Relationship between clinical characteristics of polypoidal choroidal vasculopathy and choroidal vascular hyperpermeability

Pachychoroid disease: review and update

The pachychoroid disease spectrum is a phenotype characterized by alterations in choroidal vasculature which result in outer retinal and choriocapillaris damage and visual loss. The presence of pachyvessels is one of the key features of the pachychoroid phenotype. Recent imaging studies suggest that pachyvessels may form because of choroidal venous congestion in one or more quadrants. The formation of intervortex anastomosis may function as a compensatory mechanism to dissipate the increased venous pressure, while outflow obstruction has been hypothesized to occur at the site of the vortex vein exiting the sclera. This review aims to summarize recent imaging findings and discuss evolution in the understanding of pathogenesis of the pachychoroid disease spectrum. We have summarized notable treatment trials in central serous chorioretinopathy and polypoidal choroidal vasculopathy and included an update of the current diagnostic and management strategies of the entities that are part of the pachychoroid disease spectrum.

BULBOSITIES AND INTERVORTEX VENOUS ANASTOMOSIS IN VENOUS OVERLOAD CHOROIDOPATHY MASQUERADING AS POLYPOIDAL CHOROIDAL VASCULOPATHY

PURPOSE

To describe a patient with venous overload choroidopathy in whom venous bulbosities masqueraded as polyps and intervortex venous anastomosis mimicked a branching vascular network, giving the appearance of polypoidal choroidal vasculopathy.

METHODS

The patient had complete ophthalmic examination including indocyanine green angiography and optical coherence tomography. Venous bulbosities were defined on indocyanine green angiography as focal dilations in which the diameter of the dilation is two times that of the host vessel.

RESULTS

A 75-year-old woman presented with combined subretinal and subretinal pigment epithelium hemorrhages in the right eye. During indocyanine green angiography, focal nodular hyperfluorescent lesions connected to a network of vessels were observed, which looked like polyps and branching vascular network in polypoidal choroidal vasculopathy. In both eyes, the midphase angiogram had multifocal choroidal vascular hyperpermeability. There was late-phase placoid staining nasal to the nerve in the right eye. During enhanced depth imaging-optical coherence tomography evaluation, there were no retinal pigment epithelium elevations that would be expected with polyps or branching vascular network in the right eye. A double-layer sign was seen corresponding to the placoid area of staining. Diagnosis of venous overload choroidopathy and choroidal neovascularization membrane was made. She was treated with intravitreal antivascular endothelial growth factor injections for the choroidal neovascularization membrane.

CONCLUSION

Indocyanine green angiography findings in venous overload choroidopathy may mimic polypoidal choroidal vasculopathy, but differentiation is essential because it has implications for treatment. Similar findings may have been misinterpreted in the past and may have previously contributed to conflicting clinical and histopathologic descriptions of polypoidal choroidal vasculopathy.

Intravitreal anti-vascular endothelial growth factor and combined photodynamic therapy for pachychoroid neovasculopathy: long-term treatment outcomes

PURPOSE

To examine the long-term visual outcomes after initial treatment with combined photodynamic therapy (PDT) or aflibercept treat-and-extend (TAE) monotherapy in patients with pachychoroid neovasculopathy (PNV).

METHODS

Patients diagnosed with PNV, initially treated with PDT combined with anti-vascular endothelial growth factor (VEGF) or intravitreal aflibercept (IVA) monotherapy in the TAE protocol and followed up for at least 6 months, were included in the study. Medical records were retrospectively reviewed. Survival analysis was performed, in which deterioration in logMAR visual acuity by 0.1 or 0.3 is defined as "death." The annual number of treatments was also analyzed. Sub-analysis was performed on 33 patients diagnosed with PNV without polypoidal lesions.

RESULTS

This study included 46 patients (23 in the initial combined PDT group and 23 in the IVA TAE group). Mean age, sex, mean baseline logMAR visual acuity, or duration of observation (3.6 ± 3.2 years vs. 3.1 ± 1.9 years) in both groups were comparable. As for visual outcome, no significant differences were found in survival analysis based on worsening of 0.1 or 0.3 logMAR (3-year survival; 26% vs. 26%, 91% vs. 90%, respectively). Meanwhile, the additional number of anti-VEGF injections per year was significantly lower in the initial combined PDT group than in the IVA TAE group (1.0 ± 1.3 vs. 4.1 ± 1.5, p < 0.0001). No significant differences were found in the number of additional PDTs per year (0.07 ± 0.20 vs. 0.02 ± 0.09, p = 0.27). Similar results were found in a sub-analysis of 33 patients without polyps.

CONCLUSION

In the treatment of PNV, regardless of the presence of polyps, the long-term visual outcomes were similar between the initial combined PDT and IVA TAE monotherapy. However, the annual number of anti-VEGF injections was lower in the initial combined PDT group than in the aflibercept TAE group, whereas that of PDT was comparable.

Evaluating photodynamic therapy versus brolucizumab as a second-line treatment for polypoidal choroidal vasculopathy

BACKGROUND

To compare the one-year outcomes between intravitreal brolucizumab (IVBr) monotherapy and photodynamic therapy (PDT) as a second-line treatment in patients with polypoidal choroidal vasculopathy (PCV) who did not respond to first-line therapy.

METHODS

This case-control study included eyes with PCV that do not respond to aflibercept or ranibizumab. The patients were retrospectively registered. We compared outcomes, including best-corrected visual acuity (BCVA), anatomical results, and the need for additional treatments, between IVBr and a combination therapy using PDT as second-line treatments for refractory PCV, after adjusting for potential confounders. We analyzed E-values to evaluate the robustness of the results against unmeasured confounders.

