RELATIONSHIP BETWEEN CHOROIDAL VASCULAR HYPERPERMEABILITY, CHORIOCAPILLARIS FLOW DENSITY, AND CHOROIDAL THICKNESS IN EYES WITH PACHYCHOROID PIGMENT EPITHELIOPATHY

Clinical Characteristics of Punctate Hyperfluorescence Spots in the Fellow Eye of Patients with Unilateral Macular Neovascularization with No Drusen

Objectives: To assess the clinical characteristics of patients with macular neovascularization (MNV) with no drusen in the fellow eye, we investigated the incidence of MNV in fellow eyes and the outcomes of intravitreal aflibercept (IVA) monotherapy in MNV eyes of patients with unilateral MNV with a punctate hyperfluorescence spot (PHS) in the fellow eye. Methods: We retrospectively studied 58 treatment-naïve patients with unilateral MNV with no drusen in the fellow eye. Patients were classified into a PHS group (n = 29) or no-PHS group (n = 29) based on the presence of PHS. We evaluated the incidence of MNV in the fellow eye, and the retreatment rate after initiation of three monthly aflibercept injections over one year. Results: Fellow eyes in the PHS group had a thicker choroid (p < 0.05) and higher prevalence of pachychoroid pigment epitheliopathy (PPE) (p < 0.001). MNV eyes in the PHS group had a thicker choroid (p = 0.09). The PHS group had a lower retreatment rate (p < 0.05) and required fewer injections (p < 0.05) than the no-PHS group. MNV developed in one eye in both the PHS and no-PHS groups, and both cases occurred in areas of hypofluorescence on indocyanine green angiography within the PPE area before the onset of MNV. Conclusions: The PHS group frequently exhibited pachychoroid disease characteristics and responded better to IVA monotherapy than the no-PHS group. These groups may represent distinct populations of patients with unilateral MNV with no drusen in the fellow eye.

Pachychoroid pigment epitheliopathy in keratoconic eyes

PURPOSE

To report the association between keratoconus (KC) and pachychoroid pigment epitheliopathy (PPE). As secondary outcome, we explored the relation between subfoveal choroidal thickness (SFCT) and topometric indexes.

METHODS

Retrospective, observational, cross-sectional, case-control study. Multicentric study including patients with KC and healthy controls. Each subject underwent a complete ophthalmological visit, Placido-based corneal topography, Scheimpflug corneal tomography and spectral-domain OCT (SD-OCT) with the enhanced depth imaging (EDI) mode on. Linear mixed models (LMM) were employed for comparison between groups, and to examine the impact of different topometric factors on SFCT. KC stages were defined according to Belin grading.

RESULTS

Overall, 56 eyes from 35 KC patients and 52 eyes from 27 healthy, age- and axial length-matched control subjects were included in the study. PPE was found in 10 (17.9%) eyes from 8 KC patients, whereas was absent in all healthy controls. SFCT was statistically significantly higher in keratoconic eyes (median: 390 µm; interquartile range (IQR): 339 - 425 µm) compared to healthy eyes (median: 240 µm; IQR: 200 - 288 µm) (p < 0.001). SFCT did not differ across different KC stages and between keratoconic eyes with and without PPE.

CONCLUSIONS

PPE is a relatively frequent finding in eyes with KC, being present in about 1 out of 6 cases, regardless of disease stage.

KEY MESSAGES

What is known: Keratoconus (KC) is a corneal disorder commonly associated with other chorioretinal abnormalities. It is well known that keratoconic eyes display increased choroidal thickness, and the rare association between KC and central serous chorioretinopathy (CSC) has already been reported in the literature.

WHAT IS NEW

We identified an association between KC and pachychoroid pigment epitheliopathy (PPE), a precursor or forme fruste of pachychoroid diseases, such as CSC. PPE presence is independent from corneal parameters and is observed in about 1 out 6 KC eyes.

CHOROIDAL AND RETINAL ABNORMALITIES IN CUSHING SYNDROME: Correlation with the Cortisol Level

PURPOSE

To investigate the structure and blood flow of the retina and choroid in Cushing syndrome and their relationship with cortisol levels.

METHODS

A consecutive series of patients with Cushing syndrome with adrenocortical carcinoma were included in this study. Cortisol levels gradually returned to normal after adrenalectomy. Optical coherence tomography and optical coherence tomography angiography were used to assess patients with Cushing syndrome before and after the surgery for retina and choroid. Correlation analysis was performed between cortisol level and fundus changes.

