Axial Length In Children Research Articles

Daily Low-Level Red Light for Spherical Equivalent Error and Axial Length in Children With Myopia

Treatments are needed to slow progression of or reduce incidence of myopia. To evaluate the efficacy and safety of daily 650-nm low-level red light (LLRL) for myopia treatment. Single-masked, randomized clinical trial at 1 site in China. Baseline measurements were completed from August to September 2021. Participants were children aged 6 to 12 years with spherical equivalent error (SER) of -6 diopters (D) to 3 D. Data were analyzed from March to July 2023. Irradiation daily with 650-nm LLRL for 3 minutes twice daily 4 or more hours apart or no intervention. Primary outcomes were changes in cycloplegia SER and axial length (AL) at 6- and 12-month follow-up visits. Safety was assessed on masked fundus photograph evaluations. A total of 336 children were randomly allocated into the LLRL group or control group in a 1:1 ratio. The control group contained 86 female patients (51.2%), and the treatment group contained 90 female patients (53.6%). The mean (SD) age, SER, and AL were 9.0 (1.9) years, -1.3 (1.5) D, and 23.8 (1.0) mm for all patients. A total of 161 (95.8%) in the LLRL group and 159 (94.6%) in the control group returned for the 6-month follow-up. A total of 157 (93.5%) in the LLRL group and 152 (90.5%) in the control group returned for the 12-month follow-up. Mean (SD) changes in SER were 0.15 (0.16) D and -0.26 (0.21) D for the LLRL group and the control group, respectively (difference, -0.41 D; 95% CI, -0.48 to -0.34 D; P < .001), at 6 months and 0.24 (0.27) D and -0.65 (0.33) D for the LLRL group and the control group, respectively (difference, -0.89 D; 95% CI, -0.95 to -0.83 D; P < .001), at 12 months. Mean (SD) changes in AL were -0.06 (0.08) mm and 0.13 (0.12) mm for the LLRL group and control group, respectively (difference, 0.19 mm; 95% CI, 0.16 to 0.22 mm; P < .001), at 6 months and -0.11 (0.10) mm and 0.26 (0.16) mm for the LLRL group and control group, respectively (difference, 0.37 mm; 95% CI, 0.34 to 0.40 mm; P < .001). Masked fundus photograph review did not identify retinal changes in either group. These findings suggest daily use of 650-nm LLRL for 1 year can slow progression of SER and AL without safety concerns identified. Confirmation of these findings at independent sites seems warranted, as well as determining whether these effects can be sustained with or without continued treatment and whether LLRL has any effect on pathological myopia. ChiCTR2200058963.

External Validation of a Model to Predict Postoperative Globe Axial Length in Children After Bilateral Cataract Surgery

PURPOSETo perform the external validation of a model to predict postoperative axial length (AL) in children undergoing bilateral cataract surgery with primary intraocular lens (IOL) implantation older than 2 years. DESIGNValidation study using a retrospective case series METHODSUsing a different population than the one that created the model, but with the same characteristics regarding age, bilateral cataract, primary IOL implantation, and follow-up assessment, AL was estimated. The AL values ​​estimated by the model were compared with the AL measured in the follow-ups. RESULTSFifty-five eyes of 30 children were selected for this study; in five children with bilateral cataracts, only one eye was included. The median age at the time of surgery was 5.01 years. Follow-up AL measurements were obtained for 179 visits. The median age at the final follow-up visit was 10.15 years. The median AL measured and estimated by the model in all visits were 22.37 mm and 22.16 mm respectively (Person's coefficient: 0.9534; Lin's correlation: 0.9258). In the Bland-Altman analysis, the 95% limit of agreement between the two methods (measured and estimated AL) was 0.71 to -1.19. In three eyes (1.68%) with AL shorter than 21.2 mm, the difference was >0.71, and in nine eyes with AL longer than 22.5 (5.03%), it was less than -1.19. The Median AL measured and estimated at the final visit were 22.69mm and 22.43mm, respectively. CONCLUSIONOur previously developed prediction model for globe AL growth demonstrated good external validity by accurately predicting measured AL changes with growth in the validation cohort.

