Wide-Field Swept-Source Optical Coherence Tomography Analysis of Interocular Symmetry of Choroidal Thickness in Healthy Young Individuals.

Purpose: The purpose of this paper was to study the bilateral choroidal thickness (CT) symmetry and differences in healthy individuals using wide-field swept-source optical coherence tomography (SS-OCT). Methods: All participants underwent a wide-field 16-mm 1-line scan using SS-OCT. CTs were measured at the following 12 points: 3 points at 900 µm, 1800 µm, and 2700 µm away from the nasal optic disc margin (nasal peripapillary area), 1 point at the subfovea, 6 points at 900 µm, 1800 µm, and 2700 µm away from the subfovea to the nasal and temporal areas (macular area), and 2 peripheral points at 2700 and 5400 µm from temporal point 3 (peripheral area). Bilateral CTs were measured; their correlations and differences in the corresponding regions were analyzed. Results: There were no statistically significant differences in CTs between the right and left eyes in all corresponding areas (all P > 0.05); they all showed significant positive correlation coefficients (r) (all P < 0.001). However, the nasal peripapillary and peripheral areas had relatively low correlation coefficients, compared to the macular areas. In addition, the bilateral CT differences were 32.60 ± 25.80 µm in the macular area, 40.67 ± 30.58 µm in the nasal peripapillary area, and 56.03 ± 45.73 µm in the peripheral area (all P < 0.001). Conclusions: Overall, the CTs of each region were bilaterally symmetrical. However, the differences in CTs increased from the center to the periphery, which indicated that the anatomic variation of the nasal peripapillary and peripheral choroid was greater than that of the macula.

A comparison of choroidal thicknesses between pachychoroid and normochoroid eyes acquired from wide-field swept-source OCT.

PURPOSE: We investigated the wide-field choroidal thickness (CT) using swept-source optical coherence tomography (SS-OCT) and compared the characteristics of the choroidal layer between pachychoroid and normochoroid groups. METHODS: A total of 120 eyes from 120 normal subjects were included. All subjects were divided into two groups according to the subfoveal CT (≥300 µm, pachychoroid group; <300µm, normochoroid group). All subjects underwent an HD spotlight 16 mm scan using SS-OCT. The CT was measured at the following 12 points: subfoveal, 3 points in the nasal peripapillary area, 6 points in the macular area and 2 peripheral points at 5400 and 8100 µm from the fovea. The CT measurements were compared between the two groups, and statistical analyses were performed to determine clinical factors associated with each point of the CT. RESULTS: The CT in the pachychoroid group was thicker than that in the normochoroid group at all points (p < 0.01). The CTs of the two groups in the macular area were highly associated with the subfoveal CT. However, the CTs of the nasal peripapillary and peripheral areas showed lower associations with the subfoveal CT and lower diagnostic abilities for the pachychoroid group. The existence of pachyvessels was found to be a significant factor causing the regional variations. CONCLUSIONS: The CTs in the peripapillary and peripheral areas showed different patterns than the subfoveal CT. Regional variations by pachyvessels were more frequent in the peripapillary and peripheral areas than in the macular area, and the subfoveal CT did not represent the whole choroidal area.

Repeatability of measuring the vessel density in patients with retinal vein occlusion: An optical coherence tomography angiography study.

