Asymmetry of choroidal venous vascular patterns in the human eye

Diurnal Variation in Choroidal Parameters Among Healthy Subjects Using Wide-Field Swept-Source Optical Coherence Tomography Angiography

Purpose

The purpose of this study was to evaluate the diurnal variation in choroidal parameters in a wide field area among healthy subjects and to identify correlations between choroidal luminal area and stromal area and various systemic factors.

Methods

In this cross-sectional study, 42 eyes from 21 healthy participants (mean age = 32.4 ± 8.8 years) were examined using wide-field swept-source optical coherence tomography angiography (WF SS-OCTA, 24 mm × 20 mm). Measurements of choroidal parameters, including choroidal volume (CV), choroidal thickness (CT), choroidal vessel volume (CVV), and choroidal stromal volume (CSV), were taken at 8:00, 12:00, 18:00, and 22:00. Systemic factors, such as blood pressure and heart rate, were concurrently monitored.

Results

Our study observed significant diurnal variations in the mean total CV, CT, CVV, and CSV, with minimum measurements around 12:00 (P < 0.001) and peak values at 22:00 (P < 0.001). Furthermore, changes in CV in specific regions were more closely associated with fluctuations in CVV than CSV in the same regions. No significant diurnal variations were found in systolic (P = 0.137) or diastolic blood pressure (P = 0.236), whereas significant variations were observed in the heart rate (P = 0.001).

Conclusions

Our study reveals diurnal variations in choroidal parameters and their associations, emphasizing that changes in choroidal volume relate more to the luminal than the stromal area in vessel-rich regions. This enhances our understanding of choroidal-related ocular diseases.

Translational Relevance

Regions with higher choroidal vasculature observed greater choroidal volume changes.

Age-Related Macular Degeneration Choroidal Vascular Distribution Characteristics Based on Indocyanine Green Angiography

Purpose

The purpose of this study was to present our findings of the distribution pattern of choroidal arteries and large veins in patients with age-related macular degeneration (AMD) using indocyanine green angiography (ICGA).

Methods

A retrospective analysis was conducted on 980 patients who underwent ICGA at The Second Affiliated Hospital of Xi'an Jiaotong University from 2017 to 2023, including 240 patients with AMD. Secondary image processing was applied to the angiographic videos to obtain posterior distribution maps of choroidal arteries and large veins. Differences between different distribution patterns regarding age, gender, eye laterality, and circulation time were compared. We also conducted a comparison of choroidal vascular distribution characteristics between patients with AMD and patients with diabetic retinopathy (DR) and provided a summary of choroidal vascular distribution patterns in AMD.

Results

The filling patterns of choroidal arteries can be classified into the invisible trunk arteries type, the partially masked trunk arteries type, and the exposed trunk arteries type. The vascular topography of the large choroidal vein can be classified into the watershed type, the non-watershed type, and the unknown type, further divided into six subtypes. The distribution patterns of choroidal arteries and veins were significantly correlated with age (P < 0.001). Left eye, older age, and the exposed trunk arteries type were independent risk factors for non-watershed large choroidal vein (P < 0.05). The non-watershed type was the main characteristic of the venous phase in AMD.

Conclusions

The distribution characteristics of the arterial and venous patterns in AMD suggest atrophy of the small blood vessels in the choroid and insufficient perfusion pressure of the blood flow.

Long-term effect of orthokeratology on choroidal thickness and choroidal contour in myopic children

PURPOSE

To investigate the long-term effect of orthokeratology (ortho-k) on the choroidal thickness and choroidal contour in myopic children.

METHODS

Subjects were from a conducted 2-year randomised clinical trial. Children (n=80) aged 8-12 years with spherical equivalent refraction of -1.00 to -6.00D were randomly assigned to the control group (n=40) and ortho-k group (n=40). Optical coherence tomography images were collected at the baseline, 1-month, 6-month, 12-month, 18-month and 24-month visits, then the choroidal thickness and choroid contour were calculated. Axial length (AL) and other ocular biometrics were also measured.

RESULTS

During 2 years, in the control group, the choroidal thickness became thinning and the choroidal contour became prolate with time at all visits (all p<0.001). Ortho-k can improve the choroidal thickness (all p<0.001) and maintain the choroidal contour at all visits (all p<0.05). In the ortho-k group, the choroidal contour was less changed in the temporal than nasal (p=0.008), and the choroidal thickness was more thickening in the temporal 3 mm (p<0.001). Two-year change in choroidal thickness was significantly associated with the 2-year AL change in the control group (r=-0.52, p<0.001), however, this trend was broken by ortho-k (r=-0.05, p=0.342). After being adjusted by other variables in the multivariable regression model, the effect of ortho-k on choroidal thickness was stable.

CONCLUSIONS

In the current 2-year prospective study, ortho-k can improve the choroidal thickness and maintain the choroidal contour, but this effect diminished in a long term. Further study with larger sample size and longer follow-up is warranted to refine this issue.

Vortex Veins in Eyes With Pachychoroid Spectrum Disorders Evaluated by the Adjusted Reverse 3-Dimensional Projection Model

Purpose

To compare the distribution of vortex vein ampulla (VVA) between pachychoroid spectrum disorder (PSD) and controls.

Design

A single-center, case-control study.

Participants

This study included 75 PSD, 35 fellow, and 65 control eyes.

Methods

We quantified VVA distribution using a 3-dimensional reverse projection model corrected for image distortion. We investigated the distribution of major drainage veins (MDV), in which macular Haller's vessels directly influx.

Main Outcome Measures

The mean distances from the optic disc to VVAs and the mean angles between VVAs and the fovea-disc line.

Results

The PSD group had significantly fewer VVA in infranasal sector (PSD, fellow, control; 1.6 ± 0.6, 1.8 ± 0.6, 1.9 ± 0.6, respectively, P = 0.026). In supralateral sector, for PSD, fellows, and controls, the mean distances from the optic disc to VVAs were 14.1 ± 1.0 mm, 14.1 ± 1.1 mm, and 13.6 ± 1.4 mm, respectively, and were significantly farther in PSD than in controls (P = 0.023). The mean angles between VVAs and the fovea-disc line were 64.8 ± 5.9°, 66.4 ± 6.4°, and 61.7 ± 6.4°, respectively, and were significantly higher in PSD and fellows than in controls (P = 0.008). The mean distances from the optic disc to MDV in supratemporal sector were 14.1 ± 1.2 and 13.7 ± 1.2 in eyes whose Haller's vessels extended beyond the fovea-disc line (asymmetry), and those that did not, respectively, with the asymmetric eyes significantly farther (P = 0.016).

