The Effect of Lens Design on Corneal Power Distribution in Orthokeratology.

SIGNIFICANCE: This study will enhance our understanding of the effects of orthokeratology lens design on corneal profile, the results of which may be useful in developing future orthokeratology lens designs. PURPOSE: This study aimed to evaluate the effect of lens design on corneal power distribution after orthokeratology using mathematical methods. METHODS: Sixty-five subjects were enrolled in this prospective study and assigned to four groups: Euclid with 6.2-mm back optic zone diameter (aged <14 years), Euclid with 6.2-mm back optic zone diameter (aged ≥14 years), double tear reservoir lens with 5.0-mm back optic zone diameter, and double tear reservoir lens with 6.0-mm back optic zone diameter. Manifest refraction and corneal topography were checked at baseline and 1 day, 1 week, 2 weeks, and 1 month after lens wear. Relative corneal refractive power change was calculated by a polynomial function and a monomial function. The maximum relative corneal refractive power change (Ymax) and the corresponding distance from the corneal center (Xmax) were analyzed. Relative corneal refractive power change over time and between groups was compared using repeated-measures analysis of variance. RESULTS: Refractive reduction and central corneal flattening were seen at all follow-up visits after orthokeratology lens wear, being fastest in the 5.0-mm back optic zone diameter group (P < .001). The cornea steepened in an aspheric way toward the midperiphery and peaked at approximately 2 to 3 mm off the apex. Overall, Ymax was not different among the four groups, but Xmax was smallest in the 5.0-mm back optic zone diameter group (P < .001). At 1/2 Xmax, relative corneal refractive power change of the 5.0-mm back optic zone diameter design was significantly higher than that of the other three groups (P < .001). The power exponent of the monomial of the 5.0-mm back optic zone diameter design was greater than that of the other three groups (P < .001). CONCLUSIONS: An orthokeratology lens design with smaller back optic zone diameter might yield a faster myopic reduction and a smaller aspheric treatment zone.

Optic disc shape in patients with long-lasting unilateral esotropia and exotropia.

BACKGROUND: Horizontal eye movements have been proposed to induce biomechanical stress and strain on optic nerve head. Since strabismus may lead to sustained adduction or abduction, we investigate the effects of long lasting unilateral horizontal strabismus on the morphology of optic disc. METHODS: The observational cross-sectional study included patients with unilateral constant horizontal strabismus lasting for more than two years. The patients underwent an ophthalmological examination including refraction and morphometry of the optic nerve head. A prism cover test using right angle glass prism was performed to measure the magnitude of the ocular deviation. RESULTS: The study included 70 patients with a unilateral constant strabismus (35 esotropic patients, 35 exotropic patients) with a mean age of 26 ± 19 years, mean refractive error of - 0.72 ± 3.3 diopters, mean axial length of 23.8 ± 1.7 mm, and a mean angle of deviation of 87 ± 36 prism diopters (Chinese right-angle glass method) in the esotropic group and - 97 ± 29 prism diopters in the exotropic group. In the whole study population and taken separately in the esotropic group and exotropic group, the disc ovality index (defined as ratio of minimal-to-maximal optic disc diameter) did not differ significantly between the deviating eyes and the contralateral fixating eyes (all P > 0.05). As a corollary, the disc ovality index and the prevalence of parapapillary beta/gamma zone did not differ significantly between the esotropic group and the exotropic group (all P > 0.05). CONCLUSIONS: Optic disc ovality did not differ markedly among long-lasting esotropic eyes, exotropic eyes, and non-strabismic eyes. It suggests that optic disc shape may not be markedly influenced in non-highly myopic eyes by a potential backward pull of the optic nerve on the optic disc structures in adduction or abduction.

Acquired distance esotropia associated with myopia in the young adult.