RESULTS

Compared with normal cortisol levels, patients with Cushing syndrome had significantly lower central macular thickness with increased cortisol level (220.82 ± 16.59 µ m and 223.68 ± 15.78 µ m, P = 0.019). However, the central choroidal thickness was higher with increased cortisol level (255.18 ± 105.89 µ m and 205.94 ± 87.04 µ m, P < 0.001). The choriocapillaris flow area was higher with increased cortisol level (2.05 ± 0.14 mm 2 and 2.00 ± 0.13 mm 2 , P = 0.02). The change of choriocapillaris flow area was correlated with the score of Huaxi Emotional-distress Index and 24-hour urine-free cortisol (24h-UFC).

CONCLUSION

The increased cortisol level was correlated with lesser central macular thickness and thicker central choroidal thickness. The decrease of choriocapillaris flow area was correlated with 24h-UFC, indicating the effect of increased cortisol level on choroidal vessels.

Pushing Retinal Imaging Forward: Innovations and Their Clinical Meaning - The 2022 Ophthalmologica Lecture

Retinal imaging has greatly expanded our understanding of various pathological conditions. This article presents a summary of the key points covered during the 2022 Ophthalmologica Lecture held at the Euretina Congress in Hamburg. The first part of the article focuses on the use of optical coherence tomography angiography to examine and comprehend the choroid in age-related macular degeneration (AMD). Subsequently, we delve into the discussion of the "postreceptor neuronal loss" theory in AMD, which was studied using en face structural optical coherence tomography (OCT). Following that, we explore pertinent findings obtained through cross-sectional OCT in retinal and optic nerve diseases, such as AMD, diabetic macular edema, pathologic myopia, central serous chorioretinopathy, and Leber's hereditary optic neuropathy.

Vortex vein engorgement and different shapes of venous drainage systems in polypoid choroidal vasculopathy vs. age‑related macular degeneration on indocyanine green angiography

There are differences in vortex vein engorgement and appearance in polypoid choroidal vasculopathy (PCV), age-related macular degeneration (AMD), and healthy eyes. The present study aimed to use indocyanine green angiography (ICGA) to find a simple, clinically meaningful method for evaluating the filling degree of vortex veins in various eye diseases. Participant clinical characteristics were recorded. The number of vortex veins (NVV), central vortex vein diameter (CVVD), mean root area of the vortex vein (MRAVV), mean diameter of the thickest peripheral branch (MDPTB), subfoveal choroidal thickness and percentage of vortex vein anastomosis (PVVA) were obtained by marking the vortex veins on ICGA. The proportion of subretinal haemorrhage and the numbers and types of vortex veins in each quadrant were counted separately. The CVVD and MDPTB were significantly increased in the PCV compared with those in the AMD group (P<0.05). The CVVD, MRAV, and PVVA were significantly increased in the PCV compared with those in the healthy group (P<0.05). The type IV vortex vein (complete with ampulla) proportion was the lowest while the type I (vortex vein absent) proportion was the highest in the PCV group (P<0.001). NVV in the inferior-temporal region was increased in the PCV compared with that in the AMD group (P=0.034). Subretinal haemorrhage occurred in the inferior temporal choroid in 47.62% of examined eyes in PCV group, and in the superior temporal choroid in 23.81% of the PCV group, with significant differences between the quadrants (P<0.001). Vortex vein engorgement and shape differed significantly between PCV, AMD and healthy eyes. The vortex vein branches in PCV eyes were significantly dilated in the posterior pole; moreover, the peripheral choroid and the lower proportion of type IV vortex veins may be pathognomonic for PCV.

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.

Hyper- and hypo-perfusion of choriocapillaris in the eyes with pachychoroid pigment epitheliopathy

PURPOSE

To evaluate the changes in choriocapillaris vessel density (VD) in eyes with pachychoroid pigment epitheliopathy (PPE) using swept-source optical coherence tomography (OCT) angiography (OCTA).

METHODS

This study included 83 eyes with PPE and 42 control eyes. We collected OCT and OCTA parameters, including central point thickness, subfoveal choroidal thickness (SFChT), and choriocapillaris VD of the fovea (CC fovea) and parafovea. The parafoveal area was divided into superior, nasal, inferior, and temporal choriocapillaris areas. Maximum (CC max) and minimum (CC min) choriocapillaris VD were defined as the highest and lowest values among the four parafoveal subfield VDs, respectively. We analyzed the average choriocapillaris VD, CC max, CC min, CC fovea, and the difference between CC max and CC min (CC delta) individually and compared all the parameters between PPE and control eyes.