PURPOSE: To determine the repeatability of superficial vessel density measurements using Spectral domain Ocular coherence tomography angiography(SD-OCTA) in patients diagnosed with retinal vein occlusion(RVO). DESIGN: Prospective observational study. SUBJECTS: Patients who visited our retinal clinic from August 2017 to August 2018, diagnosed with RVO were recruited for the study. METHODS: Two consecutive 3×3 mm pattern scans were performed using the Cirrus HD-OCT 5000 along with AngioPlex software (Carl Zeiss Meditec) in each eye by single skilled examiner. All scans were analyzed using en face OCTA images to measure vessel density (VD) automatically. For further analysis of the effect of central macular thickness(CMT), eyes were divided into two groups according to CMT of 400µm (Group 1: CMT > 400µm, Group 2: CMT < 400µm). To identify factors affecting the repeatability of VD measurements, linear regression analyses were conducted for the coefficient of variation (CV) of VD by investigating demographics and ocular variables. MAIN OUTCOME MEASURES: The intraclass correlation coefficient (ICC), coefficient of variation (CV) of VD measurements. RESULTS: A total of 57 eyes from 57 patients were examined: 35 eyes with BRVO and 22 eyes with CRVO. In all 57 eyes with RVO, the ICC and CV of the full VD(VD of 3mm diameter circle) were 0.800 and 10.61%, respectively. Univariate analyses showed that the mean CMT (B, 0.001; p<0.001) and mean ganglion cell-Inner plexiform layer (GC-IPL) thickness (B, -0.002; p = 0.020) were significant factors that affected the repeatability. Multivariate analyses of these two factors showed that only mean CMT was a significant factor. The ICC and CV of the full VD in group 1 (CMT > 400µm) were 0.348 and 22.55% respectively. In group 2 (CMT < 400µm), the ICC and CV of the full VD were 0.910 and 7.76%, respectively. CONCLUSIONS: The repeatability of VD measurement in eyes with RVO was reasonably comparable to previous studies. Repeatability of VD measurement was significantly affected by central macular thickness.

Publisher Correction: Factors Affecting Repeatability of Assessment of the Retinal Microvasculature Using Optical Coherence Tomography Angiography in Healthy Subjects.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Long-term results of focal laser photocoagulation and photodynamic therapy for the treatment of central serous chorioretinopathy.

PURPOSE: To evaluate the long-term results of focal laser photocoagulation and photodynamic therapy (PDT) for treatment of central serous chorioretinopathy (CSC). STUDY DESIGN: Retrospective chart review. METHODS: Sixty-two patients with CSC, thirty-three of whom were treated with focal laser photocoagulation, and 29 with PDT and who were followed up for > 6 months, were enrolled. The focal laser was performed at sites of focal leakage (but not subfoveal leaks) shown in fluorescein angiography. PDT was performed at sites of subfoveal or juxtafoveal focal leakage or not definite focal leakages. Best corrected visual acuity (BCVA), central macular thickness (CMT), resolution of subretinal fluid (SRF) and recurrence were analyzed. RESULTS: The follow-up duration of the focal laser group was 35.2 ± 22.6 and of the PDT group, 46.4 ± 21.5 months. Time to resolution of SRF was 1.8 ± 1.5 months for the focal laser group and 1.2 ± 0.5 months for the PDT group. SRF was rapidly absorbed in the PDT group. In both groups, the CMT was decreased 1 month after treatment. The BCVA improved significantly 1 month after treatment in the focal laser group and 3 months after treatment in the PDT group. However, there was no significant difference in CMT reduction and BCVA improvement between the two groups. It subsequently remained similar for up to 3 years. Ten patients (30.3%) in the focal laser group and three patients (10%) in the PDT group recurred during the follow-up period. CONCLUSIONS: PDT showed early resolution of the SRF compared to focal laser. In CSC patients, both the CMT and BCVA remained stable for 3 years after treatment. After 3 or more years of follow-up, PDT showed a lower recurrence rate than focal laser.

Longitudinal changes in the thickness of the ganglion cell-inner plexiform layer in patients with hypertension: a 4-year prospective observational study.

