Increased Vertical Asymmetry of Macular Retinal Layers in Myopic Chinese Children

Correlation between refractive errors and ocular biometric parameters in children and adolescents: a systematic review and meta-analysis

BACKGROUND

Refractive errors are one of the most common ocular conditions among children and adolescents, with myopia showing an increasing prevalence and early onset in this population. Recent studies have identified a correlation between refractive errors and ocular biometric parameters.

METHODS

A systematic search was conducted in electronic databases including PubMed, EMBASE, Cochrane Library, Web of Science, and Medline from January 1, 2012, to May 1, 2023. Various ocular biometric parameters were summarized under different refractive states, including axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), corneal curvature (CC), Corneal curvature radius (CR),axial length-to-corneal radius ratio (AL/CR ratio), choroidal thickness (ChT), retinal thickness (RT), retinal nerve fiber layer thickness (RNFL), and retinal blood density (VD). The differences in these parameters among different refractive states were analyzed using Stata software with fixed or random-effects models, taking into account the assessed heterogeneity level.

RESULTS

This meta-analysis included a total of 69 studies involving 128,178 eyes, including 48,795 emmetropic eyes, 60,691 myopic eyes, 13,983 hyperopic eyes, 2,040 low myopic eyes, 1,201 moderate myopic eyes, and 1,468 high myopic eyes. The results of our study demonstrated that, compared to the control group (emmetropic group), the myopic group and low, moderate, and high myopic groups showed significant increases in AL, AL/CR ratio, and ACD, while the hyperopic group exhibited significant decreases. Compared to the control group, the myopic group had a significantly increase for CC, while CR, CCT, perifoveal RT, subfoveal ChT, foveal ChT, parafoveal ChT, perifoveal (except nasal) ChT, and pRNFL (except temporal) significantly decreased. Compared to the control group, the hyperopic group had a significantly increase for subfoveal ChT, foveal ChT, parafoveal ChT, perifoveal ChT, and nasal pRNFL. Compared to the control group, the low and moderate myopic groups had a significantly decreases for the CCT, parafoveal RT (except nasal), perifoveal RT (except nasal), and pRNFL (except superior and temporal). Compared to the control group, the high myopic group had a significantly increase for CR, while LT, perifoveal ChT (except nasal), parafoveal RT, perifoveal RT, and pRNFL (except temporal) had significant decreased.

CONCLUSION

The changes of ocular biometric parameters in children and adolescents are closely related to refractive errors. Ocular biometric parameters devices, as effective non-invasive techniques, provide objective biological markers for monitoring refractive errors such as myopia.

The characteristics of dome-shaped macula in Chinese children aged 4-6 years using optical coherence tomography angiography

PURPOSE

To evaluate the characteristics of dome-shaped macula (DSM) in children aged 4-6 years with normal visual acuity using optical coherence tomography angiography.

METHOD

This is a cross-sectional study. A total of 19 children aged 4-6 years were included. The results of optical coherence tomography angiography images were analysed to identify and quantify retinal structural and vascular parameters in DSM children. The dome height, dome base, and sub-dome choroidal thickness were manually measured. Participants with DSM and those without DSM from our previous study were compared on these parameters.

RESULTS

Nineteen eyes of the preschool subjects with normal visual acuity showed horizontal DSM on optical coherence tomography (OCT). The DSM was significantly smooth and low in the children, and we did not observe differences between sex and age. Compared to the children without DSM, the average axial length was longer, and the average macular vessel density was lower in the DSM group, especially in the deep retinal vascular density. Additionally, the dome height was positively correlated with the sub-dome choroidal thickness. When the dome base/height was increased, the fovea avascular zone (FAZ) area was larger.

CONCLUSION

Dome-shaped macula was detected in the preschool children in the process of the emmetropization with normal visual acuity. The changes in macular structure and vasculature provide new ideas for further investigation into the characteristics of DSM formation.

An analysis of macular ganglion cell complex in 7-year-old children in China: the Anyang Childhood Eye Study

BACKGROUND

This study used spectral-domain optical coherence tomography (SD-OCT) imaging to describe the distribution of macular ganglion cell complex (GCC) thickness and its association with ocular and systemic parameters in 7-year-old children in China.

METHODS

The study involved a school-based, cross-sectional analysis of the Anyang Childhood Eye Study (ACES) and included 2,505 first-grade students from urban areas in Anyang, Henan Province, Central China. All participants underwent systemic and ocular examinations. Both GCC and retinal nerve fiber layer (RNFL) thickness were measured using the iVue-100 OCT (Optovue, Fremont, CA, USA). Intraocular pressure (IOP) was recorded with noncontact tonometer (Huvitz, HNT-7000). Axial length (AL) was measured using optical biometry (Lenstar LS 900, Haag-Streit Diagnostics, Koniz, Switzerland).