RESULTS

Twenty-two eyes received IVBr, and twenty-four underwent PDT. No apparent differences were observed in BCVA and central macular thickness (CMT) changes from baseline between the groups (IVBr vs. PDT: BCVA, 0.01 ± 0.47 logMAR vs. 0.04 ± 0.18 logMAR, P-value = 0.756; CMT: - 36.3 ± 99.4 μm vs. - 114.7 ± 181.4 μm, P-value = 0.146). Only in the PDT group, five eyes (20.8%) did not require additional treatment after the second-line treatment, the adjusted odds ratio indicating no further treatment needed was 11.98 (95% confidence interval: 1.42-2070.07, P-value = 0.019). The E-value for the adjusted odds ratio was 23.44.

CONCLUSIONS

Both second-line treatments for PCV exhibited similar visual and anatomical outcomes. Only in the PDT-treated eyes were there some patients who did not require further treatment after second-line therapy.

Factors Influencing Visual Acuity in Patients with Active Subfoveal Circumscribed Polypoidal Choroidal Vasculopathy and Changes in Imaging Parameters

We performed a retrospective, observational study of 51 eyes in 51 treatment-naïve patients with polypoidal choroidal vasculopathy (PCV), whose lesion ranged within the 6 × 6 mm scope of optical coherence tomography angiography (OCTA). The patients were divided into an ill-defined group and a well-defined group based on the pattern of branching vascular network (BVN) on OCTA. BVN morphology was not related to baseline best-corrected visual acuity (BCVA). However, the BCVA in the ill-defined BVN group (-0.18 [interquartile range: -0.40 to 0.00]) was significantly improved after anti-vascular endothelial growth factor (VEGF) injections, compared with that (0.00 [interquartile range: -0.18 to 0.00]) in the well-defined group (z = 2.143, p = 0.032). Multiple logistic regression analysis showed that male sex, fewer injections, and the presence of polypoidal lesions on OCTA images at baseline predicted a poor prognosis in patients with polypoidal lesions on OCTA images after anti-VEGF therapy (all p < 0.05). Finally, BCVA at baseline and the number of injections were protective factors for BCVA after anti-VEGF therapy (all p < 0.05). In contrast, a history of hypertension and macular edema at baseline were risk factors for BCVA after anti-VEGF injections (all p < 0.05). Our results revealed the visual and morphological prognosis of patients with active subfoveal circumscribed PCV after anti-VEGF therapy.

New Concepts for the Diagnosis of Polypoidal Choroidal Vasculopathy

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

Pachychoroid neovasculopathy has clinical properties that differ from conventional neovascular age-related macular degeneration

To determine the clinical properties of pachychoroid neovasculopathy (PNV) that differ from conventional neovascular age-related macular degeneration (nAMD) and suggest that they are different clinical entities. To accomplish this, we reviewed the medical records of 100 consecutive patients diagnosed with nAMD. All of the patients were Japanese, and their mean age was 75.5 years. There were 72 men and 28 women. For the bilateral cases, only the right eye was analyzed. An eye was diagnosed with PNV when a macular neovascularization (MNV) was detected just above the dilated choroidal vessels. The Indocyanine green angiographic (ICGA) and en face optical coherence tomographic (OCT) images were used to assess the vertical symmetry of the medium and large choroidal vessels. The subfoveal choroidal thickness (SCT) was also measured manually in the OCT images. After reclassification, there were 29 (29%) patients with typical nAMD (25 with type 1 MNV, 4 with type 2 MNV), 43 (43%) with PNV, 21 (21%) with polypoidal choroidal vasculopathy, and 7 (7%) with retinal angiomatous proliferation. Of the 43 PNV, 17 (39.5%) had polypoidal lesions and 26 (60.5%) had no polypoidal lesions. The percentage of eyes with vertical asymmetry of the medium and large choroidal vessels was significantly greater in the 35 PNV (81.4%) than in the 16 non-PNV (28.1%; P < 0.01) cases. The mean SCT was significantly thicker in the PNV eyes than in the non-PNV eyes (298 ± 96 μm vs. 228 ± 82 μm; P < 0.01). The response of PNV to anti-vascular endothelial growth factor treatments was better than that of non-PNV eyes [higher dry macula rate after the loading period (90.9% vs. 59.1%), fewer total number of injections (11.0 ± 2.9 vs. 13.4 ± 3.2), and longer treatment intervals for the anti-VEGF therapy (8.4 ± 3.1 vs. 13.4 ± 3.2 weeks) at 2 years (all P < 0.01)]. These differences in the morphology and response to anti-VEGF treatments suggest that PNV is a separate clinical entity to conventional nAMD.