RESULTS

CC max (56.0% ± 1.7%) was significantly higher and CC min (50.9% ± 2.0%) significantly lower in eyes with PPE than in control eyes (CC max, 55.3% ± 1.0%, P = 0.006; CC min, 51.5% ± 1.3%, P = 0.046). The CC delta value (5.0% ± 2.1%) and SFChT (389.9 ± 129.9 μm) were also significantly higher in eyes with PPE than in the control group (3.7% ± 1.5%, P < 0.001; 268.2 ± 102.2 μm, P < 0.001; respectively).

CONCLUSIONS

Choriocapillaris VD showed higher variability (hyperperfusion and hypoperfusion) in eyes with PPE than in control eyes. Choriocapillaris hypoperfusion may precede the development of PPE; however, choriocapillaris hyperperfusion is associated with projection artifacts.

Choroidal Vasculature Changes in Age-Related Macular Degeneration: From a Molecular to a Clinical Perspective

The contribution of choroidal vasculature to the pathogenesis of age-related macular degeneration (AMD) has been long debated. The present narrative review aims to discuss the primary molecular and choroidal structural changes occurring with aging and AMD with a brief overview of the principal multimodal imaging modalities and techniques that enable the optimal in vivo visualization of choroidal modifications. The molecular aspects that target the choroid in AMD mainly involve human leukocyte antigen (HLA) expression, complement dysregulation, leukocyte interaction at Bruch’s membrane, and mast cell infiltration of the choroid. A mechanistic link between high-risk genetic loci for AMD and mast cell recruitment has also been recently demonstrated. Recent advances in multimodal imaging allow more detailed visualization of choroidal structure, identifying alterations that may expand our comprehension of aging and AMD development.

Choriocapillaris flow deficit in a pachychoroid spectrum disease using en face optical coherence tomography angiography averaging

Purpose

To investigate the choriocapillaris changes associated with pachychoroid pigment epitheliopathy (PPE) in comparison with healthy eyes.

Methods

Nine 3 × 3 mm macular optical coherence tomography angiography images were acquired in patients with PPE and age-matched healthy participants. Multiple en face image averaging of the choriocapillaris was binarized for quantitative image analysis of the flow voids. In PPE eyes, we evaluated the presence of pachyvessels and the association between the location of the choriocapillaris flow deficit and pachyvessels.

Results

Thirty-two eyes with PPE and 30 eyes of healthy participants were included. In PPE eyes, the mean total area (1.16 ± 0.18 vs. 0.91 ± 0.16, p < 0.001) and average size of the flow voids (790 ± 144 vs. 520 ± 138; p < 0.001) were significantly larger than those in control eyes. Composite images of the choriocapillaris and choroid showed choriocapillaris flow deficits just above and outside the pachyvessels. The mean proportion of the flow void area overlying the pachyvessels against the whole flow void area of the choriocapillaris was 21.3% ± 10.2% (9.38%-44.42%) in PPE eyes.

Conclusions

In PPE eyes, the blood flow area of the choriocapillaris decreased diffusely within the macular area compared to control eyes, and the choriocapillaris flow deficit was not necessarily related to pachyvessel location.

Volumetric quantification of choroid and Haller's sublayer using OCT scans: An accurate and unified approach based on stratified smoothing

BACKGROUND AND OBJECTIVE

The choroid, a dense vascular structure in the posterior segment of the eye, maintains the health of the retina by supplying oxygen and nutrients, and assumes clinical significance in screening ocular diseases including age-related macular degeneration (AMD) and central serous chorioretinopathy (CSCR). As a technological assist, algorithmic estimation of choroidal biomarkers has been suggested based on sectional (B-scan) optical coherence tomography (OCT) images. However, most such 2D estimation techniques are compute-intensive, yet enjoy limited accuracy and have only been validated on OCT image datasets of healthy eyes. Not surprisingly, fine-scale analyses, including those involving Haller's sublayer, remain relatively rare and unsophisticated. Against this backdrop, we propose an efficient algorithm to quantify desired biomarkers with improved accuracy based on volume OCT scans. Specifically, we attempted an accurate, computationally light volumetric segmentation method involving stratified smoothing to detect choroid and Haller's sublayer.

