Peripapillary and Macular Choroidal Vascularity Index in Eyes with Fuchs' Uveitis

Simultaneous evaluation of iris area and subfoveal choroidal thickness in Fuchs uveitis syndrome

BACKGROUND/AIMS

To simultaneously evaluate iris area (IA) and subfoveal choroidal thickness (SFCT) in eyes with Fuchs Uveitis Syndrome (FUS).

METHODS

We prospectively recruited a case series of patients with FUS at our institution, simultaneously measuring IA with anterior segment spectral domain optical coherence tomography (SD-OCT) and SFCT with enhanced depth imaging optical coherence tomography (EDI-OCT). Iris images were analyzed by ImageJ software. We tested the differences in intereye IA and SFCT with the healthy eye (HE) using the Wilcoxon test, and clinical interpretation was controlled by intraclass correlation coefficient (ICC) between two masked specialists.

RESULTS

Sixteen patients with unilateral FUS were included. Six were female, and the age range was 37 to 67 (median age 48 years, IQR 41-60). ICC of 98.9%, with a lower confidence interval of 97%. Eyes with FUS had a significant thinning of the total iris median area (p < 0.002), restricted to the temporal and nasal areas compared to the HE (p < 0.01 and < 0.001, respectively). SFCT was also significantly thinner compared to the HE (p < 0.0001). A low correlation was found between iris and choroidal thinning in FUS eyes (rs = 0.21; p = 0.4).

CONCLUSIONS

This study found reduced iris area and subfoveal choroidal thickness in eyes with FUS compared to the normal fellow eye.

Choroidal vascularity index and submacular choroidal thickness in patients with Behçet disease assessed with enhanced-depth OCT

PURPOSE

To investigate changes in the choroid using the choroidal vascularity index (CVI) and choroidal thickness (ChT) in patients with ocular (OBD) and non-ocular Behçet disease (non-ocular BD).

METHODS

Sixty-eight OBD patients, 40 non-ocular BD patients, and 40 healthy control subjects were included. ChT was measured using optical coherence tomography (OCT) in enhanced-depth imaging (EDI) mode (EDI-OCT; sub-foveal ChT at 1000 μm, nasal ChT at 1000 μm temporal ChT). The CVI value (%) was calculated by dividing the luminal area by the sub-foveal total choroidal area.

RESULTS

The mean sub-foveal ChT (297 ± 68 µm), nasal ChT (261 ± 66 µm), and temporal ChT (272 ± 68 µm) in eyes with OBD and the mean sub-foveal ChT (286 ± 31 µm), nasal ChT (266 ± 29 µm), and temporal ChT (269 ± 32 µm) in eyes with non-ocular BD were significantly decreased compared with those regions in healthy control subjects (333 ± 69, 301 ± 75, and 312 ± 70 µm, respectively). Additional subgroup analysis was performed for active OBD, inactive OBD, non-ocular BD, and the control group, and in pairwise comparisons, the CVI value was significantly decreased in both active (64.3 ± 3.1) and inactive OBD groups (64.2 ± 4.5) compared with healthy control subjects (67.2 ± 3.6; p = 0.026 and p < 0.001, respectively). There was no significant difference between non-ocular BD (65.9 ± 3.4) and control subjects (67.2 ± 3.6) for CVI measurements (p > 0.05).

CONCLUSIONS

Decreased CVI values in OBD suggest that uveitis affects the choroidal vasculature and that perfusion is affected by uveitis, whereas systemic inflammation in non-ocular BD does not affect them. In addition, the choroid in uveitis is affected by the chronicity of the disease rather than disease activity. ChT measurements and CVI values may be a novel and robust prognosticating biomarker to evaluate choroidal vasculature and to monitor disease progression in OBD patients because EDI-OCT is a non-invasive imaging modality. However, CVI does not seem to be a biomarker for monitoring of disease activity or treatment efficacy.

Short-term postoperative changes in the choroidal vascularity index in patients with a unilateral epiretinal membrane

BACKGROUND

To investigate short-term choroidal structural and vascular changes after epiretinal membrane (ERM) surgery.

METHODS

In this retrospective study, 65 patients with unilateral ERM underwent pars plana vitrectomy combined with cataract surgery and were examined one day before surgery and one week, one month, and three months after surgery. Choroidal thickness (CT) and choroidal vascular index (CVI) were evaluated using horizontal enhanced depth imaging optical coherence tomography (EDI-OCT) scans and were further calculated using semi-automatic algorithms using MATLAB R2017a.

RESULTS

Preoperatively, CVI was higher in eyes with ERM (61.70 ± 5.17%) than in fellow eyes (59.99 ± 5.26%). CVI increased significantly at one week after surgery (62.14 ± 5.02%) and decreased at 1 and 3 months after surgery (60.76 ± 4.97% and 60.4 ± 4.83%, respectively). The change was pronounced in the nasal region (p < 0.001) and central region (p < 0.05). CT in the temporal macula increased at 1 week (239.65 ± 72.98 μm) after surgery and decreased at 1 and 3 months after surgery (222.15 ± 71.91 μm and 222.33 ± 65.72 μm, respectively; p < 0.01).

CONCLUSIONS

Short-term postoperative variations in the choroid have been demonstrated in eyes with ERM. This may be related to the release of macular traction. CVI assessment using EDI-OCT may be a useful tool for investigating choroidal structural changes accompanying ERM and postoperative period.

The status of the choroid in patients with optic disc drusen

PURPOSE

To investigate the subfoveal and peripapillary choroidal thickness (CT) and the choroidal vascularity index (CVI) in patients with optic disc drusen (ODD).

METHODS

This cross-sectional study examined the eyes of 17 patients with ODD and 18 healthy control subjects. The CT values were calculated manually from the images captured by enhanced depth imaging-optical coherence tomography (EDI-OCT). The CVI was defined as the proportion of the vascular area to the total choroidal area at the subfoveal and peripapillary areas after binarization of the EDI-OCT images.

RESULTS

It was found that the mean subfoveal CVI value in the ODD group was significantly lower than that in the control group (p = 0.006). The mean peripapillary CVI values were significantly lower in all of the quadrants in the ODD group when compared with the control group (p = 0.008 for the temporal quadrant, p = 0.014 for the nasal quadrant, p = 0.024 for the superior quadrant, and p = 0.038 for the inferior quadrant). Regarding the CT, there were no significant differences in the subfoveal and peripapillary CT values between the ODD group and the control group (p >  0.05 for all values).

CONCLUSION

The findings of this study indicate ODD to be associated with decreased subfoveal and peripapillary CVI, even though the subfoveal and peripapillary CT values were within the normal range. This result may prove important in relation to identifying a choroidal vascular network that appears to be morphologically normal but microstructurally impaired due to ODD. Further studies are required to verify the significance of CVI in the pathogenesis and complications of ODD.