDV-T may relate to refractive development, and a negative correlation between SE and RDV-I in pre-myopic children.

AIM:To compare relative peripheral refractive errors (RPREs) in Chinese children with and without myopic anisometropia (MAI) and to explore the relationship between RPRE and myopia. METHODS:This observational cross-sectional study included 160 children divided into two groups according to the interocular spherical equivalent refraction (SER) difference ≥1.0 D in the MAI group (=80) and <1.0 D in the non-MAI group (=80). The MAI group was further divided into two subgroups: ∆SER<2.0 D group and ∆SER≥2.0 D group. Basic ocular biometric parameters of axial length (AL), average keratometry (Ave K), cylinder (CYL), surface regularity index (SRI), and surface asymmetry index (SAI) were recorded. In addition, multispectral refraction topography was performed to measure RPRE, and the parameters were recorded as total refraction difference value (TRDV), refraction difference value (RDV) 0-10, RDV10-20, RDV20-30, RDV30-40, RDV40-53, RDV-superior (RDV-S), RDV-inferior (RDV-I), RDV-temporal (RDV-T) and RDV-nasal (RDV-N). RESULTS:In the non-MAI group, the interocular differences of all parameters of RPRE were not significant. In the MAI group, the interocular differences of TRDV, RDV10-53, RDV-S, RDV-I, RDV-T, and RDV-N were significant. In subgroup analysis, the interocular differences of TRDV, RDV30-53, RDV-I, and RDV-T were significant in ∆SER<2.0 D group and ∆SER≥2.0 D group, but the interocular differences of RDV10-30, RDV-S and RDV-N were only significant in the ∆SER≥2.0 D group. In correlation analysis, ∆TRDV, ∆RDV 10-53, ∆RDV-S, and ∆RDV-N were negatively correlated with ∆SER but positively correlated with ∆AL. CONCLUSION:The more myopic eyes have larger hyperopic RPRE in Chinese children with MAI in certain retinal range, and partial ∆RPRE is closely associated with ∆SER and ∆AL.

AIM:To present the 1-year results of a prospective cohort study investigating the efficacy, potential mechanism, and safety of orthokeratology (ortho-k) with different back optic zone diameters (BOZD) for myopia control in children. METHODS:This randomized clinical study was performed between Dec. 2020 and Dec. 2021. Participants were randomly assigned to three groups wearing ortho-k: 5 mm BOZD (5-MM group), 5.5 mm BOZD (5.5-MM group), and 6 mm BOZD (6-MM group). The 1-year data were recorded, including axial length, relative peripheral refraction (RPR, measured by multispectral refractive topography, MRT), and visual quality. The contrast sensitivity (CS) was evaluated by CSV-1000 instrument with spatial frequencies of 3, 6, 12, and 18 cycles/degree (c/d); the corneal higher-order aberrations (HOAs) were measured by iTrace aberration analyzer. The one-way ANOVA was performed to assess the differences between the three groups. The correlation between the change in AL and RPR was calculated by Pearson's correlation coefficient. RESULTS:The 1-year results of 20, 21, and 21 subjects in the 5-MM, 5.5-MM, and 6-MM groups, respectively, were presented. There were no statistical differences in baseline age, sex, or ocular parameters between the three groups (all >0.05). At the 1-year visit, the 5-MM group had lower axial elongation than the 6-MM group (0.07±0.09 0.18±0.11 mm, =0.001). The 5-MM group had more myopic total RPR (TRPR, =0.014), with RPR in the 15°-30° (RPR 15-30, =0.015), 30°-45° (RPR 30-45, =0.011), temporal (RPR-T, =0.008), and nasal area (RPR-N, <0.001) than the 6-MM group. RPR 15-30 in the 5.5-MM group was more myopic than that in the 6-MM group (=0.002), and RPR-N in the 5-MM group was more myopic than that in the 5.5-MM group (<0.001). There were positive correlations between the axial elongation and the change in TRPR (=0.756, <0.001), RPR 15-30 (=0.364, =0.004), RPR 30-45 (=0.306, =0.016), and RPR-N (=0.253, =0.047). The CS decreased at 3 c/d (<0.001), and the corneal HOAs increased in the 5-MM group (=0.030). CONCLUSION:Ortho-k with 5 mm BOZD can control myopia progression more effectively. The mechanism may be associated with greater myopic shifts in RPR.

