Hideki Shiihara

Reproducibility and differences in area of foveal avascular zone measured by three different optical coherence tomographic angiography instruments

This study was performed to compare the area of the foveal avascular zone (FAZ-area) obtained by three optical coherence tomography angiography (OCTA) instruments. This was a cross-sectional, non-interventional study of twenty-seven healthy right eyes. The superficial and deep FAZ-area was measured manually with three OCTA instruments: Triton (Topcon), RS3000 (Nidek), and CIRRUS (Zeiss). The intra-rater, inter-rater, and inter-instrument correlation coefficients (CC) were assessed. The intra-rater and inter-rater CC were significantly high for the superficial and deep FAZ-areas (P < 0.001). The inter-instrument CC (95% confidence interval) for the superficial FAZ-area was 0.920 (0.803–0.965) for Triton vs RS3000, 0.899 (0.575–0.965) for RS3000 vs CIRRUS, and was 0.963 (0.913–0.983) for CIRRUS vs Triton (P < 0.001). For the deep FAZ-area, the inter-instrument CC was 0.813 (0.633–0.910) for Triton vs RS3000, 0.694 (0.369–0.857) for RS3000 vs CIRRUS, and 0.679 (0.153–0.872) for CIRRUS vs Triton (P < 0.001). The superficial FAZ-area (mm2) was 0.264 ± 0.071 with Triton, 0.278 ± 0.072 with RS3000 and 0.257 ± 0.066 with CIRRUS. For deep FAZ-area, it was 0.617 ± 0.175 with Triton, 0.646 ± 0.178 with RS3000 and 0.719 ± 0.175 with CIRRUS. The FAZ-area from these instruments was clinically interchangeable. However, the absolute values of FAZ-area are significantly different among them. These differences must be considered in comparing the FAZ-areas from different OCTA instruments.

Semi-automated software to measure luminal and stromal areas of choroid in optical coherence tomographic images

PurposeTo determine the capabilities of “EyeGround” software in measuring the choroidal cross sectional areas in optical coherence tomographic (OCT) images.Study designCross sectional, prospective study.MethodsThe cross-sectional area of the subfoveal choroid within a 1500 µm diameter circle centered on the fovea was measured both with and without using the EyeGround software in the OCT images. The differences between the evaluation times and the results of the measurements were compared. The inter-rater, intra-rater, inter-method agreements were determined.ResultsFifty-one eyes of 51 healthy subjects were studied: 24 men and 27 women with an average age of 35.0 ± 8.8 years. The time for analyzing a single image was significantly shorter with the software at 3.2±1.1 min than without the software at 12.1±5.1 min (P <0.001). The inter-method correlation efficient for the measurements of the whole choroid was high [0.989, 95% CI (0.981-0.994)]. With the software, the inter-rater correlation efficient was significantly high [0.997, 95% CI (0.995-0.999)], and the intra-rater correlation efficient was also significantly high [0.999, 95% CI (0.999-1.0)].ConclusionThe EyeGround software can measure the choroidal area in the OCT cross sectional images with good reproducibility and in a significantly shorter times. It can be a valuable tool for analyzing the choroid.

AMOUNT OF RESIDUAL SILICONE OIL IN VITREOUS CAVITY IS SIGNIFICANTLY CORRELATED WITH AXIAL LENGTH.

Purpose: To determine the parameters of the eye that are significantly correlated with the amount of residual silicone oil remaining after most of it is removed by vitrectomy. Methods: Nineteen eyes of 19 patients who had silicone oil removed were studied. The day after the surgery for silicone oil removal, B-scan ultrasonography was performed, and the residual silicone oil droplets were observed as hyperechoic particles in the ultrasonographic images. The images of the vitreous cavity were binarized, and the ratio of area of hyperechoic particles to the total vitreous area was quantified and named the silicone oil index (SOI). The correlations between SOI and clinical findings were determined. Results: The SOI was significantly and positively correlated with the axial length (AL) and the preoperative intraocular pressure (AL, R = 0.676, P = 0.002; preoperative intraocular pressure, R = 0.771, P < 0.001). Partial correlation analysis showed that the AL remained significantly correlated with the SOI but the preoperative intraocular pressure was not (AL, R = 0.734, P = 0.001; preoperative intraocular pressure, R = 0.417, P = 0.096). None of the other clinical factors was significantly correlated with the SOI. Conclusion: Considering the significant correlation between the amount of residual silicone oil and the AL of the eye, myopic eyes should be carefully scrutinized for residual silicone oil.