BACKGROUND: To describe the clinical features of acquired progressive esotropia, with a larger angle at distance than near, associated with myopia in young adults. METHODS: Eleven adults (ages ranging from 18 to 37 years) with constant or intermittent horizontal diplopia at distance were recruited. Subjective refraction, ocular alignment, fusional amplitudes and horizontal eye movements were measured at distance and near. RESULTS: Distance esotropia varied from 20 to 60 prism diopters (PD). At near, the esotropic deviation ranged from 10 to 30 PD. Spherical equivalents (SE) of the right eye ranged from - 3.50 to - 8.25 diopters (D) while SE of the left eye ranged from - 0.375 to - 7.25 D. Ten of the eleven patients presented with constant diplopia at distance. Horizontal ductions and versions were full in all patients. The pathological report of seven patients who underwent lateral rectus resection showed that there were no muscle fibres, but rather, collagenous fibres. CONCLUSIONS: This unusual sub-type of strabismus is a benign entity with slow progression that can occur in young adults with myopia. The cause of this condition is still unknown, and may be related to long periods of near work.

Prediction of Orthokeratology Lens Decentration with Corneal Elevation.

SIGNIFICANCE: Lens decentration is common and unavoidable to some extent during ortho-k treatment. By using a simplified method, we are able to predict the magnitude and direction of ortho-k lens decentration, which provides useful insights in screening for ideal ortho-k candidates and to make a quick decision when decentration happens. PURPOSE: The aim of this study was to investigate the influence of corneal elevation asymmetry on ortho-k lens decentration. METHODS: Thirty-six eyes of 36 subjects were fitted with four-curve reverse geometry ortho-k contact lenses. Corneal topography was collected before and 1 month after ortho-k lens wear. The difference in corneal elevation at the 8-mm chord of the respective two principal meridians of corneal astigmatism was calculated. Vector analyses were performed on these differences to calculate the magnitude and direction of a vector (corneal asymmetry vector). The relationship between the angle and magnitude of corneal asymmetry vector and lens decentration was analyzed. RESULTS: Baseline refractive sphere and cylinder for the 36 tested eyes were -2.84 ± 1.04 diopters (D) (range, -4.75 to -1.00 D) and -0.21 ± 0.28 D (range, -1.00 to 0 D), respectively. The mean magnitude of lens decentration was 0.72 ± 0.26 mm (0 to 1.34 mm). For overall displacement, inferotemporal decentration was the most common as observed in 24 eyes (67%). The mean angle of the corneal asymmetry vector (202 ± 39 degrees) was significantly correlated to the mean angle of lens decentration (200 ± 39 degrees) (r = 0.76, P < .001). The magnitude of corneal asymmetry vector significantly contributed to the magnitude of lens decentration (standardized ß = 0.448, P = .002) whereas the other tested variables did not affect lens decentration (all P > .05). CONCLUSIONS: Lens decentration is a common phenomenon in ortho-k that mostly happens toward the inferotemporal quadrant of the cornea. The magnitude and direction of lens decentration are predetermined by paracentral corneal asymmetry.

Effects of Orthokeratology on Choroidal Thickness and Axial Length.

PURPOSE: To investigate the effect of orthokeratology (ortho-k) treatment on choroidal thickness and its relationship with axial length change. METHODS: Seventy-seven myopic subjects aged between 7 and 17 years were treated with ortho-k lenses (n = 39) or single-vision spectacle lenses (SVL, n = 38). Choroidal thickness and axial length measurements were taken at baseline and repeated 1 week and 3 weeks after lens wear for the ortho-k group and at 3 weeks for the SVL group. Parafoveal choroidal thickness was assessed using optical coherence tomography and segmented into nine regions according to the Early Treatment Diabetic Retinopathy Study (ETDRS) within a 6 × 6 mm circular zone centered on the fovea. Axial length was measured using partial coherence interferometry. The changes in subfoveal choroidal thickness were compared to the changes in axial length in both study groups. RESULTS: The change in axial length was significantly correlated with the change in choroidal thickness in both groups at 3 weeks (ortho-k, r = -0.351, p = 0.028 vs. SVL, r = -0.408, p = 0.011). Parafoveal choroidal thickness increased after 3 weeks of lens wear in the ortho-k group (mean, 21.8 ± 25.2 µm) but did not change in the SVL group (mean, 0.1 ± 19.7 µm). Choroidal thickness significantly varied across the posterior retinal regions (F = 82.14, p < 0.001), with the temporal regions being thickest and nasal regions being thinnest. After 3 weeks of ortho-k treatment, the magnitude of change (range, 14.1-27.6 µm) in choroidal thickness of the nine ETDRS regions was proportional to the baseline choroidal thickness in those regions (r = 0.88, p = 0.002). Axial length did not significantly change over time (F = 0.001, p = 0.975) and did not differ between the two treatment modalities (F = 0.305, p = 0.582). CONCLUSIONS: Choroidal thickness increases after short-term ortho-k treatment. Regional choroidal thickening after ortho-k treatment may be attributable to the altered retinal defocus profile associated with ortho-k lens wear.