Introduction:Peripheral retinal refraction plays a crucial role in myopia, but the specific mechanism is not clear. We refined the retinal partitions to explore the characteristics of peripheral retinal refraction and its role in emmetropic, low, and moderate myopic children aged 6 to 12 years. Methods:A total of 814 subjects (814 eyes) were enrolled in the study. The participants were divided into three groups according to the central spherical equivalent refraction (SER), which were emmetropia group (E), low myopia group (LM) and moderate myopia group (MM). Multispectral refractive topography (MRT) was used to measure the retinal absolute and relative refractive difference value (RDV) in different regions. The range was divided into superior, inferior, temporal, and nasal RDV (SRDV, IRDV, TRDV, and NRDV) on the basis of several concentric circles extending outward from the macular fovea (RDV15, RDV30, RDV45, RDV30-15, RDV45-30, and RDV-45). Kruskal-Wallis test was used to analyze the differences of peripheral refraction for all the regions among the three groups. Spearman rank correlation was performed to explore correlations between SER and RDV, axial length (AL) and RDV. Results:The absolute value of RDV decreased with increasing degree of myopia in all regions ( < 0.01). Subjects with different refractive degrees had different relative value of RDV. In nasal position within 45° and temporal position within 30°, the peripheral retina exhibited significantly different relative hyperopic refractive status among Group , Group LM, and Group MM ( < 0.05). SER was negatively correlated with NRDV within 30° (especially in the range of NRDV30-15) ( = -0.141, < 0.01), positively correlated with TRDV within 15° ( = 0.080, = 0.023), and not significantly correlated with SRDV and IRDV when the retina was divided into four parts. AL was positively correlated with NRDV within 30° (especially in the range of NRDV30-15) ( = 0.109, = 0.002), negatively correlated with TRDV within 15° ( = -0.095, = 0.007). Conclusions:The peripheral defocus has significant implications for the genesis of myopia. The peripheral defocus of the horizontal direction, especially within the range of NRDV30, has greater effect on the development of myopia in children. Higher NRDV30 is associated with lower SER and longer AL.

Purpose:To investigate the difference in the retinal refraction difference value (RDV) using multispectral refractive topography (MRT). Methods:Ninety myopic participants, who met the enrolment requirements, were examined with an automatic optometer after mydriasis. According to the value of the spherical equivalent (SE), the participants were divided into Emmetropia group (E, +0.5D < SE < -0.5D), Low Myopia (LM, -0.5D < SE ≤ -3D), and Moderate and high Myopia (MM, -3D < SE ≤ -10D). The ocular biological parameters were detected by optical biometrics (Lenstar 900, Switzerland), including axial length (AL), lens thickness (LT), and keratometry (K1, K2). Furthermore, the MRT was used to measure the retinal RDV at three concentric areas, with 15-degree intervals from fovea into 45 degrees (RDV-15, RDV 15-30, and RDV 30-45), and four sectors, including RDV-S (RDV-Superior), RDV-I (RDV-Inferior), RDV-T (RDV-Temporal), and RDV-N (RDV-Nasal). Results:In the range of RDV-15, there was a significant difference in the value of RDV-15 between Group E (-0.007 ± 0.148) . Group LM (-0.212 ± 0.399), and Group E . Group MM (0.019 ± 0.106) ( < 0.05); In the range of RDV 15-30, there was a significant difference in the value of RDV 15-30 between Group E (0.114 ± 0.219) . Group LM (-0.106 ± 0.332), and Group LM . Group MM (0.177 ± 0.209; < 0.05); In the range of RDV 30-45, there was a significant difference in the value of RDV 30-45 between Group E (0.366 ± 0.339) . Group LM (0.461 ± 0.304), and Group E . Group MM (0.845 ± 0.415; < 0.05); In the RDV-S position, there was a significant difference in the value of RDV-S between Group LM (-0.038 ± 0.636) and Group MM (0.526 ± 0.540) ( < 0.05); In the RDV-I position, there was a significant difference in the value of RDV-I between Group E (0.276 ± 0.530) . Group LM (0.594 ± 0.513), and Group E . Group MM (0.679 ± 0.589; < 0.05). In the RDV-T position, there was no significant difference in the value of RDV-T among the three groups. In the RDV-N position, there was a significant difference in the value of RDV-N between Group E (0.352 ± 0.623) . Group LM (0.464 ± 0.724), and Group E vs. Group MM (1.078 ± 0.627; < 0.05). The RDV analysis in all directions among the three groups showed a significant difference between RDV-S and RDV-I in Group LM ( < 0.05). Moreover, the correlation analysis showed that SE negatively correlated with AL, RDV 30-45, RDV-S, RDV-I, and RDV-N. Conclusions:In this study, there was a significant difference in the value of RDV among Group E, Group LM, and Group MM, and the value of RDV in Group MM was the highest on the whole. In the range of RDV 30-45, there was a growing trend with the increase in the degree of myopia among the three groups. Furthermore, the SE negatively correlated with AL, RDV 30-45, RDV-S, RDV-I, and RDV-N.