The association between pupillary responses and axial length in children differs as a function of season

The association between pupillary responses to repeated stimuli and adult refractive error has been previously demonstrated. This study evaluated whether this association exists in children and if it varies by season. Fifty children aged 8–17 years (average: 11.55 ± 2.75 years, 31 females) with refractive error between + 1.51 and − 5.69 diopters (non-cycloplegic) participated (n = 27 in summer, and n = 23 in winter). The RAPDx pupilometer measured pupil sizes while stimuli oscillated between colored light and dark at 0.1 Hz in three sequences: (1) alternating red and blue, (2) red-only, and (3) blue-only. The primary outcome was the difference in pupillary responses between the blue-only and red-only sequences. Pupillary constriction was greater in response to blue light than to red for those with shorter eyes in summer (β = − 9.42, P = 0.034) but not in winter (β = 3.42, P = 0.54). Greater constriction comprised faster pupillary escape following red light onset and slower redilation following stimulus offset of both colors (P = 0.017, 0.036, 0.035 respectively). The association between axial length and children’s pupillary responses in summer, but not winter may be explained by greater light-associated release of retinal dopamine in summer. Shorter eyes’ more robust responses are consistent with greater light exposure inhibiting axial elongation and reducing myopia risk.

Factors influencing axial elongation in myopic children using overnight orthokeratology

Several factors influence axial length in children with myopia treated using overnight orthokeratology. To identify these factors, this retrospective study collected axial length and corneal aberration data on 78 eyes before and 1-year after orthokeratology. Patients were divided according to axial elongation (cut-off, 0.25 mm/year). Baseline characteristics included age, sex, spherical equivalent refraction, pupil diameter, axial length, and orthokeratology lens type. Corneal shape effects were compared through tangential difference maps. Group differences in higher-order aberrations of a 4 mm zone were compared at baseline and 1-year following therapy. Binary logistic regression analysis was conducted to identify the variables determined for axial elongation. Significant differences between both groups included the initial age of wearing orthokeratology lenses, type of orthokeratology lens, size of central flattening area, corneal total surface C12 (1-year), corneal total surface C8 (1-year), corneal total surface spherical aberration (SA) (1-year root mean square [RMS] values), change in total corneal surface C12, and change in front and total corneal surface SA (RMS values). The age when wearing an orthokeratology lens was the most important factor influencing axial length in children with orthokeratology-treated myopia, followed by lens type and change in the C12 of the total corneal surface.

Prediction of spherical equivalent refraction and axial length in children based on machine learning.

Recently, the proportion of patients with high myopia has shown a continuous growing trend, more toward the younger age groups. This study aimed to predict the changes in spherical equivalent refraction (SER) and axial length (AL) in children using machine learning methods. This study is a retrospective study. The cooperative ophthalmology hospital of this study collected data on 179 sets of childhood myopia examinations. The data collected included AL and SER from grades 1 to 6. This study used the six machine learning models to predict AL and SER based on the data. Six evaluation indicators were used to evaluate the prediction results of the models. For predicting SER in grade 6, grade 5, grade 4, grade 3, and grade 2, the best results were obtained through the multilayer perceptron (MLP) algorithm, MLP algorithm, orthogonal matching pursuit (OMP) algorithm, OMP algorithm, and OMP algorithm, respectively. The R2 of the five models were 0.8997, 0.7839, 0.7177, 0.5118, and 0.1758, respectively. For predicting AL in grade 6, grade 5, grade 4, grade 3, and grade 2, the best results were obtained through the Extra Tree (ET) algorithm, MLP algorithm, kernel ridge (KR) algorithm, KR algorithm, and MLP algorithm, respectively. The R2 of the five models were 0.7546, 0.5456, 0.8755, 0.9072, and 0.8534, respectively. Therefore, in predicting SER, the OMP model performed better than the other models in most experiments. In predicting AL, the KR and MLP models were better than the other models in most experiments.

Retrospective Comparison of the Myopia Master and the Lenstar LS900 Axial Length Measurements in Children with Myopia.

