Morphologic features of large choroidal vessel layer: age-related macular degeneration, polypoidal choroidal vasculopathy, and central serous chorioretinopathy

Choroidal biomarkers in age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of central visual impairment in the elderly. The exact pathophysiological mechanisms for AMD remain uncertain. Several studies suggest that choroidal abnormalities and alterations are critical in AMD progression. The transition from manual to automated segmentation and binarization techniques has resulted in accurate and precise measurements of different choroidal parameters. These qualitative and quantitative parameters, known as choroidal imaging biomarkers, have advanced from basic vertical subfoveal choroidal thickness to more intricate 3-dimensional choroidal reconstruction methods in the last decade. Therefore, a comprehensive evaluation of choroidal metrics may investigate valuable insights into AMD, potentially guiding the future development of customized therapeutic strategies and personalized patient care in AMD management. We describe the role of different choroidal biomarkers in evaluating patients with AMD and their contribution to management.

Morphometrics of polypoidal choroidal vasculopathy lesions and choroidal vascular associated with treatment response using swept-source optical coherence tomography angiography

PURPOSE

To evaluate quantitative metrics of neovascularization lesions and choroidal vascular using swept-source optical coherence tomography angiography (SS-OCTA) in polypoidal choroidal vasculopathy (PCV) eyes, and investigate the relationship between imaging biomarkers and treatment outcomes of intravitreal anti-vascular endothelial growth factor (VEGF).

METHODS

We retrospectively recruited 56 PCV patients. Choroidal features included subfoveal choroidal thickness (SFCT) and choroidal vascularity index (CVI). Quantitative metrics of neovascularization lesions included total vessel length (TVL), average vessel length (AVL), junction density (JD), total number of endpoints (TNE), and mean lacunarity (ML). We performed multivariate logistic and linear regression models to determine the prognostic factors for functional and morphological outcomes.

RESULTS

By comparison, functional good-responders had poorer best corrected visual acuity, higher TNE, and lower ML at baseline. Morphological good-responders had higher central retinal thickness, higher TNE, lower TVL and AVL, lower ML, lower SFCT and CVI. High-shrinkage of vessel area subgroup had higher JD and TNE, lower TVL and AVL, lower ML, lower SFCT and CVI. Multivariate analysis showed good morphological response was correlated with lower SFCT (P < 0.01). High-shrinkage subgroup was correlated with lower AVL (P = 0.017) and higher TNE (P < 0.01).

CONCLUSION

Quantitative metrics of neovascularization lesions and choroidal characteristics using SS-OCTA had the potential to be imaging biomarkers for predicting the response to anti-VEGF treatment. PCV lesions with higher TNE and lower AVL tended to appear higher shrinkage of vessel area, and lower SFCT was correlated with good morphological response.

Three-Dimensional Choroidal Vessels Assessment in Age-Related Macular Degeneration

Purpose

To compare the choroidal vasculature in eyes with early- and intermediate-stage age-related macular degeneration (dAMD) and healthy using a novel three-dimensional algorithm.

Methods

Patients with dAMD and healthy controls underwent clinical examinations and swept-source optical coherence tomography scans (PlexElite-9000 device) centered on the fovea. Scans with quality scores >6 were included. Eyes with any signs of neovascular AMD or geographic atrophy were excluded. The choroidal layer was segmented using ResUNet model and volumetric smoothing. Phansalkar thresholding was used to binarize the choroidal vasculature. The three-dimensional maps were divided into five sectors. The three largest vessels in each sector were measured to determine the mean choroidal vessel diameter (MChVD) and inter-vessel distance (IVD). Volumetric choroidal thickness (ChT) and vascularity index (CVI) were also calculated.

Results

This retrospective cross-sectional study analyzed 60 eyes from 45 dAMD patients (27 early-stage, 33 intermediate-stage) and 26 eyes from 16 healthy controls. The average MChVD was increased in dAMD eyes compared to healthy eyes (239.559 ± 47.058 µm vs. 197.873 ± 49.047 µm, P < 0.001). The average MChVD in each sector increased significantly in eyes with dAMD (P < 0.05). The average IVD was increased significantly in dAMD eyes compared to healthy eyes (234.128 ± 69.537 µm vs. 179.914 ± 49.995 µm, P < 0.001). The average IVD in each sector was significantly increased in eyes with dAMD (P < 0.05). Average ChT and CVI in dAMD were reduced compared to healthy eyes (P < 0.05).

Conclusions

Eyes with dAMD demonstrated increased MChVD and IVD and decreased ChT and CVI, possibly related to smaller-vessel atrophy and larger-vessel dilation.

Quantitative assessment of choroidal parameters in type 1 macular neovascularization linked to central serous chorioretinopathy and neovascular age-related macular degeneration

OBJECTIVE

To use ultra-widefield swept-source optical coherence tomography angiography (UWF SS-OCTA) to evaluate the choroidal features of neovascular age-related macular degeneration (nAMD) and type 1 macular neovascularization (MNV) attributable to central serous chorioretinopathy (CSC).

METHOD

A cross-sectional research was carried out to examine patients with type 1 MNV due to CSC (50 eyes) and nAMD (98 eyes) utilizing UWF SS-OCTA examinations. The scan procedure covered a vertical 20 mm × horizontal 24 mm region with 9 subfields. A typical set of 68 healthy eyes was used for comparison. The effects of different diagnoses on choroidal parameters were assessed using covariance tests, using gender and age as variables.

RESULTS

The research showed that all choroidal characteristics were age-related (all p < 0.05). The calculated marginal averages of choroidal thickness (ChT) and choroidal volume (CV) in the central area were substantially lower in the nAMD group than in the CSC group and the normal group after age differences were taken into account (all p < 0.05). In both the superotemporal and temporal areas, the CSC group had a greater choroidal vascular index (CVI) compared to the nAMD group (p < 0.05). Additionally, the CSC group had a greater temporal area choriocapillaris density (CCD) than the nAMD group (p < 0.05).

CONCLUSION

At the choroidal level, type 1 MNV due to CSC and nAMD may be distinguished by UWF SS-OCTA. Compared to the nAMD affected eyes, the CSC affected eyes had increased ChT, CV, CVI, and CCD in several areas. The two diseases could be distinguished based on ChT and CV.

Exploring the Ability of Novel Choroidal Biomarkers in Predicting Treatment Outcomes of Polypoidal Choroidal Vasculopathy

INTRODUCTION

The aim of this study was to explore the relationship between choroidal biomarkers and the response to anti-VEGF in PCV eyes.

METHODS

We conducted a hospital-based retrospective study. We included 54 patients diagnosed with PCV who had received standard 3 monthly anti-VEGF monotherapy and had finished regular follow-ups. Choroidal thickness (CT), three-dimensional choroidal vascularity index (CVI), and the vascular density of choriocapillaris (CCVD) were measured utilizing swept-source optical coherence tomography angiography (SS-OCTA). Effective and poor responders were classified based on the changes in morphologic features. Multivariate linear regression models were performed for the outcomes to determine independent prognostic factors. Receiver operating characteristic (ROC) curves were used to compare the predictive ability of CT and CVI as biomarkers between effective and poor responders.

RESULTS

A higher CVI at baseline was the only factor that correlated with the poor response after 3 monthly injections of anti-VEGF (p = 0.038). The greater change of central macular thickness (CMT) was significantly correlated with increased CMT (p = 0.030), decreased CT (p = 0.042), and decreased CVI (p = 0.038) at baseline. Using ROC curves, we found that the CVI value demonstrated superior predictive ability compared to the CT value, with AUC of 0.842 and the best cut-off value of 0.445.

CONCLUSION

A higher three-dimensional CVI using SS-OCTA is a promising biomarker to predict the poor anatomical response to anti-VEGF treatment in PCV patients.

Choroidal features in non-neovascular and neovascular pachychoroid diseases

PURPOSE

To evaluate choroidal findings on multimodal imaging in eyes within pachychoroid spectrum diseases and to compare quantitative and qualitative choroidal features between non-neovascular (NNV-PDS) and neovascular (NV-PDS) pachychoroid diseases.

METHODS

Retrospective cross-sectional study comparing between NV-PDS and NNV-PDS. All patients underwent multimodal imaging including infracyanine green angiography (IFCGA) and swept source optical coherence tomography (OCT) and angiography (OCT-A). The following parameters were analyzed: subfoveal choroidal thickness (SFCT), choroidal vascular index (CVI), presence of pachyvessels and choroidal vascular interconnections (CVIC), presence of choroidal neovascularization and choriocapillaris density.

RESULTS

Of the 87 eyes included in the study, 63 eyes (73%) had NNV-PDS and 24 eyes (27%) had NV-PDS. Mean SFCT and CVI were significantly higher in NNV-PDS group (p = 0.01; p = 0.022). Pachyvessels were more diffusely distributed in NNV-PD group and more focally distributed in NV-PDS group (p = 0.029). CVIC were more frequently noted in NV-PDS group (p = 0.024). A higher CVI was associated to a thicker choroid (p < 0.001), with significant negative correlations between the presence of CVIC and both SFCT (p = 0.015) and CVI (p = 0.002). We also observed a lower choriocapillaris vascular density and higher number of choriocapillaris flow voids in eyes with NNV-PDS (p = 0.24; p = 0.61).

CONCLUSION

NNV-PDS eyes had a significantly thicker SFCT, higher CVI and a lower rate of detected CVIC than eyes with NV-PDS. These highlighted choroidal vascular changes might lead to a better understanding of pachychoroid disease pathophysiology. More frequently observed in NV-PDS group, CVIC are believed to assess the development of vortex vein anastomoses as a remodelling process for vascular decongestion.

Qualitative and quantitative comparisons of type 1 macular neovascularizations between pachychoroid neovasculopathy and neovascular age-related macular degeneration using optical coherence tomography angiography

OBJECTIVES

To compare qualitative and quantitative features of type 1 macular neovascularizations (MNV) in pachychoroid neovasculopathy (PNV) and neovascular age-related macular degeneration (nAMD).

