Corrigendum: Optical coherence tomography angiography microvascular findings in macular edema due to central and branch retinal vein occlusions

Correlation between the Nonperfusion Area on Ultra-Widefield Fluorescein Angiography and Nonflow Area on Optical Coherence Tomographic Angiography in Retinal Vein Occlusion

Aims

To compare the relationship between the nonperfusion area (NPA) on ultra-widefield fluorescein angiography (UWFFA) and the nonflow area (NFA) on optical coherence tomographic angiography (OCTA) in retinal vein occlusion (RVO).

Methods

Cross-sectional study. 46 eyes of 46 RVO patients who underwent UWFFA and OCTA. NPA and ischemic index (ISI) were quantified on UWWFA. NFA, vessel density (VD) of the superficial capillary plexus (SCP), the deep capillary plexus (DCP), and the size foveal avascular zone (FAZ) on 3 ∗ 3 mm OCTA were measured. The association of the NPA and ISI on UWWFA and the parameters on OCTA were analyzed. Spearman correlation was used for statistical testing.

Results

The NPA and ISI on UWFFA were significantly correlated with the NFA on OCTA in RVO, and r values were 0.688 (p < 0.01) and 0.680 (p < 0.01), respectively. VD in the SCP of the temporal quadrant was negatively correlated with NPA and ISI, and r values were -0.346 (p < 0.05) and -0.337 (p < 0.05), respectively. VD in the DCP of the temporal quadrant was negatively correlated with the NPA, and the r value was -0.246 (p < 0.05). No significant correlation was found between the NPA and ISI on UWFFA and VD of other quadrants in the SCP or DCP and the FAZ area on OCTA.

Conclusion

NPA in the peripheral retina was correlated with NFA in macula. NFA detected by OCTA could be an indicator of the ischemic status in RVO.

Retinal vascular metrics difference by comparison of two image acquisition modes using a novel OCT angiography prototype

PURPOSE

To assess the different impact of two enface OCTA image simultaneously acquired by means of a new prototype of Spectral-Domain Optical Coherence Tomography Angiography (SD-OCTA) on quantitative retinal vascular metrics.

METHODS

In this prospective observational cross-sectional study 28 healthy subjects were enrolled. Macular (3x3 mm) OCTA images were acquired for all participants using Solix Fullrange OCT (Optovue Inc, Freemont CA, USA). The main outcome measurements were: Perfusion density (PD), vessel length density (VLD), and vessel diameter index (VDI) of both superficial capillary plexus (SCP) and deep capillary plexus (DCP), and choriocapillaris (CC) total flow-deficits area. Quantitative retinal vascular metrics were measured on binarized and skeletonized OCTA images by comparing not averaged and fast automated multiple averaged en face OCTA images.

RESULTS

In both SCP and DCP, PD significantly increased (p = 0,005 and p = 0,030, respectively), and VLD significantly decreased (p<0,001 and p = 0,004, respectively), and VDI increased (p<0,001 and p = 0,068, respectively), and total CC flow deficits area significantly decreased (p<0,001) by averaging multiple OCTA images.

CONCLUSIONS

In this study, we found a significant difference of quantitative retinal metrics by comparing two different image acquisition modes using a novel and fully automated averaging OCTA system in young healthy subjects.

Clinical validation of the RTVue optical coherence tomography angiography image quality indicators

IMPORTANCE

All automated image quality indicators for en face optical coherence tomography angiography (OCTA) images require gold standard validation for determining optimum thresholds.

BACKGROUND

A manual grading system (gold standard) for OCTA images was validated and compared to two automated image quality indicators: signal strength index (SSI) and scan quality index (SQI) generated by different software versions of the Optovue OCTA device.

DESIGN

Retrospective cross-sectional study.

PARTICIPANTS

A total of 52 eyes of 52 healthy individual and 77 eyes of 51 patients with retinal vascular diseases.

METHODS

A total of 129 OCTA images of the superficial vascular plexus were graded manually by three independent examiners. Each image was assigned grades 1 to 4 (1-2, unacceptable; 3-4, acceptable) masked to the software-generated quality indicators.

MAIN OUTCOME MEASURES

Inter-grader agreement and comparison of the utility of SSI and SQI in discriminating between acceptable and unacceptable OCTA images.

RESULTS

There was a substantial agreement between the three graders (κ = 0.63). Mean SSI and SQI was significantly different between acceptable and unacceptable images (P < .001). SQI outperformed SSI in separating acceptable from unacceptable images (areas under the receiver operating characteristic curve: 0.87 vs 0.80) and the optimum cut-off was ≥7 for SQI and ≥70 for SSI for acceptable images. Up to 30% of images with quality indicators reaching the optimum SQI and SSI cut-off thresholds still had unacceptable quality on manual grading. Unacceptable images were found in 33% and 66% of healthy and diseased eyes, respectively.

