Myopia correction in children: a meta-analysis.

Background: Rigid gas permeable (RGP) and silicone hydrogel (SH) contact lenses with specific designs are currently being used to improve visual function in patients with keratoconus. However, there are minimal data available comparing the effects of these lenses on visual function in patients with keratoconus. The objectives of this study were to compare visual acuity and contrast sensitivity using spectacles, RGP lenses, and SH lenses, and to evaluate the effects of RGP and SH lenses on higher-order aberrations and visual quality in eyes with keratoconus. The relationship between visual outcomes, aberration, and visual quality were also examined. Methods: This was a pilot study involving 13 eyes from nine subjects with keratoconus. Subjects were fitted with RGP and SH contact lenses. Visual acuity and contrast sensitivity were measured using Snellen and Pelli-Robson charts, respectively. Ocular aberrations and visual quality were measured using an OPD-Scan II device. All measurements were conducted before and after contact lens wear. Results: Significantly better visual acuity was obtained with RGP lenses than with spectacles or SH lenses ( P <0.001). No significant difference in contrast sensitivity values was detected between RGP and SH lenses ( P =0.06). Both SH and RGP lenses significantly reduced total ocular and higher-order aberrations ( P <0.001) when compared with spectacles, but RGP lenses reduced trefoil, coma, and spherical aberrations more than SH lenses. No significant difference in astigmatic aberrations was found between RGP and SH lenses ( P =0.12). Negative correlations were found between visual acuity and coma aberration and contrast sensitivity with higher-order aberrations and coma, trefoil, and astigmatic aberrations. Regarding visual quality, no significant difference was found between RGP and SH lenses, but RGP significantly improved visual quality when compared with spectacles ( P =0.04). Conclusion: RGP lenses provided better visual acuity and greater reduction of aberrations than spectacles or SH lenses in patients with keratoconus. However, more data are needed to confirm these findings. Keywords: visual acuity, contrast sensitivity, aberration, visual quality, keratoconus

BackgroundTo compare axial elongation in 8–11-year-old myopes wearing orthokeratology (OK) lenses with different back optic zone diameters (BOZD), defocus incorporated soft contact (DISC) lenses, and single-vision soft contact lenses (SCLs).MethodsA total of 122 children (aged 8–11 years) with spherical equivalent refraction (SER) between − 1.00 D and − 4.00 D were enrolled in this prospective study and randomly assigned to four groups: 5.0 mm-BOZD OK, 6.2 mm-BOZD OK, DISC, and single-vision SCLs. Children in each group were further divided into subgroups stratified by the average baseline SER: low myopic eyes (SER: − 1.00 D to − 2.50 D) and moderate myopic eyes (SER: − 2.50 D and over). Axial length (AL) was measured at baseline and after one year.ResultsThe 5.0 mm-BOZD OK, 6.2 mm-BOZD OK, and DISC groups exhibited significantly slower AL elongation than the SCL group. The proportion of slow progressors (AL elongation ≤ 0.18 mm/year) in the first three groups was 42%, 23%, and 29%, respectively. Furthermore, one-year AL elongation was significantly smaller in the 5.0 mm-BOZD OK group compared with the 6.2 mm-BOZD OK group. Regardless of SER, children in the 5.0 mm-BOZD OK and DISC groups showed comparably slower AL elongation than those in the SCL group. However, fitting with 6.2 mm-BOZD OK lenses significantly retarded AL elongation in moderate myopic eyes, but not in low myopic eyes.ConclusionsOverall, 5.0 mm-BOZD OK lenses, 6.2 mm-BOZD OK lenses, and DISC lenses were effective in retarding AL elongation in 8–11-year-old myopes compared with single-vision SCLs, but for children with SER less than − 2.50 D, fitting with 5.0 mm-BOZD OK lenses and DISC lenses yielded better myopia control efficacy compared to wearing single-vision SCLs or 6.2 mm-BOZD OK lenses.

This study aimed to compare the efficacy and safety of four types of orthokeratology (OK) lenses (CRT, Lucid, Euclid, and IBright) in controlling mild to moderate myopia progression among children and adolescents over 36 months. This retrospective study analyzed clinical records of 219 children (438 eyes) who wore OK lenses for 36 months. Clinical data for the four commonly used OK lenses were collected and analyzed using one-way analysis of variance (ANOVA) and Pearson's chi-squared test. At baseline, no significant differences were observed among the four groups in terms of age, sex, spherical equivalent, corneal curvature, or corneal thickness (all P > 0.05). All OK lenses effectively controlled myopia progression over the observation period, with axial length changes not exceeding 1.0 mm. At the 36-month follow-up, the IBright group showed the largest flat keratometry (K1) curvature change at 3 months (-2.40 ± 0.97 D), while other groups showed no significant differences at subsequent time points. In terms of steep keratometry (K2) curvature, the Lucid group exhibited the largest change at 24 months (-3.07 ± 1.50 D), but no significant differences were observed among groups at other time points. Axial length changes showed no statistically significant differences among the four OK lenses across follow-up visits (P > 0.05). Subgroup analysis indicated greater axial elongation in children under 12 years old compared to those over 12 years. Among children with corneal thickness less than 530μm, the CRT group demonstrated the largest K1 curvature change. The incidence of adverse events was comparable across groups (P > 0.05). All four OK lenses demonstrated comparable efficacy and safety in controlling myopia progression, providing effective treatment options for children and adolescents with mild to moderate myopia. However, differences in curvature changes and age-related effects warrant further attention.