METHODS

Forty-three treatment-naive eyes of 41 PNV patients and 40 treatment-naive eyes of 38 patients with nAMD were included. The patients were classified as PNV or nAMD according to the presence of pachychoroid features and soft/reticular drusen. Presence of central trunk and maturity of the MNV were evaluated on optical coherence tomography angiography (OCTA) images. MNV area, vessel density (VD), total vessel length (VL), number of intersection points (IPs), fractal dimension (FD), and lacunarity (LAC) were calculated using ImageJ software and FracLac plugin.

RESULTS

The mean age was 56.8 ± 8.7 years in PNV and 70.4 ± 8.8 years in neovascular AMD groups (p < 0.001). Compared to nAMD, the presence of central trunk was less frequent in PNV (48.8% vs 77.5%, p = 0.007). Immature MNV pattern was observed more frequently in PNV eyes than nAMD (41.9% vs 20.0%, p = 0.009). PNV cases had significantly lower median MNV area [0.913(1.115) vs 2.542(3.273) mm²], total VL [14.84 (20.46) vs 36.34 (44.68) mm], number of IPs [104(140) vs 335(417.3)], and FD [1.56(0.10) vs 1.59(0.11)] comparing to nAMD cases (p < 0.001, p = 0.001, p < 0.001, p = 0.043 respectively). However, the mean VD (42.4 ± 6.8 vs 42.9 ± 9.0%) and the median LAC values [0.42 (0.09) vs 0.42 (0.09)] did not differ significantly between groups (p = 0.776, p = 0.526, respectively).

CONCLUSION

Morphological and quantitative differences exist in type 1 neovascular lesions. Type 1 MNVs in the PNV group are characterized by a smaller and less complex structure.

Choroidal and Retinal Thicknesses in Healthy Eyes Measured with Ultra-Wide-Field Optical Coherence Tomography

Ultra-wide-field optical coherence tomography (UWF-OCT) has been recently introduced into clinical ophthalmological practice. To date, there are few data on the reference values of the retinal thickness (RT) and choroidal thickness (CT) measured with this technique. This study aimed to analyze the variance in RT and CT in the healthy eyes of white Caucasian patients with UWF-OCT tests performed with the largest available scan size of 23 × 20 mm. The data were analyzed with reference to the patients' age and gender and the axial length of the eyeball. The results of UWF-OCT scanning enabled us to visualize the shape of the retina and choroid in a large portion of the eyeball. Both anatomical entities became significantly thinner at the periphery. The peripheral CT was greater in the upper and temporal sectors; the RT was higher in the nasal compared to the temporal sectors. Both the choroid and retina showed a reduced thickness with age; however, the CT and RT did not show a statistically significant correlation with the axial length after adjusting for age and gender. Age-related variations in thickness were especially prominent in the choroid. The CT in UWF-OCT testing was significantly greater in females, while the RT was greater in males. UWF-OCT testing provides additional information on the anatomical structure of the retina and choroid compared to standard-field OCT.

Quantification of Choroidal Vascular Hyperpermeability on Ultra-Widefield Indocyanine Green Angiography in Macular Neovascularization

To obtain a quantitative parameter for the measurement of choroidal vascular hyperpermeability (CVH) on ultra-widefield indocyanine green angiography (UWICGA) using an objective analysis method in macular choroidal neovascularization (CNV). A total of 113 UWICGA images from 113 subjects were obtained, including with 25 neovascular age-related macular degeneration (nAMD), 37 with polypoidal choroidal vasculopathy (PCV) (19 with thin-choroid and 18 with thick-choroid), 33 with pachychoroid neovasculopathy (PNV), and 18 age-matched controls. CVH was quantified on a gray image by the subtraction of 2 synchronized UWICGA images of early and late phases. The measured CVH parameter was compared with human graders and among CNV subtypes and correlated with choroidal vascular density (CVD) and subfoveal choroidal thickness (SFCT). The mean CVH values were 28.58 ± 4.97, 33.36 ± 8.40, 33.61 ± 11.50, 42.19 ± 13.25, and 43.59 ± 7.86 in controls and patients with nAMD, thin-choroid PCV, thick-choroid PCV, and PNV, respectively (p < 0.001). CVH was higher in thick-choroid PCV and PNV compared to the other groups (all p ≤ 0.006). The measured CVH value positively correlated with those reported by human graders (p < 0.001), CVD, and SFCT (p = 0.001 and p < 0.001, respectively). CVH can be measured objectively using quantitative UWICGA analysis. The CVH parameter differs among macular CNV subtypes and correlates with CVD and SFCT.

Choroidal Vessel and Stromal Volumetric Analysis After Photodynamic Therapy or Focal Laser for Central Serous Chorioretinopathy

Purpose

To utilize volumetric analysis to quantify volumetric changes in choroidal vessels and stroma after photodynamic therapy (PDT) and focal laser photocoagulation (PC) for central serous chorioretinopathy (CSCR).

Methods

This retrospective, comparative study included 58 eyes (58 patients) with CSCR (PC, 33 eyes; PDT, 25 eyes) followed up with swept-source optical coherence tomography at 3 months after treatment. Three-dimensional (3D) choroidal vessel and stromal volumes in each area of the central 1.5-mm-diameter circle, the torus-shaped area with 6-mm-diameter circle excluding the area of the central 1.5-mm-diameter circle, and the treated area of the Early Treatment Diabetic Retinopathy Study (ETDRS) grid centered at the fovea were analyzed using a deep learning-based method. Changes in volume at baseline and 1 and 3 months after treatment were compared.

Results

The mean patient age was 49.3 ± 10.5 years. In the central 1.5-mm-diameter circle, the mean vessel and stromal volume rates significantly decreased after the treatment in both the PDT and PC groups (P = 0.00029 and P = 0.0014, respectively), and significant differences between the PDT and PC groups of continuous variables within times were observed in both volumes (P = 0.024 and P = 0.037, respectively). In the torus-shaped area and treated area, the PDT and PC groups both showed similar decreases in vessel and stromal volume over time.

Conclusions

In the 3D optical coherence tomography volumetric analysis, both PDT and focal PC reduced choroid vessel volume in eyes with CSCR.

Translational Relevance

This new finding is useful in elucidating the pathogenesis and healing mechanisms of CSCR.

The choroidal nervous system: a link between mineralocorticoid receptor and pachychoroid

Central serous chorioretinopathy (CSCR) belongs to the pachychoroid spectrum, a pathological phenotype of the choroidal vasculature, in which blood flow is under the choroidal nervous system (ChNS) regulation. The pathogenesis of CSCR is multifactorial, with the most recognised risk factor being intake of glucocorticoids, which activate both the gluco- and the mineralocorticoid (MR) receptors. As MR over-activation is pathogenic in the retina and choroid, it could mediate the pathogenic effects of glucocorticoids in CSCR. But the role of MR signalling in pachychoroid is unknown and whether it affects the ChNS has not been explored. Using anatomo-neurochemical characterisation of the ChNS in rodents and humans, we discovered that beside innervation of arteries, choroidal veins and choriocapillaris are also innervated, suggesting that the entire choroidal vasculature is under neural control. The numerous synapses together with calcitonin gene-related peptide (CGRP) vesicles juxtaposed to choroidal macrophages indicate a neuro-immune crosstalk. Using ultrastructural approaches, we show that transgenic mice overexpressing human MR, display a pachychoroid-like phenotype, with signs of choroidal neuropathy including myelin abnormalities, accumulation and enlargement of mitochondria and nerves vacuolization. Transcriptomic analysis of the RPE/choroid complex in the transgenic mice reveals regulation of corticoids target genes, known to intervene in nerve pathophysiology, such as Lcn2, rdas1/dexras1, S100a8 and S100a9, rabphilin 3a (Rph3a), secretogranin (Scg2) and Kinesin Family Member 5A (Kif5a). Genes belonging to pathways related to vasculature development, hypoxia, epithelial cell apoptosis, epithelial mesenchymal transition, and inflammation, support the pachychoroid phenotype and highlight downstream molecular targets. Hypotheses on the imaging phenotype of pachychoroid in humans are put forward in the light of these new data. Our results provide evidence that MR overactivation causes a choroidal neuropathy that could explain the pachychoroid phenotype found in transgenic mice overexpressing human MR. In patients with pachychoroid and CSCR in which systemic dysautonomia has been demonstrated, MR-induced choroidal neuropathy could be the missing link between corticoids and pachychoroid.

Classification of Color Fundus Photographs Using Fusion Extracted Features and Customized CNN Models

This study focuses on overcoming challenges in classifying eye diseases using color fundus photographs by leveraging deep learning techniques, aiming to enhance early detection and diagnosis accuracy. We utilized a dataset of 6392 color fundus photographs across eight disease categories, which was later augmented to 17,766 images. Five well-known convolutional neural networks (CNNs)-efficientnetb0, mobilenetv2, shufflenet, resnet50, and resnet101-and a custom-built CNN were integrated and trained on this dataset. Image sizes were standardized, and model performance was evaluated via accuracy, Kappa coefficient, and precision metrics. Shufflenet and efficientnetb0demonstrated strong performances, while our custom 17-layer CNN outperformed all with an accuracy of 0.930 and a Kappa coefficient of 0.920. Furthermore, we found that the fusion of image features with classical machine learning classifiers increased the performance, with Logistic Regression showcasing the best results. Our study highlights the potential of AI and deep learning models in accurately classifying eye diseases and demonstrates the efficacy of custom-built models and the fusion of deep learning and classical methods. Future work should focus on validating these methods across larger datasets and assessing their real-world applicability.

CHOROIDAL VASCULAR ALTERATIONS IN AGE-RELATED MACULAR DEGENERATION AND POLYPOIDAL CHOROIDAL VASCULOPATHY

PURPOSE

To evaluate morphologic alterations in choroidal veins in eyes with typical neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV).