Clinical implications of choroidal vascular brightness using ultra-widefield indocyanine green angiography in polypoidal choroidal vasculopathy

Polypoidal choroidal vasculopathy (PCV) is characterized by choroidal vascular abnormalities including polypoidal lesion and branching vascular networks. Not only choroidal structural changes, but also choroidal hyperpermeability and congestion are also thought to be involved in pathogenesis of PCV. We investigated choroidal vascular brightness intensity (CVB) using ultra-widefield indocyanine green angiography (UWF-ICGA) images and analyzed its association with clinical features in patients with PCV. In this study, 33 eyes with PCV and 27 eyes of age-matched controls were included. CVB was measured by extracting the enhanced pixels of choroidal vessels after the reference brightness across the images was adjusted to be uniform. Associations between choroidal vascular features and the clinical features of PCV were also determined. The mean CVB was higher in PCV than control eyes, regardless of the segmented region (all p < 0.001). CVB was also higher at the posterior pole than at the periphery, and the inferior quadrants were brighter than the superior quadrants in both the PCV and control group (all p < 0.05). In affected eyes, CVB was higher than in unaffected fellow eyes at the posterior pole, whereas there was no difference at the periphery. Posterior pole CVB correlated significantly with subfoveal choroidal thickness (r = 0.502, p = 0.005), polyp number (r = 0.366 p = 0.030), and the greatest linear dimension (r = 0.680, p = 0.040). Greatest linear dimension was positively correlated with CVB at posterior pole (p = 0.040), whereas SFCT or CVD in all regions didn't show the significant correlation. The UWF ICGA results showed an increase in CVB at the inferior quadrants and posterior pole, suggesting venous outflow congestion in PCV eyes. CVB might provide more substantial information on the phenotype than other choroidal vascular features.

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.

Pachychoroid neovasculopathy can mimic wet type age-related macular degeneration

Purpose

to determine the percentage of patients with pachychoroid neovasculopathy (PNV) among patients who have been misdiagnosed and treated with wet age-related macular degeneration (AMD).

Methods

In this retrospective cross-sectional study, patients over 55 years old, who were diagnosed with wet AMD, were re-evaluated. All patients were recalled for examination and imaging. Patients with PNV were differentiated form wet AMD based on inclusion and exclusion criteria.

Results

Overall, 120 patients (137 eyes) were recorded with wet AMD in the clinic. Finally, after complete re-evaluation, 94 (106 eyes) and 26 patients (31 eyes) were assigned to the AMD and the PNV group, respectively. Thus, a total of 20% of patients with primary mistake diagnosis of wet AMD, actually had PNV. The mean sub field choroidal thickness (SFCT) in the AMD and PNV groups was 173.8 ± 69 μm and 342 ± 27 μm, respectively. Drusen and pachydrusen were found in 69.9% and 24% of the cases with AMD and PNV, respectively (P = 0.001). The average number of intravitreal injections of anti-VEGF (vascular endothelial growth factor) required in the AMD and PNV groups was about 5 and 3, respectively, which was statistically significant (P-value 0.02).

Conclusion

This study revealed that about a one-fifth of wet AMD patients are actually pachychoroid neovasculopathy. These patients were younger and had thicker SFCT, and developed less subretinal scarring. Thus, the disorder must be considered as an important differential diagnosis of AMD-CNV.

Visualizing lipid behind the retina in aging and age-related macular degeneration, via indocyanine green angiography (ASHS-LIA)

Age-related macular degeneration (AMD) causes legal blindness in older adults worldwide. Soft drusen are the most extensively documented intraocular risk factor for progression to advanced AMD. A long-standing paradox in AMD pathophysiology has been the vulnerability of Asian populations to polypoidal choroidal vasculopathy (PCV) in the presence of relatively few drusen. Age-related scattered hypofluorescent spots on late phase indocyanine green angiography (ASHS-LIA) was recently proposed as precursors of PCV. Herein, we offer a resolution to the paradox by reviewing evidence that ASHS-LIA indicates the diffuse form of lipoprotein-related lipids accumulating in Bruch's membrane (BrM) throughout adulthood. Deposition of these lipids leads to soft drusen and basal linear deposit (BLinD), a thin layer of soft drusen material in AMD; Pre-BLinD is the precursor. This evidence includes: 1. Both ASHS-LIA and pre-BLinD/BLinD accumulate in older adults and start under the macula; 2. ASHS-LIA shares hypofluorescence with soft drusen, known to be physically continuous with pre-BLinD/BLinD. 3. Model system studies illuminated a mechanism for indocyanine green uptake by retinal pigment epithelium. 4. Neither ASHS-LIA nor pre-BLinD/ BLinD are visible by multimodal imaging anchored on current optical coherence tomography, as confirmed with direct clinicopathologic correlation. To contextualize ASHS-LIA, we also summarize angiographic characteristics of different drusen subtypes in AMD. As possible precursors for PCV, lipid accumulation in forms beyond soft drusen may contribute to the pathogenesis of this prevalent disease in Asia. ASHS-LIA also might help identify patients at risk for progression, of value to clinical trials for therapies targeting early or intermediate AMD.

Relationship between Pachychoroid and Polypoidal Choroidal Vasculopathy

Previous clinical studies have suggested that pachychoroid can induce macular neovascularization (MNV) to develop pachychoroid neovasculopathy (PNV) and that PNV can progress to polypoidal choroidal vasculopathy (PCV). Recent studies based on the pachychoroid concept are now gradually revealing the true nature of, at least some part of, PCV. However, previous studies on PNV and/or PCV have used different frameworks for the classification of PNV, PCV, and neovascular age-related macular degeneration (nAMD). These have hampered the rapid overhaul of the understanding of PCV. Some investigators have assumed that all PCV is pachychoroid-driven whereas other investigators have classified PCV into “pachychoroid PCV” and “non-pachychoroid PCV”. Furthermore, since there is no consensus as to whether PNV includes PCV, some studies have included PCV with PNV, while other studies have excluded PCV from PNV. To address these gaps, we summarize previous studies on PCV and pachychoroid. Even before the proposal of the pachychoroid concept, previous studies had suggested that PCV could be divided into two subtypes, of which one was characterized by pachychoroid features. Previous studies had also provided keys to understand relationship between PCV and PNV. We here recommend a refined conceptual framework for future studies on PNV, PCV, and nAMD. Considering the current inconsistent understanding of PCV, we should be cautious about using the term PCV until we understand the true nature of PCV.

