Novel Findings of Polypoidal Choroidal Vasculopathy via Optical Coherence Tomography Angiography

New Concepts for the Diagnosis of Polypoidal Choroidal Vasculopathy

Polypoidal choroidal vasculopathy (PCV) is a subtype of neovascular age-related macular degeneration (nAMD) that is characterized by a branching neovascular network and polypoidal lesions. It is important to differentiate PCV from typical nAMD as there are differences in treatment response between subtypes. Indocyanine green angiography (ICGA) is the gold standard for diagnosing PCV; however, ICGA is an invasive detection method and impractical for extensive use for regular long-term monitoring. In addition, access to ICGA may be limited in some settings. The purpose of this review is to summarize the utilization of multimodal imaging modalities (color fundus photography, optical coherence tomography (OCT), OCT angiography (OCTA), and fundus autofluorescence (FAF)) in differentiating PCV from typical nAMD and predicting disease activity and prognosis. In particular, OCT shows tremendous potential in diagnosing PCV. Characteristics such as subretinal pigment epithelium (RPE) ring-like lesion, en face OCT-complex RPE elevation, and sharp-peaked pigment epithelial detachment provide high sensitivity and specificity for differentiating PCV from nAMD. With the use of more practical, non-ICGA imaging modalities, the diagnosis of PCV can be more easily made and treatment tailored as necessary for optimal outcomes.

Optical coherence tomography angiography analysis of aneurismal type 1 neovascularization in a cohort of white patients

INTRODUCTION

To evaluate the detection rate of aneurysmal type 1 neovascularization (AT1) in Caucasian patients using optical coherence tomography angiography (OCTA) and to describe OCTA characteristics of AT1 in a cohort of white patients.

METHODS

We conducted an observational retrospective study in 44 eyes of 43 patients with AT1. All patients underwent a complete ophthalmologic examination, including fundus imaging, indocyanine green angiography, optical coherence tomography, and OCTA. Branching vascular network (BVN) and polyp detection rates by OCTA were evaluated. Furthermore, we described BVN and polyp morphologies on en face OCTA and flow of polyps on B-scan OCTA.

RESULTS

En face OCTA revealed BVN in 84.09% of cases and polypoidal lesions in 86.36% of cases. B-scan OCTA showed BVN and polyps in 95.45% and 93.18% of the patients, respectively. "Trunk" BVNs (51.35%) and "ring" polyps (47.37%) were the most frequent morphologies observed in our cohort, and "patchy hyperflow" (80.49%) signal was the most common visualized in our patients. Regarding OCT parameters, CT under polyps was higher in patients with positive detection of polyps on B-scan OCTA.

CONCLUSION

OCTA is a possible diagnosis tool in Caucasian patients with AT1. To the best of our knowledge, this is the largest study performed in Caucasian patients regarding OCTA diagnostic abilities and features.

Comparison of Indocyanine Green Angiography and Optical Coherence Tomography Angiography for Polypoidal Choroidal Vasculopathy

Purpose: To assess the diagnostic value of optical coherence tomography angiography (OCTA), and the factors affecting the diagnosis of polypoidal choroidal vasculopathy (PCV) by OCTA and indocyanine green angiography (ICGA). Methods: The numbers and area of polyps, and the presence and area of a branched vascular network (BVN) as revealed by ICGA and OCTA, were retrospectively analyzed in 43 patients with active PCV. The patients were divided into two groups according to whether the number of polyps matched between the two methods: group 1, equal number of polyps revealed by ICGA and OCTA; group 2, different number of polyps revealed by ICGA and OCTA. Results: In 43 PCV patients, the total number of polyps was 1.47 ± 0.83 in ICGA and 1.07 ± 0.91 in OCTA (<i>p</i> < 0.001), and the polyp area was 0.27 ± 0.42 mm² in ICGA and 0.17 ± 0.15 mm² in OCTA (<i>p</i> = 0.023). BVN was found in 33 eyes (76.7%) by ICGA and 29 eyes (67.4%) by OCTA (<i>p</i> < 0.001). The BVN area was 3.61 ± 2.59 mm² in ICGA and 2.74 ± 2.76 mm² in OCTA (<i>p</i> = 0.002). Central retinal thickness and central choroidal thickness were significantly greater in group 2 than group 1 (<i>p</i> < 0.001, respectively). Subretinal fluid (SRF) (<i>p</i> = 0.009) and subretinal hemorrhage (SRH) (<i>p</i> = 0.005) were significantly more prevalent in group 2 than group 1. Polyp height (<i>p</i> = 0.022) and diameter (<i>p</i> = 0.042) were significantly greater in group 2 than group 1. Conclusions: OCTA is a supplementary diagnostic technique for detecting PCV. The presence of SRF and SHR, and large polyp height and diameter, were associated with the polyp detection rate of OCTA for PCV.

A Comparison Study of Polypoidal Choroidal Vasculopathy Imaged with Indocyanine Green Angiography and Swept-Source Optical Coherence Tomography Angiography

PURPOSE

Indocyanine green angiography (ICGA) was compared with swept-source optical coherence tomography angiography (SS-OCTA) for the detection of polypoidal choroidal vasculopathy (PCV).

DESIGN

Retrospective, cross-sectional.

METHODS

Patients with treatment-naïve PCV based on ICGA imaging underwent same-day SS-OCTA imaging at Kyung Hee University Medical Center between April 2017 and November 2018. ICGA and SS-OCTA images were graded independently. SS-OCTA images were graded using both flow and structural information. Images were graded for the number of polypoidal lesions and the total lesion area, which included both the polypoidal lesions and the branching vascular networks (BVNs).

RESULTS

A total of 31 eyes from 30 patients were enrolled. Polypoidal lesions were identified in all eyes using both modalities, and there was agreement on the number of polypoidal lesions in 17 eyes (55%). In 12 eyes (39%), SS-OCTA graders identified a greater number of polypoidal lesions, and in 2 eyes (6%) ICGA graders identified more lesions. There was no significant difference in the lesion area measurements (standard deviation = 1.09, P = .08). The lesion with the largest difference in area measurements resulted from focal areas of atrophy, misdiagnosed as polypoidal lesions on ICGA, and a low-lying serous retinal pigment epithelial detachment erroneously identified as part of the BVN by ICGA graders. SS-OCTA imaging correctly diagnosed the focal areas of atrophy and the serous retinal pigment epitheial detachment.

CONCLUSIONS

SS-OCTA imaging was comparable to ICGA for the diagnosis of treatment-naïve PCV. However, SS-OCTA might be better than ICGA in correctly identifying both polypoidal lesions and BVNs in treatment-naïve PCV.