This study is a retrospective analysis to compare ocular biometry measurements of axial length in children with myopia using Myopia Master (OCULUS, Wetzlar, Germany) and Lenstar LS900 (HAAG-STREIT AG, Köniz, Switzerland). Axial length measurements obtained with both instruments within a 3-week period were collected retrospectively. Measurements were visualized with a Bland-Altman plot. For statistical evaluation, a paired t-test was applied, and the Pearson correlation coefficient (r) was established. Sixty-one eyes from 31 myopic patients (59% male, 41% female) with a mean age of 11.34 ± 3.25 years (range: 6 - 18 years) were identified. Mean axial length was 24.7 mm (SD 1.29) with the Myopia Master and 24.69 mm (SD 1.30) with the Lenstar LS900 (Pearson correlation: r = 0.9991). The average difference of the axial length measurement between the two biometers was 0.00 064 mm ± 0.056 SD (p = 0.9293). The axial length measured by Myopia Master and Lenstar LS900 did not differ significantly. Thus, previous values obtained with the Lenstar LS900 can be applied to assess myopia progression.

Relationship Between Autonomic Nervous System Activity and Axial Length in Children.

BACKGROUND The aim of this work was to compare autonomic nervous system activity between eyes with axial and non-axial myopia and to investigate the relationship between autonomic nervous system activity and axial length (AL) in children. MATERIAL AND METHODS Seventy-eight eyes of 78 children were included in this study. Static and dynamic pupillary responses, including pupil diameter, latency, and velocity of pupil contraction and dilation, were recorded using automatic pupillometry to evaluate autonomic nervous system activity. AL was measured using the IOL-Master device. RESULTS In terms of static pupillary responses, the pupil diameter at mesopic condition (1 candelas/m²) (PD1) (4.06±0.64 vs 3.80±0.87 mm, P=0.045) and pupil diameter at low photopic condition (10 candelas/m²) (PD10) (3.40±0.49 vs 3.22±0.66 mm, P=0.046) were significantly larger in axial myopic eyes than in non-axial myopic eyes. In terms of dynamic pupillary responses, velocity of pupil contraction (Vel-C) (5.93±0.89 vs 6.75±1.60 mm/s, P=0.019) and velocity of pupil dilation (Vel-D) (2.28±0.38 vs 2.89±1.17 mm/s, P=0.002) were significantly slower in axial myopic eyes than in non-axial myopic eyes. Moreover, PD1 and PD10 were significantly and positively associated with AL, while Vel-C and Vel-D were significantly and negatively associated with AL (all P<0.05). CONCLUSIONS There was significant decrease in autonomic nervous system activity in axial myopia compared with non-axial myopia, and autonomic nervous system activity was significantly and negatively associated with AL in children. Decreases in autonomic nervous system activity in axial myopia may contribute to the excessive axial elongation in pediatric axial myopia.

Clinical and functional characteristics of pseudophakic myopia in children after congenital cataract extraction in infancy

One of the serious challenges facing surgeons after congenital cataract extraction with IOL implantation in infancy is unplanned refractive results revealed in the long-term period, including the cases of myopia higher than 3.0 D in approximately 50 %. Purpose. The study aimed to evaluate the clinical and functional condition of the eyes in children with moderate to high myopia. Material and methods. Our study included a total of 33 patients (61 eyes) with pseudophakia, of which 16 (26 eyes) developed moderate (12 eyes) or high (14 eyes) myopia at the age of 5 to 15 years. Parameters of the anterior and posterior eye segments were evaluated using Galilei Dual Scheimpflug Analyzer and Optical Coherence Tomography RS-3000 Advance 2, and the axial length using Optical Biometer Al-Scan. Results. The central corneal thickness (CCT) was found considerably above the norm (up to 580 ± 35 pm) in most cases of pseudophakic myopia (72.2 %). Anterior chamber depth in children (4.07 ± 0.39 mm) was equal to that in adults with pseudophakia. Astigmatism and axial length in children with highmyopia significantly exceeded those in children with moderate myopia (3.5 and 1.88 D; 23.57 ± 1.31 and 25.04 ± 1.90 mm, respectively), while choroidal thickness and best corrected visual acuity (BCVA) were much lower (268 and 181 pm; 0.1 and 0.3, respectively). There were no variations in spherical equivalent between different axial length in high and moderate myopia. Conclusion. Taken together these results suggest that with the increase of astigmatism axial length elongated and high myopia developed in children with pseudophakia. Choroidal thickness declined due this process and may be a cause of poor functional outcome. Sufficient CCT opens possibilities for refractive surgery in those patients to improve visual outcomes.