METHODS

A retrospective review of baseline indocyanine green angiography in eyes with typical nAMD and PCV. We evaluated Haller layer veins in the early-phase indocyanine green angiography (before 2 minutes) for 1) macular anastomosis, 2) dilated Haller veins, and 3) focal variation in vessel caliber by at least 50% from the narrowest to largest diameters.

RESULTS

We included 70 patients with gradable indocyanine green angiography for the prespecified features in the study eye (36 typical nAMD and 34 PCV) and 59 fellow eyes. The median subfoveal choroidal thickness was 167 µm versus 219 µm, P = 0.08, in the presenting eyes in typical nAMD and PCV, respectively. Macular anastomosis was common in both typical nAMD and PCV (presenting eyes 58.3% vs. 58.8%. P = 0.97; fellow eyes 65.5% vs. 63.3%, P = 0.86). Dilated Haller veins were numerically less common in typical nAMD than PCV (presenting eyes 52.8% vs. 67.6%, P = 0.21; fellow eyes 65.5% vs. 70.0%, P = 0.71), while vascular caliber variation was numerically more common in typical nAMD than PCV (presenting eyes 72.2% vs. 63.8%, P = 0.45; fellow eyes 69.0% vs. 56.7%, P = 0.33). The presence of all three features was more common in the presenting eyes with PCV compared with typical nAMD (35.3% vs. 13.9%, P = 0.03). In a multivariable analysis, every increase of 100 µm of CT conferred a 2.75 risk of having all three features present.

CONCLUSION

Choroidal vascular remodeling is common in both tAMD and PCV but may be driven by different stimuli.

Clinical features and outcomes of breakthrough vitreous hemorrhage secondary to polypoidal choroidal vasculopathy

Polypoidal choroidal vasculopathy (PCV) with hemorrhagic complications is at higher risk for breakthrough vitreous hemorrhage (VH). This study aimed to evaluate the clinical features and outcomes of breakthrough VH secondary to PCV. Data of patients receiving pars plana vitrectomy for breakthrough VH secondary to PCV (VH group) were evaluated retrospectively and compared statistically to data of age and sex-matched PCV patients without breakthrough VH (control group). Among PCV patients, 36 eyes with breakthrough VH and 62 eyes without VH were included. Compared with baseline, best corrected visual acuity (BCVA) was worse in the VH group (P < 0.001), and improved postoperatively (P < 0.001). Percentages of pigmented epithelial detachment (PED), hemorrhagic PED, massive subretinal hemorrhage, hemorrhagic retinal detachment (RD), and hemorrhagic choroidal detachment (CD) (P = 0.007) were higher in the VH group (P < 0.001). Incidence of choroidal vascular hyperpermeability (P < 0.001), massive subretinal hemorrhage (P = 0.001), hemorrhagic retinal detachment (P = 0.001) and hemorrhagic type PCV (P = 0.001) was higher in patients with pachychoroid PCV, while fibrovascular type had lower incidence (P < 0.001). Better initial BCVA (P < 0.001), higher frequency of anti-VEGF treatment (P = 0.009), and previous photodynamic therapy (P = 0.017) showed better visual outcomes. Breakthrough VH risk is higher in PCV patients with massive subretinal hemorrhage, hemorrhagic PED and hemorrhagic RD. BCVA and hemorrhagic complications improve significantly postoperatively. Higher frequency of anti-VEGF treatment and previous photodynamic therapy are associated with better visual prognosis in PCV patients with breakthrough VH.

Association between central serous chorioretinopathy susceptibility genes and choroidal parameters

PURPOSE

To evaluate the association between central serous chorioretinopathy (CSC) susceptibility genes and choroidal parameters in a large Japanese cohort.

STUDY DESIGN

Retrospective cohort study.

METHODS

Of the 9850 individuals in the Nagahama study whose second visit was between 2013 and 2016, those with optical coherence tomography (OCT) images with enhanced depth imaging (EDI), axial length, and genome-wide single nucleotide polymorphism (SNP) genotyping data were included. We calculated subfoveal choroidal thickness (SFCT), choroidal vascularity index (CVI), normalized choroidal intensity (NCI), and vertical asymmetry of choroidal thickness. Genome-wide quantitative trait locus (QTL) analyses were performed for each parameter. We screened for four CSC susceptibility SNPs: CFH rs800292, TNFRSF10A rs13278062, GATA5 rs6061548, and VIPR2 rs3793217. Whenever an SNP was not included in the genotyping data after quality control, its proxy SNP was selected.

RESULTS

In total, 4586 participants were evaluated. CFH rs800292 was significantly associated with SFCT (P < 0.001) and CVI (P < 0.001). VIPR2 rs3793217 was significantly associated with SFCT (P < 0.001) but not with CVI. Whereas, TNFRSF10A rs13254617 and GATA5 rs6061548 were not significantly associated with SFCT or CVI. None of these SNPs was associated with NCI_EDI and asymmetry of choroidal thickness.

CONCLUSION

CFH, VIPR2, TNFRSF10A, and GATA5 showed different association patterns with choroidal parameters. Although the mechanism of CSC pathogenesis by choroidal changes is not fully understood, this finding suggests that each gene may be involved in different mechanisms of CSC development. Our genetic study provides a basis for understanding the role of CSC susceptibility genes.

Understanding Ocular Findings and Manifestations of Systemic Lupus Erythematosus: Update Review of the Literature

Systemic lupus erythematosus (SLE) is a chronic multisystem autoimmune disease. Up to one-third of patients suffering from SLE have various ocular manifestations. The ocular findings may represent the initial manifestation of the systemic disease and may lead to severe ocular complications, and even loss of vision. Ocular manifestations are often associated with degree of systemic inflammation, but also can precede the occurrence of systemic symptoms. Early diagnosis and adequate management of patients with SLE are crucial and require cooperation between various specialists. Proper preparation of ophthalmologists can help to differentiate between complication of SLE and other ocular disorders. New therapies for SLE are promising for potential benefits, however, ocular side effects are still unknown.

Differentiating a pachychoroid and healthy choroid using an unsupervised machine learning approach

The purpose of this study was to introduce a new machine learning approach for differentiation of a pachychoroid from a healthy choroid based on enhanced depth-optical coherence tomography (EDI-OCT) imaging. This study included EDI-OCT images of 103 eyes from 82 patients with central serous chorioretinopathy or pachychoroid pigment epitheliopathy, and 103 eyes from 103 age- and sex-matched healthy subjects. Choroidal features including choroidal thickness (CT), choroidal area (CA), Haller layer thickness (HT), Sattler-choriocapillaris thickness (SCT), and the choroidal vascular index (CVI) were extracted. The Haller ratio (HR) was obtained by dividing HT by CT. Multivariate TwoStep cluster analysis was performed with a preset number of two clusters based on a combination of different choroidal features. Clinical criteria were developed based on the results of the cluster analysis, and two independent skilled retina specialists graded a separate testing dataset based on the new clinical criteria. TwoStep cluster analysis achieved a sensitivity of 1.000 (95-CI: 0.938-1.000) and a specificity of 0.986 (95-CI: 0.919-1.000) in the differentiation of pachy- and healthy choroid. The best result for identification of pachychoroid was obtained for a combination of CT, HR, and CVI, with a correct classification rate of 0.993 (95-CI: 0.980-1.000). Based on the relative variable importance (RVI), the cluster analysis prioritized the choroidal features as follows: HR (RVI: 1.0), CVI (RVI: 0.87), CT (RVI: 0.70), CA (RVI: 0.59), and SCT (RVI: 0.27). After performing a receiver operating characteristic curve analysis on the cluster membership variable, a cutoff point of 389 µm and 0.79 was determined for CT and HR, respectively. Based on these clinical criteria, a sensitivity of 0.793 (95-CI: 0.611-0.904) and a specificity of 0.786 (95-CI: 0.600-0.900) and 0.821 (95-CI: 0.638-0.924) were achieved for each grader. Cohen's kappa of inter-rater reliability was 0.895. Based on an unsupervised machine learning approach, a combination of the Haller ratio and choroidal thickness is the most valuable factor in the differentiation of pachy- and healthy choroids in a clinical setting.

The Association of Pachydrusen Characteristics with Choroidal Thickness and Patient's Age in Polypoidal Choroidal Vasculopathy versus Central Serous Chorioretinopathy

We investigated the relationship between pachydrusen and choroidal thickness and age in eyes with polypoidal choroidal vasculopathy (PCV) and fellow eyes, compared to eyes with central serous chorioretinopathy (CSC). This retrospective study included 89 eyes with PCV and 146 eyes with CSC. The number, location, and shape of the pachydrusen and their association with choroidal thickness and age were analyzed. PCV eyes showed pachydrusen more frequently than eyes with CSC (52% vs. 20%, p < 0.001). Large solitary type and clustered type were more frequent in PCV eyes compared to CSC eyes (p = 0.003 and p = 0.001, respectively). Subfoveal choroidal thickness was associated with pachydrusen in eyes with PCV (odds ratio [OR] 1.006, 95% confidence interval [CI] 1.001−1.011, p = 0.027), while age was associated with pachydrusen in CSC eyes (OR 1.137, 95% CI, 1.073−1.205; p < 0.001). Pachydrusen were localized directly over the pachyvessel on optical coherence tomographic findings in approximately two thirds of PCV eyes and fellow eyes (62% and 67%, respectively). Risk factors for pachydrusen differ according to diseases. The presence of pachydrusen was associated with choroidal thickness in PCV, while the association with age was more prominent in CSC.