Conclusions

The VVA position in supralateral sector was farther and higher in PSD than in controls, suggesting that the distribution of VVA may be associated with the development of PSD.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

ASSESSMENT AND ROLE OF ARTERY-VEIN COMPLEX IN MYOPIC CHOROIDAL NEOVASCULARIZATION USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

PURPOSE

To analyze the presence of an artery-vein complex (AVC) underneath myopic choroidal neovascularization (mCNV) and to determine its relationship with neovascular activity.

METHODS

Retrospective analysis of 681 eyes from 362 patients with high myopia defined by an axial length of >26 mm using optical coherence tomography (OCT) and OCT angiography imaging. Patients with clinical diagnosis of mCNV and good quality OCT angiography images were then selected. An AVC was defined by the identification of both perforating scleral vessels and dilated choroidal veins under or in contact with the mCNV in the same case. Swept source OCT (SS-OCT) and SS-OCT angiography images (TRITON; Topcon Corporation, Tokyo, Japan) were reviewed to detect AVC in the mCNV area.

RESULTS

Fifty eyes of 49 highly myopic patients with mCNV were analyzed. Eyes with AVC were statistically older (69.95 ± 13.53 vs. 60.83 ± 10.47 years old; P < 0.01), needed less intravitreal injections/year along the follow-up period (0.80 ± 0.62 vs. 1.92 ± 0.17; P < 0.01), and showed less relapses/year (0.58 ± 0.75 vs. 0.46 ± 0.42; P < 0.05) when compared with eyes without AVC. Moreover, eyes with AVC were less likely to relapse during the first year from mCNV activation (n = 5/14 vs. n = 14/16; P < 0.01; P < 0.01). No significant differences were found regarding either axial length (30.55 ± 2.31 vs. 29.65 ± 2.24, P > 0.05) or best-corrected visual acuity (0.4 ± 0.5 vs. 0.4 ± 0.5 Logarithm of the Minimum Angle of Resolution (logMAR), P > 0.05) between groups.

CONCLUSION

AVC complex has an influence over myopic choroidal neovascularization activity resulting in less aggressive neovascular lesions than those with perforating scleral vessels only.

Choroidal Vortex Vein Drainage System in Central Serous Chorioretinopathy Using Ultra-Widefield Optical Coherence Tomography Angiography

Purpose

To evaluate differences in the choroidal vortex vein drainage system (VV) in eyes between patients with central serous chorioretinopathy (CSC) and unaffected individuals using ultra-widefield optical coherence tomography angiography (UWF-OCTA).

Methods

In this cross-sectional observational study, 40 eyes of patients with CSC and 28 eyes of healthy volunteers were included. The analysis involved the use of UWF-OCTA to analyze the proportion of the choroidal vortex vein drainage system (VV%), choroidal thickness, choroidal vascular volume (CVV), and choroidal vascularity index (CVI) of the VV in each drainage quadrant. The location relationship between the leakage points in fluorescein angiography and the VV was also explored.

Results

A within-group analysis of VV% showed a statistically significant difference in the CSC group (P < 0.001) but not in the control group (P = 0.270). Compared to healthy eyes, CSC eyes had a significantly larger CVV and higher CVI in all regions (all P < 0.05). The superotemporal (ST) drainage system had the largest CVV and thickest choroidal layer among the four drainage quadrants (all P < 0.05) in CSC eyes. The leakage rate in the ST quadrant was significantly higher than that in the inferotemporal quadrant (P < 0.001).

Conclusions

CSC eyes have an asymmetric vortex vein drainage system, with relative hyperperfusion in all VV. Further, the preferential drainage route of the submacular choroid may be the ST drainage system in CSC eyes.

Translational Relevance

Targeting the imbalanced drainage system could be a potential therapeutic approach for CSC.

Choroidal Vein Alterations in Pachychoroid Disease With Choroidal Vascular Hyperpermeability: Evaluated by Wide-Field Indocyanine Green Angiography

Purpose

The purpose of this study was to investigate choroidal vein (ChV) morphological features in pachychoroid disease (PCD) with choroidal vascular hyperpermeability (CVH).

Methods

This retrospective study assessed subfoveal choroidal thickness (SFCT) and CVH area numbers and locations of recruited patients with PCD using multimodal images. ChV alteration patterns, including fusiform, bulbosity, sausaging, confluence, and anastomoses, as well as asymmetric ChVs, dominant ChVs, and non-dominant ChVs, were evaluated using wide-field indocyanine green angiograms.

Results

Of 68 PCD eyes from 35 patients (mean age: 46.16 ± 6.28 years, 71.4% men), 2.9% had uncomplicated pachychoroid, 32.4% had pachychoroid pigment epitheliopathy (PPE), 55.9% central serous chorioretinopathy (CSC), and 8.8% pachychoroid neovasculopathy (PNV). Mean SFCT was 468.65 ± 131.40 µm. Among 419 CVH areas, ChV fusiform, ChV bulbosity, and ChV sausaging accounted for 35.8%, 35.1%, and 29.1%, respectively; 21.2% had ChV confluence and 11.9% had ChV anastomoses. At CVH areas, 13.1% had retinal pigment epithelium (RPE) leakage. ChV fusiform is steadily declining (37.4%, 36.8%, and 22.9%, respectively), and ChV sausaging, ChV anastomoses, and ChV confluence are increased gradually in the PPE, CSC, and PNV groups (21.4%, 30.0%, and 37.1%; 11.4%, 11.1%, and 20.0%; and 19.8%, 20.9%, and 28.6%, respectively). Dominant ChVs had higher CVH area numbers than non-dominant ChVs in the PPE and CSC groups (P = 0.010, P = 0.001).

Conclusions

Different patterns of ChV alterations, including the newly identified ChV confluence, are commonly present at CVH areas in PCD. The CVH areas in PCD eyes are primarily located within the dominant ChVs. These findings provide crucial evidence for advancing our understanding of the underlying mechanisms of PCD pathogenesis.

NORMAL PERIPHERAL CHOROIDAL THICKNESS MEASURED BY WIDEFIELD OPTICAL COHERENCE TOMOGRAPHY

PURPOSE

Choroidal stasis plays an important role in the pathogenesis of many conditions and leads to choroidal thickening. However, the normal peripheral choroidal thickness (PCT) pattern remains unknown. This study investigated PCT and associated factors using ultrawidefield optical coherence tomography in healthy eyes.

METHODS

This cross-sectional study included 120 healthy eyes (57 males; age, 52.0 ± 20.5 years). We used choroidal thickness maps created by ultrawidefield optical coherence tomography (viewing angle, 200°) with real-shape correction. The peripheral area was defined from 60° to 100° and further separated vertically and horizontally. The PCT and the correlations between PCT and subjects' characteristics were examined.