Background:The change in refraction caused by accommodation inevitably affects the peripheral defocus state and thus may influence the effect of retinal peripheral myopic defocus measures in myopia control. This study investigated accommodation changes in different peripheral retinas under cycloplegia to help improve myopia control. Methods:Fifty-six eyes of fifty-six myopic subjects were recruited for this prospective study. The center and peripheral retina refractions were measured using multispectral refractive topography. The subjects were divided into low-to-moderate myopia group (range: -1.25 D to -6.00 D) and high myopia group (range: -6.25 D to -9.75 D) according to spherical equivalent (SE). The compound tropicamide (0.5% tropicamide and 0.5% phenylephrine) was used to relax the accommodation. The difference between cycloplegia and non-cycloplegia peripheral retinal refraction was analyzed using the -test. The correlation between eccentricity and changes in peripheral refraction was analyzed using Pearson's correlation analysis. Results:The manifest refraction of the retina significantly decreased with an increase in eccentricity after cycloplegia. The annular refraction difference value at 50°-53° (ARDV 50-53) showed the largest refraction decrease of 1.31 D compared with the central retinal refraction decrease of 0.84 D. The inferior quadrantal refraction difference value had the least change compared to the other quadrants. The relative peripheral refraction (RPR) changes in refraction difference value (RDV) at 15° (RDV-15), RDV-30, and RDV-45 were less than 0.15 D. When the range of annulus narrowed to 5°, the narrower annulus showed faster change with eccentricity increase in ARDV 30-35, ARDV 35-40, ARDV 40-45, ARDV 45-50, and ARDV 50-53. The RPR was highly correlated with eccentricity ( = 0.938 and < 0.001). The high myopia group had a greater hyperopic shift in the periphery than the low-to-moderate group after cycloplegia. Conclusions:Peripheral refraction showed a significant hyperopic shift after cycloplegia with an increase in eccentricity. The RPR became more hyperopic than the central refraction. The high myopia group showed more hyperopic shifts in the peripheral region. Accommodation should be taken into consideration in peripheral defocus treatment.

OBJECTIVE:To observe the associations between regional peripheral refraction and myopia development in young Chinese people. METHODS:Two hundred and forty-one young adult subjects (21 emmetropes, 88 low myopes, 94 moderate myopes, and 38 high myopes) aged 18-28 years were included, and only the right eyes were tested. Eye biometrics were measured before pupil dilation using the Lenstar. Relative peripheral refractive errors (RPRE) were measured after pupil dilation using multispectral refractive topography (MRT), at nine retinal eccentricities: 0-5, 5-10, 10-15, 15-20, 20-25, 25-30, 30-35, 35-40, and 40-45 degrees. RESULTS:In this study, RPRE increased with eccentricity, and it shows a growing trend with the increase of the degree of myopia among emmetropia, low myopia and moderate myopia groups, and RPRE varied with myopia severity at eccentricities between 20 and 35 degrees only. In addition, axial length (AL) and RPRE were positively correlated between 20 and 45 degrees, and AL was an independent risk factor for RPRE between 20 and 35 degrees. CONCLUSION:These findings indicate that the eccentricities between 20 and 35 degrees RPRE may be closely related to refractive development and eye growth in young Chinese people.