Objective evaluation of size and shape of superficial foveal avascular zone in normal subjects by optical coherence tomography angiography

This study was conducted to investigate the size and shape of the foveal avascular zone (FAZ) determined by optical coherence tomography angiography (OCTA) and the relationship of the size and shape to the clinical findings in normal subjects. This was a cross-sectional study with seventy eyes of 70 volunteers. The size of the superficial FAZs were assessed by its area, length of perimeter, and Feret’s diameter, and the shape by the circularity, axial ratio, roundness, and solidity. The correlations between each parameter and the clinical findings were statistically determined. The coefficients of variation (CV) of the parameters of FAZ size were higher than that of the parameters of FAZ shape. The refractive error and axial length were significantly correlated with area-related factors. The central macular thickness (CMT) was significantly correlated with all parameters. Although the CMT was a critical factor that was significantly correlated with the size and shape characteristics of the FAZ, the shape might be a better factor for characterizing the FAZ than the size because of the low CV of shape-related factors and the characteristics are less affected by the other ocular factors.

Evaluation of Shape of Foveal Avascular Zone by Optical Coherence Tomography Angiography in Eyes With Branch Retinal Vein Occlusion

Purpose: To determine the relationship between morphological parameters of the foveal avascular zone (FAZ) in the optical coherence tomography angiographic (OCTA) images and the best-corrected visual acuity (BCVA) in branch retinal vein occlusion (BRVO). Methods: This was a retrospective cross-sectional study. Eyes with BRVO without apparent macular edema were studied. The superficial FAZ in 3 × 3 mm OCTA images were delineated manually. The size and shape, the circularity and axial ratio, of the FAZ were determined, and the values were compared to that of the controls. The correlation of these parameters with the BCVA was analyzed. Results: The mean FAZ area was larger in BRVO eyes than in controls, but the larger size was not correlated with the BCVA (BRVO, 0.49 ± 0.12 mm2; control, 0.38 ± 0.12 mm2; P = .135). The axial ratio of the BRVO eyes was significantly larger than that of controls (P < .001). The axial ratio was significantly correlated with BCVA (R = .382, P = .050). Although the circularity was significantly smaller in the BRVO eyes than that in controls (P < .001), it was not significantly correlated with the BCVA. Conclusion: The shape of the FAZ would be a more appropriate parameter than the size in determining BCVA in eyes with BRVO.

Kago-Eye2 software for semi-automated segmentation of subfoveal choroid of optical coherence tomographic images

PurposeTo determine the capabilities of the “Kago-Eye2” software to semi-automatically segment the choroid in the optical coherence tomographic (OCT) images.Study designA cross-sectional, prospective study of 44 healthy volunteers.MethodsThe Kago-eye2 software was developed to detect the border between Choriocapillaris and Sattler’s layer (C–S) and between Sattler’s layer and Haller’s layer (S–H). The intra- and inter-grader agreements were determined for the segmentations made with semi-automated and manual analysis using the Kago-Eye2 software. The inter-method agreements were determined for two independent graders.ResultsForty-four right eyes of 44 heathy volunteers (22 men) with a mean age of 35.0 ± 8.8 years were studied. The intra-grader agreement of the C–S border was 0.97 for grader 1 and 0.892 for grader 2 for the manual segmentation, and 0.908 for grader 1 and 0.842 for grader 2 for the Kago-Eye2 segmentation. For the S–H border, the intra-grader agreement was 0.96 for grader 1 and 0.981 for grader 2 for manual segmentation and 0.855 for grader 1 and 0.839 for grader 2 with the Kago-Eye2. For the C–S and S–H border, the inter-grader agreement was 0.548 and 0.902 for manual segmentation and 0.947 and 0.833 for the Kago-Eye2. The inter-method agreement was 0.565 for the C–S border and 0.759 for the S–H border.ConclusionThe Kago-Eye2 software can segment the layers of the subfoveal choroid with good reproducibility and repeatability. We conclude that the Kago-Eye2 software can be used for semi-automatic segmentation of the choroidal layers.

Acute bacterial endophthalmitis after scleral buckling surgery with chandelier endoillumination

Purpose The non-contact wide-angle viewing system (WAVS) with chandelier endoillumination is being used more commonly during scleral buckling surgery for rhegmatogenous retinal detachments although its safety has not been established. We report our findings in a case of bacterial endophthalmitis that developed after scleral buckling surgery with WAVS and chandelier endoillumination. Observations A 42-year-old man underwent scleral buckling surgery for a rhegmatogenous retinal detachment in his right eye using a WAVS with chandelier endoillumination. Three days after the surgery, the patient noticed a marked decrease in his vision with ocular pain. Slit-lamp examination showed dense infiltration in the anterior chamber and vitreous body. Pars plana vitrectomy with antibiotic irrigation was done immediately, and Staphylococcus epidermidis was detected in the vitreous fluid. After vancomycin 6/day for 4 weeks, the inflammation gradually subsided, and the visual acuity recovered to 20/20 in 3 months. Conclusions and importance Acute bacterial endophthalmitis can develop after scleral buckling surgery performed with WAVS and chandelier endoillumination.