Imaging Characteristics of Neovascular and Atrophic Pachychoroidal Spectrum Diseases

Background

This study qualitatively and quantitatively compared imaging characteristics between neovascular and atrophic pachychoroid spectrum disease (PSD) by optical coherence tomography (OCT), and OCT angiography (OCTA).

Methods

The subtypes of PSD were identified by multi-modality imaging approaches. Subfoveal choroidal thickness (SFCT), choroidal vascular index (CVI), and vascular density of choroidal neovascularization (CNV) were measured.

Results

The CVI and SFCT of 174 PSD eyes were 67.6% ± 5.48% and 362.2 ± 131.88 μm, respectively. After adjustment for age, linear regression indicated that SFCT was positively associated with CVI (p &lt; 0.001), and patched hyper-reflective lesions in choriocapillaris layers (p = 0.009). Compared with neovascular PSD eyes, atrophic PSD eyes had similar patient age (57.1 ± 16.72 years, p = 0.639), SFCT (332.0 ± 111.00 μm, p = 0.51), and CVI (67.6% ± 3.94%, p = 0.527). There were no differences between polypoidal choroidal vasculopathy (PCV) eyes with aneurysmal polypoidal lesions and PCV eyes with tangled polypoidal lesions in terms of age, CVI, SFCT, vascular density, or the occurrence of double layer signs (DLSs, all p &gt; 0.05). Logistic regression indicated that age (p = 0.003), SFCT (p = 0.003), patched hyper-reflective lesions in choriocapillaris layers (p = 0.009), and DLSs (p &lt; 0.001) were predictive factors for CNV progression in PSD eyes (all p &lt; 0.05).

Conclusions

Our study highlighted the similarities in SFCT and CVI between neovascular and atrophic PSD, both of which were late stage lesions. Besides, age, SFCT, patched hyper-reflective lesions in choriocapillaris layers, and DLSs were risk factors for CNV in PSD. Our results showed that atrophic PSD is an important change in the late stage of PSD disease, which is helpful for in-depth understanding of the pathological mechanism of PSD and corresponding intervention.

A Randomized, Controlled Trial of Treat-and-Extend vs. Pro Re Nata Regimen for Neovascular Age-Related Macular Degeneration

Purpose

To compare the efficacy and safety of conbercept using a treat-and-extend (T&E) regimen vs. a pro re nata (PRN) regimen in Chinese patients with neovascular age-related macular degeneration (nAMD).

Methods

This was a randomized, multicenter, non-inferiority study. After an initial loading phase of three consecutive monthly intravitreal injections of 0.5 mg Conbercept, the patients were treated to PRN or T&E regimen. The prespecified retreatment criteria was defined as a more than 5-letter decrease in BCVA from the previous visit or any evidence of new retinal hemorrhages, or the presence of any IRF and any SRF of more than 200 μm in height at the sub-foveal center. The primary outcome was the mean change in best-corrected visual acuity (BCVA) from baseline to 24 months, with a prespecified non-inferiority limit of -5 letters.

Results

From July 2016 through August 2018, 141 participants were allocated and treated (T&E, n = 69; PRN, n = 72). About one fifth of the overall participants were dropped out during the 12-month follow-up (28/141, 19.9%), and about one thirds of the overall participants were lost during the 24-month follow-up (51/141, 36%). At 2 years, mean BCVA letter improvement was + 4.0 in the T&E group vs. + 5.1 in the PRN group, and T&E regimen was not non-inferior to PRN regimen [difference, -1.169 letters; 95% confidence interval (CI): -6.864 ∼ 4.526]. Subgroup analyses also demonstrate the similar results in PCV patients, naive patients and no-naive patients. The mean decrease in central subfield thickness were 180 ± 165 μm in the T&E group and 247 ± 230 μm in the PRN group, respectively. The patients in the PRN group had required significantly fewer injections than those in the T&E group (12.4 vs. 14.6 injections, P = 0.041). The types and rates of adverse events were comparable in the two treatment groups.

Conclusion

These findings suggest that the T&E regimen was not non-inferior to the PRN regimen in patients with nAMD in terms of BCVA outcomes through 24 months.

Clinical Trial Registration

ClinicalTrials.gov, identifier NCT02802657.

Photodynamic therapy as a treatment option for peripapillary pachychoroid syndrome: a pilot study

BACKGROUND

To investigate the anatomical and functional results in eyes with peripapillary pachychoroid syndrome (PPS) undergoing photodynamic therapy (PDT).

METHODS

A total of 25 eyes from 23 patients with PPS treated with PDT were retrospectively evaluated in this multicentric study. Main outcome measure was the proportion of eyes that achieved treatment success, defined as a decrease in both subretinal fluid (SRF) height and central subfield thickness (CST), at 3 months after PDT compared to baseline. Secondary outcomes were the change in CST, SRF, and best-corrected visual acuity (BCVA) 3 months after treatment and predictive factors for treatment success. When available, data between 3 and 12 months were also reviewed.

RESULTS

Treatment success was achieved in 16 eyes (64%). In the total cohort, CST decreased significantly from 356 ± 118 µm at baseline to 282 ± 90 µm and 270 ± 91 µm at 1 and 3 months, respectively (p < 0.001). Maximal SRF height decreased significantly from 102 ± 83 µm at baseline to 38 ± 46 µm and 32 ± 42 µm at 1 and 3 months, respectively (p < 0.001), and remained stable at month 6 (29 ± 44 µm) and month 12 (23 ± 35 µm). BCVA improved significantly from baseline to month 3 (p = 0.021).