Adjunctive effects of orthokeratology and atropine 0.01% eye drops on slowing the progression of myopia

ABSTRACT Clinical relevance All eye health care practitioners should know how to control myopia. Background Investigating the adjunctive effects of orthokeratology and 0.01% atropine eye drops on controlling the progression of myopia in Chinese children. Methods The prospective study included Chinese children aged 8 to 13 years having a spherical equivalent refractive error ranging from −2.00 to −5.00 D. Participants were categorised into two groups: combination group (orthokeratology and 0.01% atropine) or atropine group (0.01% atropine). The axial length and spherical equivalent refraction were measured at baseline and every three months post-treatment and compared over two years. Results The combinaion and atropine groups comprised 20 and 22 participants. Following two years of treatment, the average spherical equivalent refraction change was 0.88 ± 0.31 D and 1.14 ± 0.63 D in the combination group and atropine group, respectively (P = 0.026), with an average increment in axial length of 0.50 ± 0.17 mm and 0.61 ± 0.21 mm, respectively (P = 0.091). In the atropine group, increased axial length was positively correlated with baseline spherical equivalent refraction (P = 0.018) and negatively correlated with baseline age (P = 0.003). However, these correlations were not observed in the combination group. In the subgroup of subjects aged 8-10 years and another subgroup of subjects with shorter initial axial length (22.00 to 24.50 mm), the changes in axial length over two years were significantly smaller in the combination group than the atropine group. Conclusion Orthokeratology and 0.01% atropine eye drops combination therapy were found to be more effective in reducing progression of myopia, as measured through spherical equivalent refraction changes, than atropine monotherapy in children over two years. Combinatorial therapy was more effective in controlling the elongation of axial length in children with younger baseline age or shorter baseline axial length.

Our Experience of Using Soft Bifocal Contact Lenses in Children with Progressive Myopia

Introduction. According to the studies, one out of three myopic patients with refraction greater than –6.00 D and an axial length greater than 26 mm is at high risk of facing low vision and loss of sight in the future. According to the results of medical examinations and screenings in carried out in Ivanovo, the prevalence of myopia in primary school children has increased three times during the past twenty years. Myopic children under 7 years old are six times more likely to have myopia progressed to higher degrees than children in which myopia onset took place later (at the age of 11–12 years). Optical interventions for myopia control such as orthokeratology and soft bifocal contact lenses have a strong body of evidence and are well accepted by ophthalmologists.Purpose. The purpose of the present study was to investigate the effect of soft bifocal contact lenses on refraction, accommodation and axial length in children with progressive myopia.Materials and methods. We observed 30 children aged 8–15 years with myopia progression rate of 0.82 D/year and accommodative weakness and instability. We prescribed OKVision PrimaBio Bi-focal design soft bifocal contact lenses (OKVision, Russia) that feature +4.00 D addition power on periphery. The effectiveness was estimated by monitoring refraction, accommodation and axial length every three months within a year.Results. After 12 months of wearing soft bifocal contact lenses, the annual myopia progression rate decreased 4.3 times on average. We were able to stabilize myopia in 50% of the children during the period of monitoring. The use of this intervention had a strong effect on accommodation resulting in an increase of its amplitude and reserve.Conclusion. The use of soft bifocal contact lenses has been proven to have a strong inhibitory effect on myopia progression rate. Myopia stabilization manifested itself as the absence of increase in myopic refraction and axial length as well as normalization of accommodative function.

Low concentration atropine combined with orthokeratology in the treatment of axial elongation in children with myopia: A meta-analysis.

To evaluate the effect of low concentration atropine combined with Orthokeratology (OK) lens compared with the OK lens on the changes of axial length in children with moderate and low myopia by meta-analysis. Databases such as PubMed, Web of Science, Embase, and Cochrane Library were comprehensively searched to collect related studies on atropine combined with the OK lens in the treatment of children with moderate and low myopia. The retrieval time was from the establishment of the database to December 2020. The standardized mean difference (SMD) and its 95% confidence interval (CI) were selected as the effect to analyze the changes of the axial length of the eye axis in children with low and moderate myopia treated with low concentration atropine combined with OK lens. A total of eight articles were included in this study. Compared with OK lens treatment, low concentration atropine combined with the OK lens significantly slowed down the axial elongation of low and moderate myopia, SMD = -0.68(95% CI: -0.86--0.50, p < 0.05). According to the subgroup analysis of treatment time, when the treatment time was less than or equal to 6 months, SMD = -0.63(95% CI: -0.88--0.37, p < 0.05), when the treatment time was 1 year, SMD = -0.76(95% CI: -1.08--0.43, p < 0.05), and when the treatment time was 2 years, SMD = -0.69(95% CI: -1.07--0.31, p < 0.05). Low concentration atropine combined with the OK lens is more effective than the OK lens in the treatment of children with low to moderate myopia in reducing axial elongation.