BackgroundMany efforts have been invested in slowing progression of myopia. Among the methods, atropine administration and orthokeratology (OK) are most widely used. This study analyzed the efficacy of atropine and OK lens in controlling myopia progression and elongation of axial length.MethodsThis retrospective study included 105 patients (210 eyes) who wore OK lenses and 105 patients (210 eyes) who applied 0.125% atropine every night during the 3 following period. Student t-test, linear regression analysis, repeated measure ANOVA, and Pearson’s correlation coefficient were used for statistical analysis.ResultsThe change in axial length per year was 0.28 ± 0.08 mm, 0.30 ± 0.09 mm, and 0.27 ± 0.10 mm in the OK lens group, and 0.38 ± 0.09 mm, 0.37 ± 0.12 mm, and 0.36 ± 0.08 mm in the atropine group for years 1, 2, and 3, respectively. Linear regression analysis revealed an increase in myopia of 0.28 D and 0.34 D per year, and an increase in axial length of 0.28 mm and 0.37 mm per year in the OK lens and atropine groups, respectively. Repeated measure ANOVA showed significant differences in myopia (p = 0.001) and axial length (p < 0.001) between the atropine and OK lens groups; in astigmatism, there was no significant difference in these parameters (p = 0.320). Comparison of increases in axial length in relation to baseline myopia showed significant correlations both in the OK lens group (Pearson’s correlation coefficient, r = 0.259; p < 0.001) and atropine group (r = 0.169; p = 0.014). High myopia patients benefited more from both OK lenses and atropine than did low myopia patients. The correlation of baseline myopia and myopia progression was stronger in the OK lens group then in the atropine group.ConclusionsOK lens is a useful method for controlling myopia progression even in high myopia patients.

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

Rigid gas permeable contact lenses: Out in the cold

BackgroundThe non‐predictable variability in the capability of sensory adaptation to rigid gas permeable (RGP) contact lenses (CLs) represents a considerable challenge for CL practitioners and patients when choosing this CL type. This study explored if lid margin sensitivity and general pain sensitivity at baseline may help predict experienced subjective comfort of RGP CL wear.MethodsFor this prospective clinical cohort study, subjects filled in the Pain Sensitivity Questionnaire and lid margin sensitivity was measured at the lid wiper of the upper and lower lid at baseline, using the Cochet Bonnet aesthesiometer. RGP CL parameters were determined based on corneal topography, with additional use of fluorescein simulation. During the second visit, lid wiper sensitivity measurement was repeated and the RGP CLs were worn for 40-minutes. Upon removal of the CLs, lid wiper sensitivity measurement was repeated and spontaneous CL comfort was rated.ResultsThirty‐four subjects participated (mean age: 23.85 ± 5.39-years; 17 male). No correlation could be observed between the baseline lid margin sensitivity and spontaneous CL comfort (r = 0.013, p = 0.9417, upper lid; r = 0.016, p = 0.9277, lower lid). A decrease in lid margin sensitivity was obtained after CL wear (p = 0.0004, upper lid; p = 0.0001, lower lid). A good correlation was observed between Pain Sensitivity Questionnaire score and spontaneous CL comfort (r = 0.62, p = 0.0007).ConclusionThe results of this study suggest that lid margin sensitivity may not play an important role in spontaneous RGP CL comfort. The use of the Pain Sensitivity Questionnaire may well help select patients who are more likely to show good spontaneous tolerance of RGP CLs.

Comparison of the efficacy of orthokeratology and highly aspherical lenslets in slowing myopia progression.