METHODS

For detecting the various boundaries of the choroid and the Haller's sublayer, we propose a common volumetric method that performs suitable exponential enhancement and maintains smooth spatial continuity across 2D B-scans. Further, we achieve suitable volumetric smoothing by primarily deploying light-duty linear regression, and sparingly using compute-intensive tensor voting, and hence significantly reduce overall complexity. The proposed methodology is tested on five health and five diseased OCT volumes considering various metrics including volumetric Dice coefficient and corresponding quotient measures to facilitate comparison vis-à-vis intra-observer repeatability.

RESULTS

On five healthy and five diseased OCT volumes, respectively, the proposed method for choroid segmentation recorded volumetric Dice coefficients of 93.53 % and 93.30 %, which closely approximate the respective reference observer repeatability values of 95.60 % and 95.49 %. In terms of related quotient measures, our method achieved more than 50 % improvement over a recently reported method. In detecting Haller's sublayer as well, our algorithm records statistical performance closely matching that of reference manual method.

CONCLUSION

Advancing the state-of-the-art, the proposed volumetric segmentation, tested on both healthy and diseased datasets, demonstrated close match with the manual reference. Our method assumes significance in accurate screening of chorioretinal diseases including AMD, CSCR and pachychoroid. Further, it enables generating accurate training data for developing deep learning models for improved detection of choroid and Haller's sublayer.

Case series: pachychoroid pigment epitheliopathy transformed to polypoidal choroidal vasculopathy after long-term follow-up

Background

Pachychoroid pigment epitheliopathy (PPE), a retinal disorder that falls into the pachychoroid spectrum, is characterized by retinal pigment epithelium changes in pachychoroid eyes without existing or previous subretinal fluid or soft drusen. Previous reports have indicated that PPE may share some pathophysiologic component with other pachychoroid spectrum diseases and could transform into central serous chorioretinopathy (CSC) during follow-up. CSC transformation to PNV and PCV has also been reported, but PPE transformation to PCV has not been reported. 

Case presentation

Seven eyes of seven patients (four male three female, aged 62.7 ± 8.4 years) who presented with PPE at baseline transformed to PCV during follow-up. All study eyes had baseline contralateral eye diagnoses of PCV. All PPE eyes reported no symptoms at baseline and were followed up regularly for the treatment of their contralateral eyes. All PPE presented as pigment epithelium detachment (PED) at baseline. The mean central macular thickness (CMT) was 217.6 ± 14.6 µm, the mean subfoveal choroidal thickness (SFCT) was 354.9 ± 94.9 µm, and the mean sub-PPE choroidal thickness was 332.3 ± 84.6 µm. The mean PPE width and height were 1326.4 ± 791.4 µm and 58.7 ± 23.6 µm, respectively, at baseline. Disruption of the ellipsoid zone (EZ) was noted in 3 eyes, while choroidal vascular hyperpermeability (CVH) was noted in 5 eyes at baseline. The follow-up period was 75.0 ± 41.1 months, and the mean transformation time was 49.6 ± 24.8 months. All study eyes received no intervention before transformation.

Conclusions

PPE could transform to PCV after a long follow-up period. Regular follow-ups for a long time should be recommended for patients with PPE.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02487-8.

Examination of Macular Retina and Choroidal Thickness in High Myopic Amblyopia Using Spectral-Domain Optical Coherence Tomography

Purpose

The aim of this study was to investigate changes in the retinal and choroidal thickness between high myopic amblyopia (HMA), low myopia (LM), moderate myopia (MM), high myopia (HM), and normal group (NG) using a spectral-domain optical coherence tomography (SD-OCT).

Materials and Methods

A total of 75 Chinese children (128 eyes; mean age 10.5 years) were recruited. Retinal thickness (RT) and choroidal thickness (CT) were measured at different locations including subfoveal (SF), and at 0.5 mm/1.0 mm/1.5 mm/2.0 mm/2.5 mm/3.0 mm to the fovea in superior, nasal, inferior, and temporal sectors using enhanced depth imaging (EDI) system of SD-OCT. Axial length (AL), best-corrected visual acuity (BCVA), and refraction errors were also collected.