AIM:To compare relative peripheral refraction (RPR) in Chinese school children with different refractive errors using multispectral refraction topography (MRT). METHODS:A total of 713 eyes of primary school children [172 emmetropia (E), 429 low myopia (LM), 80 moderate myopia (MM), and 32 low hypermetropia (LH)] aged 10 to 13y were analyzed. RPRs were measured using MRT without mydriasis. MRT results showed RPR at 0-15° (RPR 0-15), 15°-30° (RPR 15-30), and 30°-45° (RPR 30-45) annular in the inferior (RPR-I), superior (RPR-S), nasal (RPR-N), and temporal (RPR-T) quadrants. Spherical equivalent (SE) was detected and calculated using an autorefractor. RESULTS:There were significant differences of RPR 15-30 between groups MM [0.02 (-0.12; 0.18)] and LH [-0.13 (-0.36; 0.12)] (<0.05), MM and E [-0.06 (-0.20; 0.10)] (<0.05), and LM [-0.02 (-0.15; 0.15)] and E (<0.05). There were also significant differences of RPR 30-45 between groups MM [0.45 (0.18; 0.74)] and E [0.29 (-0.09; 0.67)] (<0.05), and LM [0.44 (0.14; 0.76)] and E (<0.001). RPR values increased from the hyperopic to medium myopic group in each annular. There were significant differences of RPR-S between groups MM [-0.02 (-0.60; 0.30)] and E [-0.44 (-0.89; -0.04)] (<0.001), and LM [-0.28 (-0.71; 0.12)] and E (<0.05). There were also significant differences of RPR-T between groups MM [0.37 (0.21; 0.78)] and LH [0.14 (-0.52; 0.50)] (<0.05), LM [0.41 (0.06; 0.84)] and LH (<0.05), and LM and E [0.29 (-0.10; 0.68), <0.05]. A Spearman's correlation analysis showed a negative correlation between RPR and SE in the 15°-30° (=0.005), 30°-45° (<0.05) annular (=0.002), superior (<0.001), and temporal (=0.001) quadrants. CONCLUSION:Without pupil dilation, values for RPR 15-30, 30-45, RPR-S, and T shows significant differences between myopic eyes and emmetropia, and the differences are negatively correlated with SE.

AIM:To investigate the differences in retinal refraction difference values (RDVs) of adult patients with myopic anisometropia compared with those without myopic anisometropia, and to investigate the relationship between ocular biometric measurements and relative peripheral refraction. METHODS:This clinical observation study included 130 patients with myopia (-0.25 to -10.00 D) between October 2022 and January 2023 aged between 18 and 40y. The patients were divided into anisometropia (=63; difference in binocular anisometropia ≥1.00 D) and non-anisometropia (=67; difference in binocular anisometropia <1.00 D) groups accordingly. Ocular biometric measurements were performed by optical biometrics and corneal topography to assess the steep keratometry (Ks), flap keratometry (Kf), axial length (AL), corneal astigmatism (CYL; Ks-Kf), surface regularity index (SRI), surface asymmetry index (SAI), and central corneal thickness (CCT). The RDV was measured at five retinal areas from the fovea to 53 degrees (RDV-0-10, RDV-10-20, RDV-20-30, RDV-30-40, and RDV-40-53), the total RDV (TRDV) of 53 degrees, and four regions, including RDV-superior, RDV-inferior, RDV-temporal, and RDV-nasal. An analysis of Spearman correlation was carried out to examine the correlation between RDV and the spherical equivalent (SE) and ocular biological parameters. RESULTS:Within RDV-20-53, both groups showed relative hyperopic defocus, and the increase in RDV corresponds to the increase in eccentricity. In the myopic anisometropia group, the TRDV, RDV-20-53, RDV-superior, and more myopic eyes had significantly higher RDV-temporal values than less myopic eyes. (<0.05). In the non-anisometropia group, there was no significant difference in the RDV between the more and less myopic eyes at different eccentricities (>0.05). There was a negative correlation between SE and TRDV (=-0.205, =0.001), RDV-20-53 (=-0.281, -0.183, -0.176, <0.05), RDV-superior (=-0.251, <0.001), and RDV-temporal (=-0.230, <0.001), a negative correlation between CYL and RDV-10-30 (=-0.147, -0.180, <0.05), and a negative correlation between SRI and RDV-0-20 (=-0.190, -0.170, <0.05). AL had a positive correlation with RDV-20-30 (=0.164, =0.008) and RDV-temporal (=0.160, =0.010). CONCLUSION:More myopic eyes in patients with myopic anisometropia show more peripheral hyperopic defocus. Diopter and corneal morphology may affect peripheral retinal defocus.