PURPOSE: Hypertension (HTN) is expected to accelerate age-related ganglion cell-inner plexiform layer thickness (GC-IPLs) reduction, but there is limited information on the reduction rate of GC-IPLs in HTN patients. We investigate longitudinal changes in the thickness of GC-IPL in patients with HTN. METHODS: We performed a prospective, longitudinal and observational study design. Participants were divided into two groups: HTN group (49 eyes) and control group (56 eyes). After the initial visit, GC-IPLs were measured four times at 1-year intervals using spectral-domain optical coherence tomography. The GC-IPL reduction rate was estimated using a linear mixed model and compared between the two groups. Univariate and multivariate generalized linear mixed models were used to identify factors associated with reductions in GC-IPLs over time. RESULTS: In a linear mixed model, the GC-IPL reduction rates for the HTN and control groups were -0.64 (p < 0.001) and -0.19 (p < 0.001) µm/year, respectively, and the interaction between group and follow-up duration was significant (p < 0.001). In the HTN group, all sectors exhibited significant reductions over time (all p < 0.001). Results from univariate and multivariate linear mixed model analyses revealed that age and IOP were significantly associated (p = 0.009 and 0.047, respectively) with reductions in GC-IPLs in HTN patients. CONCLUSION: Patients with HTN exhibited a significant reduction in GC-IPLs compared to normal subjects. Additionally, age and IOP affected the reduction rate of GC-IPLs in HTN patients. In various ophthalmic diseases, physicians should consider the longitudinal effect of HTN on GC-IPLs.

Factors Affecting Repeatability of Assessment of the Retinal Microvasculature Using Optical Coherence Tomography Angiography in Healthy Subjects.

Various factors can affect repeatability of optical coherence tomography angiography (OCTA) measurements, and they have not been studied sufficiently. We aimed to investigate the factors associated with the repeatability of automated superficial retinal vessel density (VD) and foveal avascular zone (FAZ) metrics acquired from OCTA. A total of 141 normal eyes from 141 healthy subjects were included, and two consecutive macular 6 × 6-mm angiography scans were performed. VD, perfusion density (PD), and FAZ of the superficial capillary plexus were calculated automatically. Reproducibility was assessed based on intraclass correlations (ICCs) and coefficients of variation (CVs). VD (ICC: 0.824, CV: 3.898) and PD (ICC: 0.845, CV: 4.042) over the entire 6-mm scan area showed better repeatability than VD (ICC: 0.752, CV: 17.470) and PD (ICC: 0.752, CV: 18.552) in the 1-mm scan, and with respect to the obtained FAZ metrics (ICC < 0.75, CV > 10.0%). Regression analyses showed that two factors, signal strength (p = 0.004) and average VD over the total 6-mm scan area (p < 0.001), were significantly correlated with the CV of the VD. Signal strength was associated with the repeatability of OCTA measurements and should be considered in the analysis of retinal VD and FAZ.

Changes in Ganglion Cell-Inner Plexiform Layer Thickness and Retinal Microvasculature in Hypertension: An Optical Coherence Tomography Angiography Study.

PURPOSE: To investigate retinal blood flow in patients with hypertension using optical coherence tomography angiography (OCTA) and the relationship between blood flow metrics and ganglion cell-inner plexiform layer (GC-IPL) thickness. DESIGN: Retrospective, cross-sectional study. METHODS: A total of 201 eyes from 117 healthy subjects and 84 hypertensive patients without any ocular abnormalities were included. Hypertensive patients were divided into the 2 groups according to disease periods (<5 years: Hypertension Group 1; ≥5 years: Hypertension Group 2). Macular 3 × 3-mm angiography was acquired using the Zeiss Cirrus 5000 OCT instrument. Vessel density (VD), perfusion density (PD), and foveal avascular zone metrics of the superficial capillary plexus were automatically calculated, and the thicknesses of the central fovea, GC-IPL, and peripapillary retinal nerve fiber layer (RNFL) were measured. All measurements were compared among the 3 groups, and retinal blood flow metrics were correlated with the thickness of each retinal layer. Logistic regression analyses were performed to determine the factors associated with prolonged hypertension. RESULTS: The average GC-IPL (P < .001) and peripapillary RNFL (P = .048) thicknesses in Hypertension Group 2 were significantly thinner compared to the control group. The 3 mm total area of the VD and PD was also decreased compared to the control group and Hypertension Group 1 (all P < .05), and was significantly correlated with the GC-IPL (VD: r = 0.450, P = .001; PD: r = 0.467, P < .001) and peripapillary RNFL (VD: r = 0.314, P = .027; PD: r = 0.328, P = .023) thicknesses in Hypertension Group 2. Using multivariate logistic analyses, only the average GC-IPL thickness was a significant factor for prolonged hypertension (odds ratio = 0.911, P = .002). CONCLUSIONS: In patients with hypertension lasting more than 5 years, inner retinal layer thinning, particularly GC-IPL thinning, was observed, which was significantly correlated with a decrease in retinal blood flow. Therefore, physicians should consider the effects of hypertension on the GC-IPL.