Morphology of en face Haller vessel and macular neovascularization at baseline and 3 months as predictive factors in age-related macular degeneration

The clinical implication of en face imaging of Haller vessels and macular neovascularization (MNV) in neovascular age-related macular degeneration (nAMD) is not well established. The purpose of this study is to investigate whether the early-phase morphology of en face Haller vessel and MNV is related to the injection frequency and visual outcome in treatment-naïve nAMD. En face images of Haller vessel and MNV were acquired from 52 eyes at baseline, after three loading doses and at 12 months later using optical coherence tomography (OCT) and OCT angiography. Vessel area, diameter, length, intersection number, fractal dimension, and lacunarity were calculated. Patients were classified according to the injection frequency (< 5 as the infrequent group) and visual gain (≥ 0.3 logMAR) over 12 months. The infrequent group was associated with a longer Haller vessel length after loading doses (OR 3.05, P = 0.01), while visual gain was associated with a smaller maximal MNV diameter after loading doses (OR 0.22, P = 0.03). A predictive model for frequent injection based on the Haller vessel length demonstrated an AUC of 0.71. In conclusion, the en face Haller vessel and MNV morphology after loading doses can be used as biomarkers for the injection frequency and visual gain during the first year in treatment-naïve nAMD patients.

Characterization of Choroidal Morphology and Vasculature in the Phenotype of Pachychoroid Diseases by Swept-Source OCT and OCTA

The objective of this study was to characterize the choroidal morphology and vasculature in pachychoroid diseases (PCD). A total of 49 eyes with polypoidal choroidal vasculopathy (PCV), 43 eyes with neovascular age-related macular degeneration (nAMD), and 50 eyes with central serous chorioretinopathy (CSC), along with 80 healthy eyes, were enrolled in this nested case-control study. The swept-source optical coherent tomography (OCT), OCT angiography, and En face images were quantitatively analyzed. Multivariate logistic regression models showed that older age and increased vessel density (VD) in the choriocapillaris (CC) layer were independent risk factors for both PCV (page < 0.001, pVD = 0.004), and nAMD (page < 0.001, pVD = 0.005). Decreased VD in the Sattler’s layer was an independent risk factor for PCV (p = 0.014). Increased VD in the Haller’s layer was an independent risk factor for CSC (p = 0.001). The proportion of the diffuse type of collateral circulation in the Sattler’ layer in CSC group was significantly higher than in the other three groups (p < 0.001). We concluded that the involvement of the blood flow in the CC, Haller’s, and Sattler’s layers are differently affected in CSC, nAMD, and PCV eyes, indicating the different pathological mechanism underlying the phenotype of PCD. The age-dependent establishment of collateral circulation in the Sattler’s layer may play a compensatory role regarding ischemic injury in the development of PCD.

Predicting persistent central serous chorioretinopathy using multiple optical coherence tomographic images by deep learning

We sought to predict whether central serous chorioretinopathy (CSC) will persist after 6 months using multiple optical coherence tomography (OCT) images by deep convolutional neural network (CNN). This was a multicenter, retrospective, cohort study. Multiple OCT images, including B-scan and en face images of retinal thickness (RT), mid-retina, ellipsoid zone (EZ) layer, and choroidal layer, were collected from 832 eyes of 832 CSC patients (593 self-resolving and 239 persistent). Each image set and concatenated set were divided into training (70%), validation (15%), and test (15%) sets. Training and validation were performed using ResNet50 CNN architecture for predicting CSC requiring treatment. Model performance was analyzed using the test set. The accuracy of prediction was 0.8072, 0.9200, 0.6480, and 0.9200 for B-scan, RT, mid-retina, EZ, and choroid modalities, respectively. When image sets with high accuracy were concatenated, the accuracy was 0.9520, 0.8800, and 0.9280 for B-scan + RT, B-scan + EZ, and EZ + RT, respectively. OCT B-scan, RT, and EZ en face images demonstrated good performances for predicting the prognosis of CSC using CNN. The performance improved when these sets were concatenated. The results of this study can serve as a reference for choosing an optimal treatment for CSC patients.

Progression of pachychoroid neovasculopathy into aneurysmal type 1 choroidal neovascularization or polypoidal choroidal vasculopathy

PURPOSE

To describe the progression of pachychoroid neovasculopathy (PNV) into pachychoroid aneurysmal type 1 choroidal neovascularization (PAT1) / polypoidal choroidal vasculopathy (PCV).

DESIGN

Retrospective longitudinal cohort study.

SUBJECTS

Patients diagnosed with PNV with a follow-up of ≥ 2 years.

METHODS

Multimodal imaging, including optical coherence tomography and fluorescein and indocyanine green angiography, was reviewed for the presence of choroidal neovascularization (CNV), aneurysms within/at the margins of the CNV and sub-foveal choroidal thickness (SFCT).

MAIN OUTCOME MEASURES

Rate of PNV to PAT1/PCV conversion and risk factors thereof.

RESULTS

In total, 37 PNV eyes of 32 patients with a mean follow-up of 3.3±1.1 (2.0 - 5.2) years were included in the study. At PNV diagnosis, mean age was 59.7±8.7 (range: 38.5 - 78.0) years and mean SFCT was 357±92 (185 - 589) μm. During follow-up, 5 eyes (13.5 %) developed aneurysms after a mean 3.4±0.8 years (2.3 - 4.2 years) years, defining PAT1/PCV. Risk of PAT1/PCV conversion was 7.4 % at year 3, 13.6 % at year 4 and 30.7 % at year 5. Mean 5.2±4.0 to 8.1±3.4 intravitreal anti-VEGF injections were given per year, resulting in a significant reduction of SFCT to 317±104 (122 to 589) μm (p= 0.0007). Age at diagnosis of PNV was significantly lower in eyes that later went on to develop PAT1/PCV (54.0±5.6 (45.9 to 60.5) vs. 61.2±8.4 (38.5 - 78.0) years, p=0.025). At end of follow-up, SFCT had on average decreased by -14.0±17.6 (-55.9 to 23.1) % in the PNV group, while it had increased by mean 6.9±4.4 (0.00 to 10.8) % in the PAT1/PCV conversion group (p=0.0025).

CONCLUSION

PNV can develop aneurysms within its type 1 CNV, defining conversion to PAT1/PCV. In this study, conversion to PAT1/PCV was seen in 13.5 % of eyes, resulting in Kaplan Meier estimates of risk for conversion of 7.4 % at year 3, 13.6 % at year 4 and 30.7 % at year 5. Younger age at diagnosis of PNV and sustained choroidal thickening despite anti-VEGF therapy might be risk factors for PNV to progress into PAT1/PCV.

Investigation of Serum and Macular Carotenoids in Central Serous Chorioretinopathy

Purpose

This study aimed to evaluate serum lutein and zeaxanthin levels and macular pigment optical density (MPOD) in central serous chorioretinopathy (CSC).

Methods

Fifty-four patients with acute CSC (28–56 years old; 44 men and 10 women) and 62 matched controls were enrolled. Serum lutein and zeaxanthin were measured using the high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) method. MPOD was measured at 7° of eccentricity and reported in parameters as “max” and “mean” optical density (OD) (Visucam 200; Carl Zeiss Meditec). MPOD was re-measured in 9 patients whose subretinal fluid was absorbed.

Results

The average max OD and the mean OD in CSC were 0.275 ± 0.047 d.u. and 0.098 ± 0.018 d.u., respectively, which were significantly lower than the control (p &lt; 0.001). The average MPOD value in the unaffected eyes of patients with CSC was 0.298 ± 0.045 for max OD, 0.106 ± 0.017 for mean OD, and both were significantly lower compared with the affected eyes (p &lt; 0.001 for max OD, p = 0.01 for mean OD). In the 9 follow-up patients, the decrease in MPOD was partially recovered. The mean serum level was 409.80 ± 182.52 ng/ml for lutein and 22.97 ± 12.23 ng/ml for zeaxanthin in patients with CSC. In controls, the mean serum level was 393.38 ± 202.44 ng/ml for lutein and 22.16 ± 10.12 ng/ml for zeaxanthin. The difference was not statistically significant (p = 0.649, p = 0.698, respectively).

Conclusion

MPOD decreased within 7° of eccentricity in CSC without serum lutein and zeaxanthin changes. The decrease may be due to the subretinal fluid. Whether local oxidative stress is involved in CSC and the supplementation with lutein and zeaxanthin is helpful for CSC requires further investigation.

Classifying central serous chorioretinopathy subtypes with a deep neural network using optical coherence tomography images: a cross-sectional study

Central serous chorioretinopathy (CSC) is the fourth most common retinopathy and can reduce quality of life. CSC is assessed using optical coherence tomography (OCT), but deep learning systems have not been used to classify CSC subtypes. This study aimed to build a deep learning system model to distinguish CSC subtypes using a convolutional neural network (CNN). We enrolled 435 patients with CSC from a single tertiary center between January 2015 and January 2020. Data from spectral domain OCT (SD-OCT) images of the patients were analyzed using a deep CNN. Five-fold cross-validation was employed to evaluate the model’s ability to discriminate acute, non-resolving, inactive, and chronic atrophic CSC. We compared the performances of the proposed model, Resnet-50, Inception-V3, and eight ophthalmologists. Overall, 3209 SD-OCT images were included. The proposed model showed an average cross-validation accuracy of 70.0% (95% confidence interval [CI], 0.676–0.718) and the highest test accuracy was 73.5%. Additional evaluation in an independent set of 104 patients demonstrated the reliable performance of the proposed model (accuracy: 76.8%). Our model could classify CSC subtypes with high accuracy. Thus, automated deep learning systems could be useful in the classification and management of CSC.

Factors for Visual Acuity Improvement After Anti-VEGF Treatment of Wet Age-Related Macular Degeneration in China: 12 Months Follow up

Purpose: To evaluate the treatment solutions and effectiveness of intravitreal ranibizumab (RBZ) or conbercept in patients with wet age-related macular degeneration (wAMD) in a real-life setting in China.

Methods: The medical records of 368 patients with wAMD who started RBZ or conbercept treatment between 1 May 2014 and 30 April 2018 were evaluated. All patients were defined on fundus angiography at baseline to determine the subtype of AMD (PCV or CNV). We report visual acuity (VA) and central retinal thickness (CRT) measurements at baseline and 12 months.