Is It Possible to Predict Progression of Childhood Myopia Using Short-Term Axial Change After Orthokeratology?

To investigate changes in axial length in children undergoing orthokeratology (OK) and evaluate short-term axial change in predicting post-OK myopia progression. In this retrospective study, the subjects included 70 myopic children aged 8 to 15 years wearing OK contact lenses for more than 3 years. Axial length changes at 0.5, 1, 2, and 3 years relative to the baseline were measured. Patients were evaluated for age, spherical equivalent refraction (SER), pupil size, and half-year axial change using repeated analysis of variance and multivariate linear regression analysis to predict half to 3 year-axial elongation (AE, seventh-36th month post-OK). The axial length grew significantly during the 3 years; the mean annual axial growth was 0.20±0.12 mm. The half-year axial change was 0.04±0.12 mm. The univariate linear analyses showed that half to 3-year AE was correlated with baseline age (r=-0.393, P<0.001) and half-year axial change (r=0.379, P=0.001), but not pupil diameter (P=0.692) or SER (P=0.673). In a multiple linear regression model, the half to 3-year AE was related with the baseline age (standardized β=-0.312, P=0.007) and half-year axial change (standardized β=0.293, P=0.01). The model was fair (adjusted R=0.21) and statistically significant (F=10.24, P<0.001). It is practical to predict long-term AE with half-year axial change for children with OK correction. Therefore, this may aid in fast and timely measures in children who are predicted to have rapid myopia progression.

A Model to Predict Postoperative Axial Length in Children Undergoing Bilateral Cataract Surgery With Primary Intraocular Lens Implantation

To develop a model for predicting postoperative globe axial length (AL) in children undergoing bilateral cataract surgery with primary intraocular lens (IOL) implantation in children older than 2 years. Retrospective case series. Children were included only if AL data were available for both eyes before surgery and at least 1 year after surgery. We analyzed variables that could influence globe axial growth and developed a multivariable generalized estimating equation regression model to predict postoperative AL. Sixty-four children were included. The median age at surgery and at follow-up was 5.1 and 12.5 years, respectively. AL measurements were obtained in both eyes during 242 visits. The median AL before and at last follow-up was 22.2 and 23.1mm, respectively. Beta value for the final model to predict postoperative AL is as below: intercept (1.93), preoperative AL (0.91), age at cataract surgery (-0.07), age at follow-up (0.14), and interaction between age at surgery and age at follow-up (-0.005). Using this model, for a hypothetical patient operated at 2.5 years of age with a 20.5mm AL would be estimated to have a 22.8mm AL at 18 years of age. IOL power selection is a major challenge of pediatric cataract surgery attributable to unpredictable future eye growth. This model theoretically could be used to predict individual future adult size AL for each child undergoing cataract surgery, helping the surgeon to customize the selection of an IOL power at implantation and also to help the parents understand what to expect.

Effect of Orthokeratology on Axial Length Elongation in Anisomyopic Children.