CONCLUSIONS

PDT can be considered an efficacious treatment option in patients with PPS. Prospective data with longer follow-up in a bigger cohort are needed in order to determine the optimal treatment algorithm in this relatively novel disease.

Novel volumetric imaging biomarkers for assessing disease activity in eyes with PCV

The aim of this study was to evaluate influence of baseline imaging features on visual and anatomical outcomes in eyes with PCV treated with anti-VEGF monotherapy. In this prospective study we enrolled participants with treatment-naïve PCV who followed a treat-and-extend protocol using intravitreal aflibercept (IVA) monotherapy. Baseline clinical features evaluatedincluded best corrected visual acuity (BCVA), traditional features such as lesion size, fluid-related OCT parameters and novel parameters using automated software. This included quantitative and qualitative pigment epithelium detachment (PED) parameters [height, volume]; and choroidal parameters. [choroidal thickness (CT), choroidal volume (CV) and choroidal vascularity index (CVI). We evaluated the predictive value of each parameter on visual and anatomical outcome at month 12. We additionally evaluated initial treatment response after 3 monthly injections with respect to month 12 outcomes. Fifty-two eyes from 52 participants were included in the study. The BCVA increased from 61.1 ± 13.2 to 69.6 ± 13.2 early treatment diabetic retinopathy study (ETDRS) letters (p < 0.01) and CRT reduced from 455.7 ± 182.4 µm to 272.7 ± 86.2 (p < 0.01) from baseline to month 12. The proportion of eyes with PED decreased significant from 100% at baseline to 80% at month 12 (p < 0.01). Reduction in the mean maximum height of PED (from 381.3 ± 236.3 µm to 206.8 vs ± 146.4 µm) and PED volume (from 1322 ± 853 nl to 686 ± 593 nl) (p < 0.01) was also noted from baseline to month12. Baseline features associated with better month 12 BCVA included baseline BCVA (β =  − 0.98, 95%CI − 3.38 to − 1.61, p = 0.02) and baseline CRT (β =  − 0.98, 95%CI − 1.56 to − 0.40, p = 0.04) while the disease activity at month12 was significantly associated with lower baseline CRT (366.0 ± 129.5 vs 612.0 ± 188.0 , p < 0.001), lower baseline PED height (242.0 ± 150.0 vs 542.0 ± 298.0 µm, p < 0.01), lower baseline PED volume (0.6 ± 0.3 mm³ vs 2.2 ± 1.3 mm³ vs, p < 0.01), lower proportion with marked CVH (17.9% vs 46.2%, p = 0.02) and lower mean CVI (61.8 ± 1.4 vs 63.0 ± 1.4, p < 0.02). Additionally, a larger decrease in CRT (per 100 nm) and larger PED volume reduction (per 100 nl) at month 3 from baseline were associated with greater BCVA gain and inactive disease. PED-related volumetric parameters have an additional predictive value to traditional biomarkers of disease activity in eyes with PCV undergoing anti-VEGF monotherapy. With increasingly precise quantification, PEDs can be a crucial biomarker in addition to traditional parameters and may aid in retreatment decisions.

Choroidal imaging using optical coherence tomography: techniques and interpretations

The choroid is vascularized membranous tissue that supplies oxygen and nutrients to the photoreceptors and outer retina. Choroidal vessels underlying the retinal pigment epithelium are difficult to visualize by ophthalmoscopy and slit-lamp examinations. Optical coherence tomography (OCT) imaging made significant advancements in the last 2 decades; it allows visualization of the choroid and its vasculature. Enhanced-depth imaging techniques and swept-source OCT provide detailed choroidal images. A recent breakthrough, OCT angiography (OCTA), visualizes blood flow in the choriocapillaris. However, despite using OCTA, it is hard to visualize the choroidal vessel blood flow. In conventional structural OCT the choroidal vessel structure appears as a low-intensity objects. Image-processing techniques help obtain structural information about these vessels. Manual or automated segmentation of the choroid and binarization techniques enable evaluation of choroidal vessels. Viewing the three-dimensional choroidal vasculature is also possible using high-scan speed volumetric OCT. Unfortunately, although choroidal image analyses are possible using the images obtained by commercially available OCT, the built-in function that analyzes the choroidal vasculature may be insufficient to perform quantitative imaging analysis. Physicians must do that themselves. This review summarizes recent choroidal imaging processing techniques and explains the interpretation of the results for the benefit of imaging experts and ophthalmologists alike.

Quantitative analysis of branching neovascular networks in polypoidal choroidal vasculopathy by optical coherence tomography angiography after photodynamic therapy and anti-vascular endothelial growth factor combination therapy

PURPOSE

To study serial changes in branching neovascular networks (BNN) by using optical coherence tomography angiography (OCTA) in patients with polypoidal choroidal vasculopathy (PCV) who underwent combined photodynamic therapy (PDT) and anti-vascular endothelial growth factor (anti-VEGF) therapy.

METHODS

In this retrospective study of 30 PCV patients who underwent combined therapy, OCTA images obtained at baseline and 1, 3, and 6 months after treatment were collected. The vessel area, vessel percentage area, average vessel length, and presence of polypoidal lesions on OCTA images as well as best-corrected visual acuity (BCVA), central retinal thickness (CRT), and central choroidal thickness (CCT) were recorded at each time point.