[The impact of amplitude of accommodation on controlling the development of myopia in orthokeratology].

OBJECTIVE: To evaluate the impact of amplitude of accommodation on controlling the development of myopia in orthokeratology. METHODS: Forty-nine children aged 7 to 14 years were enrolled in this prospective clinical study.Orthokeratology was performed to correct the refractive errors of these children after measurement of refraction, corneal topography, amplitude of accommodation and axial length. Axial length (AL) and amplitude of accommodation was measured after treatment. The average amplitude of accommodation was calculated and was used as the cutting point for dividing the cohort into "amplitude of accommodation above average" vs. "amplitude of accommodation below average". Data were analyzed by paired t-test, independent t-test, repeated measures-ANOVAs and Pearson correlation analysis. RESULTS: The AL before and after 1- year and 2-year treatment was (24.98 ± 0.75) mm, (25.13 ± 0.74) mm and (25.32 ± 0.78) mm, respectively. AL increased significantly throughout the observed 24-month period (F = 75.848, P < 0.001) . Amplitude of accommodation increased from (13.68 ± 2.65) D to (16.12 ± 2.41) D in 2 years (t = -6.461, P < 0.001) and amplitude of accommodation significantly affected axial growth (F = 7.395, P = 0.009) . The axial growth of subjects with below average amplitude of accommodation and those with above average amplitude of accommodation was (0.23 ± 0.25) and (0.44 ± 0.30) mm, indicating a statistically difference(t = -2.719, P = 0.009). AL change in subjects with below average amplitude of accommodation was 55.81% that of the subjects with above average amplitude of accommodation. Baseline amplitude of accommodation was positively correlated to axial growth at 24-month visit (r = 0.502, P < 0.001). Linear regression analysis was used between baseline amplitude of accommodation and 2-year axial growth: Axial growth = 0.055· Baseline amplitude of accommodation-0.409(F = 15.806, P < 0.001). The change of amplitude of accommodation for subjects with below average amplitude of accommodation and those with above average amplitude of accommodation after 2-year was (4.04 ± 2.16) D and (0.91 ± 2.15) D, indicating statistically difference (t = 5.084, P < 0.001). CONCLUSIONS: Myopic control effect would be more beneficial to lower amplitude of accommodation children than that to higher amplitude of accommodation children in orthokeratology. The enhancement of accommodation provides some basis for slowing myopia progression with orthokeratology.

Effects on radius of curvature and refractive power of the cornea and crystalline lens by atropine 0.01% eye drops.

