Abnormal Outer Choroidal Vasculature in Amblyopia

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.

Quantitative evaluation of anisometropic amblyopia treatment efficacy by coupling multiple visual functions via CRITIC algorithm

BACKGROUND

The evaluation of amblyopia treatment efficacy is essential for amblyopia prevention, control, and rehabilitation.

METHODS

To evaluate the amblyopia treatment efficacy more precisely and quantitatively, this study recorded four visual function examination results, i.e., visual acuity, binocular rivalry balance point, perceptual eye position, and stereopsis before and after amblyopia treatment.

RESULTS

We found that all these four results had a significant difference between before and after treatment, and the relationship between visual acuity improvement and the difference of BRBP, PEP, and stereoacuity cannot show a fitting correlation regarding the widely used index of visual acuity as the standard of treatment efficacy. By using the Criteria Importance Through Inter-criteria Correlation (CRITIC) method, a more comprehensive and quantitative index by coupling the selected four indexes with objective weights was obtained for further training efficacy representation, and the validation dataset also showed a good performance.

CONCLUSIONS

This study proved that our proposed coupling method based on different visual function examination results via the CRITIC algorithm is a potential means to quantify the amblyopia treatment efficacy.

Evaluation of Choroidal Vascular Structure in Hyperopic Anisometropic Amblyopia

Objectives

The aim of the study was to investigate the choroidal structure of patients with anisohypermetropic amblyopia compared to that of healthy eyes in controls of the same age.

Methods

The study comprises three groups: One group was the amblyopic eyes of patients with anisometropic hypermetropia (AE group), another group was the fellow eyes of patients with anisometropic hypermetropia (FE group), and a final group of healthy controls. Both the choroidal thickness (CT) and choroidal vascularity index (CVI) values were obtained using the spectral-domain optical coherence tomography (OCT) method of improved depth imaging (EDI-OCT; Heidelberg Engineering GmbH, Spectralis, Germany, Heidelberg).

Results

This study included 28 anisometropic amblyopic patients (AE and FE groups) and 35 healthy controls. Regarding the distribution of ages and sexes (p=0.813 and p=0.745), the groups were the same. The mean best-corrected visual acuity in AE, FE, and the control group was 0.58±0.76, 0.008±1.30, and 0.004±1.20 logMAR units, respectively. There was a significant difference in terms of CVI, luminal area (LA), and all the CT values between groups. Post hoc univariate analyses indicated that CVI and LA were significantly higher in AE compared to FE and the control group (p<0.05, for each). The temporal, nasal, and subfoveal CT values were considerably higher in AE compared to FE and the control groups (p<0.05, for each). However, there was no difference between FE and the control group (p>0.05, for each).

Conclusion

The AE group had larger LA, CVI, and CT values compared to the FE and control groups. These results show that choroidal changes in amblyopic eyes in children are permanent in adulthood if untreated and are involved in the pathogenesis of amblyopia.

Changes in Choroidal Thickness and Structure Induced by 1% Atropine Instillation in Children With Hyperopic Anisometropic Amblyopia

PURPOSE

To investigate the effects of 1% atropine eye drops on the choroidal thickness and structure of amblyopic and fellow eyes in children with hyperopic anisometropic amblyopia.

METHODS

This study included 16 children with hypermetropic anisometropic amblyopia. All patients received 1% atropine eye drops in both eyes twice a day for 7 days. In the subfoveal choroidal region, choroidal thickness, total choroidal area, luminal area, and stromal area were measured quantitatively using swept-source optical coherence tomography. The choroidal parameters of the amblyopic and fellow eyes were compared between the baseline and atropine conditions.

RESULTS

There were no significant differences in all choroidal parameters of the amblyopic eye between baseline and atropine conditions. However, the subfoveal choroidal thickness in the fellow eye was significantly higher for the atropine condition than the baseline condition. This change was accompanied by a significant increase in both the luminal and stromal areas of the choroid. The median differences of subfoveal choroidal thickness between the conditions were larger for the fellow eye (6.46%) than the amblyopic eye (0.26%).

