Topographic distribution features of the choroidal and retinal nerve fiber layer thickness in Chinese school-aged 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.

Choroidal thickness, myopia, and myopia control interventions in children: a Meta-analysis and systemic review

AIM

To investigate changes of choroidal thickness (ChT) in children with myopia and the effect of current myopia control interventions on ChT.

METHODS

Major literature databases were searched for studies relevant to myopia in children. All studies used swept-source optical coherence tomography (SS-OCT) or enhanced depth imaging optical coherence tomography (EDI-OCT) to measure the ChT value. The weighted mean difference (WMD) and 95% confidence interval (CI) were pooled to evaluate ChT in myopia children.

RESULTS

A total of 11 eligible articles, including 1693 myopic and 1132 non-myopic eyes, were included in the first Meta-analysis. The sub-foveal choroidal thickness (SFCT; WMD=-40.06, 95%CI, -59.36 to -20.75, P<0.001) and ChT at other sectors were significantly thinner in myopic eyes compared with the non-myopic eyes. The Meta-analysis revealed that the ChT decreased horizontally from the temporal sector toward the nasal sector in the pediatric myopia population. Another 11 studies reporting the effect of myopia control interventions were included in the second Meta-analysis for the relationship between myopia control treatments and ChT. SFCT significantly increased after orthokeratology (OK) treatment and OK combined with 0.01% atropine (OKA) treatment (WMD=19.47, 95%CI, 15.96 to 22.98, P<0.001; WMD=21.81, 95%CI, 12.92 to 29.70, P<0.001, respectively). The forest plots showed that SFCT changed little in myopic children receiving 0.01% atropine (P=0.30). Furthermore, the Meta-analysis showed that OK treatment had a stronger effect on the value of SFCT in myopic children as compared with 0.01% atropine (WMD=9.86; 95%CI, -0.21 to 19.93, P=0.05). There is no difference between the treatment with OK and OKA treatment in ChT in myopic children (P=0.37).

CONCLUSION

The ChT in myopic eyes is thinner than that in non-myopic eyes in pediatric population. Myopia control interventions including OK and OKA lead to ChT thickening, but other treatments such as 0.01% atropine did not show an increase in ChT.

Effect of FFP2/N95 facemask wear on retinal and choroidal thickness profile in healthy subjects

AIM

To investigate the influence of non-oil 95 (N95)/filtering facepiece 2 (FFP2) facemask wear on retinal thickness, choroidal thickness (CT), retinal nerve fiber layer thickness (RNFLT), and ganglion cell layer thickness (GCLT) in healthy subjects.

METHODS

In this prospective study, 53 healthy participants who used FFP2/N95 facemask were enrolled. Participants underwent optical coherence tomography imaging before and at 1 and 4h following FFP2/N95 facemask wear. The last imaging session was performed 1h after FFP2/N95 removal. Retinal thickness, CT, RNFLT, and GCLT were assessed at each session. Vital parameters were also assessed.

RESULTS

The pulse rate of the subjects significantly decreased at 1 and 4h compared to baseline values (P<0.05). No significant changes in retinal thickness, RNFLT, and GCLT were observed in the study. CT profile showed a significant increase at all measured locations except 1-mm temporal, 1-mm inferior and 2-mm inferior points following FFP2/N95 wear which turned to baseline values after FFP2/N95 removal. Pulse rate and CT changes at 4h were significantly correlated (P<0.05).

CONCLUSION

Parasympathetic activation during FFP2/N95 facemask wear might have a role on elevated CT measurements in healthy individuals by virtue of increased choroidal blood flow.

Change of peripapillary retinal nerve fiber layer and choroidal thickness during 4-year myopic progress: Boramae Myopia Cohort Study Report 4

AIMS

To investigate the longitudinal changes of peripapillary retinal nerve fibre layer (RNFL) and choroidal thickness during myopic axial elongation.

METHODS

Peripapillary RNFL and choroidal thickness were prospectively evaluated by spectral-domain optical coherence tomography (SD-OCT) in 46 eyes of 23 myopic children over the course of 4 years. Using serial OCT images acquired based on a fixed scan circle in the glaucoma progression analysis mode, general and sectoral RNFL thicknesses were acquired at the same position and the angular location of the peak was measured. The peripapillary choroidal thickness likewise was measured at eight positions in serial OCT images.

RESULTS

The mean age at the baseline was 9.6±1.7 years. The mean axial length increased from 24.80±1.28 mm to 25.64±1.35 mm. The global peripapillary RNFL thickness was 98.54±12.06 µm at baseline. The global and sectoral RNFL thicknesses did not change during the 4 years. The angular location of RNFL peaks was also stable and was located in the superotemporal (64.18±10.85°) and inferotemporal (293.98±11.62°) sectors. The global peripapillary choroidal thickness was 145.40±28.67 µm at the baseline. The global and sectoral choroidal thicknesses did not change during the 4 years.

CONCLUSIONS

The peripapillary RNFL and choroidal thicknesses as well as the locations of the RNFL peaks had been preserved, during the 4-year follow-up on myopic children, when traced and measured from the same location.