PURPOSE: The morphological changes in the cornea and crystalline lens have not been closely evaluated after the administration of atropine 0.01%. This study aims to evaluate the radii of curvature and refractive power of the cornea and lens in myopic eyes during atropine 0.01% treatment. METHODS: Children aged 6-14 years with myopia <-6.0 D were randomized to receive atropine 0.01% once nightly with single vision lenses or simply wear single vision lenses. Ocular biometric parameters were measured using the IOLMaster 700 biometry and the radii of corneal and lenticular curvature were simulated using a customized program. RESULTS: At the 9-month visit, 69 atropine-treated eyes and 50 control eyes were included in the final analyses. In atropine-treated eyes, the posterior corneal surface steepened (-0.05 ± 0.13 mm) and the anterior lenticular surface flattened (0.20 ± 0.69 mm) significantly within 3-6 months, whereas the posterior corneal surface and anterior lenticular surface gradually flattened (0.07 ± 0.23 and 0.32 ± 0.80 mm respectively) in the control eyes over 9 months. The difference in the change of corneal refractive power was significant between groups (-0.03 ± 0.18 D vs. 0.11 ± 0.24 D, p = 0.001), while that in the change of lenticular refractive power was statistically insignificant (0.01 ± 0.92 D vs. -0.22 ± 0.86 D, p = 0.161). CONCLUSIONS: The administration of atropine 0.01% exhibited a clinically short and subtle impact on the cornea and lens, which may shed light on new targets of action for atropine in inhibiting myopia.

Repeatability of Epithelium Thickness Measured by an AS-OCT in Different Grades of Keratoconus and Compared to AS-OCT/Placido Topography.

PURPOSE: To compare agreement of corneal epithelium thickness (ET) between AS-OCT system (RTVue, Optovue) and AS-OCT/Placido topographer (MS-39, CSO) in eyes with different stages of keratoconus (KC), and to assess the repeatability of RTVue AS-OCT. DESIGN: Prospective reliability analysis. METHODS: KC eyes were classified into forme fruste KC (FFKC), mild, moderate, and severe KC. Agreement was evaluated with Bland-Altman plots and 95% limits of agreement (LoA). The repeatability of RTVue was assessed via within-subject standard deviation (Sw), test-retest variability (TRT), coefficient of variation (CoV), and intraclass correlation coefficient (ICC). RESULTS: A total of 119 KC eyes were enrolled, with 21 being FFKC, 26 mild, 39 moderate, and 34 severe. The 95% LoA ranged between -5.9 and 4.8 µm for center epithelium thickness (CET), between -5.7 and 8.2 µm for thinnest epithelium thickness (TET). At 1-mm measuring points, the 95% LoA of superior, inferior, nasal, and temporal were -4.2 to 4.7 µm, -5.2 to 6.0 µm, -7.9 to 10.2 µm, and -11.2 to 6.0 µm. At 3-mm measuring points, the corresponding values were -2.8 to 9.3 µm, -2.0 to 13.0 µm, -4.6 to 9.6 µm, and -6.3 to 9.7 µm, indicating that the 2 instruments were not interchangeable without adjustment. Despite that the repeatability of RTVue measurements in KC patients were acceptable, repeatability decreased gradually with the peripheralization of the measurement points. CONCLUSIONS: The 2 OCT-based devices, RTVue and MS-39, do not provide interchangeable measurements of epithelium thickness in KC patients. Repeatability decreases in cases of more severe KC, emphasizing the importance of grading before clinical examination to avoid diagnostic errors.

Myopia screening: combining visual acuity and noncycloplegic autorefraction.

PURPOSE: To explore the effectiveness of combining uncorrected visual acuity (UCVA) and noncycloplegic autorefraction (NCAR) for large-scale myopia screening in schoolchildren with a high prevalence of myopia. METHODS: A total of 1687 children aged between 6 and 12 years, from five primary schools in the Baoshan district of Shanghai participated in the study. We measured UCVA and autorefraction before and after cycloplegia by a Topcon KR-8800. We drew receiver operating characteristic curves to achieve the best cutoff points and their corresponding sensitivities and specificities for the UCVA and NCAR, respectively. We then combined the UCVA and NCAR in serial order to explore the optimal criterion and its effectiveness. A specificity of 90% was set to compare the sensitivities among the three tests. The children were divided into three age groups (aged 6 to 7, 8 to 10, 11 to 12 years) to further examine this new method. RESULTS: A total of 1639 children with an average age of 9.35 (SD, 1.6) years were finally included, among which 428 (26.11%) children were diagnosed as being myopic (spherical equivalent refraction (SER) less than or equal to -0.5 diopters [D]). For the UCVA, the cutoff point is 0.2 logarithm of the minimum angle of resolution (20/32), with a sensitivity and specificity of 63.6% and 94.0%, respectively. For NCAR, the cutoff point is SER less than or equal to -0.75 D, with a sensitivity and specificity of 88.6% and 86.1%, respectively. When UCVA is combined with NCAR, the best cutoff point is UCVA less than or equal to 0 logarithm of the minimum angle of resolution (20/20) and SER less than or equal to -0.75 D, with a sensitivity and specificity of 84.4% and 90.5%, respectively. At a specificity of 90%, the sensitivities are 63.55%, 78.50%, and 84.35%, respectively, for UCVA, NCAR, and the combination test. In all age groups, the combination test had the highest sensitivities among the three tests. CONCLUSIONS: In a population with a high prevalence of myopia, combining the UCVA and NCAR in serial order achieved higher sensitivity than either of the two tests alone, when specificity was set at 90%.