In this population-based observational cross-sectional study, we investigated retinal peripheral refraction in Chinese adults with myopia. We categorized 1511 Chinese adults with myopia (18 - 55 years) into low (LM), moderate (MM), and high myopia (HM) groups. Axial length, central corneal thickness, steep keratometry, flat keratometry, and intraocular pressure were measured. Refractive difference values (RDVs) for different eccentricities (RDV0-53) and the superior (RDV-S), inferior (RDV-I), temporal (RDV-T), and nasal (RDV-N) retinal regions were measured using multispectral refractive topography. The hyperopic defocus was higher for the MM group than for the LM group in RDV20-53, RDV-S, and RDV-T and HM group in RDV20-53, RDV-S, RDV-T and RDV-N. The hyperopic defocus was higher for the HM group than for the LM group in RDV20-53, RDV-S and RDV-T but lower for the LM group in RDV-N. RDV-N decreased with age (R = 0.0191, slope = - 0.01, p < 0.0001), whereas RDV-S (R = 0.0112, slope = 0.01,p < 0.0001) and RDV-T increased (R = 0.0038, slope = 0.01, p = 0.0160). RDV correlated with central spherical equivalent and axial length. Flat keratometry explained the most RDV variation (RDV20-30: β = 0.0714, p < 0.0001; RDV-N: β = 0.1801, p < 0.0001; RDV-S: β = 0.1426, p < 0.0001; RDV-T: β = 0.1239, p < 0.0001). Reference values for peripheral retinal defocus are provided for Chinese adults with different myopia ranges.

To evaluate the repeatability of a multispectral-based refractor in central and peripheral refraction measurement, and to assess the agreement of such measurements with objective refraction (OR) and subjective refraction (SR) in patients with myopia. A total of 60 subjects were recruited in this prospective research. Patients were divided into three groups according to the refractive error. Next, the central and peripheral refraction parameters were measured using multispectral refractive tomography (MRT) before and after cycloplegia. In addition, OR and SR measurements were also performed. The intraobserver repeatability was analyzed using within-subject standard deviation (Sw), test-retest repeatability (TRT), and intraclass correlation coefficient (ICC). Agreement was evaluated using Bland-Altman plot and 95% limits of agreement (LoA). The ICC value of central and peripheral refraction were all higher than 0.97 with or without cycloplegia. The peripheral refraction in the nasal, temporal, superior, and inferior quadrants was slightly worse than other parameters, with the largest error interval being 1.43 D. The 95% LoA of the central refraction and OR or SR ranged from -0.89 to 0.88 D and -1.24 to 1.16 D without cycloplegia, respectively, and from -0.80 to 0.42 D and -1.39 to -0.84 D under cycloplegia, respectively. The novel multispectral refraction topography demonstrated good repeatability in central and peripheral refraction. However, the refraction in the nasal, temporal, superior, and inferior quadrants were not as good as that of central and circle peripheral refraction.

Purpose:To determine the distribution and characteristics of peripheral refraction in adults with myopia using the novel multispectral refraction topography. Method:A total of 187 adults with myopia were recruited for this study. This study was conducted in two stages. Part I: participants were divided into 6 groups based on the central refraction of the right eyes, Part II: according to the interocular differences in refractive error (IOD) of the central refraction, we divided the participants into isomyopia group (IOD<1.00 D) and anisomyopia group (IOD≥1.0 D). We surveyed the characteristics of peripheral refraction and relative peripheral refraction (RPR), as well as the correlation between RPR and central refraction, age, sex, and axial length. Result:Part I: With an increase in the degree of myopia, relative peripheral hyperopia developed from the center to the periphery. A statistically significant hyperopia shift compared to the center ( < 0.05) was first observed on the temporal side within a 40° field of view at the posterior pole of the retina. The RPR of the temporal, superior, and inferior retinas positively correlated only with age. Part II: In the isomyopic participants, there was no difference in peripheral refraction between the eyes ( < 0.05). In the anisomyopic participants, the RPR of the more myopic eyes was more hyperopic than that of the less myopic eyes in NRDV40-50, SRDV10-20, SRDV30-50, TRDV20-30, TRDV40-50, and IRDV10-40. Conclusion:With an increase in the degree of myopia, relative peripheral hyperopia developed from the center to the periphery, and peripheral refraction progressed at different rates in various retinal zones.

