The correlation of hyperopia and choroidal thickness, vessel diameter and area

Quantitative assessment of colour fundus photography in hyperopia children based on artificial intelligence

OBJECTIVES

This study aimed to quantitatively evaluate optic nerve head and retinal vascular parameters in children with hyperopia in relation to age and spherical equivalent refraction (SER) using artificial intelligence (AI)-based analysis of colour fundus photographs (CFP).

METHODS AND ANALYSIS

This cross-sectional study included 324 children with hyperopia aged 3-12 years. Participants were divided into low hyperopia (SER+0.5 D to+2.0 D) and moderate-to-high hyperopia (SER≥+2.0 D) groups. Fundus parameters, such as optic disc area and mean vessel diameter, were automatically and quantitatively detected using AI. Significant variables (p<0.05) in the univariate analysis were included in a stepwise multiple linear regression.

RESULTS

Overall, 324 children were included, 172 with low and 152 with moderate-to-high hyperopia. The median optic disc area and vessel diameter were 1.42 mm2 and 65.09 µm, respectively. Children with high hyperopia had larger superior neuroretinal rim (NRR) width and larger vessel diameter than those with low and moderate hyperopia. In the univariate analysis, axial length was significantly associated with smaller superior NRR width (β=-3.030, p<0.001), smaller temporal NRR width (β=-1.469, p=0.020) and smaller vessel diameter (β=-0.076, p<0.001). A mild inverse correlation was observed between the optic disc area and vertical disc diameter with age.

CONCLUSION

AI-based CFP analysis showed that children with high hyperopia had larger mean vessel diameter but smaller vertical cup-to-disc ratio than those with low hyperopia. This suggests that AI can provide quantitative data on fundus parameters in children with hyperopia.

Choroid vascular changes in hyperopic anisometropia amblyopia using SS-OCTA

PURPOSE

To observe and understand the structural changes in choroidal vessels in eyes with hyperopic anisometropic amblyopia using swept-source optical coherence tomography angiography (SS-OCTA).

METHODS

A total of 44 patients were enrolled in this study: 22 children with hyperopic anisometropic amblyopia and 22 age-matched controls. SS-OCTA was used to scan the 6*6 mm macular area of their eyes. The average choroidal thickness (CT) and choroidal capillary flow area (CC) in a 3 mm diameter area centered on the macular area were obtained. The choroidal vascularity volume (CVV) was automatically extracted and 3D reconstructed by inbuild software, and the three-dimensional choroidal vascularity index (3D-CVI) was calculated. The effect of amblyopia on the choroidal vessel structure was assessed using generalized linear estimating equations (GEEs) corrected for axial length, sex, age, and best-corrected visual acuity.

RESULTS

The CC was greater in amblyopic eyes than in fellow eyes (P = 0.014) but was not significantly different from that in control eyes (P = 0.963). After correcting for sex, age, axial length, and visual acuity using GEEs, the mean CT in the amblyopic eyes was greater than that in the fellow eyes (P = 0.030) but was not significantly different from that in the control eyes (P = 0.160). The 3D-CVI in amblyopic eyes was higher than that in control eyes (P = 0.038) but was not significantly different from that in fellow eyes (P = 0.407). The three-dimensional choroidal vascularity volume (3D-CVV) was higher in amblyopic eyes than in fellow eyes (P = 0.046) and control eyes (P = 0.023).

CONCLUSIONS

We found that eyes with hyperopic anisometropic amblyopia demonstrated higher CT, CC and 3D-CVV values than the contralateral eyes after correction, while the 3D-CVI was unchanged. Compared with control eyes, amblyopic eyes had higher 3D-CVV and 3D-CVI values but similar CT and CC values. Amblyopic eyes may have different choroidal vascular structures from fellow and control eyes.

Choroidal and retinal thickness variations in ocular albinism

Purpose

To study the retinal and choroidal thickness variations on enhanced depth imaging optical coherence tomography scans in ocular albinism (OA) and compare with age-matched healthy subjects.