RESULTS

The BNN- and polypoidal lesion-detection rates on baseline OCTA images were 100% and 71%, respectively. The vessel area decreased during the first 3 months, and increased 6 months post-treatment, showing significant differences from baseline (p = 0.031). The vessel percentage area also reduced 1 and 3 months post-treatment (p = 0.025) and increased 6 months post-treatment. Continuous polypoidal lesion regression was observed from 1 to 3 and 6 months post-treatment (p = 0.031, p = 0.004, p = 0.002, respectively, in comparison with baseline). Patients with a decreasing vessel area over 6 months showed greater choroidal thickness than those with increasing vessel area (p = 0.004).

CONCLUSIONS

The BNN showed initial regression but were enlarged at 6 months after therapy. Patients showing continuous BNN regression showed a thicker choroid at baseline. This difference should be considered during treatment for PCV, and OCTA could be used for follow-up evaluations of PCV patients.

Evolving treatment paradigms for PCV

Polypoidal choroidal vasculopathy (PCV) is a subtype of neovascular AMD (nAMD) that accounts for a significant proportion of nAMD cases worldwide, and particularly in Asia. Contemporary PCV treatment strategies have closely followed those used in typical nAMD, though there are significant gaps in knowledge on PCV management and it remains unclear if these strategies are appropriate. Current clinical trial data suggest intravitreal anti-vascular endothelial growth factor (VEGF) therapy alone or in combination with photodynamic therapy is effective in managing haemorrhage and exudation in PCV, although the optimal treatment interval, including as-needed and treat-and-extend approaches, is unclear. Newer imaging modalities, including OCT angiography and high-resolution spectral domain OCT have enabled characterisation of unique PCV biomarkers that may provide guidance on how and when treatment and re-treatment should be initiated. Treatment burden for PCV is a major focus of future therapeutic research and several newly developed anti-VEGF agents, including brolucizumab, faricimab, and new modes of drug delivery like the port delivery system, offer hope for dramatically reduced treatment burden for PCV patients. Beyond anti-VEGF therapy, recent developments in our understanding of PCV pathophysiology, in particular the role of choroidal anatomy and lipid mediators in PCV pathogenesis, offer new treatment avenues that may become clinically relevant in the future. This article explores the current management of PCV and more recent approaches to PCV treatment based on an improved understanding of this unique disease process.

The characteristics of choriocapillaris flow void in the unilateral polypoidal choroidal vasculopathy fellow eyes

To evaluate the morphological characteristics of flow void (FV) in the fellow eyes of the unilateral polypoidal choroidal vasculopathy (PCV). Fifty PCV fellow eyes (PCVF) and 31 age-matched normal ocular circulation controls were recruited in this retrospective study. The number of FV was analyzed according to the size in a centered 5 × 5 mm swept source optical coherence tomography angiography scans. We used indocyanine green angiography images to determine whether choroidal vascular hyperpermeability (CVH) has occurred. For the PCVF, the prevalence rate of CVH was 70% (35 of 50) The number of FVs was significantly lower in 400-25,000 μm2 (P = 0.005), 400-500 μm2 (P = 0.001), 525-625 μm2 (P = 0.001) and 650-750 μm2 (P = 0.018). compared to the controls. And showed no difference in size from 775 to 1125 μm2 between the two groups. The area under the receiver operating characteristic curve of PCVF with CVH and controls was 0.94 (95% CI 0.88-1.00) (P < 0.001). We found that the number of small FVs was significantly lower in the PCV fellow eyes than that in the eyes with control group.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Association between Vortex Vein Engorgement and Treatment Outcomes of Intravitreal Aflibercept for Polypoidal Choroidal Vasculopathy

Purpose: To investigate the influence of the number of engorged vortex veins on treatment outcomes in eyes with treatment-naïve polypoidal choroidal vasculopathy (PCV) undergoing intravitreal aflibercept monotherapy.Methods: The medical charts of 65 patients with PCV who underwent intravitreal aflibercept injection were reviewed retrospectively. The number of quadrants of vortex vein engorgement was evaluated in the middle phase of ultra-widefield indocyanine green angiography, which was classified as extended engorgement if the dilated choroidal vessels expanded the macula. Associations between treatment outcomes with age, subfoveal choroidal thickness (SFCT), central retinal thickness, and vortex vein engorgement were investigated using univariate and multivariate analyses.Results: There were no significant differences in best-corrected visual acuity (BCVA), SFCT, and central retinal thickness at baseline and 12 months, according to the number of vortex vein engorgement. However, an increase in the number of vortex vein engorgement extending to the macula was associated with a thick SFCT (p = 0.038), a greater number of injections (p = 0.041), low BCVA at 12 months (p = 0.038), and a less dry macula at 12 months (p = 0.026). In the multivariate analysis, the number of quadrants with vortex vein engorgement extending to the macula was significantly associated with BCVA changes at 12 months, total number of injections, and a dry macula at 12 months (p = 0.030, p = 0.030, p = 0.020, respectively).Conclusions: More quadrants with vortex vein engorgement extending to the macula in PCV was associated with unfavorable visual outcomes, a less dry macula at 12 months, and a greater number of injections at 1 year after intravitreal aflibercept injection. Clinicians should keep in mind that vortex vein engorgement extending to the macula may be a new biomarker in predicting treatment outcomes in PCV.

Pachychoroid disease spectrum: review article

PURPOSE

The aim of this article is to do a comprehensive literature review about the current understandings of the pachychoroid disease spectrum, describing its multimodal imaging analysis, pathophysiology, differential diagnosis, and current types of management.

METHODS

This comprehensive literature review was performed based on a search on the PubMed database, of relevant pachychoroid published papers according to our current knowledge.