CONCLUSIONS

The choroidal structural change induced by 1% atropine instillation was smaller for the amblyopic eye than the fellow eye in children with hyperopic anisometropic amblyopia. Mechanisms of choroidal thickness changes could be inhibited in amblyopic eyes. [J Pediatr Ophthalmol Strabismus. 2023;60(1):39-45.].

Features of the Choroidal Structure in Children With Anisometropic Amblyopia

PURPOSE

To examine the choroidal structure in children with anisometropic amblyopia using the binarization method.

METHODS

Thirty children with unilateral anisometropic amblyopia and 30 healthy age- and sex-matched controls were included in the study. Choroidal thickness was measured with optical coherence tomography. The choroidal layer was examined with the binarization method using ImageJ software (National Institutes of Health). The total choroidal area, stromal area, luminal area, luminal area to stromal area ratio, and choroidal vascular index were calculated. The values were compared by correlating the spherical equivalent (SE) (determined by an autorefractometer) with anterior chamber depth, axial length, central corneal thickness (measured by optical biometry), and choroidal thickness values.

RESULTS

Mean SE values were 3.75 ± 2.16 diopters (D) in the amblyopic eyes, 2.39 ± 2.09 D in the fellow eyes, and -0.27 ± 0.53 D in the control eyes. Best corrected visual acuity (BCVA) was 0.29 ± 0.11 logarithm of the minimum angle of resolution (logMAR) in the amblyopic eyes, 0.02 ± 0.04 logMAR in the fellow eyes, and 0 ± 0 logMAR in the control eyes. Choroidal thickness values were 351 ± 47 µm in the amblyopic eyes, 333 ± 55 µm in the fellow eyes, and 324 ± 51 µm in the control eyes. Luminal area to stromal area ratio values were 1.73 ± 0.13 in the amblyopic eyes, 1.76 ± 0.15 in the fellow eyes, and 2.02 ± 0.25 in the control eyes. Choroidal vascular index values were 63% ± 0.02 in the amblyopic eyes, 64% ± 0.02 in the fellow eyes, and 66% ± 0.03 in the control eyes. BCVA, SE, choroidal thickness, luminal area to stromal area ratio, and choroidal vascular index were significantly different in each group. The total choroidal area, luminal area, and stromal area were similar in all eyes. No correlation was found between choroidal vascular index and choroidal thickness, anterior chamber depth, axial length, and central corneal thickness.

CONCLUSIONS

In children with anisometropic amblyopia, the total choroidal area was relatively larger in both the amblyopic and the fellow eyes compared to the control eyes. Due to the higher stromal area and lower luminal area, both the amblyopic and the fellow eyes also had lower choroidal vascular index values than control eyes. [J Pediatr Ophthalmol Strabismus. 2022;59(5):320-325.].

The iridocorneal angle and related anterior segment structures in pediatric anisohyperopic amblyopic eyes

Objectives:

We aimed at investigating the iridocorneal angle, anterior segment structural differences, and their relationship in pediatric anisohyperopic amblyopic eyes.

Methods:

This study was designed as an observational case-control study. We prospectively evaluated the pediatric patients who were newly diagnosed with hyperopic anisometropic amblyopia. Iridocorrneal angle in four sectors, axial length, and anterior segment structures were compared to emmetropic fellow and control eyes using Pentacam and IOLMaster 700 devices. The anisohyperopia and iridocorneal angle related factors were determined in hyperopic anisometropic amblyopic eyes.

Results:

Forty-three hyperopic anisometropic amblyopic eyes, 43 fellow eyes, and 44 control eyes were included. The mean axial length, anterior chamber volume, and anterior chamber depth were significantly reduced in the study eyes compared to the fellow (p < 0.001, p = 0.021, and p = 0.045, respectively) and control eyes (p < 0.001, p = 0.001, and p = 0.009, respectively). The average iridocorneal angle was significantly lower in the study eyes than in the fellow and control eyes (p < 0.001 and p = 0.018, respectively). The iridocorneal angle correlated with anterior chamber depth (r = 0.49, p = 0.013), anterior chamber volume (r = 0.42, p = 0.038), the anterior radius of curvature (r =−0.54, p = 0.005), the posterior radius of curvature (r =−0.58, p = 0.002), and lens thickness (Rho =−0.41, p = 0.033) in the study eyes. Anisohyperopia was related to the interocular difference in axial length (Rho = 0.53, p = 0.005), anterior chamber depth (Rho = 0.53, p = 0.005), and anterior chamber volume (Rho = 0.42, p = 0.031).