CONCLUSIONS AND RELEVANCE

SQI is closely related to manual grading but we caution reliance on the optimized threshold to determine image quality. SQI is superior to SSI in discriminating between acceptable and unacceptable images.

Anatomical and functional changes after dexamethasone implant and ranibizumab in diabetic macular edema: a retrospective cohort study

AIM

To investigate the efficacy and safety of ranibizumab (RZB group) and dexamethasone implant (DEX group) intravitreal treatments in patients with treatment-naïve center involved diabetic macular edema (DME) by means of functional and morphological assessments.

METHODS

This retrospective cohort study included 50 eyes of 50 patients with DME treated either with RBZ or DEX. Best-corrected visual acuity (BCVA) and microperimetry were evaluated at baseline and during a 6-month follow-up. In addition, central macular thickness (CMT) by means of structural optical coherence tomography (OCT) and retinal capillary plexus density and choriocapillary density by means of OCT angiography were assessed in all cases.

RESULTS

Functional and morphological parameters significantly improved during the study period in both groups. BCVA improved significantly in both groups with a greater increase in the DEX group compared to the RBZ group (P=0.030). Microperimetry significantly differed during follow-up between the two treatments (P=0.031). In both groups CMT significantly decreased (P<0.001) without statistically significant differences between the two groups. A statistically significant increase of deep capillary plexus density was detected in both groups at 30d after therapy. The retreatment rate was 0.70±0.10 and 0.65±0.10 in the RBZ group and 0.65±0.10 and 0.50±0.11 in DEX group at 120 and 180d respectively. Two out of 25 patients in DEX group showed intraocular pressure increase requiring hypotonic eye drops.

CONCLUSION

Both treatments are very effective for DME treatment during 6mo of follow-up with a lower retreatment rate in DEX group.

Papillary Vessel Density Changes After Intravitreal Anti-VEGF Injections in Hypertensive Patients with Central Retinal Vein Occlusion: An Angio-OCT Study

Purpose: To investigate papillary microvascular changes in patients affected by macular edema due to Central Retinal Vein Occlusions (CRVO) after anti-Vascular Endothelial Growth Factor (VEGF) therapy. Methods: Prospective analysis of papillary and peripapillary vessel density (VD) changes in 18 eyes of 18 hypertensive patients affected by CRVO before and after the loading-phase of intravitreal Ranibizumab (IVR) injections. Data were quantitatively measured by optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) before as well as 1 month and 4 months after injections. The correlation between post-treatment best-corrected visual acuity (BCVA) and changes in the retinal microvasculature evaluated by OCTA was assessed. Results: 18 eyes of 18 consecutive patients with a known history of arterial hypertension and affected by an acute CRVO episode were enrolled. Central macular thickness (CMT) was significantly reduced after IVR injections (p < 0.001), while mean BCVA improved from 0.70 ± 0.26 logarithm of the minimal angle of resolution (logMAR) units at baseline to 0.25 ± 0.18 logMAR units after 4 months (p < 0.001). VD inside disc and peripapillary significantly increased (p < 0.001 and p = 0.01, respectively) after treatment. Conclusions: OCTA showed VD increase in the papillary area in patients affected by CRVO after anti-VEGF therapy. This area could represent a new region of interest to study microvasculature changes concomitant with severe macular edema.

[Anatomo-functional study in branch retinal vein occlusion using Swept Source Optical Coherence Tomography Angiography]

INTRODUCTION

The purpose of our study was to describe the microvascular abnormalities on OCT-angiography in eyes with branch retinal vein occlusion (BRVO), to measure the surface of the foveal avascular zone (FAZ) and the capillary density, and to establish anatomic-functional correlations.

METHODS

We conducted an observational prospective study in the ophthalmology department of Habib Thameur Hospital in Tunis, which included 17 eyes of patients with unilateral BRVO. We studied the microvascular abnormalities and areas of capillary non-perfusion in the deep and superficial capillary plexuses (DCP, SCP). The area of the FAZ was measured in the SCP and correlated to visual acuity. The foveal and parafoveal capillary density was measured with flow quantification software.

RESULTS

The mean patient age was 57.94 ±18.04 years. Male:female ratio was approximately 1. Fourteen eyes (82.4%) showed cystoid macular edema which was significantly correlated to poor visual acuity (P=0.02). Vascular congestion was present in 12 eyes (70.60%) in the DCP and 8 eyes (47.1%) in the SCP. Intraretinal loops were found in 5 eyes (29.4%) in the DCP and 8 eyes (47.1%) in the SCP. Thirteen eyes (76.5%) exhibited vascular tortuosity in the DCP, and 14 eyes (82.4%) in the SCP. Areas of capillary non-perfusion were observed in 12 eyes (70.60%). The mean area of the FAZ was 617.53±525.75μ in eyes with BRVO. Enlargement of the FAZ was correlated to visual loss (P=0.01). Mean foveal capillary density was 15.49% (±5.18%), and mean peripheral capillary density was 44% (±4.75%). There was no correlation between vascular density and visual acuity in our series.