RESULTS

The PCT were 227.1 ± 57.0 µ m, 199.6 ± 53.9 µ m, 196.6 ± 57.1 µ m, and 148.0 ± 38.2 µ m in supratemporal, infratemporal, supranasal, and infranasal areas, respectively. The thickest peripheral sector was most frequently observed in supratemporal (69.2%). The PCT negatively correlated with age in all regions ( P -values < 0.001) and axial length in supratemporal, supranasal, and infranasal areas ( P -values ≤ 0.003). The temporal PCT was thicker on the side contiguous with the posterior pole Haller's vessels ( P -values ≤ 0.020).

CONCLUSION

The PCT is associated with age, axial length, and the running pattern of Haller's vessels.

Pathomechanisms in central serous chorioretinopathy: A recent update

BACKGROUND

Central serous chorioretinopathy (CSCR) is a potentially blinding choroidal disease. Despite decades of research, the pathological mechanisms of CSCR are still poorly understood. In recent years, there has been a strong emphasis on choroidal dysfunction as a primary cause of CSCR.

MAIN BODY

The concept of the pachychoroid disease spectrum and pachychoroid-driven processes are central to current theories regarding the pathophysiological underpinnings of CSCR. Choroidal hyperpermeability and subsequent leakage of fluid seen in CSCR may be due to several causes. Among them are venous congestion, inflammation, mineralocorticoid receptor activation, systemic factors including hemodynamic changes, obstructive sleep apnea, phosphodiesterase inhibitor use, pregnancy, and genetic predispositions. Congestion of vortex veins that drain blood from the choroid may contribute to the dilation of Haller vessels and cause fluid leakage. Vortex veins exit the eye through the sclera; thus, increased scleral thickness has been proposed to be a factor in venous congestion. Asymmetric vortex vein drainage may similarly result in congestion of the local venous system. Vortex vein anastomoses may overload the venous system and form secondary to venous congestion. Recent studies suggest inflammation and mineralocorticoid activation may factor into the development of CSCR, though more research in these areas is called for. Systemic conditions and genetics may predispose individuals to develop CSCR.

CONCLUSIONS

By striving to understand the molecular and physiological mechanisms of this disease, we can better diagnose and treat CSCR to improve outcomes for patients.

En face ultra-widefield optical coherence tomography of the vortex vein system in central serous chorioretinopathy

PURPOSE

To investigate whether noninvasive en face ultrawidefield (UWF) OCT can demonstrate salient features of the choroidal vasculature in eyes with central serous chorioretinopathy (CSC).

DESIGN

Retrospective observational case series.

PARTICIPANTS

Patients diagnosed with CSC who underwent UWF indocyanine green angiography (ICGA) and widefield OCT imaging were included.

METHODS

Widefield OCT imaging was performed with a horizontal 23-mm × vertical 20-mm field of view of 5 visual fixations (1 central and 4 peripheral fixations) to compose structural en face UWF OCT montage images and UWF choroidal thickness maps. Automated image alignment was performed before grading.

MAIN OUTCOME MEASURES

A comparison of choroidal vascular findings seen with UWF ICGA and en face UWF OCT images, including size and distribution of choroidal venous drainage areas and identification of dilated choroidal veins (pachyvessels) crossing the physiologic choroidal watershed zones. The spatial correlation between choroidal vascular hyperpermeability on UWF ICGA images and areas of choroidal thickening on UWF choroidal thickness maps was determined.

RESULTS

Forty-two eyes from 27 patients with CSC with a mean age of 56 ± 12 years (range, 31-77 years) were included. Quantitative measures of vortex vein drainage areas on en face UWF OCT images were significantly and positively correlated with those obtained with UWF ICGA (mean Pearson r = 0.825, P < 0.01). Identification of pachyvessels crossing the choroidal watershed zones showed an excellent correlation between UWF ICGA and en face UWF OCT images (mean Spearman ρ = 0.873, P < 0.01). In all cases, choroidal vascular hyperpermeability was observed on UWF ICGA spatially colocalized with areas of choroidal thickening on the UWF choroidal thickness map. Congestion within the entire drainage area of the dominant vortex systems was observed on UWF choroidal thickness maps.

CONCLUSIONS

In eyes with CSC, noninvasive en face UWF OCT imaging can show distinctive features of choroidal venous insufficiency previously identified with UWF ICGA. Ultrawidefield OCT choroidal thickness maps enable quantitative assessment of choroidal congestion.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Asymmetry between right and left optical coherence tomography images identified using convolutional neural networks

In a previous study, we identified biocular asymmetries in fundus photographs, and macula was discriminative area to distinguish left and right fundus images with > 99.9% accuracy. The purposes of this study were to investigate whether optical coherence tomography (OCT) images of the left and right eyes could be discriminated by convolutional neural networks (CNNs) and to support the previous result. We used a total of 129,546 OCT images. CNNs identified right and left horizontal images with high accuracy (99.50%). Even after flipping the left images, all of the CNNs were capable of discriminating them (DenseNet121: 90.33%, ResNet50: 88.20%, VGG19: 92.68%). The classification accuracy results were similar for the right and left flipped images (90.24% vs. 90.33%, respectively; p = 0.756). The CNNs also differentiated right and left vertical images (86.57%). In all cases, the discriminatory ability of the CNNs yielded a significant p value (< 0.001). However, the CNNs could not well-discriminate right horizontal images (50.82%, p = 0.548). There was a significant difference in identification accuracy between right and left horizontal and vertical OCT images and between flipped and non-flipped images. As this could result in bias in machine learning, care should be taken when flipping images.

Ultra-Widefield Indocyanine Green Angiography Reveals Patterns of Choroidal Venous Insufficiency Influencing Pachychoroid Disease

Purpose

To compare patterns of choroidal venous drainage in eyes with pachychoroid disease to those of healthy subjects using ultra-widefield indocyanine green angiography (UWF ICGA).

Methods

Patients with pachychoroid disease and healthy controls were recruited at two referral centers. UWF ICGA images were used to evaluate the proportion of the postequatorial fundus drained by major vortex vein systems in each quadrant and to study the incidence and topography of choroidal vascular hyperpermeability (CVH) and intervortex venous anastomoses. Widefield swept-source optical coherence tomography (SS-OCT) was used to evaluate choroidal thickness at the posterior pole in eyes with pachychoroid disease.

Results

Fifty-two pachychoroid eyes and 26 healthy eyes were evaluated. Eyes with pachychoroid disease showed a significant within-subject variance in the proportion of the postequatorial fundus drained by each vortex vein system (range, 4.1%–48.1%; P < 0.0001) that was not seen in controls (range, 17.3%–31.7%; P = 0.11). CVH was present in all pachychoroid disease eyes and three of 26 controls. Intervortex venous anastomoses were present in 46 of 52 pachychoroid disease eyes and nine of 26 control eyes. Vortex vein systems with large drainage areas showed greater density of CVH spots. SS-OCT demonstrated asymmetric choroidal drainage in the macula of 59% of pachychoroid eyes. CVH and intervortex venous anastomoses were more prominent in areas showing maximal choroidal thickness.