Methods

This retrospective observational study had 48 eyes of 24 patients diagnosed clinically as OA and age, sex, and axial length-matched control healthy subjects. All patients underwent detailed ophthalmic examination and a single-line horizontal-raster enhanced depth imaging - optical coherence tomography scan (Spectralis, Heidelberg Engineering). Retinal and choroidal thickness was measured, compared, and analyzed between the two groups. Mann-Whitney U test was used for analysis between the two groups. P < 0.05 was considered significant.

Results

The mean age was 28.3 ± 11.6 and 29.9 ± 10.6 years in the OA group and control group, respectively. Spherical equivalents ranged from -8.5D to +10.5D in the OA group and from -8.0D to +10.0D in the control group. The mean axial length between the two groups (P = 0.652) were comparable. The average retinal thickness (272 ± 34.3 vs. 213 ± 13.8 μm; P < 0.001) was greater in the OA group as compared to controls. The mean choroidal thickness (184 ± 78.4 vs. 287 ± 46.4 μm; P < 0.001) was significantly thinner in the OA group.

Conclusion

Acquisition of OCT scans in OA can be challenging. This study showed that the subfoveal retinal thickness and choroidal thickness measured across the scans were significantly different in the OA group compared to controls. In the future, more studies are required to evaluate the role of the choroid and its relationship to emmetropization in albinism.

Quantitative Assessment of the Choroidal Vessel Diameter during the Recovery of Form-Deprivation Myopia in Guinea Pigs

PURPOSE

The development and recovery (REC) of myopia is associated with changing of choroidal thickness (CT) in the model of guinea pigs. Nitric oxide synthase (NOS) is an enzyme which can affect choroidal vasodilatation. This study wants to investigate the changes of choroidal vessel diameter (CVD) and NOS during the REC of form-deprivation (FD) myopia in guinea pigs.

METHODS

Forty-eight guinea pigs were randomly assigned to the normal control (NC) group, FD group (FD for 21 d), and four REC groups: REC1/2 group (removal the deprivation and re-exposure to the normal environment for 1/2 d), REC1 group (1 d), REC 2 group (2 d), and REC7 group (7 d). CT was measured by optical coherence tomography (OCT), and CVD of foveal choroid was quantitatively assessed on OCT angiography images using MATLAB software at each time point. NOS in choroid was measured using enzyme-linked immunosorbent assays. Measurements were compared between groups and correlations between CT, CVD, and NOS were assessed using regression analyses.

RESULTS

CVD and CT in FD group were significantly smaller than in NC group (both p < .05), while the NOS significantly larger (p < .001). When deprivation was removed, CVD and NOS were significantly larger and reached a peak in the REC1 group, while CT reached the peak in the REC2 group, then all gradually decreased, and no significant differences were observed in NC and REC7 group (all p > .05). In the REC and NC groups, there was a significant positive correlation between CVD and NOS (p < .001), CVD and CT (p = .0092), but no correlation was found between NOS and CT (p > .05).

CONCLUSIONS

This study indicated that the CVD in guinea pigs could be significantly dilated following myopia REC, and this change coincides with changes in NOS and CT.

Assessment of choroidal vascularity and choriocapillaris blood perfusion in Chinese preschool-age anisometropic hyperopic amblyopia children

PURPOSE

To determine the macular and peripapillary area choroid microstructure parameters of hyperopic anisometropic amblyopia eyes and compare to fellow and age-matched control eyes. To assess the correlation between the axial length (AL), choroidal thickness (CT) and choroid microstructure parameters.

METHODS

This cross-sectional comparative, non-interventional study involved 52 hyperopic anisometropic amblyopia children and 48 age-matched heathy controls. 52 eyes with hyperopic anisometropic amblyopia and 48 age-matched control eyes were studied. The peripapillary and subfoveal CT were determined. The total choroidal area (TCA), luminal area (LA), and stromal area (SA) of the subfoveal and peripapillary choroid were measured. In addition, the correlation between the AL, CT and choroid microstructure parameters were calculated.