Results

No significant differences were found in subfoveal retinal thickness (SFRT). Moreover, a significantly thinner subfoveal choroidal thickness (SFCT) was found in HMA compared to NG, LM, and MM, but not compared to HM. RT at 0.5 mm to fovea, HMA was significantly thinner compared to LM and MM in the three sectors (superior, inferior, and temporal). Nevertheless, no significant differences were found compared to NG and HM. CT at 0.5 mm to fovea, HMA was the significantly thinnest in all four sectors compared to NG, LM, and MM. RT at 1.0 mm/1.5 mm/2.0 mm/2.5 mm/3.0 mm to fovea, HMA was thinner compared to NG, LM, and MM. CT at 1.0 mm/1.5 mm/2.0 mm/2.5 mm/3.0 mm to fovea, HMA was thinner compared to NG, LM, and MM. At the superior and inferior sectors, HMA showed to be statistically thinner compared with HM. Moreover, SFCT in the HMA, HM, and NG were negatively correlated with AL.

Conclusions

Thinner retina and choroidal tissue appear to be related to HMA, and thus can be used as useful parameters for discovering the underlying mechanisms of the disease.

Optical Coherence Tomography Angiography Predicts Visual Outcomes for Craniopharyngioma in Children by Quantifying Choroidal Capillaries

Purpose: To predict the prognosis of craniopharyngioma in children by optical coherence tomography angiography (OCTA).

Methods: We evaluated if the relationship between preoperative OCTA of the choroidal capillary density (CCD) and visual outcome continued over long-term visual recovery in 38 patients undergoing craniopharyngioma resection. Patients were evaluated 3 times: 1 week before surgery (Visit1), followed-up at 6–10 weeks (Visit2), and 9–15 months (Visit3) after surgery.

Results: In total 38 patients (70 eyes) with craniopharyngiomas, which included 20 (52.6%) boys and 18 (47.4%)girls, the mean age was 11.8 ± 2.7 years (range: 6–18 years). The age (p = 0.71), gender (p = 1.00), mean refractive error (p = 0.55), and axial length (p = 0.23) of 38 normal volunteers (76 eyes) were matched. After surgery, the cross-compression of patients was relieved. The average visual acuity change in the normal CCD group was 0.07 ± 0.02; the average visual acuity change in the low CCD group was 0.01 ± 0.01, p < 0.001. Preoperative CCD value is related to the preoperative BCVA (p < 0.001), and the visual function after the long-term follow-up (9–15 months) (p < 0.001). The prognosis of CCD has the same trend as the BCVA. Further correlation analysis shows that CCD and BCVA are significantly correlated (r = 0.878; p < 0.001). CCD has a weak but significant correlation both with MD (r = 0.19; p < 0.001) and PSD (r = −0.21; p <0.001). A natural cutoff of CCD is approximately 38%. With the normal CCD group the maximum improvement of BCVA exceeds 0.3 post-operatively, compared to eyes in the low CCD group that improve by <0.03, and worse after surgery.

Conclusions: Long-term vision recovery after surgical decompression of craniopharyngiomas in children can be predicted by preoperative by OCTA. Patients with normal CCD before surgery showed a tendency to improve vision; this trend of improvement persisted in subsequent follow-ups. The CCD baseline natural cutoff value for predicting visual prognosis before and after surgery is about 38%.

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.

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.

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.

Exploring the choroidal vascular labyrinth and its molecular and structural roles in health and disease

The choroid is a key player in maintaining ocular homeostasis and plays a role in a variety of chorioretinal diseases, many of which are poorly understood. Recent advances in the field of single-cell RNA sequencing have yielded valuable insights into the properties of choroidal endothelial cells (CECs). Here, we review the role of the choroid in various physiological and pathophysiological mechanisms, focusing on the role of CECs. We also discuss new insights regarding the phenotypic properties of CECs, CEC subpopulations, and the value of measuring transcriptomics in primary CEC cultures derived from post-mortem eyes. In addition, we discuss key phenotypic, structural, and functional differences that distinguish CECs from other endothelial cells such as retinal vascular endothelial cells. Understanding the specific clinical and molecular properties of the choroid will shed new light on the pathogenesis of the broad clinical range of chorioretinal diseases such as age-related macular degeneration, central serous chorioretinopathy and other diseases within the pachychoroid spectrum, uveitis, and diabetic choroidopathy. Although our knowledge is still relatively limited with respect to the clinical features and molecular pathways that underlie these chorioretinal diseases, we summarise new approaches and discuss future directions for gaining new insights into these sight-threatening diseases and highlight new therapeutic strategies such as pluripotent stem cell‒based technologies and gene therapy.