Conclusions

In eyes with pachychoroid disease, imbalanced choroidal venous drainage with congestion of specific vortex vein systems may contribute to a state of choroidal venous insufficiency characterized by regional choroidal thickening, CVH and remodeling of venous drainage routes.

Regional Distribution of Choroidal Thickness and Diurnal Variation in Choroidal Thickness and Axial Length in Young Adults

Purpose

To examine the regional distribution of choroidal thickness (ChT) and the diurnal variation in ChT and axial length (AL) over a wide range of myopic refractive error.

Methods

ChT was measured in thirty-four healthy young adults (age mean ± SD: 25.2 ± 2.8, range: 18-35 years) using spectral-domain optical coherence tomography and AL using an IOL-Master 500. Participants were divided into three refractive groups: emmetropes, myopes, and high myopes. We evaluated ChT in macular (foveal, parafovea, and perifovea) and peripheral regions (6-mm from the foveal pit) in four quadrants (superior, temporal, inferior, and nasal). To assess the diurnal variation, three measurement sessions of ChT and AL were taken at 8 AM, 12 PM, 4 PM.

Results

ChT thins progressively towards the periphery. Superior and nasal quadrants exhibited the thickest (277 ± 73 µm) and thinnest (218 ± 89 µm) choroid, respectively. Higher myopic eyes showed an overall thinner choroid (237 ± 48 µm) compared to myopic eyes (264 ± 78 µm) (P < 0.05). Higher myopes exhibited a significant choroidal thinning in all quadrants except in the temporal quadrant (all p < 0.05). Both ChT and AL underwent a significant diurnal variation (p < 0.05). The ChT and AL diurnal variation amplitudes in higher myopes were significantly reduced (ChT: 14.6 ± 11, AL: 14.5 ± 13 µm), compared to those in emmetropes (ChT: 21.4 ± 15, AL: 21.3 ± 8.5 µm) and myopes (ChT: 19 ± 17, AL: 19 ± 9.7 µm). Diurnal variation amplitude in ChT did not differ significantly across quadrants and choroidal eccentricity regions (p > 0.05).

Conclusion

ChT distribution varies based on quadrant and eccentricity; superior choroid exhibited the thickest, and nasal showed the thinnest choroid. Higher myopes experience a reduced diurnal variation in ChT and AL.

Short Axial Length Is Related to Asymmetric Vortex Veins in Central Serous Chorioretinopathy

Purpose

To investigate the clinical and morphologic factors related to asymmetric dilated vortex veins in central serous chorioretinopathy (CSC).

Design

Retrospective, comparative study.

Participants

One hundred fifty-eight eyes of 158 patients with CSC.

Methods

All patients with CSC underwent ophthalmic examination and multimodal imaging, including measurements of axial length (AL), fluorescein angiography, indocyanine green angiography, swept-source OCT, and anterior segment OCT. Using en face OCT images at the level of the outer choroid, the eyes were divided into 2 groups: eyes with symmetric vortex veins (symmetry group) and those with asymmetric vortex veins (asymmetry group).

Main Outcome Measures

Clinical and morphologic factors related to asymmetric vortex veins in CSC.

Results

Of the 158 eyes, 120 eyes (75.9%) were classified into the asymmetry group and 38 eyes (24.1%) were classified into the symmetry group. The asymmetry group showed significantly greater spherical equivalent (–0.32 ± 1.78 diopters [D] vs. –1.35 ± 2.64 D; P = 0.033), shorter AL (23.52 ± 0.86 mm vs. 24.10 ± 1.06 mm; P = 0.005), and greater subfoveal choroidal thickness (414.6 ± 105.3 μm vs. 360.4 ± 91.8 μm; P = 0.005) than the symmetry group. No significant differences existed between the 2 groups regarding age, sex, or all scleral thicknesses at the superior, temporal, inferior, and nasal points. In the multivariate analyses, shorter AL (odds ratio, 0.56; 95% confidence interval, 0.36–0.88; P = 0.011) was found to be significantly associated with the presence of asymmetric vortex veins.

Conclusions

The asymmetric dilated vortex vein is a common finding in patients with CSC. Our results suggest that certain biometric factors, such as short AL, may be associated with asymmetric dilated vortex veins developing in patients with CSC.

Factors effecting the choroidal vascularity index in children with mild to moderate myopia

PURPOSE

To measure the choroidal structural parameters in a population of myopic children and determine the factors effecting the choroidal vascularity index (CVI).

METHODS

In total, 200 eyes of 200 children (100 females, 100 males) with a mean age of 11.5 ± 1.6 years were included in the study. Macular imaging was performed using EDI mode of spectral domain-optical coherence tomography. Binarization of the choroidal area was performed with ImageJ software. Total choroidal area, luminal area (LA), stromal area (SA), and CVI were automatically calculated.

RESULTS

The mean choroidal, stromal and luminal areas were measured as 0.952 ± 0.127 mm², 0.626 ± 0.103 mm² and 0.325 ± 0.076 mm², respectively. The mean CVI was 65.81% ± 6.56. Age and the axial length (AL) of the participants were not found to be associated with the LA and the CVI. (r=-0.078, p=0.274, r=0.017, p=0.808, and r=0,051, p=0.474 and r=-0.128, p=0.071, respectively). There was a statistically significant strong association between the LA and CVI measurements and SE of the participants (r=0.736, p=0.001, and r=-0.605; p=0.001).

CONCLUSION

Age and AL were not associated with the CVI, but SE was significantly associated with the CVI.

Choroidal Volume Evaluation after Photodynamic Therapy Using New Optical Coherence Tomography Imaging Algorithm

To evaluate choroidal volume and thickness changes after photodynamic therapy (PDT) for chronic central serous chorioretinopathy (CSC). Chronic CSC eyes with a history of PDT were selected. Average choroidal volume, average choroidal thickness, the maximum and minimum choroidal thickness of the macula irradiated area and peripheral non-irradiated areas before and after one and three months of treatment were examined. A total of 14 patients with chronic CSC and 9 controls without any eye pathology were enrolled. The mean choroidal volume in CSC before and, and after one and three months of treatment were 2.36 (standard deviation: 0.70), 1.90 (0.69), 1.86 (0.66) mm³ for the central area, 1.25 (0.38), 1.14 (0.35), 1.13 (0.34) mm³ for superior nasal area, 1.47 (0.41), 1.28 (0.43), 1.26 (0.43) mm³ for superior temporal area, 1.07 (0.49), 0.95 (0.38), 0.93 (0.35) mm³ for inferior nasal area, 1.17 (0.38), 1.04 (0.32), 1.03 (0.33) mm³ for inferior temporal area. This study revealed the choroidal volume changes in a short period after PDT and a decrease in unirradiated choroidal volume was also shown after the treatment. The algorithm provided on the ARI Network enables to evaluate the choroidal changes quantitatively and qualitatively.