Longitudinal Changes of Retinal Thicknesses in Branch Retinal Artery Occlusion: Spectral-Domain Optical Coherence Tomography Study.

Purpose: To analyze longitudinal thickness changes in the overall macula, ganglion cell-inner plexiform layer (GC-IPL), and peripapillary retinal nerve fiber layer (pRNFL) using spectral-domain optical coherence tomography in branch retinal artery occlusion (BRAO). Methods: A prospective analysis was conducted in patients with BRAO. The thicknesses of the overall macula, GC-IPL, and pRNFL were measured at the initial visit, and at 1, 3, 6, and 12 months. Changes in the occluded areas of the affected and unaffected eyes were analyzed, and the nonoccluded areas were compared. Results: In the occluded areas of the affected eyes, the only overall macular thickness was significantly greater when compared with that of unaffected eyes at the initial visit. At 1 month, the thickness of GC-IPL alone in the occluded areas of affected eyes decreased significantly when compared with that of unaffected eyes. The average thicknesses of all parameters in the occluded areas at 3, 6, and 12 months were significantly reduced compared with those of the unaffected eyes. In addition, the thickness of pRNFL in the nonoccluded vertical mirror areas at 6 and 12 months was significantly reduced compared with those of the unaffected eyes. Conclusions: In BRAO patients, the occluded areas of affected eyes showed significant changes in the overall macular, GC-IPL, and pRNFL thicknesses when compared with those at initial visits and normal fellow eyes. The time points at which each thickness changed significantly were different.

Repeatability of vessel density measurements using optical coherence tomography angiography in retinal diseases.

AIM: To analyse the repeatability of vessel density (VD) measurements using optical coherence tomography angiography (OCTA) in patients with retinal diseases. METHODS: Two consecutive VD measurements using OCTA were analysed prospectively in patients with retinal diseases (diabetic macular oedema (DME), retinal vein occlusion (RVO) with macular oedema, epiretinal membrane (ERM), wet age-related macular degeneration (AMD)). The intraclass correlation coefficient (ICC), coefficient of variation (CV) and test-retest SD of VD measurements were assessed, and linear regression analyses were conducted to identify factors related to repeatability. RESULTS: A total of 134 eyes were analysed involving 20 eyes with DME, 44 eyes with RVO with macular oedema, 50 eyes with ERM and 20 eyes with wet AMD. The mean age was 64.9 years, and the mean best-corrected visual acuity (BCVA) was 0.24. The mean central macular thickness (CMT) was 391.6 µm, and the mean ganglion cell-inner plexiform layer (GC-IPL) thickness was 61.4 µm. In all four diseases, the ICC and CV of the full VD were 0.812 and 6.72%, respectively. Univariate analyses showed that the BCVA (B, 8.553; p=0.031), signal strength (B, -1.688; p=0.050), CMT (B, 0.019; p=0.015) and mean GC-IPL thickness (B, -0.103; p=0.001) were significant factors that affected the repeatability. Multivariate analyses of these factors showed a significant result for the GC-IPL thickness. CONCLUSIONS: Measurements of the VD using OCTA showed relatively good repeatability for various retinal diseases. The BCVA, signal strength, CMT and GC-IPL thickness affected the repeatability, so these factors should be considered when analysing the VD.