RESULTS

The mean GCC thickness was 95.31±7.67 µm. GCC thickness had negative associations with AL (r=-0.124, P<0.001), cup-to-disc (C-D) area ratio (r=-0.068, P=0.0033), horizontal C-D (H C-D) ratio (r=-0.048, P=0.0384), and vertical C-D (V C-D) ratio (r=-0.074, P=0.0013). Positive correlations were found with spherical equivalent (SE) (r=0.080, P=0.0001), RNFL thickness (r=0.363, P<0.001), height (r=0.059, P=0.0036), fovea parameters, disc area (r=0.078, P=0.0007), rim area (r=0.115, P<0.001), rim volume (r=0.119, P<0.001), and optic nerve head volume (r=0.097, P<0.001). GCC thickness had no significant association with IOP, age, sex, or weight, waist, or head circumference.

CONCLUSIONS

This study provides normative GCC data for 7-year-old healthy children in China. The findings support an association between GCC and AL, SE, RNFL, height, and C-D ratio in children.

Associations of refractive errors and retinal changes measured by optical coherence tomography: A systematic review and meta-analysis

Studies reporting alteration in retinal thickness using optical coherence tomography (OCT) have been performed in different populations with various degrees of refractive error, producing inconsistent results. Therefore, we performed a meta-analysis to evaluate the alterations in retinal OCT measurements in myopic and hyperopic patients compared to controls. Evaluation of different retinal layers' thickness may have significance for developing novel approaches for preventing, diagnosing, and treating refractive errors and their complications. We searched PubMed and EMBASE to identify articles that reported OCT measurements of different retinal layers and regions, including macular, foveal, parafoveal, perifoveal, foveolar, ganglion cell complex (GCC), retinal nerve fiber layer (RNFL), peripapillary retinal nerve fiber layer (pRNFL), and ganglion cell and inner plexiform layer (GC-IPL) thickness in addition to macular volume, and optic disc area in myopes and hyperopes comparing their differences with controls. We applied either a fixed-effects or random-effects model for the meta-analysis of these differences based on the assessed heterogeneity level. Furthermore, subgroup analyses and metaregression, as well as publication bias and quality assessment, were conducted for the eligible studies. Forty-seven studies with a total of 12223 eyes, including 8600 cases and 3623 non-cases, are included in this meta-analysis. Our results showed that, in comparison to controls, highly myopic eyes had a significantly lower value for mean macular thickness, macular GCC, macular GC-IPL, parafoveal, perifoveal, foveal, foveolar, RNFL, and pRNFL thickness. Compared to controls, moderately myopic eyes showed a significantly thinner mean macular GCC layer and pRNFL. On the other hand, hyperopic eyes had significantly thicker average pRNFL than controls. Several other significant differences were also observed in various regional analyses. The findings of the current study affirm the retinal OCT measurement differences between myopic and hyperopic eyes compared to controls, emphasizing OCT measurements' advantages as potential biomarkers of ocular pathologies.

Evaluation of the association of macular ganglion cell-inner plexiform layer thickness and myopia in Chinese young adults

PURPOSE

To describe the distribution of ganglion cell-inner plexiform layer (GCIPL) thickness among Chinese young adults and report whether the decreased GCIPL thickness is associated with myopia.

METHODS

In this study, we included Chinese young adults who underwent Cirrus spectral domain-optical coherence tomography (SD-OCT). SD-OCT was used to measure average and minimum GCIPL thickness, and GCIPL thickness at all sectors. Subfoveal choroidal thickness (CT), axial length (AL), and spherical equivalents (SE) were also measured.

RESULTS

A total of 348 eyes were included in the analysis. Average GCIPL thickness showed a significant difference between myopes and emmetropes, with 87.89 ± 3.65 μm for emmetropic groups and 82.65 ± 4.96 μm for myopic groups. The GCIPL thickness was significantly thinner in myopia than in emmetropia at all locations (P < 0.05), affirming that myopia was associated with thinner GCIPL thickness (P = 0.001). The mean subfoveal CT also showed a significant difference between myopes and emmetropes, with 330.57 ± 9.43 μm for emmetropic groups and 265.98 ± 4.12 μm for myopic groups. GCIPL (OR 0.863, 95% CI, 0.785-0.949), AL (OR 2.499, 95% CI, 1.532-4.075) and intraocular pressure (IOP) (OR 1.250, 95% CI, 1.086-1.438) revealed significant associations with myopia. When adjusting for AL, IOP, and anterior chamber depth (ACD) in the myopia subgroup, the GCIPL thickness remained positively associated.

CONCLUSIONS

In a specific Chinese young population, myopic eyes have measurably less macular GCIPL thickness than normal eyes. Decreasing GCIPL thickness may be associated with the progression of myopia.