Framework for quantitative three-dimensional choroidal vasculature analysis using optical coherence tomography

Choroidal vasculature plays an important role in the pathogenesis of retinal diseases, such as myopic maculopathy, age-related macular degeneration, diabetic retinopathy, central serous chorioretinopathy, and ocular inflammatory diseases. Current optical coherence tomography (OCT) technology provides three-dimensional visualization of the choroidal angioarchitecture; however, quantitative measures remain challenging. Here, we propose and validate a framework to segment and quantify the choroidal vasculature from a prototype swept-source OCT (PLEX Elite 9000, Carl Zeiss Meditec, USA) using a 3×3 mm scan protocol centered on the macula. Enface images referenced from the retinal pigment epithelium were reconstructed from the volumetric data. The boundaries of the choroidal volume were automatically identified by tracking the choroidal vessel feature structure over the depth, and a selective sliding window was applied for segmenting the vessels adaptively from attenuation-corrected enface images. We achieved a segmentation accuracy of 96% ± 1% as compared with manual annotation, and a dice coefficient of 0.83 ± 0.04 for repeatability. Using this framework on both control (0.00 D to -2.00 D) and highly myopic (-8.00 D to -11.00 D) eyes, we report a decrease in choroidal vessel volume (p<0.001) in eyes with high myopia.

Artificial intelligence for classifying uncertain images by humans in determining choroidal vascular running pattern and comparisons with automated classification between artificial intelligence

Purpose

Abnormalities of the running pattern of choroidal vessel have been reported in eyes with pachychoroid diseases. However, it is difficult for clinicians to judge the running pattern with high reproducibility. Thus, the purpose of this study was to compare the degree of concordance of the running pattern of the choroidal vessels between that determined by artificial intelligence (AI) to that determined by experienced clinicians.

Methods

The running pattern of the choroidal vessels in en face images of Haller’s layer of 413 normal and pachychoroid diseased eyes was classified as symmetrical or asymmetrical by human raters and by three supervised machine learning models; the support vector machine (SVM), Xception, and random forest models. The data from the human raters were used as the supervised data. The accuracy rates of the human raters and the certainty of AI’s answers were compared using confidence scores (CSs).

Results

The choroidal vascular running pattern could be determined by each AI model with an area under the curve better than 0.94. The random forest method was able to discriminate with the highest accuracy among the three AIs. In the CS analyses, the percentage of certainty was highest (66.4%) and that of uncertainty was lowest (6.1%) in the agreement group. On the other hand, the rate of uncertainty was highest (27.3%) in the disagreement group.

Conclusion

AI algorithm can automatically classify with ambiguous criteria the presence or absence of a symmetrical blood vessel running pattern of the choroid. The classification was as good as that of supervised humans in accuracy and reproducibility.

Quantitative evaluations of vortex vein ampullae by adjusted 3D reverse projection model of ultra-widefield fundus images

The purpose of this study was to determine the number and location of vortex vein ampullae (VVA) in normal eyes. This was an observational retrospective study. Montage images of one on-axis and two off-axis ultra-widefield images of 74 healthy eyes were enhanced, and reverse projected onto a 3D model eye. The number and distance between the optic disc to each VVA in the four sectors were compared. The significance of correlations between these values and age, sex, visual acuity, refractive error, and axial length was determined. The mean number of VVA was 8.10/eye with 1.84, 2.12, 2.19 and 1.95 in upper lateral, lower lateral, upper nasal, and lower nasal sectors, respectively. The mean number of VVA/eye was significantly greater in men at 8.43 than women at 7.76 (P = 0.025). The mean distance between the optic disc and VVA was 14.15 mm, and it was 14.04, 15.55, 13.29 and 13.66 mm in the upper lateral, lower lateral, upper nasal and lower nasal sectors, respectively (all P < 0.05). The number and location of VVA can be obtained non-invasively, and the number was significantly higher in men than women. This technique can be used to determine whether these values are altered in a retinochoroidal disease.

Variation of vortex veins at the horizontal watershed in normal eyes

PURPOSE

To assess the vascular pattern of choroidal vortex veins at the horizontal watershed zone in normal eyes using optical coherence tomography (OCT).

METHODS

We retrospectively studied 207 normal eyes of 207 patients whose fellow eyes were diagnosed with unilateral retinal diseases without choroidal involvement. Venous anastomosis between the superior and inferior vortex veins and deviation of the horizontal watershed zone were evaluated using 12 × 12-mm en face OCT images. Central choroidal thickness (CCT) was measured on B-mode OCT images.

RESULTS

Vortex vein anastomosis was observed in 92 eyes (44.4%) at the horizontal watershed zone. Superior or inferior deviation of the horizontal watershed was ascertained in 69 eyes (33.3%). The frequency of the anastomosis and deviation did not differ significantly between age groups (P = 0.56 and 0.96, respectively). Mean CCT of all eyes was 221 ± 80 μm. CCT was significantly greater in eyes with anastomosis than in those without (233 ± 73 μm vs 210 ± 83 μm, P < 0.05). However, CCT did not differ significantly between eyes with and without deviation of the horizontal watershed zone (223 ± 74 μm vs 219 ± 82 μm).

CONCLUSIONS

Venous anastomosis at the horizontal watershed zone as well as superior or inferior deviation of the zone were frequently observed in normal eyes. CCT was greater in eyes with than in those without anastomosis, suggesting subclinical vortex vein congestion.

Quantitative Assessment of Asymmetric Choroidal Outflow in Pachychoroid Eyes on Ultra-Widefield Indocyanine Green Angiography

Purpose

To quantitatively demonstrate asymmetric choroidal outflow in pachychoroid (central serous chorioretinopathy [CSC]/pachychoroid pigment epitheliopathy [PPE]) eyes using mid-phase, ultra-widefield indocyanine green angiography (UWF ICGA) images.

Methods

Eyes with a clinical diagnosis of CSC/PPE were imaged with multimodal imaging including UWF ICGA (Optos California). Quadrant brightness was measured by manually segmenting based on vortex vein location, calculating the brightness “max-min” value to assess nonuniformity between quadrants, and comparing between CSC/PPE and control eyes. A multivariate linear regression was performed to determine, across individual eyes, which specific quadrants have the greatest brightness in pachychoroid eyes, after taking into account patient-eye-specific variability.