DISCUSSION

The pachychoroid disease spectrum, according to some authors, includes the following: pachychoroid pigment epitheliopathy (PPE), central serous chorioretinopathy (CSC), pachychoroid neovasculopathy (PNV), polypoidal choroidal vasculopathy (PCV)/aneurysmal type 1 neovascularization (AT1), and more recently focal choroidal excavation (FCE) and peripapillary pachychoroid syndrome (PPS). Each one of these entities will be described and discussed in this article.

CONCLUSION

Significant advances in multimodal imaging have enabled a better understanding of the typical choroidal changes in pachychoroid disease spectrum. The clinical knowledge and managing options about this disease significantly increased in the last years. However, it is still unclear why some eyes with typical pachychoroid disease phenotype show no evidence of RPE damage and subretinal fluid (uncomplicated pachychoroid) while others present progressive tissue damage, neovascularization, and atrophy.

OCTA evaluation of treatment-naïve flat irregular PED (FIPED)-associated CNV in chronic central serous chorioretinopathy before and after half-dose PDT

BACKGROUND

To qualitatively and quantitatively evaluate the features of treatment-naïve flat irregular pigment epithelial detachment (FIPED)-associated choroidal neovascularization (CNV) in chronic central serous chorioretinopathy (CSC) using swept-source (SS) optical coherence tomography angiography (OCTA) before and after half-dose photodynamic therapy (PDT).

METHODS

Retrospective case series. The multimodal imaging data of the eyes with FIPED-associated CNV in chronic CSC were reviewed. The features of FIPED-associated CNVs were evaluated by SS-OCTA.

RESULTS

Records of twenty-one patients (21 eyes) were reviewed. The mean age was 56.62 ± 6.87 years. After half-dose PDT, all patients have improved best spectacle-corrected visual acuity from 0.49 at baseline to 0.25 at 6-month visit, and subfoveal choroidal thickness decreased with subretinal fluids absorbed. By OCTA, the features of CNV at baseline included long filamentous linear vessels (21/21), branching into other large mature vessels with rare anastomoses (21/21); and/or a 'dead tree' appearance at the vessel's termini (20/21); and no perilesional hypointense halo (21/21). Compared to those at baseline, the mean vessel density of CNV showed no significant change at 1-,3-,6-month follow-up, while the mean area of CNV was significantly larger at the 6-month follow-up (p = 0.013).

CONCLUSIONS

OCT angiography allows to qualitatively and quantitatively evaluate CNV in chronic CSC. The features of FIPED-associated CNV on OCTA illustrated its quiescent characteristic and further guided therapy. Half-dose PDT showed favorable effects on chronic CSC complicated with FIPED-associated CNV.

Pachychoroid spectrum disease

Recent improvements in ophthalmic imaging have led to the identification of a thickened choroid or pachychoroid to be associated with a number of retinal diseases. The number of conditions linked to this phenotype has continued to widen with specific endophenotypes found within the pachychoroid spectrum. The spectrum includes choroidal features such as focal or diffuse choroidal thickening and thinning of the overlying inner choroid, and choroidal hyperpermeability as demonstrated by indocyanine green angiography. In addition, these diseases are associated with overlying retinal pigmentary changes and retinal pigment epithelial dysfunction and may also be associated with choroidal neovascularization. This article provides a comprehensive review of the literature looking at diseases currently described within the pachychoroid spectrum including central serous chorioretinopathy, pachychoroid pigment epitheliopathy, pachychoroid neovasculopathy, polypoidal choroidal vasculopathy/aneurysmal type 1 neovascularization, peripapillary pachychoroid disease and focal choroidal excavation. We particularly focus on clinical imaging, genetics and pathological findings in these conditions with the aim of updating evidence suggesting a common aetiology between diseases within the pachychoroid spectrum.

Chronic choriocapillaris ischemia in dilated vortex vein region in pachychoroid neovasculopathy

We evaluated choroidal congestion using multimodal imaging in pachychoroid neovasculopathy (PNV). In a retrospective case series of 100 eyes of 99 treatment-naïve PNV patients, their clinical records were reviewed and the corresponding multimodal imaging studies were analyzed. We assessed areas of choriocapillaris filling delay which overlapped with dilated outer choroidal vessels, choroidal neovascularization (CNV), and retinal pigment epithelium (RPE) atrophy. The study subjects were 78 men (78.8%) and 21 women (21.2%). The mean patient age was 67.5 ± 10.5 years. On indocyanine green angiography, all eyes showed choriocapillaris filling delay in the early phase. Dilated outer choroidal vessels were demonstrated in all eyes by en face optical coherence tomography. The areas of choriocapillaris filling delay overlapped extensively with that of dilated outer choroidal vessels. All eyes showed CNV localized within the sites of choriocapillaris filling delay. RPE atrophy was noted in 71 eyes (71.0%), and 68 of these (95.8%) had RPE atrophy within the areas showing choriocapillaris filling delay. These findings indicate that chronic choriocapillaris ischemia secondary to vortex vein congestion may lead to CNV development as well as RPE atrophy in eyes with PNV.