Results: The average number of anti-VEGF injections was 2.1 ± 1.2. The BCVA improvement of these two groups was similar with a difference of 1.00 letter (95% CI: −1.4~3.4, p = 0.8505). At the end of the study, a BCVA increase of at least 5 letters was determined to be a satisfactory efficacy endpoint. Several factors were related to the possible improvement in the satisfactory efficacy endpoint, including female sex (OR 2.07, 95% CI 1.22~3.51), number of injections (OR 1.40, 95% CI 1.12~1.75) and VA change at the first month (OR 13.75, 95% CI 7.41~25.51). Additionally, some factors were related to the possible reduction in the satisfactory efficacy endpoint, including diabetes (OR 0.27, 95% CI 0.10~0.73) and disease history (OR 0.75, 95% CI 0.57~0.98).

Conclusion: Our study demonstrates that anti-VEGF drugs can effectively improve BCVA and reduce CRT in AMD patients. Sex, number of injections, VA change at the first month, diabetes and disease history are the most important factors affecting visual acuity.

Structural and vascular changes of the choroid in polypoidal choroidal vasculopathy after intravitreal anti-VEGF therapy

INTRODUCTION

To identify the changes in vessel density (VD) of choriocapillaris (CC) and in subfoveal choroidal thickness (SFCT) and to evaluate their correlation with functional response after three monthly intravitreal injections of Ranibizumab (loading phase) in patients affected by Polypoidal Choroidal Vasculopathy (PCV).

METHODS

A total of 30 eyes of 30 PCV patients and 30 eyes of 30 healthy subjects as control group were enrolled in this prospective study. The best corrected visual acuity (BCVA) was measured at baseline and after one month from third intravitreal injections in each patient. The VD of CC was evaluated in macular area by means of Optical Coherence Tomography Angiography (OCTA). Central macular thickness (CMT) and SFCT were analyzed by Enhanced Depth Imaging (EDI)-OCT.

RESULTS

The VD of CC showed statistically lower values in PCV patients at baseline respect to after loading phase (LP) and normal eyes (p<0.001). CMT and SFCT revealed a statistically significant reduction after LP (p<0.001). Multiple regression analysis revealed a significant negative correlation between the reduced SFCT, CMT at baseline and the improvement of BCVA after LP (p<0.05).

CONCLUSION

The close relationship between the thinner SFCT and better visual outcome after LP reveals the role of the EDI-OCT assessment of choroid as predictive biomarker of functional response to anti-VEGF therapy. This tool could provide a quantitative evaluation of structural features of choroid avoiding mistakes of evaluation at OCTA.

Long-term results of rescue photodynamic therapy for type 1 neovascularization refractory to anti-vascular endothelial growth factor

PURPOSE

To evaluate long-term results of photodynamic therapy (PDT) as a rescue treatment in patients with type 1 neovascularization refractory to intravitreal anti-vascular endothelial growth factor (VEGF).

METHODS

Patients who underwent reduced-fluence PDT for refractory type 1 neovascularization, which showed persistent subretinal and/or intraretinal fluid after three or more consecutive anti-VEGF treatments, and were followed up for ≥24 months were reviewed.

RESULTS

Seventy-eight eyes of 78 patients were included, and 37 (47%) were classified as polypoidal choroidal vasculopathy (PCV). The mean number of anti-VEGF injections before rescue PDT was 8.5 ± 5.4, and the mean follow-up period after rescue PDT was 74.0 ± 29.4 months. At 3 months after rescue PDT, exudation completely resolved in 55 (71%) patients and vision significantly improved (p = 0.021). Resolution of exudation was associated with choroidal vascular hyperpermeability [odds ratio (OR), 3.82; p = 0.031] and lower maximal height of pigment epithelial detachment (OR, 0.69; p = 0.018). In these patients, exudation recurred in 49 (89%) after mean period of 13.5 months. Vision significantly worsened at 24 months after rescue PDT, and thereafter, and the vision decrease was more prominent in patients with PCV. Rescue PDT could be repeated for recurrent or persistent exudation without increasing the risk of complications.

CONCLUSION

In patients with type 1 neovascularization refractory to anti-VEGF, reduced-fluence PDT is an effective and safe rescue treatment. Therapeutic efficacy wore off during long-term follow-up, but rescue PDT may be repeated safely.

SENSITIVITY AND SPECIFICITY OF MULTISPECTRAL IMAGING FOR POLYPOIDAL CHOROIDAL VASCULOPATHY

PURPOSE

To evaluate the sensitivity and specificity of multispectral imaging (MSI), a noninvasive imaging technique composed of a series of monochromatic scanning light, for polypoidal choroidal vasculopathy (PCV).

METHODS

This was a prospective observational study. Polypoidal lesions on MSI are defined by oval or lobular hyperreflective oval lesion with dark hyporeflective center. Branching vascular networks on MSI is featured by hyperreflective interlacing signal. Detection sensitivity and specificity of polypoidal lesions was compared with indocyanine green angiography, whereas sensitivity and specificity of branching vascular networks, subretinal fluid, and pigment epithelium detachment were compared with optical coherence tomography.

RESULTS

Among 67 eyes, 38 eyes (56.7%) were diagnosed with PCV, 7 eyes (10.4%) with neovascular age-related macular degeneration, 13 eyes (19.4%) with central serous chorioretinopathy, 6 eyes (9.0%) with pathological myopia, and 3 eyes (4.5%) with idiopathic choroidal neovascularization. Compared with indocyanine green angiography, the sensitivity and specificity for diagnosing PCV by MSI alone was 84.21% and 93.10%, respectively, and the positive predictive value and the negative predictive value for PCV by MSI was 94.12% and 81.82%, respectively. The sensitivity and specificity for detecting polypoidal lesions were 84.21% and 93.10% compared with indocyanine green angiography. Compared with optical coherence tomography, the sensitivity and specificity for detecting branching vascular networks were 95.83% and 88.37%, for the subretinal fluid were 76.92% and 86.67%, and for the pigment epithelium detachment were 91.11% and 90.91%, respectively.

CONCLUSION

Multispectral imaging allowed noninvasive visualization of polypoidal lesions and branching vascular networks and may serve as a new diagnostic option for PCV.

A comparative study of type 1 neovascularization: Neovascular age-related macular degeneration versus pachychoroid neovasculopathy

PURPOSE

This study aimed to compare type 1 choroidal neovascularization (CNV) characteristics in eyes with pachychoroid neovasculopathy (PNV) and neovascular age-related macular degeneration (nAMD) using optical coherence tomography angiography (OCTA).

METHODS

Treatment naive 23 eyes of 23 patients with PNV and 24 eyes of 24 patients with nAMD were evaluated. The height of pigment epithelial detachment (PED) and the central macular thickness were determined. OCTA sensitivity, CNV area, morphological patterns, and retinal superficial capillary plexus vessel density (SCP-VD) values were compared. The frequency of quiescent CNV, subretinal hyperreflective exudation (SHE), subretinal/intraretinal fluid, serous PED, double-layer sign (DLS), and pachyvessels were noted.

RESULTS

CNV was detected on OCTA in 83.3% of nAMD eyes and 91.3% of PNV eyes (p = 0.66). Indistinct pattern was more common (74% vs 50%) and the CNV area (mm²) was smaller in PNV (0.77 ± 0.54 vs 1.57 ± 1.43) but did not reach significant levels (p = 0.27 and 0.33 respectively). SCP-VD was similar between the groups (p = 0.38). Statistically significant differences were found between groups in age and subfoveal choroidal thickness (p < 0.05). DLS and pachyvessels were found to be more frequently in PNV (p < 0.05). However, both groups had similar rates of quiescent CNV, SHE, subretinal/intraretinal fluid, and serous PED (p > 0.05).

CONCLUSION

Morphological features, area, and activation findings of type 1 CNV may play a limited role in differentiating nAMD and PNV cases.

Pachychoroid Spectrum Disease: Underlying Pathology, Classification, and Phenotypes

PURPOSE

Pachychoroid spectrum disease encompasses a set of macular disorders secondary to an abnormally thick choroid. However, the pathological process underlying pachychoroid spectrum disease and its overlap with age-related macular degeneration (AMD) remain unclear. This review aimed to understand the underlying pathology, classification, and phenotypes of pachychoroid spectrum disease.

METHODS

This comprehensive literature review was performed based on a search of peer-reviewed published papers relevant to the current knowledge of pachychoroid disease spectrum.

RESULTS

Pachychoroid is primarily a bilateral phenomenon; the main pathological lesions include choriocapillaris attenuation and abnormally dilated pachyvessels. Chronic central serous chorioretinopathy (CSC) and pachychoroid neovasculopathy (PNV) show similar morphological changes and angiogenic cytokine levels. The subretinal fluid in PNV may not accurately indicate PNV activity. Besides, types 1 and 2 of choroidal neovascularization (CNV) may be involved in primary pachychoroidal disease. Both choroidal arteriosclerosis and higher hydrostatic pressure contribute to hyalinized choroidal arteries and aneurysmal dilatations, resulting in PNV progression to polypoidal choroidal vasculopathy (PCV). Thus, pachychoroid-related type 2 CNV and chronic CSC could be considered as PNV (IIIc) and as a precursor of PNV (IIIa), respectively. Tangled PCV on optical coherence tomography angiography that fails to develop aneurysms should be classified as a subtype of PNV or a forme fruste of PCV.

CONCLUSIONS

Multiple disorders of the pachychoroid spectrum are considered as a continuous disease process, ultimately stimulated by choroidal malfunction. PCV overlaps both AMD and pachychoroid disease, especially for thin-choroid and bilateral types. The terminology and classification of pachychoroid spectrum disease should be used cautiously.