Effects of atropine 0.01% on refractive errors in children with myopia.

Background: Little is known about changes in astigmatism during atropine treatment. We aimed to explore the effects of atropine 0.01% eye drops on both spherical and cylindrical refractive errors in myopic children. Methods: Children aged 6-14 years with myopia ≥ -6.00 D and < -0.50 D, and total astigmatism > -2.00 D in at least one eye were enrolled. Subjects were randomised either to receive atropine 0.01% once nightly with single-vision lenses or simply to wear single-vision lenses and were followed up at 3-month intervals. Cycloplegic refraction and axial length were measured. The magnitude and direction of total astigmatism (TA), corneal astigmatism (CA), and residual astigmatism (RA) were evaluated. Results: Overall, 119 eyes (69 eyes in the atropine group and 50 eyes in the control group) were included in the final analyses after 9 months. Atropine-treated eyes showed significantly less progression of myopia than did control eyes (spherical equivalent: -0.35 ± 0.33 vs. -0.56 ± 0.49 D, p = 0.001; axial length: 0.20 ± 0.19 vs. 0.33 ± 0.19 mm, p < 0.001). Compared with control eyes (-0.04 ± 0.23 D), a significant increase in TA was observed in the atropine-treated eyes (-0.14 ± 0.29 D); this was mainly attributed to the increase in CA (-0.17 ± 0.26 D) rather than the minor decrease in RA (0.02 ± 0.32 D). Conclusions: Atropine 0.01% was effective in preventing myopia progression, whereas 9 months of atropine treatment resulted in a clinically small, but statistically significant increase in TA in myopic Chinese children.

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

PURPOSE: To investigate the relationship between myopia progression and axial length (AL) elongation in orthokeratology (ortho-k) patients. METHODS: This 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. RESULTS: Myopia 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. CONCLUSIONS: The 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.

Corneal and lenticular biometry in Chinese children with myopia.

CLINICAL RELEVANCE: The measurement and simulation of corneal and lenticular curvature radii using a single swept-source biometry device enables a more thorough evaluation of the shape and refractive power of the cornea and lens during emmetropization or myopia progression in children. BACKGROUND: This study aimed to evaluate the distribution characteristics of corneal and lenticular parameters in Chinese children with myopia and explored their association with other ocular components. METHODS: In this cross-sectional study, all ocular biometric parameters were measured using a Zeiss IOLMaster 700 Biometry. Simulations of the corneal and lenticular curvature radii were implemented using a customised MATLAB program based on cross-sectional swept-source optical coherence tomography images obtained from the same device. The associations of the calculated and simulated refractive powers of the cornea and lens with other ocular parameters were evaluated. RESULTS: In total, 119 children with myopia were recruited. Boys had a deeper anterior chamber and longer axial length (AL) than girls, while girls had steeper anterior corneal and lenticular curvatures and greater corneal and lenticular power. Children aged 10 years and older showed a larger anterior lenticular radius of curvature (sRal) and less lenticular power (PL,OCT) than younger participants. There was a significant positive correlation between AL and the anterior corneal radius of curvature, regardless of sex or age. The sRal exhibited a significant increasing trend, and PL,OCT exhibited a declining trend with a longer AL only in children younger than 10 years. CONCLUSION: AL is the most influential factor in the determination of spherical equivalent refractive error, while decreases in both corneal and crystalline lens power are significantly inversely correlated with axial elongation.