CONCLUSIONS

OCT-angiography is part of the current diagnostic workup for RVO. It has a relevant role in establishing a prognosis by studying the area of the FAZ and the capillary density.

Optical Coherence Tomography Angiography Findings in X-Linked Retinoschisis

BACKGROUND AND OBJECTIVE

The aim of the study was to determine optical coherence tomography angiography (OCTA) findings and to identify mutations in the RS1 gene in a three-generation family with X-linked juvenile retinoschisis (XLRS).

PATIENTS AND METHODS

Clinical and genetic assessments were performed in 12 family members. OCTA was performed at baseline (12 members including cases and carriers) and after acetazolamide administration (three cases). Twenty healthy subjects (20 eyes, controls) were chosen for comparison. Molecular genetic analysis of the RS1 gene was performed in all family members.

RESULTS

Deep capillary plexus density was reduced in cases compared with controls (P < .01) and was negatively related with retinal thickness (P < .05). After treatment, retinal thickness decreased (P < .05) and deep capillary plexus density increased (P < .05) in cases. In three cases and in four carriers, p.Arg197 His mutation was found.

CONCLUSION

OCTA shows reduced macular deep vessel density in patients with XLRS probably related to vessel displacement and disruption due to schitic cysts. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:e20-e31.].

Optical coherence tomography angiography of normal skin and inflammatory dermatologic conditions

BACKGROUND

In clinical dermatology, the identification of subsurface vascular and structural features known to be associated with numerous cutaneous pathologies remains challenging without the use of invasive diagnostic tools.

OBJECTIVE

To present an advanced optical coherence tomography angiography (OCTA) method to directly visualize capillary-level vascular and structural features within skin in vivo.

METHODS

An advanced OCTA system with a 1310 nm wavelength was used to image the microvascular and structural features of various skin conditions. Subjects were enrolled and OCTA imaging was performed with a field of view of approximately 10 × 10 mm. Skin blood flow was identified using an optical microangiography (OMAG) algorithm. Depth-resolved microvascular networks and structural features were derived from segmented volume scans, representing tissue slabs of 0-132, 132-330, and 330-924 μm, measured from the surface of the skin.

RESULTS

Subjects with both healthy and pathological conditions, such as benign skin lesions, psoriasis, chronic graft-versus-host-disease (cGvHD), and scleroderma, were OCTA scanned. Our OCTA results detailed variations in vascularization and local anatomical characteristics, for example, depth-dependent vascular, and structural alterations in psoriatic skin, alongside their resolve over time; vascular density changes and distribution irregularities, together with corresponding structural depositions in the skin of cGvHD patients; and vascular abnormalities in the nail folds of a patient with scleroderma.

CONCLUSION

OCTA can image capillary blood flow and structural features within skin in vivo, which has the potential to provide new insights into the pathophysiology, as well as dynamic changes of skin diseases, valuable for diagnoses, and non-invasive monitoring of disease progression and treatment. Lasers Surg. Med. 50:183-193, 2018. © 2018 Wiley Periodicals, Inc.

Qualitative and Quantitative Assessment of Vascular Changes in Diabetic Macular Edema after Dexamethasone Implant Using Optical Coherence Tomography Angiography

The aim of this study was to investigate retinal and choriocapillaris vessel changes in diabetic macular edema (DME) after the intravitreal dexamethasone implant (IDI) using optical coherence tomography angiography (OCTA). Moreover, a comparison between morphological and functional parameters of DME and healthy patients was performed. Twenty-five eyes of 25 type 2 diabetic retinopathy patients complicated by macular edema (DME group) and 25 healthy subjects (control group) were enrolled. Superficial capillary plexus density (SCPD) and deep capillary plexus density (DCPD) in the foveal and parafoveal areas, choricapillary density (CCD) and optic disc vessel density (ODVD) were detected using OCTA at baseline and after 7, 30, 60, 90 and 120 days post injection. Best corrected visual acuity (BCVA), retinal sensitivity, and central retinal thickness (CMT) were also evaluated in both groups of patients. A statistically significant difference between the two groups (DME and controls) was found in terms of functional (MP, p < 0.001 and BCVA, p < 0.001) and morphological (CMT, p < 0.001; SCPD in the parafoveal area, p < 0.001; DCPD in the foveal area, p < 0.05 and parafoveal area, p < 0.001; CCD, p < 0.001) parameters. After the treatment, SCPD and DCPD in the foveal and parafoveal areas did not modify significantly during the follow up.