Results

Thirty-three eyes (18 patients) with CSC/PPE along with 16 eyes of 9 controls had a mean age of 51.94 ± 9.72 vs. 53.78 ± 17.92 years (P = 0.731), respectively. Max-min analysis showed significantly increased likelihood of nonuniform drainage between vortex veins in both CSC/PPE and control eyes. Multivariate linear regression in control eyes showed that on average, the inferotemporal quadrant was significantly brighter than the superonasal quadrant (9.72 units, P < 0.001). Among CSC/PPE eyes, adjusting for the preferential, nonuniform drainage in control eyes, the inferonasal and inferotemporal quadrants in CSC/PPE eyes remained significantly brighter than the reference quadrant by 5.36 units (P = 0.034) and 7.51 units (P = 0.008), respectively.

Conclusions

Asymmetric choroidal venous outflow occurs in both control and CSC/PPE eyes based on UWF ICGA quantitative brightness levels in each quadrant. Increased brightness levels along inferior quadrants in mid-phase ICGA images suggest venous outflow congestion among eyes with CSC or PPE.

Topographic Variations of Choroidal Thickness in Healthy Eyes on Swept-Source Optical Coherence Tomography

Purpose

To assess topographic variations of choroidal thickness (CT) in the fovea and beyond in healthy eyes.

Methods

This cross-sectional study included healthy subjects ≤ 55 years of age with axial lengths (22-26 mm) and refractive error margins (-4D, +4D) in normal ranges. Images were acquired using swept-source optical coherence tomography angiography (OCT-A). Corneal thickness (CT) maps from 12 × 12-mm radial scans and 9 × 9-mm OCT-A B-scans were analyzed.

Results

The study included 64 eyes of 33 subjects (mean age, 37 years). Mean CT was >300 µm in all locations except the nasal outer macula. The subfoveal CT was >395 µm in 30% of cases; in 38.7% of cases, >50% of the CT map was thicker than 395 µm. The mean thickest choroidal point was 395.2 µm (range, 164-548 µm), located superior and temporal to the macula in 72.2% of cases and subfoveally in 1.8% of cases. The CT pattern was symmetrical (58%) or asymmetrical (42%) along a horizontal axis correlating with choroidal vein distribution. Half of the asymmetrical patterns were thicker in the inferior quadrants, with an oblique temporal watershed of venous drainage, and the other half were thicker superiorly. The mean vascularity index was ∼75% regardless of the mean CT.

Conclusions

One-third of healthy eyes of patients younger than age 55 had a thick choroid (>395 µm). In these normal eyes, the thickest choroidal point was not subfoveal, CT symmetry above and below the fovea depended on choroidal vein distribution, and choroidal vascularity index was independent from CT. No patients demonstrated fundus autofluorescence abnormalities, and the choriocapillaris remained visible even in thick choroids. These features could be interesting when differentiating normal versus pathological states.

Pachychoroid disease: a new perspective on exudative maculopathy

BACKGROUND

Pachychoroid, or the structural and functional abnormalities of the choroid, is one of the most important causes of exudative maculopathies. The purpose of this article is to review the current definitions of pachychoroid and their potential consequences. Most publications are from Asian countries. Although no consensus diagnosis has been reached, pachychoroid is defined by thickened choroid and choroidal vascular hyperpermeability, pachyvessels with inner choroidal attenuation; it is closely linked to pachydrusen. Although some studies suggest choroidal congestion may play a role in its pathogenesis, the exact causes of this condition are still unknown. Pachychoroid is associated with exudative maculopathies including central serous chorioretinopathy, pachychoroid neovasculopathy and polypoidal choroidal vasculopathy (PCV). It is widely accepted that macular neovascular membranes may develop secondary to pachychoroid. Recent clinical observations illustrate the importance of pachychoroid in the etiology of macular neovascularization including neovascular age-related macular degeneration (nAMD).

CONCLUSION

Pachychoroid is an important cause of exudative maculopathies. Both drusen and pachychoroid are increasingly recognized as important causes of macular neovascularization, and eyes formally categorized as typical nAMD or PCV can be further sub-categorized based on the presence or absence of pachychoroid and drusen. There is a need to develop a consensus definition, which will greatly enhance our understanding of pachychoroid and facilitate the development of individual interventions in pachychoroid diseases.

Running pattern of choroidal vessel in en face OCT images determined by machine learning-based quantitative method

PURPOSE

To evaluate the new method to quantitate the running pattern of the vessels in Haller's layer in en face optical coherence tomographic (OCT) images using the new algorithm.

METHODS

A retrospective and cross-sectional study. The en face image of top 25% slab of Haller's layer was analyzed. The vascular area in these images was calculated after binarization. Then, the vessels were thinned, and the total length of the vessels and the mean vessel diameter were calculated. Based on the angle of vessel running, "natural oblique vessel" was defined. The ratio of the natural oblique vessel to the whole vessels was defined as the "symmetry index". To examine the reproducibility of the software, the images obtained on two different examination dates of the same subject (25 eyes of 25 healthy subjects) were analyzed. Also, to compare the symmetry index and subjective evaluations, 180 eyes and 180 healthy subjects were analyzed. The subjective evaluations classified the images into 3 groups, the Symmetrical, Semi-symmetrical, and Asymmetrical types. Symmetry index was compared in each group.

RESULTS

The inter-measurement correlation coefficient (ICC) of the vessel area, vessel length, and vessel diameter were 0.955, 0.934, and 0.954, respectively. The ICC of the symmetry index was 0.926. The symmetry index of the Symmetrical type was 60.4 ± 7.2%, that of the Semi-symmetry type was 56.2 ± 4.6%, and that of the Asymmetry type was 52.6 ± 5.2%.

CONCLUSIONS

The present algorithm can analyze vessels in Haller's layer of the en face images of choroid in an objective manner with good repeatability.

Wide-field choroidal thickness in myopes and emmetropes

There is a paucity of knowledge regarding the normal in-vivo thickness of the choroid beyond the macula (~17°). In this study, the choroidal thickness of 27 healthy young adults was examined across the macular (the central 5 mm including the fovea, parafovea, and perifovea) and extra-macular (a 5–14 mm annulus including the near-periphery and periphery) regions using wide-field optical coherence tomography, and compared between emmetropes (n = 14) and myopes (n = 13). The choroid progressively thinned beyond the parafovea (350 ± 86 µm) towards the periphery (264 ± 44 µm), and was thickest superiorly (355 ± 76 µm) and thinnest nasally (290 ± 79 µm). Choroidal thickness also varied with refractive error; myopes exhibited a thinner choroid than emmetropes in the macular region (311 ± 88 vs. 383 ± 66 µm), however, this difference diminished towards the periphery (251 ± 48 vs. 277 ± 37 µm). Meridional variations in choroidal thickness were not different between myopes and emmetropes. In conclusion, the choroid was thickest within the perifovea; thinned substantially towards the periphery, and exhibited the minimum and maximum peripheral thinning superiorly and nasally across a 55° region respectively. Choroidal thinning associated with myopia was more pronounced in the macular than extra-macular regions.