RESULTS

The peripapillary and subfoveal CT of the amblyopic eyes was significantly thicker than the fellow and control eyes (all P < 0.05). The subfoveal and peripapillary choroidal SA, LA and TCA of the amblyopic eyes were significantly increased than that of the fellow and control eyes (all P < 0.05). The choroidal vascularity index (CVI) values of the amblyopic eye were significantly different among the three groups (P < 0.05). There was a statistically significant negative correlation between AL and subfoveal CT (SFCT), LA and TCA levels (P < 0.001, P = 0.039, P = 0.027, respectively). Spherical equivalent (SE) was positive correlated with SFCT, LA and TCA levels (P = 0.456, 0.229 and 0.240, respectively; all P < 0.05). There was a statistically significant positive correlation between SFCT, SE, LA, SA, TCA and CVI levels (all P < 0.05).

CONCLUSION

The subfoveal and peripapillary CT of amblyopic children abnormally increased and correlated with shorter AL and higher SE. The choroidal structure of the amblyopic eyes was different from the fellow and control eyes, the hyperopic anisometropic amblyopic eyes had significantly thicker sub-foveal choroid, higher LA, SA, and TCA. AL and CT affect choroidal structure and vascular density. Choroidal blood flow may be increased in amblyopic eyes. The larger LA, SA, TCA, and lower CVI were characteristic of the amblyopic eye.

Increased Choroidal Thickness in Morquio Syndrome

The purpose of this clinical case report is to describe a case of mucopolysaccharidosis type IVA (MPS IVA), or Morquio syndrome, with increased choroidal thickness in enhanced-depth imaging optical coherence tomography (EDI-OCT) which can represent choroidal deposition of glycosaminoglycans (GAGs). A 21-year-old male with genetically confirmed diagnosis of MPS IVA was examined at our Pediatric Ophthalmology clinic as part of our follow-up protocol for MPS patients. His best-corrected visual acuity was 4/10 in his right eye (OD) and 6/10 in the left eye (OS). Mild diffuse corneal opacification was evident. Intraocular pressure was within normal range. Fundus examination and color fundus photography revealed no abnormalities. EDI-OCT revealed significantly increased choroidal thickness in his right eye and in his left eye, suggesting the presence of choroidal deposition of GAGs, despite absence of retinal or optic disc GAG deposition or other chorioretinal involvement. To our knowledge, this is the first case of MPS IVA described in the literature with suspected choroidal deposition of GAGs. With improved control of systemic features of MPS IVA, life expectancy of these patients has increased, allowing for more ocular manifestations to develop. The parallel development of technology in ophthalmology, such as the EDI-OCT, further contributes to the detection of these unprecedented ocular features in MPSs.

Retinal and Choroidal Changes in Children with Moderate-to-High Hyperopia

Purpose

This study aimed to investigate the characteristics of retinal nerve fiber layer (RNFL) thickness, ganglion cell layer (GCL) thickness, and choroidal thickness in children with moderate-to-high hyperopia (MHH).

Methods

This was a cross-sectional study that enrolled 53 children with MHH and 53 emmetropic children. Subjects with a spherical equivalent refraction (SER) of +4.0 D or higher were included in the MHH group, and subjects with SER between −1.0 D and +1.0 D were included in the emmetropic group. Ophthalmic examinations, including uncorrected visual acuity, cycloplegic refraction, slit-lamp examination, axial length, and swept-source optical coherence tomography (SS-OCT; DRI OCT Triton-1, Topcon, Tokyo, Japan), were performed.

Results

The RNFL and GCL in the temporal and inferior quadrants in 1–3 mm of the macular fovea were thinner in the MHH group than in the emmetropic group (all P < 0.05). The MHH group also had a thicker choroidal thickness in all regions (all P < 0.05). The SER was independently correlated with the average choroidal thickness in the optic disc and fovea (coefficient = 4.853, P < 0.001 for the optic disc; coefficient = 5.523, P=0.004 for the fovea), while axial length was negatively correlated with choroidal thickness (coefficient = −12.649, P < 0.001). Axial length was positively associated with RNFL and GCL thickness in the temporal quadrant in 1–3 mm of the macular fovea (coefficient = 0.966, P=0.007 for RNFL and coefficient = 1.476, P=0.011 for the macular fovea).