CHOROIDAL INFLAMMATION AND CHORIOCAPILLARIS ISCHEMIA IN FOCAL CHOROIDAL EXCAVATION IN COMPARISON TO PACHYCHOROID NEOVASCULOPATHY

PURPOSE

To investigate the choriocapillaris and choroidal characteristics of focal choroidal excavation (FCE) to establish pathomechanisms of the disease.

METHODS

Thirty eyes with FCE, 26 eyes with pachychoroid neovasculopathy (PNV), and 25 participants without any conditions (control group) were analyzed retrospectively. The thickness of both choriocapillaris equivalent and whole choroid was measured at three different points: under the lesion (excavation or neovascularization), in the normal retina, and in the fovea of fellow eye. Indocyanine green angiographic images were collected to confirm choriocapillaris ischemia and the presence of choroidal inflammation.

RESULTS

In both FCE and PNV, choriocapillaris-equivalent attenuation was observed under the lesion compared with other region of the retina (28.1 ± 11.3 μm vs. 69.4 ± 20.0 μm in FCE; 23.5 ± 9.7 μm vs. 62.3 ± 14.7 μm in PNV; both P < 0.001). We also observed focal thinning of the whole choroid under the lesion (149.7 ± 88.7 μm vs. 296.6 ± 83.2 μm; P < 0.001) in FCE but not in PNV. Pachyvessels distribution on optical coherence tomography and numerous dark areas on indocyanine green angiography implied that choroidal inflammation was related to the FCE occurrence.

CONCLUSION

Choriocapillaris ischemia was related to both FCE and PNV. The choroidal thinning under the excavation and adjacent pachyvessels observed in FCE suggested that focal inflammation and scarring may contribute to choriocapillaris ischemia and eventual retinal pigment epithelium retraction with dysfunction in the pathomechanism.

Clustering of eyes with age-related macular degeneration or pachychoroid spectrum diseases based on choroidal thickness profile

Choroidal changes have been suggested to be involved in the pathophysiology of both age-related macular degeneration (AMD) and pachychoroid spectrum diseases (PSD). To find out the choroidal characteristics of each disease groups, various groups of AMD and PSD were classified into several clusters according to choroidal profiles based on subfoveal choroidal thickness (CT), peripapillary CT, the ratio of subfoveal CT to peripapillary CT and age. We retrospectively analyzed 661 eyes, including 190 normal controls and 471 with AMD or PSDs. In the AMD groups, eyes with soft drusen or reticular pseudodrusen were belonged to the same cluster as those with classic exudative AMD (all p < 0.001). However, eyes with pachydrusen were not clustered with eyes from other AMD groups; instead, they were classified in the same cluster as eyes from the PSD group (all p < 0.001). In the PSD group, eyes with pachychoroid neovasculopathy were grouped in the same cluster of those with polypoidal choroidal vasculopathy (p < 0.001). The cluster analysis based on the CT profiles, including subfoveal CT, peripapillary CT, and their ratio, revealed a clustering pattern of eyes with AMD and PSDs. These findings support the suggestion that pachydrusen has the common pathogenesis as PSD.

OCT Risk Factors for 3-Year Development of Macular Complications in Eyes With "Resolved" Chronic Central Serous Chorioretinopathy

PURPOSE

To assess the relationship between demographics, clinical characteristics, and structural optical coherence tomography (OCT) findings and the development of sight-threatening macular complications (choroidal neovascularization [CNV], large areas of retinal pigment epithelium [RPE] atrophy, and cystoid macular degeneration [CMD]) in a cohort of eyes with "resolved" chronic central serous chorioretinopathy (CSC) at study baseline.

DESIGN

Retrospective cohort study.

METHODS

In this study, a total of 71 eyes with "resolved" (absence of subretinal fluid) chronic CSC at baseline and 36 months of regular follow-up examinations were retrospectively enrolled. Structural OCT scans were reviewed. Baseline OCT qualitative features reflecting distress of the neuroretina, RPE, or choroid were assessed and included ellipsoid zone discontinuity, outer nuclear layer (ONL) thinning; presence of hyper-reflective intraretinal foci; dome-shaped pigment epithelium detachment (PED); hyper-reflective flat, irregular PED; hyporeflective flat, irregular PED; and inner choroidal attenuation. OCT images obtained at follow-up visits were also reviewed for development of macular complications (CNV, large areas of RPE atrophy [at least 250 μm in diameter], and CMD). Main outcome measurements included incidence of macular complications and hazard ratio (HR) for demographics, clinical characteristics, and OCT risk factors.