BACKGROUND:Myopia, as one of the common ocular diseases, often occurs in adolescence. In addition to the harm from itself, it may also lead to serious complications. Thus, prevention and control of myopia are attracting more and more attention. Previous research revealed that single-focal glasses and orthokeratology lenses (OK lenses) played an important part in slowing down myopia and preventing high myopia. AIM:To compare the clinical effects of OK lenses and frame glasses against the increase of diopter in adolescent myopia and further explore the mechanism of the OK lens. METHODS:Changes in diopter and axial length were collected among 70 adolescent myopia patients (124 eyes) wearing OK lenses for 1 year (group A) and 59 adolescent myopia patients (113 eyes) wearing frame glasses (group B). Refractive states of their retina were inspected through multispectral refraction topography. The obtained hyperopic defocus was analyzed for the mechanism of OK lenses on slowing down the increase of myopic diopter by delaying the increase of ocular axis length and reducing the near hyperopia defocus. RESULTS:Teenagers in groups A and B were divided into low myopia (0D - -3.00 D) and moderate myopia (-3.25D - -6.00 D), without statistical differences among gender and age. After 1-year treatment, the increase of diopter and axis length and changes of retinal hyperopic defocus amount of group A were significantly less than those of group B. According to the multiple linear analysis, the retinal defocus in the upper, lower, nasal, and temporal directions had almost the same effect on the total defocus. The amount of peripheral retinal defocus (15°-53°) in group A was significantly lower than that in group B. CONCLUSION:Multispectral refraction topography is progressive and instructive in clinical prevention and control of myopia.

BACKGROUND:The purpose of this study was to evaluate the repeatability and agreement of multispectral refraction topography (MRT) in measuring retinal refraction before and after cycloplegia in children. The results of this study will provide valuable insights into the accuracy and reliability of MRT as a tool for assessing retinal refraction in pediatric patients. METHODS:Children aged 7 to 18 years old were recruited for this prospective research. The central and peripheral retinal refraction was measured three times using multispectral refraction topography (MRT) before and after cycloplegia. The retinal deviation value (RDV) was used to describe the average peripheral refractive error of the retina. In addition, objective refraction (OR) and subjective refraction (SR) measurements were also performed. RESULTS:A total of 60 children with a mean age of 10.50 ± 1.81 years were enrolled. Before cycloplegia, all the central and peripheral retinal refraction parameters showed good repeatability with the lowest intraclass correlation coefficient (ICC) being 0.78 in the retinal deviation value from 45° eccentricity to 53° of the retina (RDV 45-53). After cycloplegia, the repeatability of MRT was significantly enhanced (lowest ICC = 0.91 in RDV-I). The 95% limits of agreement (LoA) of the central refraction and OR ranged from - 2.1 to 1.8 D before cycloplegia, and from - 1.69 to 0.27 D after cycloplegia. The 95% LoA of the central refraction and SR ranged from - 1.57 to 0.36 D after cycloplegia. All the 95% LoA demonstrated high agreement. CONCLUSIONS:The MRT shows high agreement with autorefractometry and experienced optometrist in measuring central refraction. Additionally, the MRT provides good repeatable measurements of retinal peripheral refraction before and after cycloplegia in schoolchildren.