Visual performance in the correction of astigmatism with contact lenses: Spherical RGPs versus tonic hydrogels

The effectiveness of hard orthokeratology (OK) lenses in controlling myopia has been confirmed in clinical practice. However, there exist defects including wear discomfort, limited regulation of mechanical properties and geometry, and effectiveness inconsistency with the expected efficacy. Herein, we analyze the relationship between the mechanical properties of OK lenses and the vertex displacement of the human cornea through the finite element model. It is noted that the expected corneal deformation of 15-20 μm can be achieved by soft OK lenses with an elasticity modulus above 9 MPa, which is far lower than the 2.7 GPa of commercial OK lenses. No obvious displacement difference occurred when the elasticity modulus of the OK lenses exceeded 200 MPa. Thus, we propose the hypothesis of soft OK lenses based on hydrogel materials for controlling myopia. The soft OK lenses are fabricated by a two-step 3D printing technology using a multicomponent bioink containing methyl methacrylate, hydroxyethyl methacrylate, polyethylene glycol diacrylate, and 3-(trimethoxysilyl)propyl methacrylate (KH-570). The printed OK lenses possess comfort wear, high light transmittance, smooth surface, regulated elasticity modulus (from 33 to 535 MPa) and geometry, and excellent biocompatibility. Additionally, the effectiveness of soft OK lenses is confirmed through a porcine corneal model with obvious corneal deformation comparable to that of the commercial ones. This study demonstrates the feasibility of soft OK lenses for controlling myopia and provides support for the design and fabrication of soft OK lenses for comfortable wear.

This evaluation was conducted as part of a protocol entitled Evaluation of the Menicon Z Rigid Gas Permeable Contact Lens for up to 30 Days Extended Wear. The purpose of the protocol was to compare corneal endothelial morphology changes after wearing rigid gas-permeable (RGP) Menicon Z contact lenses, continuously for up to 30 days, with ACUVUE (Johnson & Johnson Vision Care) hydrogel contact lenses, worn for up to 6 nights of extended wear. Sixty patients, who were adapted to RGP daily wear and soft contact lens daily wear, were recruited at two study sites. The thirty subjects who wore RGP daily wear lenses were fitted with the Menicon Z (tisilfocon A, oxygen permeablility [Dk] = 163) RGP contact lens comprised the test group. The control group subjects (n = 30 former users of daily wear soft contact lenses) were fitted with ACUVUE (etafilcon A, Dk = 28) hydrogel contact lenses. After a 2-week adaptation period of daily wear, subjects began extended wear. Endothelial imaging was performed at the two study sites in this multicenter study (University Hospitals of Cleveland/Case Western Reserve University Department of Ophthalmology [CWRU] and The Ohio State University [OSU]). The hydrogel lens group was instructed to wear their lenses for 7 days and 6 nights before discarding the lenses and to sleep with no lenses on the seventh night. The RGP group was permitted to wear the lenses for up to 30 days and 29 consecutive nights before removing the lenses for cleaning and overnight soaking. CWRU had 24 patients (12 soft contact lens and 12 rigid contact lens) and OSU had 21 patients (12 soft contact lens and 9 rigid contact lens) who completed the study and were included in the analyses. Patients who were withdrawn from the study at CWRU included one RGP patient dropped out because of pregnancy; one RGP patient developed vascularized limbal keratitis and discomfort; one could not be fitted with a bitoric RGP; two soft lens patients moved from the area, and one dropped out because of dry eyes. At OSU, four patients dropped out due to discomfort (two in each lens type);one moved from the study area; one decided not to participate soon after the consent visit; one had worries of reduced vision at 6 months; one subject's attitude changed prior to the 6 month visit; and one subject was withdrawn for reasons of poor study schedule compliance. The Menicon Z lens wearers in this study did not show significant endothelial cell morphology changes after 1 year of nearly continuous contact lens wear. This finding is particularly important considering the RGP wearers in this study were older by a average of 10 years (mean age approximately 40) and had worn their contact lenses an average of almost 10 years longer than the soft contact lens wearers.

PurposeTo compare peripheral defocus, higher-order aberrations (HOAs), and contrast visual acuity (CVA) in myopic children wearing orthokeratology (OK) lenses and multifocal soft contact lenses (MSCLs) designed with highly addition.MethodsThis is a prospective, nonrandomized, controlled study. Subjects at 8 to 13 years of age with spherical equivalent refraction from − 1.00 to − 5.00 dioptres (D) were included in the OK group (n = 30) and MSCL group (n = 23). Relative peripheral corneal defocus (RPCD) and relative peripheral refraction (RPR) were measured before and after wearing lenses. HOAs including spherical aberration (SA), coma, trefoil, and total HOAs, and high (100%) and low (10%) CVA were compared between the groups. Axial length (AL) was measured before and after wearing the lenses for 1 year.ResultsAfter wearing the lenses, subjects in the MSCL group had RPCD and RPR values similar to the OK group at the paracentral (within 2 mm of the cornea or 20° of the retina, all p > 0.05) but larger than the OK group at the periphery (all p < 0.05). All HOAs increased after wearing the lenses except the trefoil in the MSCL group (all p < 0.05). HOAs increased more in the OK group (all p < 0.05). The 100% and 10% CVAs were worse in the MSCL group (p = 0.02 and p = 0.004). After 1 year, AL elongation was 0.37 mm (SD = 0.16) in the MSCL group and 0.28 mm (0.16) in the OK group (p = 0.06).ConclusionMSCL produced larger myopic defocus at the periphery, increased less HOAs and had worse CVA than OK lens. The high addition of this MSCL did not result in better myopia control efficacyTrial registrationChinese Clinical Trial Registry: ChiCTR1800018564. Registered 25 September 2018; retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=31376

Near binocular visual function in young adult orthokeratology versus soft contact lens wearers.