Conclusion

Compared with emmetropic children, MMH children had greater choroidal thickness. The characteristics of the RNFL and GCL thickness in MMH children were different from those in emmetropic children.

Choriocapillaris: Fundamentals and advancements

The choriocapillaris is the innermost structure of the choroid that directly nourishes the retinal pigment epithelium and photoreceptors. This article provides an overview of its hemovasculogenesis development to achieve its final architecture as a lobular vasculature, and also summarizes the current histological and molecular knowledge about choriocapillaris and its dysfunction. After describing the existing state-of-the-art tools to image the choriocapillaris, we report the findings in the choriocapillaris encountered in the most frequent retinochoroidal diseases including vascular diseases, inflammatory diseases, myopia, pachychoroid disease spectrum disorders, and glaucoma. The final section focuses on the development of imaging technology to optimize visualization of the choriocapillaris as well as current treatments of retinochoroidal disorders that specifically target the choriocapillaris. We conclude the article with pertinent unanswered questions and future directions in research for the choriocapillaris.

Exploring choroidal angioarchitecture in health and disease using choroidal vascularity index

The choroid is one of the most vascularized structures of the human body and plays an irreplaceable role in nourishing photoreceptors. As such, choroidal dysfunction is implicated in a multitude of ocular diseases. Studying the choroid can lead to a better understanding of disease pathogenesis, progression and discovery of novel management strategies. However, current research has produced inconsistent findings, partly due to the physical inaccessibility of the choroid and the lack of reliable biomarkers. With the advancements in optical coherence tomography technology, our group has developed a novel quantitative imaging biomarker known as the choroidal vascularity index (CVI), defined as the ratio of vascular area to the total choroidal area. CVI is a potential tool in establishing early diagnoses, monitoring disease progression and prognosticating patients. CVI has been reported in existing literature as a robust marker in numerous retinal and choroidal diseases. In this review, we will discuss the current role of CVI with reference to existing literature, and make postulations about its potential and future applications.

Effect of amblyopia treatment on choroidal thickness in hypermetropic anisometropic amblyopia using swept-source optical coherence tomography

Background

Recent studies using optical coherence tomography (OCT) have indicated that choroidal thickness (CT) in the anisometropic amblyopic eye is thicker than that of the fellow and normal control eyes. However, it has not yet been established as to how amblyopia affects the choroid thickening. The purpose of the present study was to investigate the effect of amblyopia treatment on macular CT in eyes with anisometropic amblyopia using swept-source OCT.

Methods

Thirteen patients (mean age: 6.2 ± 2.4 years) with hypermetropic anisometropic amblyopia were included in this study. Visual acuity (VA), axial length (AL), and CT were measured at the enrollment visit and at the final visit, after at least 6 months of treatment. CT measurements were corrected for magnification error and were automatically analyzed using built-in software and divided into three macular regions (subfoveal choroidal thickness (SFCT), center 1 mm, and center 6 mm). A one-way analysis of covariance using AL as a covariate was performed to determine whether CT in amblyopic eyes changed after amblyopia treatment.

Results

The average observation period was 22.2 ± 11.0 months. After treatment, VA (logMAR) improvement in the amblyopic eyes was 0.41 ± 0.19 (p < 0.001). SFCT, center 1 mm CT, and center 6 mm CT were significantly thicker in the amblyopic eyes compared with the fellow eyes both before and after treatment (p < 0.05 for all comparisons). There were no significant changes in SFCT, center 1 mm CT, or center 6 mm CT before and after treatment in the amblyopic (p = 0.25, 0.21, and 0.84, respectively) and fellow (p = 0.75, 0.84, and 0.91, respectively) eyes. The correlation between changes in logMAR versus changes in CT after treatment was not significant.

Conclusions

Although VA in amblyopic eyes was significantly improved after treatment, the choroid thickening of anisometropic amblyopic eyes persisted, and there was no significant change found in the CT after the treatment. Our findings suggest that thickening of the CT in amblyopia is not directly related to visual dysfunction.