Purpose of this study is to evaluate the measuring consistency of central refraction between multispectral refraction topography (MRT) and autorefractometry. This was a descriptive cross-sectional study including subjects in Sun Yat-sen Memorial Hospital from September 1, 2020, to December 31, 2020, ages 20 to 35 years with a best corrected visual acuity of 20/20 or better. All patients underwent cycloplegia, and the refractive status was estimated with autorefractometer, experienced optometrist and MRT. We analyzed the central refraction of the autorefractometer and MRT. The repeatability and reproducibility of values measured using both devices were evaluated using intraclass correlation coefficients (ICCs). A total of 145 subjects ages 20 to 35 (290 eyes) were enrolled. The mean central refraction of the autorefractometer was -4.69 ± 2.64 diopters (D) (range -9.50 to +4.75 D), while the mean central refraction of MRT was -4.49 ± 2.61 diopters (D) (range -8.79 to +5.02 D). Pearson correlation analysis revealed a high correlation between the two devices. The intraclass correlation coefficient (ICC) also showed high agreement. The intrarater and interrater ICC values of central refraction were more than 0.90 in both devices and conditions. At the same time, the mean central refraction of experienced optometrist was -4.74 ± 2.66 diopters (D) (range -9.50 to +4.75D). The intra-class correlation coefficient of central refraction measured by MRT and subjective refraction was 0.939. Results revealed that autorefractometry, experienced optometrist and MRT show high agreement in measuring central refraction. MRT could provide a potential objective method to assess peripheral refraction.

Objective:To investigate the association between the peripheral refractive errors of the fundus in different regions and moderate and high myopia. Methods:In this case-control study, 320 children and adolescents aged 6 to 18 years were recruited. Peripheral refractive errors were measured using multispectral retinal refractive topography (MRT). Spherical equivalent (SE) and cylinder errors were classified into low, moderate, and high categories based on the magnitude range. Logistic regression was performed to test the factors associated with myopia. Results:There were 152 participants with low myopia and 168 participants with moderate and high myopia included in the current study. Participants with moderate and high myopia were most likely to be older, with larger axial length (AL), lower SE, less time to watch electronic devices on the weekend, a higher difference between central refractive error and paracentral refractive error from the superior side of the retina (RDV-S), but a smaller difference between the central refractive error and paracentral refractive error from the inferior side of the retina (RDV-I) than those with low myopia (all P <0.05). After logistic analysis, female sex (odds ratio [OR] = 4.14; 95% confidence interval [CI] = 2.16-7.97, P <0.001), AL (OR = 6.88, 95% CI = 4.33-10.93, P <0.001), and RDV-I (OR = 0.52, 95% CI = 0.32-0.86, P = 0.010) were independent factors for moderate and high myopia. Conclusion:Our study demonstrated that the retina peripheral refraction of the eyes (RDV-I) was associated with moderate and high myopia, and RDV-S was only associated with high myopia.

INTRODUCTION:Peripheral defocus was experimentally found to control the development of refraction. PURPOSE:To evaluate peripheral refraction (PR) of myopic eyes in terms of different means of correction and the direction of gaze. MATERIAL AND METHODS:The study examined 128 patients (256 eyes) aged 8-14 years (average 11.07±0.39 years) with myopia from -1.0 to -7.0 (average -3.57±0.27 D). PR was measured without correction, in perifocal (PF), monofocal (MF), progressive glasses (PAL), monofocal soft contact lenses (ΜCL) and after orthokeratological (OCL) correction with the gaze directed straightforward or head angled outward, inward, upward and downward; all measurements were performed using binocular open-field auto ref/keratometer. RESULTS:PR profile without correction and with contact (OCL, ΜCL) correction does not depend on the direction of the gaze. In glasses, peripheral defocus is different with straightforward and skewed gaze directions. OCL forms a significant myopic defocus throughout the periphery of the retina. When using MCL, hyperopic defocus increases in all zones except the extreme temporal. In MF glasses, hyperopic defocus is formed and enhanced in all areas, significantly greater with skewed gaze than with straightforward. In PALs, myopic defocus is formed with gaze directed upward and downward, as well as at the extreme temporal periphery of the retina with straightforward gaze. In all other zones, hypermetropic defocus increases. In PF, in most zones myopic defocus is formed with all gaze directions. The greatest inhibitory effect on myopia progression is provided by OCL (YPR=0.28 D/year) and PF glasses (YPR=0.26 D/year). CONCLUSION:In contrast to correction with contact lenses, PR in glasses does depend on the direction of gaze. The inhibitory effect of the optics correlates with correction of hypermetropic defocus in myopic eyes.