Chinese Parents' Perspective on Myopia: A Cross-Sectional Survey Study.

INTRODUCTION: The prevalence of myopia in young generations has dramatically increased over the years, especially in China. This study aims to understand Chinese parents' perspectives on myopia for further improvement of treatment compliance and informing future health planning and policy. METHODS: This was a prospective cross-sectional survey study. A self-administrated, internet-based questionnaire was distributed to 2545 parents in China. Detailed information about the demographics, the awareness of myopia, related complications, and practices of myopia prevention and control of the respondents were collected. The distribution of answers was compared among different groups of children's age, children's refractions, and parents' residential locations. Relationships between parental cognition and behavior were also analyzed. RESULTS: Eligible responses were returned by 2500 parents. A total of 55.1% of the respondents considered myopia as a disease and more than 70% of respondents did not realize pathological changes related to myopia. Most parents thought myopia could be prevented (82.0%) and controlled (75.2%), and these parents were more likely to take measures than the parents who did not think so (P < 0.001). The most common myopia control modality was spectacles (87.0%), among which single-vision spectacles are the most used (63.7%). CONCLUSIONS: Knowledge about health risks related to myopia was lacking in Chinese parents and their practices of myopia control mainly involved single-vision glasses. Nationwide education for parents about myopia is needed to further advance outcomes of myopia prevention and control.

Impact of pupil diameter on axial growth in orthokeratology.

PURPOSE: To compare axial elongation between myopic orthokeratology (OK) contact lens and spectacle wearers, and to investigate the impact of pupil diameter on axial growth in myopic children after OK treatment. METHODS: Fifty-two Chinese children aged 9 to 14 years were enrolled in this study, 27 for the OK group and 25 for the single vision spectacle lenses (SVL) group. Subjects in each group were further divided into two subcategories according to their baseline scotopic pupil diameters. Axial length (AL) was measured at baseline and at every 6-month visit through to 24 months. Linear mixed-effect model was used to determine myopia progression (AL changes from baseline). In this model, repeated visits were taken as within-subject effect, and treatment group as well as pupil size were taken as between-subject effects. The interaction of treatment group*pupil size was analyzed. Relationships between axial growth at 24 months and baseline pupil area were analyzed in both lens groups. RESULTS: Twenty-five subjects in the OK group and 22 subjects in the SVL group completed the 24-month study. AL increased significantly throughout the observed 24-month period (F = 32.09, p < 0.001). Pupil size significantly affected axial growth (F = 15.95, p < 0.001) and different treatment modalities (OK vs. SVL) interacted with the effect of pupil size on axial growth (F = 24.66, p < 0.001). To be more specific, axial growth was significantly slower in subjects with above average pupil sizes than those with below average pupil sizes in the OK group (F = 25.04, p < 0.001). Contrarily, pupil size did not affect axial growth in the SVL group (F = 0.46, p = 0.50). Baseline scotopic pupil area was significantly correlated to axial growth in the OK group (r = 0.405, p < 0.001) but not in the SVL group (r = 0.171, p = 0.056). CONCLUSIONS: Large pupil diameters facilitate the effect of OK to slow axial growth in myopia. We speculate that this is because of enhancement of the myopic shift in the peripheral retina.

Refractive Characteristics and Related Factors of Amblyopia after Lamellar Keratoscleroplasty in Children with Limbal Dermoids.