Integrative analysis of the choroid by quantifying Haller vessel and choriocapillaris parameters in different drusen subtypes

This study aimed to quantify the Haller vessel and choriocapillaris (CC) parameters in drusen subtypes in nonexudative age-related macular degeneration (AMD) and pachydrusen. Ninety-five eyes of 80 patients and 28 control eyes were categorized into soft drusen, subretinal drusenoid deposit (SDD), soft drusen plus SDD, pachydrusen, and control groups. The diameter, length and intersections of Haller vessels and the total area, size and number of CC flow voids were quantified using en face optical coherence tomography (OCT) or OCT angiography. The pachydrusen group showed the largest Haller vessel area and diameter and shortest total length but similar CC parameters to those in the control group. The soft drusen plus SDD group showed the largest CC flow void area and size, while the Haller parameters were similar to those in the control group. The area and size of the flow voids in the SDD group were smaller than those in the soft drusen plus SDD group. Based on unsupervised machine learning, the eyes were classified into 4 clusters—the control, pachydrusen, soft drusen plus SDD and soft drusen plus SDD groups. Cluster 3 showed a larger diameter and shorter total length of the Haller vessels than cluster 4.

Multimodal Imaging in Pachychoroid Spectrum

Diagnostic investigation on pachychoroid spectrum disease (PSD) has been growing along with the rapid advancement of imaging technology. In optical coherence tomography (OCT)-based studies, choroidal thickness profile, luminal and stromal choroidal ratio, and abnormalities in the neurosensory retina have demonstrated various patterns in different clinical entities related to PSD. The emerging role of OCT angiography (OCTA) has been expanded to involve the quantitative analysis of the OCTA parameters in different clinical entities of PSD and to evaluate the choriocapillaris signal void and vessel density as indicators of choriocapillaris ischemia. OCTA has broadened our knowledge in characterization and assessment of both active and quiescent choroidal neovascularization and its association with treatment response. Recent studies using indocyanine green angiography (ICG) have focused on the evaluation of choroidal vascular hyperpermeability and its relationship with other pachychoroid related features. Ultrawidefield ICG enables observation and characterization of peripheral choroidal pathologies and their associations with macular abnormalities. Multicolor imaging is an emerging modality with the capability to demonstrate early abnormalities in PSD. We summarize all investigations reflecting the new insights into the application of multimodal imaging for PSD and focuses on novel findings observed in different clinical entities with each imaging modality.

Choroidal Vascular Abnormalities by Ultra-widefield Indocyanine Green Angiography in Polypoidal Choroidal Vasculopathy

Purpose

To evaluate vortex vein engorgement and choroidal vascular hyperpermeability in patients with polypoidal choroidal vasculopathy (PCV) using ultra-widefield indocyanine green angiography (ICGA).

Methods

This retrospective case control study included 51 patients with unilateral PCV, 7 patients with bilateral PCV, and 43 age-matched controls. The number of quadrants of vortex vein engorgement was evaluated in the middle phase of ICGA, which was classified as extended engorgement if the dilated choroidal vessels expanded to the macula. The area of choroidal vascular hyperpermeability was quantified stereographically from the late-phase ICGA and correlated with clinical and optical coherence tomography findings.

Results

Affected eyes had a larger choroidal hyperpermeability area and a thicker subfoveal choroid than eyes in the control group or fellow eyes (P < 0.001, P < 0.001). More quadrants with extended vortex vein engorgement were observed in affected eyes than in fellow eyes (P < 0.001). Significant differences were observed in the area of choroidal hyperpermeability, Haller layer thickness and greatest linear dimension according to the extended vortex vein engorgement in eyes with PCV (P < 0.001, P = 0.001, and P = 0.001, respectively). The area of choroidal hyperpermeability was significantly correlated with subfoveal choroidal thickness (P < 0.001, Pearson's correlation coefficient = 0.471).

Conclusions

Ultra-widefield ICGA results revealed that patients with PCV had vortex vein engorgement and an increased choroidal hyperpermeability area. The results from this study provide substantial information to clarify the pathogenesis and predict the prognosis in the patients with PCV.

Classification of Pachychoroid on Optical Coherence Tomographic En Face Images Using Deep Convolutional Neural Networks

Purpose

To study the efficacy of deep convolutional neural networks (DCNNs) to differentiate pachychoroid from nonpachychoroid on en face optical coherence tomography (OCT) images at the large choroidal vessel.

Methods

En face OCT images were collected from eyes with neovascular age-related macular degeneration, polypoidal choroidal vasculopathy, and central serous chorioretinopathy. All images were prelabeled pachychoroid or nonpachychoroid based on quantitative and qualitative criteria for choroidal morphology on multimodal imaging by two retina specialists. In total, 1188 nonpachychoroid and 884 pachychoroid images were used for training (80%) and validation (20%). Accuracy for identification of pachychoroid by DCNN models was analyzed. Trained models were tested on a test set containing 79 nonpachychoroid and 93 pachychoroid images.

Results

The accuracy on the validation set was 94.1%, 93.2%, 94.7%, and 94.4% in DenseNet, GoogLeNet, ResNet50, and Inception-v3, respectively. On a test set, each model demonstrated accuracy of 80.2%, 83.1%, 89.5%, and 90.1% and an F1 score of 0.782, 0.824, 0.904, and 0.901, respectively.

Conclusions

DCNN models could classify pachychoroid and nonpachychoroid with good performance on OCT en face images. Automated classification of pachychoroid will be useful for tailored treatment of individual patients with exudative maculopathy.

Translational Relevance

En face OCT images can be used by DCNN for classification of pachychoroid.

ASSOCIATION OF TREATMENT RESPONSE WITH QUANTITATIVE CHANGES IN CHOROIDAL NEOVASCULARIZATION AND CHOROIDAL VESSEL IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION

PURPOSE

To evaluate the association between treatment response and quantitative morphological changes in choroidal neovascularization and outer choroidal vessels using optical coherence tomography angiography (OCTA) and en face OCT in neovascular age-related macular degeneration (nAMD).

METHODS

We retrospectively analyzed 75 eyes of typical nAMD patients and 53 polypoidal choroidal vasculopathy eyes of 124 patients with OCTA performed at least 6 months after initial antivascular endothelial growth factor treatment. Quantitative parameters, including vessel area, vessel diameter, branch vessel length, fractal dimension, and lacunarity were analyzed based on en face images of the choroidal neovascularization and choroidal vessel in Haller's layer. Parameters associated with loss of logarithm of the minimum angle of resolution visual acuity with the basis of 0.3 and the treatment interval (good vs. poor responder based on 12 weeks) were analyzed. Analyses were conducted for "before OCTA" (initial visit to OCTA) and "after OCTA" (OCTA to 6 months post-OCTA).

RESULTS

In typical nAMD, visual acuity loss before OCTA was associated with a higher SD of choroidal neovascularization diameter and lower choroidal fractal dimension. Visual acuity loss after OCTA in typical nAMD was associated with higher lacunarity of the choroid. Poor responders before OCTA were not associated with any factor. Poor responders after OCTA were associated with a lower SD of outer choroidal vessel diameter in typical nAMD. In polypoidal choroidal vasculopathy, no factor was associated with clinical outcomes in either period.

CONCLUSION

Quantitative analyses of choroidal neovascularization on OCTA and choroidal vessels on en face OCT provide information about treatment response, including changes in visual acuity and treatment interval, in nAMD.

Prevalence of and factors associated with dilated choroidal vessels beneath the retinal pigment epithelium among the Japanese

Pachyvessels are pathologically dilated large choroidal vessels and are associated with the pathogenesis of several pachychoroid-related disorders, including central serous chorioretinopathy. We aimed to investigate the prevalence of and risk factors for pachyvessels in the Japanese population. We included 316 participants (aged ≥ 40 years) with normal right eyes. The presence of pachyvessels (vertical diameter > 300 µm, distance to the retinal pigment epithelium < 50 µm) was determined using 6 × 6 mm macular swept-source optical coherence tomography images, and associated risk factors were investigated. Subfoveal choroidal thickness was measured, and its associated risk factors investigated. The overall prevalence of pachychoroids was 9.5%. Regression analysis showed that a younger age, shorter axial length, male sex, and smoking were significantly associated with the presence of pachyvessels (p = 0.047; odds ratio [OR] 0.96 per year, p = 0.021; OR 0.61 per 1 mm, p = 0.012; OR 3.08 vs. female, and p = 0.011; OR 3.15 vs. non-smoker, respectively) and greater choroidal thickness (p < 0.001, p < 0.001, p < 0.003, and p < 0.017, respectively). The results were consistent with other research findings which showed that pachychoroid-related disorders such as central serous chorioretinopathy were associated with younger age, male sex, shorter axial length, and smoking. Smoking may be associated with choroidal circulatory disturbance in the Japanese population.

Macular microvascular changes in resolved central serous chorioretinopaty using spectral-domain optical coherence tomography angiography

PURPOSE

The purpose of this study was to evaluate microvascular changes in the retina and choriocapillaris in central serous chorioretinopathy (CSCR) patients with resolved serous detachment using optical coherence tomography angiography (OCTA).

METHOD

49 eyes of 46 patients with CSCR were included in the study. 32 eyes of 16 age-matched controls were included in the control group. Fundus photography, fluorescein angiography, spectral-domain optical coherence tomography and OCTA were used. Choriocapillaris (CC) flow area, foveal avascular zone (FAZ), parafoveal vascular density of superficial and deep capillary plexus of the acute and chronic CSCR groups were compared with the values of the control group. Contrary to previous studies, OCTA data were obtained at a time when there was no serous detachment. This was because we aimed at minimizing erroneous measurements that might arise due to serous detachment.