RESULTS

At month 36, 20 eyes (28.2%) developed macular complications. Nine eyes (12.7%) displayed CNV, 9 eyes (12.7%) had large areas of RPE atrophy, and 2 eyes (2.8%) developed cystoid macular degeneration. The following factors were associated with an increased risk of development of CNV: intraretinal hyper-reflective foci had an HR of 11.58 (95% confidence interval [CI]: 1.10-37.24; P = .040); inner choroidal attenuation had an HR of 9.66 (95% CI: 1.07-22.34; P = .043); and the presence of macular complications in the fellow eye had an HR of 20.17 (95% CI: 1.34-39.41; P = .030). Factors associated with the development of RPE atrophy were also identified: ONL thinning had an HR of 13.47 (95% CI: 1.10-39.86; P = .042); dome-shaped PED had an HR of 21.40 (95% CI: 1.50-41.10; P = .031); and inner choroidal attenuation had an HR of 13.20 (95% CI: 1.07-39.32; P = .044).

CONCLUSIONS

OCT risk factors were identified for the development of macular complications in eyes with chronic CSC. Findings may help in the identification of high-risk patients.

Rate of misdiagnosis and clinical usefulness of the correct diagnosis in exudative neovascular maculopathy secondary to AMD versus pachychoroid disease

The aim of this study was to explore the relative prevalence and clinical differences between age-related macular degeneration (AMD) and pachychoroid disease in patients older than 50 years with newly diagnosed exudative neovascular maculopathy, and also assess the rate of misdiagnosis between these two disorders. In this retrospective observational study, we reviewed data from patients 50 years of age and older with newly diagnosed treatment-naïve exudative macular neovascularization (MNV) secondary to AMD or pachychoroid disease. Of the 139 patients (139 eyes) who fulfilled the inclusion criteria, 35 patients were graded as being affected by pachychoroid disease complicated by exudative MNV and 104 subjects had neovascular AMD. Therefore, prevalence of pachychoroid disease complicated by exudative MNV was 25.2% (confidence interval—CI 18.2–33.2%). Mean ± SD age was 67.0 ± 8.8 years in the pachychoroid disease group and 80.6 ± 6.6 years in the neovascular AMD group (P < 0.0001). At baseline, BCVA was better in patients with pachychoroid disease complicated by exudative MNV (0.4 ± 0.3 LogMAR vs. 0.7 ± 0.5 LogMAR, P = 0.003). At the 1-year follow-up visit, BCVA was still better in patients with pachychoroid-associated MNV (0.34 ± 0.32 LogMAR vs. 0.59 ± 0.52 LogMAR; P = 0.005). In our study cohort, 19 patients were graded to be affected by pachychoroid disease complicated by exudative MNV even though a diagnosis of neovascular AMD was erroneously reported in their medical records at baseline. In conclusion, pachychoroid disease is a frequent cause of exudative MNV in aged patients with a high rate of misdiagnosis. A correct diagnosis may be important as these two disorders differ in terms of clinical characteristics and prognosis.

Quantitative measures of vortex veins in the posterior pole in eyes with pachychoroid spectrum diseases

Pachychoroid spectrum diseases have attracted increasing attention, though their pathophysiology has yet to be fully elucidated. In this study, we assessed the vascular diameters of vortex veins in pachychoroid spectrum diseases such as central serous chorioretinopathy (CSC), pachychoroid neovasculopathy without polypoidal lesions (PNV), and pachychoroid neovasculopathy with polypoidal lesions (polypoidal choroidal vasculopathy: PCV). In a retrospective case series of 94 eyes with CSC, 60 eyes with PNV and 57 with PCV, we binarized en face optical coherence tomography (OCT) images of choroidal vortex veins and analyzed the mean diameter of vortex veins. The presence of anastomosis between the superior and inferior vortex veins and central choroidal thickness (CCT) were also evaluated using OCT images. CSC showed significantly larger mean diameter of vortex veins than PCV (P < 0.05). Anastomosis between superior and inferior vortex veins was observed in over 90% of eyes with each pachychoroid spectrum disease. The patients with CSC were the youngest, followed by PNV patients, and then patients with PCV. The largest CCT values were observed in CSC eyes, followed by PNV eyes, and then PCV eyes. CCT correlated with the mean diameter of vortex veins (rs = 0.51, P < 0.01). These findings suggest that congestion of vortex veins might show gradual amelioration corresponding to the development of anastomosis between the superior and inferior vortex veins during the course of progression of pachychoroid spectrum diseases. Moreover, the mean diameter of vortex veins can be used as a parameter indicating choroidal congestion.