Clinical relevance Orthokeratology (OK) lens is commonly used to control myopia progression of children. Understanding the relationship between relative peripheral refraction (RPR) and the growth rate of axial length (AL) may assist in explaining myopic progression. Background The aim of this work is to investigate the RPR in myopic children wearing OK lenses, and to evaluate its relationship with the growth rate of AL. Methods RPRs of 31 children wearing OK lenses and 31 children wearing single-vision glasses were measured with multispectral refraction topography (MRT). MRT shows the total RPR (TRPR), RPR in the superior area (RPR-S), RPR in the inferior area (RPR-I), RPR in the temporal area (RPR-T) and RPR in the nasal area (RPR-N), respectively. It also shows RPR in the visual field of 15° (RPR-15), 30° (RPR-30) and 45° (RPR-45), respectively. RPRs in the visual field from 15° to 30°, 30° to 45° and 15° to 45° are recorded as RPR-(30–15), RPR-(45–30) and RPR-(45–15), respectively. According to the growth rate of AL, children wearing OK lenses were further divided into slow and fast growth groups. Results TRPR, RPR-I, RPR-T, RPR-N, RPR-15, RPR-30, RPR-45, RPR-(30–15), RPR-(45–30), and RPR-(45–15) of children in the OK lens group were significantly smaller than in the control group (all P < 0.05). TRPR, RPR-N, RPR-15, RPR-30, RPR-45, RPR-(30–15), and RPR-(45–15) of the slow growth group were significantly smaller than in the fast growth group (all P < 0.05). The growth rate of AL were positively correlated with TRPR (R = 0.383, P = 0.040), RPR-N (R = 0.395, P = 0.034), RPR-30 (R = 0.408, P = 0.028), RPR-45 (R = 0.377, P = 0.044), RPR-(30–15) (R = 0.390, P = 0.036). Conclusions RPRs of children show relative myopic defocus after wearing OK lenses. Furthermore, the growth rate of AL is smaller with more negative RPR.

To record aberrations with a corneal topographic device on the anterior surface of the cornea at different time-points prior to wearing and following discontinued use of rigid gas permeable (RGP) contact lenses. The effect of wearing RGP on the anterior surface of the cornea was discussed to provide guidance for clinical refractive error correction. The study objects were 24 eyes from 24 patients. All patients underwent identical examination procedures prior to lens use, as well as afterwards, including slit-lamp examination, non-contact tonometer measurement, computer optometry and corneal curvature measurement, subjective refraction test, and corneal topography analysis. The patients wore contact lenses everyday for 1 month and then discontinued. Corneal topographies were recorded at certain time points of 30 minutes, 1 day, 3, 7 and 14 days following use. Total corneal aberration at each time point following discontinued use of RGP contact lenses was less than the time point prior to use. Detailed results were as follows: root mean square (RMS) (pre)=(1.438±0.328)µm, RMS (30 minutes)=(1.076±0.355)µm, RMS (1 day)=(1.362±0.402)µm, RMS (3 days)=(1.373±0.398)µm, RMS (7 days)=(1.387±0.415)µm, and RMS (14 days)=(1.430±0.423)µm. Results showed that at 30 minutes after discontinued use of RGP contact lenses, almost all 2(nd)- and 3(rd)-order aberrations change. Quadrafoil Z10 and spherical Z12 of the 4(th)-order were also changed. Alterations to Z5, Z6, and Z12 at 1 day after discontinued use were significant differences compared with the time period prior to RGP use: Z5 and Z6 decreased, and Z12 increased slightly. Z5 and Z6 remained decreased at 3 days after discontinued use, but Z9 and Z10 continued to increase and Z12 returned to levels prior to RGP use. At 14 days after discontinued use, all aberrations were not significantly different from the values prior to use. The use RGP contact lenses greatly reduced total aberration of the anterior surface of the cornea. Changes to 2(nd)- and 3(rd)-order aberrations (including Z3, Z4, Z5, Z6, Z7, and Z8) were more significant. Following discontinued use of RGP contact lenses, the majority of lower order aberrations returned to original levels in a short period of time. During this process, a transient higher order aberration appeared, but all changes disappeared within 14 days after discontinued use of RGP contact lenses.