Anisomyopia is a natural experimental paradigm that compares dose response between fellow eyes. This study is the first to explore whether orthokeratology (ortho-k) has a dose-response effect on axial length growth and reduces the interocular difference in axial length in anisomyopic children. The purpose of this study was to compare the effect of ortho-k on axial length elongation between the fellow eyes of anisomyopic children. In this retrospective study, 49 anisomyopic children who wore ortho-k lenses were assigned to the anisomyopic ortho-k group. Based on the one-to-one match principle (same age and proximate spherical equivalent), high-isomyopic and low-isomyopic groups each enrolled 49 isomyopic children who wore ortho-k lenses with spherical equivalent similar to that of the more myopic eye and the less myopic eye in the anisomyopic ortho-k group, respectively. Forty-nine anisomyopic children who wore spectacles were enrolled in the anisomyopic spectacle group. At baseline and at 1- and 2-year visits, axial length was measured. Axial length elongation and interocular difference in axial length were compared. In the anisomyopic ortho-k group, the less myopic eyes exhibited more axial length elongation than did the more myopic eyes during 1- and 2-year treatment periods (P < .01). However, there was no significant difference in axial length elongation between the fellow eyes in the isomyopic groups and anisomyopic spectacle group. At the 2-year visit, the interocular difference in axial length of children in the anisomyopic ortho-k group significantly decreased from 0.72 ± 0.34 to 0.56 ± 0.38 mm (P < .05). In contrast, ortho-k lens-wearing isomyopic children or spectacle-wearing anisomyopic children did not show a significant change in interocular difference in axial length. Orthokeratology could reduce the amount of anisomyopia in children primarily through stronger myopia control in the more myopic eye.

Developing a model for postoperative axial length in children undergoing bilateral cataract surgery to optimize visual outcomes

The purpose of this study was to develop a model for predicting postoperative globe axial length (AL) following ocular growth in children undergoing bilateral cataract surgery, with the goal of improving intraocular lens (IOL) power selection at the time of implantation.

Choroidal Thickness and Ametropia in Children: A Longitudinal Study.

To determine the relationship of subfoveal choroidal thickness (ChT), refraction, and axial length in children, and evaluate the evolution of subfoveal ChT with time in myopic versus nonmyopic eyes. A total of 229 eyes of 115 children aged 2 to 16 years were included in the study. Refraction under cycloplegia, axial length, and subfoveal ChT were measured at baseline with comparative investigations at 15 months follow-up. The probability for the subfoveal ChT to be thinner in myopic children compared to nonmyopic children was 0.9999. We found a relation between subfoveal ChT and axial length. At 15 months follow-up, subfoveal ChT was found to have increased in the nonmyopic eyes, but decreased in myopic patients. A number of studies have already shown the choroid to play an important role in the process of emmetropization. We found that ChT had a different evolution in myopic children compared to nonmyopic children. A thinner choroid may predict the onset, or progression, of myopia. Further studies, with longer follow-up, are necessary to confirm this hypothesis.

Short- and Long-Term Changes in Corneal Aberrations and Axial Length Induced by Orthokeratology in Children Are Not Correlated

To assess the correlation between changes in corneal aberrations and the 2-year change in axial length in children fitted with orthokeratology (OK) contact lenses. Thirty-one subjects 6 to 12 years of age and with myopia -0.75 to -4.00DS and astigmatism ≤1.00DC were fitted with OK. Measurements of axial length and corneal topography were taken at regular intervals over a 2-year period. Corneal topography at baseline and after 3 and 24 months of OK lens wear was used to derive higher-order corneal aberrations (HOA) that were correlated with OK-induced axial length changes at 2 years. Significant changes in (Equation is included in full-text article.)root mean square (RMS) secondary astigmatism and fourth and total HOA were found with both 3 and 24 months of OK lens wear in comparison with baseline (all P<0.05). Additionally, significant changes in (Equation is included in full-text article.)and RMS tetrafoil were found at 3 months and in second-order RMS at 24 months of OK lens wear in comparison with baseline (all P<0.05). However, none of the changes in corneal aberrations were significantly correlated with the 2-year change in axial elongation (all P>0.05). Coma angle of orientation changed significantly pre-OK in comparison with 3 and 24 months post-OK as well as secondary astigmatism angle of orientation pre-OK in comparison with 24 months post-OK (all P<0.05). However, coma, trefoil, secondary astigmatism, and tetrafoil angles of orientation pre-OK or post-OK were not significantly correlated with the 2-year change in axial elongation (all P>0.05). Short-term and long-term OK lens wear induces significant changes in corneal aberrations that are not significantly correlated with changes in axial elongation after 2-years.