Outcome of half-dose photodynamic therapy in chronic central serous chorioretinopathy with fovea-involving atrophy

PURPOSE

To evaluate the clinical outcomes after half-dose photodynamic therapy (PDT) in chronic central serous chorioretinopathy (cCSC) patients with pre-existent fovea-involving atrophy.

METHODS

In this retrospective study, cCSC patients who had a window defect of the retinal pigment epithelium (RPE) on fluorescein angiography (FA), compatible with RPE atrophy, prior to half-dose PDT were included.

RESULTS

Thirty-four cCSC eyes with typical findings of cCSC on multimodal imaging, and fovea-involving RPE atrophy on FA, were included. At the first visit after PDT (at a median of 1.8 months after half-dose PDT), 20 eyes (59%) had a complete resolution of SRF (p < 0.001), while this was the case in 19 eyes (56%) at final visit (median of 11.3 months after half-dose PDT; p < 0.001). The mean BCVA in Early Treatment of Diabetic Retinopathy Study letters was 71. 2 ± 15.9 at last visit before PDT, which increased to 74.1 ± 14.1 at first visit after PDT (p = 0.093, compared with baseline), and changed to 73.0 ± 19.1 at final visit (p = 0.392, compared with baseline). Both at first visit after PDT and at final visit, a significant decrease in subfoveal choroidal thickness was observed (p = 0.032 and p = 0.004, respectively).

CONCLUSIONS

Half-dose PDT in cCSC patients with pre-existing fovea-involving atrophy may lead to anatomical changes, but not to functional improvements. Ideally, cCSC should be treated with half-dose PDT before the occurrence of such atrophy.

Evaluation of the different thresholding strategies for quantifying choriocapillaris using optical coherence tomography angiography

BACKGROUND

In this paper, we evaluate the different thresholding strategies that have been used for the quantification of the choriocapillaris (CC) and explore their repeatability and the interchangeability of the measurements resulting from its application.

METHODS

Observational study. Eighteen eyes from nine healthy volunteers aged >18 years were imaged four consecutive times with a SD-OCTA system (Heidelberg Engineering, Germany) using a 10°×10° high-resolution protocol centered on the fovea. Projection artifacts were removed, and the CC was bracketed between 10 and 30 µm below Bruch's membrane. For the quantification of CC, we used four flow deficits (FD) parameters: FD number, mean FD size, total FD area and FD density. We performed a systematic review of literature to collect the thresholding methods that have been used for the quantification of CC. The CC quantification parameters were then evaluated after applying each of the thresholding strategies. Intraclass correlation coefficient (ICC) and Pearson's correlation analysis were used to compare the repeatability and interchangeability among the different thresholding strategies for quantifying the CC.

RESULTS

A total of 72 optical coherence tomography angiography (OCTA) examinations were considered. The systematic review allowed us to conclude that three local thresholding strategies (Phansalkar, mean and Niblack) and three global thresholding strategies (mean, default, Otsu) have been used for CC quantification. These strategies were evaluated in our observational study. We found a high agreement within the same method in the quantification of FD number, mean FD size, total FD area and FD density but a poor agreement with different strategies. Local strategies achieved a significantly superior ICC than global ones in CC quantification.

CONCLUSIONS

In conclusion, the interchangeability of the CC quantification using different thresholding strategies is low, and direct comparisons should not be performed. Local thresholding strategies are significantly superior to global ones for quantifying CC and should be preferred. There is an unmet need for a uniform strategy to quantify CC in future studies.

Current diagnosis and management strategies in pachychoroid spectrum of diseases (Review)

This review presents a systematic analysis of the literature regarding the pachychoroid disease spectrum nomenclature, diagnosis criteria and therapeutic options. Pachychoroid related diseases are a new concept, introduced into the ophthalmological nomenclature in 2013 and evolving both as concept and as classification since then. The six disorders included in this phenotype have some common characteristics (thick choroid, pachyvessels, attenuation of the choriocapillaris), but also show individual features. The classification of the pachychoroid spectrum was revised many times, with the recent addition of the focal choroidal excavation (FCE) and peripapillary pachychoroid syndrome (PPS). As the terminology is developing, so is the number of case reports and case series from the initial report in 2013 to 57 reports in 2019. This review takes into account both the current literature and the clinical experience of the authors, emphasizing the understanding of the pathogenesis and aiming to update the therapeutic options available.

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.