Determination of Referential Rates for Optical Coherence Tomography and Optical Coherence Tomography Angiography Flow Deficits in the Macular Choriocapillaris in Ophthalmologically Healthy Children

Choriocapillaris Reperfusion in Resolved Chronic Central Serous Chorioretinopathy Treated with Eplerenone: Long-Term Effects on the Fellow Eye

INTRODUCTION

The aim of this work is to utilize swept-source optical coherence tomography angiography (SS-OCTA) to assess the long-term changes in the choroidal and choriocapillaris (CC) layers of the fellow unaffected eye of patients with unilateral resolved chronic central serous chorioretinopathy (cCSC) following treatment with continuous oral eplerenone (EPL).

METHODS

The study included 35 patients with cCSC and subretinal fluid (SRF) in one eye. SS-OCTA imaging was performed on the fellow cCSC eyes at baseline, 6 months, and 12 months during eplerenone therapy. CC OCT angiography was analyzed to determine the percentage of choriocapillaris flow deficits (FD%), the number of flow deficits (FDn), and the average area of flow deficits (FDa).

RESULTS

The results demonstrated significant changes in CC flow deficits from baseline to follow-up visits. Specifically, there was a significant decrease in FD% from 28.9 ± 2.2% at baseline to 26.4 ± 1.9% at 6 months (p = 0.023), and further to 24.9 ± 1.7% at 12 months (p = 0.001). Additionally, the FD area gradually contracted over the follow-up period (p < 0.05). Conversely, there was a significant increase in the number of flow deficits compared to baseline (p < 0.05). No statistically significant changes were observed in best-corrected visual acuity (BCVA) at the follow-up visits (p > 0.05).

CONCLUSIONS

The findings of this study demonstrated long-term reperfusion of the choriocapillaris in unaffected fellow cCSC eyes during continuous oral eplerenone therapy. The beneficial effects of eplerenone therapy were observed after 6 months and maintained at 1 year. These results suggest that specific mineralocorticoid receptor (MR) antagonists may be effective in promoting choriocapillaris recovery in the unaffected eyes of patients with cCSC.

The Impact of Diabetic Retinopathy on the Choriocapillaris in Neovascular AMD

Purpose

To investigate the impact of diabetic retinopathy (DR) on morphological choriocapillaris (CC) modifications in eyes with type 1 macular neovascularization (MNV) secondary to AMD using optical coherence tomography angiography (OCTA).

Methods

Eyes with AMD-related type 1 MNV with and without DR were prospectively included. We performed 3 × 3 mm OCTA scans at two visits: before the loading phase of intravitreal injections of aflibercept (T1) and 1 month after the last injection (T2). OCTA En face flow images of the CC were analyzed for flow deficit percentage (FD%), FD average area and FD number in a 500-µm-wide ring surrounding the dark halo (DH) around type 1 MNV.

Results

A total of 65 eyes, out of which 30 eyes had mild DR, were included. In the group without diabetes, there was a gradual reduction in FD% in the CC ring around the DH after antiangiogenic therapy, indicating reperfusion of the CC (P = 0.003). However, in the DR group, there were no significant changes in CC parameters between the two study visits. Specifically, the FD% in the CC ring around the DH did not show a significant reduction at T2 compared with T1 values (P > 0.05). Furthermore, the comparison of the variation in FD% between the two groups was statistically significant. The nondiabetic group exhibited a gradual CC reperfusion after the loading phase of aflibercept, whereas the diabetic eyes did not show significant changes (P = 0.029).

Conclusions

The CC surrounding the DH associated to type 1 MNV exhibited greater hypoperfusion in diabetic eyes compared with eyes without diabetes, both before starting therapy and after the loading phase. Hence, DR may be a potential risk factor in the development and progression of late-stage AMD and may also influence the response to antiangiogenic therapy.

Diurnal changes in choroidal optical coherence tomography angiography indices over 24 hours in healthy young adults

This prospective study investigated the magnitude and pattern of variation in choroidal optical coherence tomography angiography (OCT-A) indices every 4 h over 24 h in healthy young myopic (n = 24) and non-myopic (n = 20) adults. Choriocapillaris and deep choroid en-face images from macular OCT-A scans were analysed from each session to extract magnification-corrected vascular indices including choriocapillaris flow deficit number, size and density and deep choroid perfusion density in the sub-foveal, sub-parafoveal, and sub-perifoveal regions. Choroidal thickness was also obtained from structural OCT scans. Significant variations over 24 h (P < 0.05) were observed in most of the choroidal OCT-A indices excluding sub-perifoveal flow deficit number, with peaks observed between 2 to 6 AM. For myopes, peaks occurred significantly earlier (3-5 h), and the diurnal amplitude was significantly greater for sub-foveal flow deficit density (P = 0.02) and deep choroidal perfusion density (P = 0.03) compared with non-myopes. Choroidal thickness also showed significant diurnal changes (P < 0.05) with peaks between 2 to 4 AM. Significant correlations were found between diurnal amplitudes or acrophases of choroidal OCT-A indices and choroidal thickness, intraocular pressure, and systemic blood pressure. This provides the first comprehensive diurnal assessment of choroidal OCT-A indices over 24 h.

Optical coherence tomography angiography in healthy children: A comparison of macular structure

PURPOSE

The purpose of the present study was to investigate the perfusion density (PD) of macular superficial (SCP) and deep capillary plexus (DCP), the size of foveal avascular zone (FAZ) and central macular thickness (CMT) in healthy children using optical coherence tomography angiography (OCT-A).

PATIENTS AND METHODS

About 206 eyes of 111 children were analyzed. The correlation of gestational age (GA), birth weight (BW), age, sex, refractive errors, and visual acuity (VA) with OCT-A parameters were investigated.

RESULTS

The mean PD of the fovea and the mean FAZ area of SCP were 17.1% (DS: 4.26) and 234.47 (DS: 106.39) µm². The mean PD of the fovea and the mean FAZ area of DCP were 13.5% (DS: 5.23) and 298.32 (DS: 112.37) µm². Superficial and deep FAZ areas were not correlated with sex, age, BW, refractive errors, or VA. FAZ area of SCP was correlated with foveal PD (r = -0.76) and with CMT (r = -0.68). FAZ area of DCP was correlated with foveal's PD (r = -0.61). There was no correlation between CMT and refractive errors.

CONCLUSION

OCT-A may provide a non-invasive and reliable approach to evaluate macular perfusion in children. As the FAZ area, PD, and CMT change during the growth period, we performed established a reference range for different ages.