The Association between Ocular Biometry and Retinal Vascular Caliber Is Comparable from Early Childhood to Adolescence

We aimed to establish whether the change in retinal microvascular structure observed cross-sectionally with axial elongation and larger corneal curvature is comparable from early childhood to adolescence. In all, 1077 Sydney Paediatric Eye Study participants (36 to <72 months of age) and 1740, 2353, and 1216 from the Sydney Childhood Eye Study (6, 12, and 17 years of age), respectively, were examined. Quantifiable retinal vascular caliber measurements were obtained using validated computer-based methods. Ocular biometry measurements were performed according to standardized protocols. After multivariable adjustment, in children 36 to <72 months of age, each 1.0-mm increase in axial length was associated with a 3.67- and 6.53-μm narrowing of mean retinal arteriolar caliber (P = 0.005) and venular caliber (P < 0.0001), respectively. Each 1.0-mm increase in axial length in children 6, 12, and 17 years of age was associated with a 5.30-, 3.96-, and 4.03-μm decrease in mean retinal arteriolar caliber, respectively. Each 1.0-mm increase in axial length in children 6, 12, and 17 years of age was associated with a 7.12-, 6.72-, and 6.85-μm decrease in retinal venular caliber, respectively. Corneal curvature was inversely associated with retinal vascular caliber among all age groups (P < 0.001). Among those without significant refractive error (>0.00 and <2.00 diopters), significant inverse associations were observed between axial length and corneal curvature with retinal vessel caliber among all age groups. We demonstrate a similar magnitude of retinal vessel narrowing with axial length elongation and increasing corneal curvature from childhood through to adolescence. These data confirm the robustness of the associations between ocular biometric traits and retinal microvascular structural changes during childhood development.

Ocular axial length and corneal refraction in children with mucopolysaccharidosis (MPS I‐Hurler)

To assess corneal refraction and axial length in children with mucopolysaccharidosis I-Hurler (MPS I-H), treated early with stem cell transplantation (SCT), in order to establish possible causes of hyperopia. Clinical ophthalmological follow-up included keratometry and measurements of axial length. Five patients, with SCT performed before 23 months of age, were examined. Median age was 8.2 years (range 5.2-10.5). Best-corrected decimal visual acuity was ≥ 0.5 (≥ 20/40 Snellen fraction) in seven of 10 eyes. High hyperopia, ranging from +4.0 to +9.0 spherical equivalents, was noted in all 10 eyes. Mild to moderate corneal opacities occurred in all 10 eyes. Optic disc areas, borders and cuppings were normal in all 10 eyes. No patient had glaucoma. Keratometry could be performed in five patients and demonstrated low values in the group ranging from 38.24 to 41.56 Diopters (D) right eye to 38.24-41.94 D left eye, which was significantly lower than the age matching reference material (p < 0.05). Axial lengths, available in five patients, ranged between 20.68 to 21.57 mm right eye and 20.52 to 21.38 mm left eye, which also was lower than the age matching reference material (p < 0.05). Reduced axial length together with reduced corneal refraction is suggested to be causative to the hyperopia in patients with MPS I Hurler. Detection of refractive errors and prescription of eye glasses are important to avoid amblyopia.

The relationships among cycloplegic refraction, keratometry, and axial length in children with refractive accommodative esotropia

To explore the relationships among cycloplegic refraction, keratometry, and axial length in children with refractive accommodative esotropia and to evaluate the feasibility of axial length estimation from the other 2 parameters. This is a prospective case series of children ages 4-12 years who were diagnosed with refractive accommodative esotropia, cooperative for keratometry and optical biometry by the IOLMaster, and without amblyopia in the right eye. The right eyes of the first group of patients were used to generate a linear regression formula from cycloplegic refraction, keratometry, and axial length. This formula was used in the second group of patients to estimate axial length from cycloplegic refraction and keratometry. A total of 100 children were enrolled. Cycloplegic refraction ranged from +2.25 D to +8.25 D, keratometry ranged from 38.34 D to 48.37 D, and measured axial length ranged from 19.34 mm to 23.66 mm. Estimated and measured axial lengths were strongly correlated (Pearson coefficient = 0.9; 95% CI, 0.83-0.94) with the former values having a greater mean by the paired t test (2-sided P < 0.0001; difference between means, 0.27 mm). Estimated and measured values differed by <0.5 mm for most eyes (33/50, 66%) and were within 1 mm for all eyes. In children with refractive accommodative esotropia, there exists a constant mathematical relationship among cycloplegic refraction, keratometry, and axial length. This relationship allows reasonable estimation of axial length from the other 2 parameters.