We examined the refractive characteristics and related factors of amblyopia in pediatric patients with limbal dermoids undergoing lamellar keratoscleroplasty. Forty-one children (mean age: 56.15 ± 22.47 months) were enrolled. Cycloplegic refraction, corneal topography, and anterior segment photography were performed. The corneal topographic and distribution characteristics of the refractive state were summarized, and the relationship between limbal dermoid invasion size and the refractive state was analyzed. The relationship between invasion size and amblyopia severity and the effect of clinical intervention at different times on amblyopia treatment were also analyzed. The spherical power distribution was −1.0−+10.75 D (average: +4.79 ± 3.09 D). The cylinder power was −1.25−−8.75 D (average: −4.19 ± 1.93 D). The axial range of astigmatism was 10−180° (average: 103.54 ± 58.16°). Equivalent spherical refraction was −3.88−+7.76 D (average: +2.70 ± 3.08 D). Twenty-five, fifteen, and one case had limboid dermoid invasion of the central circular zone (CCZ), paracentral annular zone (PCZ), and corneal limbus within 1 mm, respectively. Corneal topography of 39 patients showed flat, steep, and mean curvatures of 38.48 ± 2.12 D, 43.29 ± 1.97 D, and 40.70 ± 1.48 D, respectively. The mean astigmatism was 4.80 ± 2.93 D in the 3-mm optical region. Astigmatism was higher in CCZ than in PCZ invasion (p < 0.05). Postoperative visual acuity was positively correlated with patients' age and amblyopia treatment duration (r = 0.392, p = 0.048; r = 0.488, p = 0.011), and was negatively correlated with astigmatism (r = −0.646, p < 0.001). High hyperopia and astigmatism are the dominant refractive errors in patients with limbal dermoids undergoing lamellar keratoscleroplasty.

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

METHODS: Axial 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 demonstrated an axial elongation of 0.30 mm or greater. They were then divided into two groups: orthokeratology and atropine (OKA) group (n=37) being treated with nightly 0.01% atropine in addition to ortho-k treatment for another 2 years and orthokeratology (OK) group (n=36) continued to be treated with ortho-k without atropine (phase 2). Axial elongation over time and between groups was compared. RESULTS: Baseline biometrics was similar between the two groups in phase 1 (all p>0.05). The mean axial elongation was 0.47±0.15, 0.21±0.15, 0.23±0.13 mm for the OKA group and 0.41±0.09, 0.30±0.11, 0.20±0.13 mm for the OK group during the first, second and third year, respectively. The cumulative axial elongation over 3 years was 0.91±0.30 mm for the OKA group and 0.91±0.24 mm for the OK group. The overall AL change was not significantly different between the two groups (p=0.262). Baseline myopic refractive error had a significant impact on axial elongation over 3 years of treatment (p<0.001). None of baseline age (p=0.129), lens design (p=0.890) or treatment modality (p=0.579) had a significant impact on axial elongation. CONCLUSIONS: For fast myopia progressors and poor responders of ortho-k, combining 0.01% nightly atropine did not significantly change the3-year axial elongation outcome as compared to ortho-k mono-therapy.

The Influence of 0.5% Tropicamide on Anterior Segment Parameters With CASIA2 in Emmetropic, Myopic, and Hyperopic Eyes.

Aim: To evaluate the effects of 0.5% tropicamide on anterior segment parameters with the CASIA2 imaging device in emmetropic, myopic, and hyperopic eyes. Methods: In this prospective study, a total of 125 subjects (34 emmetropic subjects, 57 myopic subjects, and 34 hyperopic subjects) at the Shanghai Eye and ENT Hospital of Fudan University were recruited from June 2021 to September 2021. The 0.5% tropicamide solution was used once every 5 min a total of 5 times for cycloplegia. The anterior segment parameters were recorded by CASIA2 before and after cycloplegia. Changes in anterior segment parameters were compared among the three refractive groups. Results: Crystalline lens rise (CLR) and crystalline lens thickness (CLT) significantly decreased in all three refractive groups after cycloplegia (all p < 0.01). The anterior radius of lens (ARL) and anterior chamber depth (ACD) significantly increased in all three refractive groups after cycloplegia (all p < 0.01). Posterior radius of lens (PRL) significantly increased in hyperopic eyes after cycloplegia (p < 0.01) while it remained unchanged in emmetropic eyes and myopic eyes. Central corneal thickness (CCT), anterior chamber width (ACW), lens decentration (LD), and lens tilt (LT) remained unchanged after cycloplegia in all three refractive groups (all p > 0.05). Changes in CLR, CLT, ARL, PRL, and ACD in hyperopic eyes were greater than those in emmetropic eyes and myopic eyes (all p < 0.05). Conclusion: Apart from various changes in anterior segment parameters after application by 0.5% tropicamide in all three refractive groups, significant changes in CLR, CLT, ARL, PRL, and ACD in hyperopic eyes should be noted for proper clinical interpretation.