RESULTS

1- The acute CSCR patients (1.705±0.292mm²) were found to have lower choriocapillaris (CC) flow area compared to the control group (2.155±0.069mm²). (P<0.001). Lower CC flow area was found in the chronic CSCR patients (1.774±0.216mm²) compared to the control group (2.155±0.069mm²) (P<0.001). 2- Chronic CSCR patients (49.27%±3.84) had a lower parafoveal density in the superficial capillary plexus compared to the control group (52.25%±2.85) (P<0.05). 3- No statistically significant difference was found between the acute CSCR group (55.07%±6.29) and chronic CSCR group (52.65%±5.18) in terms of parafoveal density in the deep capillary plexus when individually compared to the control group (53.34%±2.7). 4-A positive correlation was found between the parafoveal density in the deep capillary plexus and central foveal thickness (CFT) in the chronic CSCR group (r=0.382) (P˂0.05) 5- No statistically significant difference was found in the FAZ of the acute CSCR group (0.258±0.054mm²) and chronic CSCR group (0.342±0.124mm²) when individually compared to the control group (0.311±0.1mm²). The largest mean FAZ area was found in the chronic CSCR group.

CONCLUSION

Our study showed that the pathogenesis of CSCR is characterized by choriocapillaris and retinal microvascular changes.

En-face analysis of short posterior ciliary arteries crossing the sclera to choroid using wide-field swept-source optical coherence tomography

To study the topographic distribution of the short posterior ciliary arteries (SPCA) entry sites into the choroid in normal eyes using structural en-face swept source optical coherence tomography (SS-OCT). Retrospective analysis of SS-OCT scans (wide-field structural SS-OCT 12 × 12 mm) of 13 healthy subjects was performed. Cross-sectional swept-source OCT scans derived from a volume scan were represented as en-face image display following the Choroid-Scleral Interface to obtain en-face OCT. SPCAs in their last scleral location before choroidal entrance were identified manually, counted and localized by two masked observers. Correlations between two masked observers were analyzed using inter- and intra-class correlation. Accuracy for the choroidal inner and outer border segmentation was 95-99%. Eighteen eyes from 13 normal subjects were included for SPCA analysis. The mean number of arteries was 13.8 ± 3.5 per eye. Thirty-six percent were in the center of the posterior pole image; however, 21% were in the temporal part of the posterior pole. Median accuracy of the detection is 0.94. The correlation between the two observers was fair (0.54). Our algorithm allows visualization of the SPCA at the posterior pole of the eye using wide-field en-face SS-OCT. It can also help the clinicians to study the SPCAs in numerous ocular diseases, particularly its relationship with focal choroidal diseases.

A comparative study on the choroidal vascularity index and the determination of cut-off values in the pachychoroid spectrum diseases

PURPOSE

To determine the cut-off levels for choroidal thickness and choroidal vascularity index (CVI) to differentiate among pachychoroid spectrum diseases.

STUDY DESIGN

A retrospective comparative study METHODS: A total of 143 eyes were included. Of these 29 had uncomplicated pachychoroid (UCP), 29 had pachychoroid pigment epitheliopathy (PPE), 25 had pachychoroid neovasculopathy (PNV), 30 had central serous chorioretinopathy (CSC), and 30 had polypoidal choroidal vasculopathy (PCV). The choroidal areas were measured with ImageJ software. The CVI, the proportion of the luminal area to the total choroidal area, was assessed.

RESULTS

The cut-off points of central choroidal thickness were determined as 360 µm for the PPE and PCV group pair (p < 0.001), 422 µm for the PNV and CSC group pair (p = 0.026), 271 µm for the PNV and PCV group pair (p < 0.001), and 341 µm for the CSC and PCV group pair (p < 0.001). The cut-off points of CVI were 72.7 for the PPE and PCV group pair (p < 0.001), 74.7 for the PNV and CSC group pair (p = 0.005), 72.6 for the PNV and PCV group pair (p = 0.001), and 73.6 for the CSC and PCV group pair (p < 0.001).

CONCLUSION

Pachychoroid spectrum may be composed of a combination of distinct choroidal diseases with different vascular and structural characteristics.

THE INCIDENCE OF NEOVASCULARIZATION IN CENTRAL SEROUS CHORIORETINOPATHY BY OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

PURPOSE

To evaluate the incidence of neovascularization (NV) secondary to central serous chorioretinopathy (CSC)-a condition belonging to the spectrum of pachychoroid disorders by means of optical coherence tomography angiography.

METHODS

One hundred and seventy five eyes with CSC were evaluated in this retrospective observational study. The eyes with acute or chronic CSC with no NV were included in Group 1, and those with NV were evaluated in Group 2. Only eyes that had undergone structural optical coherence tomography and optical coherence tomography angiography were included. Age, best-corrected visual acuity, and subfoveal choroidal thickness were evaluated in all eyes. In Group 2, the type and morphology of NV and the occurrence of exudation were considered.

RESULTS

Of a total of 175 eyes with CSC, 86 had the acute form and 89 the chronic. Approximately 140 belonged to Group 1 (80%) and 35 to Group 2 (20%). Approximately 39.2% of all patient with chronic CSC developed NV. Mean age in Groups 1 and 2 was 53.3 years (±10.9) and 66.6 years (±10.2), respectively. Mean best-corrected visual acuity in Groups 1 and 2 was 45.7 (±11.7) and 30.9 (±17.9) early treatment diabetic retinopathy study letters, respectively. Mean CCT in Group 1 and 2 was 417.5 µm (±123) and 344.2 µm (±165.9), respectively. In Group 2, all patients had Type 1 NV (100%); 29 eyes (83%) had filamentous feature, and 6 eyes (17%) had irregular shape. Silent nonexudative NV was observed in 7 eyes (20%), all belonging to Group 2.

CONCLUSION

The use of optical coherence tomography angiography in everyday clinical practice allows for the accurate analysis of the chorioretinal vascular setting, with the identification of new vessels that could remain misdiagnosed.

Short-term effect of anti-VEGF for chronic central serous chorioretinopathy according to the presence of choroidal neovascularization using optical coherence tomography angiography

Purpose

To analyze the short-term therapeutic efficacy of intravitreal injection of bevacizumab (IVB) for chronic central serous chorioretinopathy (CSC) according to the presence of choroidal neovascularization (CNV) using optical coherence tomography angiography (OCTA).

Methods

A retrospective chart review was perfomed on cases of CSC with CNV (Group 1: n = 31) and an age-matched cases of CSC without CNV (Group 2: n = 30). The response to IVB was evaluated by changes in best-corrected visual acuity (BCVA), central macular thickness (CMT), choroidal thickness (CT), and pachyvessel diameter. Univariate and multivariate linear regression analyses were performed to identify factors associated with the visual outcome of chronic CSC with CNV after IVB.

Results

At baseline, the CT values differed significantly between Groups 1 and 2 (371.55 ± 67.09 vs. 417.33 ± 71.32 μm, p = 0.01). In Group 1, BCVA improved significantly (p < 0.001), and CMT (p < 0.001), CT (p = 0.001) and pachyvessel diameter (p = 0.045) decreased significantly, after IVB. In Group 2, only pachyvessel diameter (p = 0.001) was significantly smaller after IVB. Univariate analysis showed that the initial CT (B = 0.002, p = 0.026) and pachyvessel diameter (B = 0.002, p = 0.001) significantly affected visual outcome. In multivariate analysis, the initial pachyvessel diameter exhibited significant results (B = 0.002, p = 0.001).

Conclusions

IVB showed less effective short-term outcomes in chronic CSC patients without CNV than in patients with CNV. In chronic CSC with CNV, the short-term visual outcome after IVB was better in patients with a thinner choroid and smaller pachyvessels.

Hypothetical pathogenesis of age-related macular degeneration and pachychoroid diseases derived from their genetic characteristics

Genetic studies have investigated the pathogenesis of age-related macular degeneration (AMD). The pachychoroid concept has recently garnered attention as a possible explanation for AMD pathogenesis; the genetic characteristics of pachychoroid diseases have also been elucidated. In this review, we summarize previously reported genetic characteristics of AMD and pachychoroid diseases, and analyze these data to understand the pathogenesis of AMD and pachychoroid diseases. Previous studies show that VIPR2 and the CFH I62V A allele promote development of pachychoroid and central serous chorioretinopathy (CSC), while the CFH I62V G allele promotes development of drusen, pachychoroid neovasculopathy (PCN/PNV), and AMD. ARMS2/HTRA1 also promotes development of drusen, PCN/PNV, and AMD. TNFRSF10A and GATA5 are associated with CSC but not with pachychoroid, and TNFRSF10A is associated with AMD that includes PCN/PNV. These genetic characteristics suggest the following mechanisms of developing AMD and pachychoroid diseases. VIPR2 and the CFH I62V A allele promote pachychoroid development, which can result in CSC development. The CFH I62V G allele promotes a common step during PCN/PNV and AMD development induced by pachychoroid or drusen, such as damage of Bruch's membrane or retinal pigment epithelium (RPE). ARMS2/HTRA1 also promotes damage of Bruch's membrane or RPE, while the association with drusen formation is stronger in ARMS2/HTRA1 than in CFH. TNFRSF10A and GATA5 promote blood-retinal-barrier breakdown to induce CSC, which could lead to PCN/PNV development. Furthermore, recently reported genetic associations with the natural course of CSC suggest the importance of reconsidering the subtype classification of CSC. These associations would enable the development of personalized/precision medicine for CSC and.

Quantitative analysis of choroidal vasculature in polypoidal choroidal vasculopathy using ultra-widefield indocyanine green angiography

Polypoidal choroidal vasculopathy (PCV) is a common choroidal vascular disease particularly in Asians. However, the underlying pathogenesis of PCV is still yet to be fully elucidated, and the correlation between choroidal vasculature and treatment response of PCV are poorly understood. Accordingly, we sought to find clues to understand the pathogenesis and prognosis of PCV by quantitatively evaluating choroidal vasculature from the entire fundus using ultra-widefield (UWF) indocyanine green angiography (ICGA). In this study, 32 eyes from 29 patients with treatment naïve PCV and 30 eyes from 30 healthy control participants were enrolled. Choroidal vascular density (CVD) of PCV eyes was higher than normal eyes in majority regions including the periphery. CVD was positively correlated with choroidal thickness and choroidal hyperpermeability, supporting that the pathogenesis of PCV may include choroidal congestion and dilatation. Thicker choroid and higher CVD were also correlated with poor treatment response after anti-VEGF injections. The CVD, quantified from UWF ICGA can also be used as an effective image biomarker to predict the treatment response in PCV.