Geographic filling delay of the choriocapillaris in the region of dilated asymmetric vortex veins in central serous chorioretinopathy

PURPOSE

To investigate the correlation between geographic filling delays in the choriocapillaris using indocyanine green angiography (ICGA) images and dilated vortex veins in central serous chorioretinopathy (CSC).

DESIGN

Observational case series.

PARTICIPANTS

Thirty-two eyes of 32 patients, 21 with acute and 11 with chronic CSC.

METHODS

Digital ICGA and fluorescein angiography (FA), with videoangiography, and swept-source optical coherence tomography (SS-OCT) for B-scan and en-face choroidal imaging were performed. Overlapping of the filling delay areas in the choriocapillaris in the early-phase ICGA images and the region of dilated vortex veins in the en-face images were analyzed. The consistency of both areas was graded as follows. Grade 3: filling delay area is entirely involved in the dilated vortex vein region. Grade 2: 50% or more of filling delay area overlaps with the dilated vortex vein region. Grade 1: less than 50% of filling delay area overlaps with the dilated vortex vein region. Grade 0: no tendency for overlapping of two areas. We evaluated the asymmetry of upper and lower vortex veins in en-face images of the Haller layer. Using the binarization method, we quantified the luminal and stromal areas of the choroid. The ratios of the Haller layer area and luminal areas in the Haller layer to total choroidal area were examined.

RESULTS

The consistency of overlapping of the two areas was grade 2.62 ± 0.49 in acute CSC and grade 1.55 ± 0.78 in chronic CSC (p = 0.0005). Asymmetry of upper and lower vortex veins was seen in 17 of 22 eyes (81%) with acute CSC and 6 of 11 eyes (54.5%) with chronic CSC (p = 0.114). Central choroidal thickness was 411 ± 79 μm in acute CSC and 326 ± 64 μm in chronic CSC (p = 0.004). In the posterior fundus with a 4500 μm diameter, the ratio of the Haller layer area to total choroidal area was 63.7 ± 8.6% in acute CSC and 57.1 ± 7.9% in chronic CSC (p = 0.047). The ratio of the luminal area in the Haller layer area to total choroidal area was 46.9 ± 7.6% in acute CSC and 40.0 ± 6.9% in chronic CSC (p = 0.014).

CONCLUSION

Filling delay areas in the choriocapillaris and dilated vortex vein regions showed marked overlapping in acute CSC. Increased choroidal thickness was attributed to dilated vortex veins. These findings suggest that the blood flow into the choriocapillaris is delayed as a result of congestion of the dominant vortex veins that supply this geographic area. CSC may be a disease characterized by vortex vein congestion that develops in eyes with asymmetric vortex veins.

Choroidal Vasculature from Ultra-Widefield Images without Contrast Dye and Its Application to Vogt-Koyanagi-Harada Disease

PURPOSE

To develop a method to obtain ultra-widefield choroidal vessel images with a fundus camera without using dye, and its application in Vogt-Koyanagi-Harada (VKH) disease.

DESIGN

Experimental study and case series.

PARTICIPANTS

Patients with unilateral retinal disorders and those with VKH disease who had undergone ultra-widefield imaging were studied.

METHODS

Indocyanine green angiography (ICGA) and the 635-nm wavelength Optos ultra-widefield fundus photography (Optos, United Kingdom) images (Optos_635-nm) were processed by KagoEye 3 software. The 2 types of images were overlapped. The degree of overlapped blood vessel areas of the ICGA image was taken as the matching ratio. The matching ratio was obtained for the peripheral, posterior pole, and overall areas. In addition, changes in the fundus findings were followed up with Optos_635-nm image analysis in patients with VKH disease. The degree of visibility of the choroidal vessels was evaluated for 5 stages. The clarity scores and the longitudinal findings were compared.

MAIN OUTCOME MEASURES

The matching ratios between the ICGA images and the Optos_635-nm images processed by KagoEye3 software were determined.

RESULTS

Initially, 10 healthy eyes were studied. The matching ratios for the overall area, the peripheral area, and the posterior pole area of the ICGA image and the Optos_635-nm image were 64.09%, 74%, and 63.10%, respectively. The correlations between the choroidal blood vessel matching ratio and the ocular axial length and refractive error were not significant, but the matching ratio was correlated significantly with the age. The average clarity score in 12 VKH disease patients was 1.6 ± 0.85 before treatment, which was significantly improved to 4.2 ± 0.75 after 1 month (P < 0.05). Many hyporeflective spotty lesions were observed on the Optos_635-nm images, which coincided with hyperfluorescent dots on the ICGA images. The lesions gradually disappeared and the vortex vein became visible after treatment.

CONCLUSIONS

The ultra-widefield Optos_635-nm images processed by KagoEye3 software can exaggerate images of the choroidal vessels in widefield fundus images without using dye. Because this method is noninvasive, it is applicable to a variety of diseased and healthy eyes.

Dilatation of Asymmetric Vortex Vein in Central Serous Chorioretinopathy

PURPOSE

To characterize the outer choroidal vessels in normal control eyes and those with central serous chorioretinopathy (CSC).

DESIGN

Prospective case-control study.

PARTICIPANTS

Thirty-eight eyes of 35 patients with acute CSC and 39 age-matched normal subjects.

METHODS

Swept-source optical coherence tomography was performed to obtain B-scan and en face images in the posterior pole in both groups. All patients with CSC underwent fluorescein angiography (FA) and indocyanine green angiography (ICGA).

MAIN OUTCOME MEASURES

Ascertainment of the patterns of the outer choroidal vessels in the en face and B-scan images in normal controls and patients, and the relationship between the en face images and dye leakage in the FA images and hyperpermeability in the ICGA images.

RESULTS

En face and ICGA images showed 2 choroidal drainage routes that served the upper and lower halves of the posterior pole. Twenty-four of the 39 eyes (62%) of the normal subjects had symmetrically distributed outer choroidal vessels; 15 eyes (38%) had asymmetrically distributed outer choroidal vessels. Asymmetry was seen in all 38 eyes (100%) of the 35 patients with CSC. The outer choroidal vessels all had vortex veins on en face and ICGA images. In eyes with CSC, a dominant vortex vein served the macular region (9 eyes) or the posterior pole (24 eyes) or extended beyond the vascular arcades (5 eyes). Dominant vortex veins were relatively dilated in normal controls but dilated markedly in CSC, with the distal ends in the macular region abruptly dilated. The sites of dye leakage on the FA images and hyperpermeability on the ICGA images corresponded to the dilated dominant vortex veins.