Conclusion:

Pentacam and IOLMaster 700 are suitable for non-contact imaging of iridocorneal angle and anterior segment structures in the pediatric age. These biometric differences and their relationship should be kept in mind whenever anterior or posterior segment surgery is planned for pediatric anisohyperopic amblyopic eyes.

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.

Choroidal vascularity index in adults with different refractive status

AIM

We aimed to perform structural analysis of the choroid in adults with different refractive status.

MATERIALS AND METHODS

A prospective, comparative study of 100 right eyes of 100 patients ages 18-40 years was conducted. The patients were divided into four groups according to spherical equivalent (SE): Group 1: -0.5 and above, low-to-moderate myopia; Group 2: -6 and above, high myopia; Group 3: +0.5 and above, hyperopia; Group 4: +/- 0.5, emmetropia. With the images obtained using enhanced depth imaging optical coherence tomography (EDI-OCT), the total choroidal area (TCA), luminal area (LA), stromal area (SA), and choroidal vascular index (CVI) were calculated using the binarization method. The anterior chamber depth (ACD), axial length (AL), and central corneal thickness (CCT) values were measured by optical biometry. All parameters were compared between groups. The correlation of biometric parameters with CVI was examined.

RESULTS

Parameters were found to be statistically different between the four groups. TCA, LA, and SA values were the highest in Group 3 and lowest in Group 2. L/S ratio and CVI values in Group 3 were significantly lower than in the other groups. There was a negative correlation between AL with SE and CT, and no correlation between the CVI and other parameters.

CONCLUSION

CVI decreases when emmetropization is disrupted and changes to hypermetropia or myopia. The reason for the decrease in myopia is the reduction of the luminal area, while in hyperopia it is due to an increase in the stromal area. When there is a shift toward myopia, there is a decrease in the TCA, but the CVI does not change significantly. Unlike CT, the CVI is not affected by factors such as SE and AL; therefore, the CVI can be a useful parameter for examining choroidal changes in refractive errors.

Choroidal vessel density in unilateral hyperopic amblyopia using en-face optical coherence tomography

Background

Structural changes of the choroid, such as choroidal thickening, have been indicated in amblyopic eyes with hyperopic anisometropia as compared to fellow or healthy eyes. The purpose of the present study was to investigate choroidal vascular density (CVD) in children with unilateral hyperopic amblyopia.

Methods

This study included 88 eyes of 44 patients with unilateral amblyopia due to hyperopic anisometropia with or without strabismus and 29 eyes of 29 age-matched normal controls. The CVD of Haller’s layer was quantified from en-face images constructed by 3-dimensional swept-source optical coherence tomography images flattened relative to Bruch’s membrane. The analysis area was a 3 × 3-mm square of macula after magnification correction. Relationships between CVD and other parameters [best-corrected visual acuity (BCVA), refractive error and subfoveal choroidal thickness (SFCT)] were investigated, and CVDs were compared between amblyopic, fellow, and normal control eyes.

Results

Mean CVD was 59.11 ± 0.66% in amblyopic eyes, 59.23 ± 0.81% in fellow eyes, and 59.29 ± 0.74% in normal control eyes. CVD showed a significant positive relationship with SFCT (p = 0.004), but no relationships with other parameters. No significant differences in CVD were evident among amblyopic, fellow, and normal control eyes after adjusting for SFCT (p = 0.502).

Conclusions

CVD was unrelated to BCVA, and CVD did not differ significantly among amblyopic, fellow and normal control eyes. These results suggest that the local CVD of Haller’s layer is unaffected in unilateral hyperopic amblyopic eyes.