Short-Term Effects of Atropine 0.01% on the Structure and Vasculature of the Choroid and Retina in Myopic Chinese Children.

INTRODUCTION: To explore the short-term effects of atropine 0.01% on the structure and vasculature of the choroid and retina in myopic Chinese children. METHODS: This study was a single-center randomized clinical trial. A total of 40 subjects with myopia < - 6.0 D were enrolled and randomized to receive atropine 0.01% once nightly with regular single-vision lenses or to simply wear regular single-vision lenses at an allocation ratio of 1:1. Follow-up visits were planned at 1 month and 3 months. Choroidal thickness (ChT) was obtained by optical coherence tomography (OCT). Retinal vessel density (RVD), retinal thickness (RT), foveal avascular zone (FAZ) and choriocapillaris flow (CCF) were measured by optical coherence tomography angiography (OCTA). The RVD and RT were measured at fovea, parafovea and perifovea area and four quadrants. RESULTS: Twenty-one subjects were allocated into the atropine group and 19 subjects into the control group. Over 3 months, the control group showed greater progression of myopia than those in the atropine group. ChT in the atropine group increased 11.12 ± 13.96 µm, which was not significant compared with that of the control group. None of the retinal sectors in atropine-treated eyes showed significant changes of RT and RVD compared with the control group. Besides, FAZ and CCF of the atropine group were not affected by atropine use over time, and there was no difference between the two groups. CONCLUSION: Administration of atropine 0.01% eye drops demonstrated no effect on RVD, FAZ and CCF over 3 months, while a modest increase of ChT was observed in atropine-treated eyes. TRIAL REGISTRATION NUMBER: ChiCTR1800017154.

Factors Affecting Long-Term Compliance with Rigid Gas-Permeable Contact Lens Wear in Patients with Keratoconus.

The purpose of the study was to investigate the factors affecting long-term compliance with rigid gas-permeable contact lens (RGPCL) wear in patients with keratoconus (KC). A total of 189 patients with KC (374 eyes) were included in the study, and were divided into two groups: the compliant group and the non-compliant group. Corneal topographic measurements, refractive results, and RGPCL parameters were compared between the two groups. A vision-related quality of life questionnaire was completed by all of the patients. The results demonstrated that patients diagnosed with bilateral KC were more compliant with RGPCL wear than patients diagnosed with unilateral KC (p = 0.0167). There were no significant differences between the compliant and non-compliant groups in terms of their corneal topographic measurements, refractive results, RGPCL parameters, or corneal cross-linking surgery history (all p > 0.05). In contrast, KC patients' subjective experience with RGPCL wear-including visual acuity (p = 0.006), overall satisfaction (p < 0.001), quality of life (p < 0.001), and good adaptation during the short-term (p < 0.001)-had a significant effect on the long-term compliance with RGPCL wear. In conclusion, patients' subjective experiences, rather than their ocular biometrics, significantly influence their long-term compliance with RGPCL wear.

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

PURPOSE: To investigate the correlation between the change in spatial corneal power distribution and axial length (AL) elongation during orthokeratology (Ortho-k) treatment using mathematical methods. METHODS: Seventy-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. RESULTS: A 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 ß = -0.292, P < 0.001) and power exponent (standardized ß = 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. CONCLUSIONS: The asphericity of the treatment zone may affect axial elongation in children undergoing ortho-k therapy. TRANSLATIONAL RELEVANCE: Because 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.