CONCLUSION

The presence of an asymmetric vortex vein was a common variation (38%) in normal subjects; this asymmetry was seen in all eyes (100%) with CSC. Dominant vortex veins were dilated markedly in CSC. Congestion of the dominant vortex veins might enhance the permeability of fenestrated choriocapillaris in the macular region. Asymmetric dominant vortex veins appear to be a predisposing factor for CSC.

Update of choroidal imaging techniques: Past, present and future

The choroid is the middle layer of the eye, a very vascular and pigmented tissue, with its role in several ophthalmological pathologies already having been clearly established. But it was not until the last few years that we have been able to reliably and precisely measure and quantify its shape and thickness. Ultrasound technology and indocyanine green angiography were the first techniques used for the study of the choroid, and they still maintain their use and clinical indications for the diagnosis and management of several pathologies. But it was the advent of optical coherence tomography that was the greatest breakthrough in choroidal imaging. In this chapter, the past, current and future image modalities for the study of the choroid will be discussed, with special focus on optical coherence tomography and its latest developments.

Combined 60° Wide-Field Choroidal Thickness Maps and High-Definition En Face Vasculature Visualization Using Swept-Source Megahertz OCT at 1050 nm

PURPOSE

To demonstrate ultrahigh-speed swept-source optical coherence tomography (SS-OCT) at 1.68 million A-scans/s for choroidal imaging in normal and diseased eyes over a ∼60° field of view. To investigate and correlate wide-field three-dimensional (3D) choroidal thickness (ChT) and vascular patterns using ChT maps and coregistered high-definition en face images extracted from a single densely sampled Megahertz-OCT (MHz-OCT) dataset.

METHODS

High-definition, ∼60° wide-field 3D datasets consisting of 2088 × 1024 A-scans were acquired using a 1.68 MHz prototype SS-OCT system at 1050 nm based on a Fourier-domain mode-locked laser. Nine subjects (nine eyes) with various chorioretinal diseases or without ocular pathology are presented. Coregistered ChT maps, choroidal summation maps, and depth-resolved en face images referenced to either the retinal pigment epithelium or the choroidal-scleral interface were generated using manual segmentation.

RESULTS

Wide-field ChT maps showed a large inter- and intraindividual variance in peripheral and central ChT. In only four of the nine eyes, the location with the largest ChT was coincident with the fovea. The anatomy of the large lumen vessels of the outer choroid seems to play a major role in determining the global ChT pattern. Focal ChT changes with large thickness gradients were observed in some eyes.

CONCLUSIONS

Different ChT and vascular patterns could be visualized over ∼60° in patients for the first time using OCT. Due to focal ChT changes, a high density of thickness measurements may be favorable. High-definition depth-resolved en face images are complementary to cross sections and thickness maps and enhance the interpretation of different ChT patterns.

Widespread choroidal thickening and abnormal midperipheral fundus autofluorescence characterize exudative age-related macular degeneration with choroidal vascular hyperpermeability

Purpose

To investigate the clinical findings that characterize exudative age-related macular degeneration (AMD) with choroidal vascular hyperpermeability (CVH).

Design

Retrospective comparative study.

Participants

Forty-eight consecutive patients attending the outpatient clinic of Tokyo University Hospital between May 2013 and July 2013.

Methods

The presence or absence of CVH was determined with indocyanine green angiography performed at the latest visit. When CVH was observed, the eye was categorized as CVH(+) AMD, otherwise it was categorized as CVH(-) AMD. Using high-penetration optical coherence tomography, we measured choroidal thickness at the fovea and at four midperipheral areas (mean choroidal thickness at points on 6- and 9-papilla diameter circles superior, inferior, temporal, and nasal to the fovea). Ultrawide field retinal imaging was used to investigate abnormalities in midperipheral fundus autofluorescence (FAF). Choroidal thickness and the proportion of FAF abnormalities were compared between the CVH(+) AMD and CVH(−) AMD eyes and between eyes with polypoidal choroidal vasculopathy and typical AMD. Multiple regression analysis was used to control for treatment history and other characteristics.

Results

CVH was observed in 17 cases. Choroidal thickness was higher in the CVH(+) AMD eyes than in the CVH(−) AMD eyes at the fovea (325 μm versus 229 μm, respectively; P=0.0010, t-test), superior point (277 μm versus 215 μm, respectively; P=0.0021, t-test), inferior point (225 μm versus 161 μm, respectively; P=0.0002, t-test), and nasal point (202 μm versus 165 μm, respectively; P=0.042, t-test). The significance was maintained after controlling for possible confounders. The choroid was thicker at the fovea and at the inferior point in polypoidal choroidal vasculopathy than in typical AMD. The rate of midperipheral FAF abnormality was significantly higher in the CVH(+) AMD eyes than in the CVH(−) AMD eyes (82% versus 48%, respectively; P=0.031).

Conclusion

AMD with CVH is associated with widespread choroidal thickening and peripheral FAF abnormalities.

DECREASED ARTERIAL DYE-FILLING AND VENOUS DILATION IN THE MACULAR CHOROID ASSOCIATED WITH AGE-RELATED MACULAR DEGENERATION

PURPOSE

To compare the angioarchitecture of choroidal arteries and veins in patients with age-related macular degeneration (AMD) to the angioarchitecture of age-matched normal subjects using indocyanine green (ICG) angiography.

METHODS

ICG angiography was performed in 35 consecutive AMD patients and 18 normal age-matched volunteers with a fundus ICG camera. ICG video images, including the arterial and venous phases, were quantitatively analyzed using image analyzing software.

RESULTS

In patients with AMD, the choroidal arterioles are dilated, fewer, run a straighter course, and possess fewer bifurcations. The number of choroidal arteries and the macular fluorescent intensity in the arterial phase of choroidal filling was significantly less in patients with AMD as compared to age-matched normal controls (P = 0.008). The mean and maximum caliber of choroidal veins in the macula was dilated in AMD eyes than in age-matched normal control eyes (P < 0.001). There was no statistically significant difference in arterial dye filling or venous caliber observed in AMD eyes, with or without choroidal neovascular membrane (CNV).

CONCLUSION

Choroidal arterial perfusion in the macula was significant decreased in eyes with AMD with and without CNV, and was associated with choroidal venous dilation. These observations implicate poor choroidal perfusion of the macula in the pathogenesis of AMD.