The effect of religious fasting and dehydration at Ramadan on choroidal thickness and Retinal vessel densities, measured with optical coherence tomography angiography

AIM

To investigate the effect of religious fasting and dehydration at Ramadan on choroidal thickness and vessel density in the superficial and deep vascular plexuses with OCTA.

METHODS

The choroidal thickness, and superficial and deep vessel density indices of fasting healthy subjects were measured with an OCTA device, and compared with non-fasting measurements.

RESULTS

The study included 70 eyes of 35 healthy subjects with a mean age of 42.86 ± 8.3 years. The measured choroidal thickness, superficial vessel density index and deep vessel density index were 288.89 ± 67 µm, 40.56% and 41.43%, respectively when measured in the fasting period, compared to 284.62 ± 65 µm, 40.41% and 41.41%, respectively when measured in the non-fasting period. The choroidal thickness under the fovea center was found to be significantly higher in the fasting period than in the non-fasting period (p = 0.014). The mean total choroidal thickness was found to be reduced in the non-fasting period, although not to a statistically significant degree (p > 0.05). An analysis of the mean total superficial and deep vascular plexuses revealed no statistically significant difference (p = 0.368, p = 0.938 respectively).

CONCLUSION

Although a significant increase was noted in central choroidal thickness in the fasting period, no significant change due to fasting was observed in the superficial and deep capillary plexuses. The choroidal layer may vary in thickness due to fasting-related metabolic factors, while retinal vessels are more stable against such effects.

The Application of Enhanced Depth Imaging Spectral-Domain Optical Coherence Tomography in Macular Diseases

The choroid plays an essential role in the pathogenesis of various posterior segment diseases. However, traditional imaging methods still have limited cross-sectional observation of choroid. Enhanced depth imaging in spectral-domain optical coherence tomography (EDI SD-OCT) uses a closer scanning position to the eye to create an inverted SD-OCT image with the advantage of better depth sensitivity, which can observe choroidal structure and measure choroidal thickness (CT) accurately. At present, more and more choroidal thickness measurements have been made in normal and pathologic states, in order to understand the pathogenesis and differential diagnosis and prognosis of various diseases, especially for macular lesions. This paper would review relevant original literatures published from January 1, 2008, to February 1, 2020, to evaluate the relationship between the changes of CT with EDI SD-OCT and macular diseases.

Visualization of deep choroidal vasculatures and measurement of choroidal vascular density: a swept-source optical coherence tomography angiography approach

BACKGROUND

To investigate swept-source optical coherence tomography angiography (SS-OCTA) for deep choroid visualization and choroidal vascular density (CVD) measurement.

METHODS

Healthy subjects and central serous chorioretinopathy (CSC) patients were recruited for macular SS-OCTA scans. We evaluated OCTA images at various depths to determine an optimal depth for visualizing choroidal vasculatures. We measured CVD with binarized OCTA images at the optimal depth. In healthy subjects, CVD was studied for its correlation with age, axial length (AL), and subfoveal choroidal thickness (SCT). In CSC eyes, CVD was compared with matched controls.

RESULTS

Ninety-one healthy eyes and 22 CSC eyes were included. SS-OCTA could display deep choroidal vasculatures as dark signals, with 100 μm beneath BM as the optimal depth. In healthy subjects, the CVD at 100 μm beneath BM (56.5 ± 10.9%) was significantly correlated with SCT (P = 0.004) but not with age (P = 0.49) or AL (P = 0.72). In CSC eyes, the CVD at 100 μm beneath BM (62.3 ± 6.6%) was larger than that in 22 matched controls (54.1 ± 8.0%) (P = 0.001). The difference remained statistically significant after adjusting for SCT (P = 0.02).

CONCLUSIONS

SS-OCTA can be used for visualizing deep choroidal vasculatures. CVD measured by OCTA at 100 μm beneath BM is a useful parameter for quantifying choroidal vascular status.

Classification of pachychoroid disease on ultrawide-field indocyanine green angiography using auto-machine learning platform

AIMS

Automatic identification of pachychoroid maybe used as an adjunctive method to confirm the condition and be of help in treatment for macular diseases. This study investigated the feasibility of classifying pachychoroid disease on ultra-widefield indocyanine green angiography (UWF ICGA) images using an automated machine-learning platform.

METHODS

Two models were trained with a set including 783 UWF ICGA images of patients with pachychoroid (n=376) and non-pachychoroid (n=349) diseases using the AutoML Vision (Google). Pachychoroid was confirmed using quantitative and qualitative choroidal morphology on multimodal imaging by two retina specialists. Model 1 used the original and Model 2 used images of the left eye horizontally flipped to the orientation of the right eye to increase accuracy by equalising the mirror image of the right eye and left eye. The performances were compared with those of human experts.

RESULTS

In total, 284, 279 and 220 images of central serous chorioretinopathy, polypoidal choroidal vasculopathy and neovascular age-related maculopathy were included. The precision and recall were 87.84% and 87.84% for Model 1 and 89.19% and 89.19% for Model 2, which were comparable to the results of the retinal specialists (90.91% and 95.24%) and superior to those of ophthalmic residents (68.18% and 92.50%).

CONCLUSIONS

Auto machine-learning platform can be used in the classification of pachychoroid on UWF ICGA images after careful consideration for pachychoroid definition and limitation of the platform including unstable performance on the medical image.

Imaging the Choroid: From Indocyanine Green Angiography to Optical Coherence Tomography Angiography

The choroid is the vascular structure nourishing the retinal pigment epithelium and the outer retina and it plays a key role in the homeostasis of the eye both under physiological and pathological conditions. In the last 20 years we have moved from "guessing" what was happening beyond the retinal pigment epithelium to actually visualize structural and functional changes of the choroid in vivo noninvasively. In this review we describe the state of the art of choroidal imaging, focusing on the multiple techniques available in the clinical and research setting including indocyanine green angiography, labeled-cells angiographies, optical coherence tomography (OCT), enhanced depth imaging, swept source OCT, and OCT angiography. In the first section of the article, we describe their main applications and the basic principles to interpret the imaging results. Increasing evidence suggests that the choroid is much more involved than we used to think in many pathological conditions from uveitis to intraocular tumors, from vascular diseases to age-related macular degeneration. All clinicians should hence know which is the most appropriate imaging investigation to explore the choroid in the disease they are dealing with and how to interpret the results. For this reason the second section of this review summarizes the best imaging approach and the most common findings visible on choroidal imaging in different diseases of the eye.

Characteristics of Pachychoroid Diseases and Age-Related Macular Degeneration: Multimodal Imaging and Genetic Backgrounds

The emergence of pachychoroid disease is changing the concept of age-related macular degeneration (AMD). The concept of pachychoroid diseases was developed through clinical observation of multimodal images of eyes with AMD and central serous chorioretinopathy; however, recent genetic studies have provided a proof of concept for pachychoroid spectrum disease, which should be differentiated from drusen-driven AMD. The genetic confirmation of pachychoroid concept further provides novel viewpoints to decode previously reported findings, which facilitates an understanding of the true nature of pachychoroid diseases and AMD. The purpose of this review was to elucidate the relationship between pachychoroid diseases and AMD by interpreting previous findings on pachychoroid diseases and AMD from the novel viewpoints of genetic associations. We confirmed that previous genetic studies supported the concept of pachychoroid diseases. From a genetic viewpoint, the presence of thick choroid and the presence of choroidal vascular hyperpermeability were important characteristics of pachychoroid spectrum diseases. Previous studies have also suggested the classification of polypoidal choroidal vasculopathy (PCV) into two subtypes, pachychoroid neovasculopathy and drusen-driven PCV. Genetic viewpoints will be beneficial to rearrange subtypes of drusen-driven AMD and pachychoroid spectrum diseases. Further genetic studies are needed to investigate pachyvessels, pachydrusen and the significance of polypoidal lesions in pachychoroid neovasculopathy and drusen-driven AMD/PCV.

Choroidal vascular densities of macular disease on ultra-widefield indocyanine green angiography

PURPOSE

We sought to compare choroidal vascular characteristics of central serous chorioretinopathy (CSC), polypoidal choroidal vasculopathy (PCV), and age-related macular degeneration (AMD) using quantitative analyses of ultra-widefield indocyanine green (UWF ICGA) images.

METHODS

Eyes with CSC (n = 57), thick-choroid PCV (n = 29), thin-choroid PCV (n = 25), neovascular AMD (n = 45), and pachychoroid neovasculopathy (PNV) (n = 28) were enrolled. On UWF ICGA images, choroidal vascular density (CVD) was assessed using binarization in the total area, posterior pole, each quadrant, and vortex ampullae. Subfoveal choroidal thickness (SFCT) was measured using optical coherence tomography.

RESULTS

The CVDs of thin-choroid PCV and typical AMD were lower than those of CSC (P = 0.002 and P < 0.001, respectively; P = 0.010 and P = 0.016 when adjusted for age.), whereas the CVDs of CSC, thick-choroid PCV, and PNV did not differ from each other (all P ≥ 0.161; all P ≥ 0.424 when adjusted for age). The CVD of the total area showed a positive correlation with SFCT in each also a whole group (all P ≤ 0.001). Meanwhile, the CVD of each ampullae positively correlated with that of the corresponding quadrant in total eyes and in each group (all P ≤ 0.001).

CONCLUSIONS

The mean CVD on UWF ICGA was increased in CSC, thick-choroid PCV, and PNV, whereas it was relatively low in thin-choroid PCV and typical AMD. Congestion at the vortex ampulla might be a cause of increased CVD, therefore increasing the SFCT in pachychoroid eyes.