Pachychoroid neovasculopathy: A comparative review on pathology, clinical features, and therapy

There have been major changes in our understanding of choroidal diseases in the last decade owing to multiple retinal and choroidal imaging related advances. A major conceptual pivot is establishment of pachychoroid and its spectrum of clinical disorders: pachychoroid pigment epitheliopathy, central serous chorioretinopathy, pachychoroid neovasculopathy, polypoidal choroidal vasculopathy/aneurysmal type 1 neovascularization, peripapillary pachychoroid syndrome, and focal choroidal excavation. However, considerable overlaps in manifestations and therapeutics of these disorders make differentiation amongst them difficult. This review is focused on pathogenesis and clinical aspects of pachychoroid neovasculopathy (PNV). Since PNV was defined as a separate entity around 5 years ago, there have been numerous contrasting observations surrounding it. We review and summarize these studies, and also compare PNV with other disorders of the pachychoroid spectrum in detail. There are important differences between etiologies of neovascular age related macular degeneration and PNV. Yet the current treatment strategies for PNV have been extrapolated from the trials for the former. Future research needs to validate this assumption with long-term results.

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Multicentre, randomised clinical trial comparing intravitreal aflibercept monotherapy versus aflibercept combined with reduced-fluence photodynamic therapy (RF-PDT) for the treatment of polypoidal choroidal vasculopathy

PURPOSE

To compare the efficacy and safety of intravitreal aflibercept (IVA) monotherapy versus aflibercept combined with reduced-fluence photodynamic therapy (RF-PDT) (IVA+RF-PDT) for the treatment of polypoidal choroidal vasculopathy (PCV).

METHODS AND ANALYSIS

Multicentred, double-masked, randomised controlled trial to compare the two treatment modalities. The primary outcome of the study is to compare the 52-week visual outcome of IVA versus IVA+RF PDT. One hundred and sixty treatment-naïve patients with macular PCV confirmed on indocyanine green angiography will be recruited from three centres in Singapore. Eligible patients will be randomised (1:1 ratio) into one of the following groups: IVA monotherapy group-aflibercept monotherapy with sham photodynamic therapy (n=80); combination group-aflibercept with RF-PDT (n=80). Following baseline visit, all patients will be monitored at 4 weekly intervals during which disease activity will be assessed based on best-corrected visual acuity (BCVA), ophthalmic examination findings, optical coherence tomography (OCT) and angiography where indicated. Eyes that meet protocol-specified retreatment criteria will receive IVA and sham/RF-PDT according to their randomisation group. Primary endpoint will be assessed as change in BCVA at week 52 from baseline. Secondary endpoints will include anatomical changes based on OCT and dye angiography as well as safety assessment. Additionally, we will be collecting optical coherence tomography angiography data prospectively for exploratory analysis.

ETHICS AND DISSEMINATION

This study will be conducted in accordance with the ethical principles that have their origin in the Declaration of Helsinki and that are consistent with the ICH E6 guidelines of Good Clinical Practice and the applicable regulatory requirements. Approval from the SingHealth Centralised Institutional Review Board has been sought prior to commencement of the study.

TRIAL REGISTRATION NUMBER

NCT03941587.

Clinical features of pachyvessels associated with polypoidal choroidal vasculopathy in chronic central serous chorioretinopathy

To investigate the association between clinical features of chronic central serous chorioretinopathy (CSC) and subsequent development of polypoidal choroidal vasculopathy (PCV). Characteristics and treatment response of PCV secondary to CSC were described. This retrospective observational study included 18 patients with chronic CSC (18 eyes) with subsequent PCV and 36 controls (36 eyes) with chronic CSC without PCV development during follow-up. Clinical features were compared between the two groups. A logistic regression model was used to evaluate the risk factor of PCV formation. Treatments for PCV included anti-vascular endothelial growth factor (VEGF) monotherapy, photodynamic therapy (PDT), or PDT and anti-VEGF combination treatment. Subretinal fluid on optical coherence tomography images were assessed after treatments. Significant between-group differences were observed in best-corrected visual acuity after disease resolution and presence of pachyvessels (P = .001 and P = .003, respectively). The presence of pachyvessels in chronic CSC was associated with subsequent PCV (odds ratio = 6.00; 95% CI, 1.74–20.68; P = .005). CSC recurrence and subfoveal choroidal thickness (SFCT) were not significantly associated with subsequent PCV development (P = .393 and P = .911, respectively). The mean age of PCV diagnosis was 51 years, and the mean time from CSC diagnosis to PCV confirmation was 77.8 months. The mean (range) SFCT of PCV was 327.7 (134–599) μm. Nine patients received anti-VEGF monotherapy and 5 had disease remission. Four patients received PDT and anti-VEGF combination treatment and all of the 4 had disease remission. In chronic CSC, pachyvessel characteristics are associated with subsequent PCV development. This result will assist clinicians to evaluate CSC in clinical practice and provide insights into the pathogenesis of PCV.

Pulsatile Filling of Dilated Choroidal Vessels in Macular Watershed Zones

PURPOSE

To describe pulsatile filling of dilated choroidal veins in the watershed zones and propose an alteration in choroidal perfusion pressure.

METHODS

Retrospective review of original and digital subtraction indocyanine green angiography (ICGA).

RESULTS

We observed pulsating blood flow within choroidal vein segments in the posterior pole in 14 eyes (diagnosis of polypoidal choroidal vasculopathy, central serous chorioretinopathy, or neovascular age-related macular degeneration). Pulsating dye front was observed in single or multiple large choroidal vein(s) in a location that is ordinarily a watershed zone between the segmental areas of venous drainage and vessels proximal and distal were often dilated. The pulsatile venous segments filled more slowly that the neighboring veins. In digital subtraction ICGA, the dye front advanced in an incremental fashion or oscillated in a back-and forth manner during several cardiac cycles during the filling of these larger choroidal veins. With ICGA, we observed dilated choroidal veins which violated the macula watershed zone, localized bulbous dilations, and arteriole-over-vein crossings with apparent compression.

CONCLUSIONS

These novel observations suggest the pressure gradient for flow in the affected veins varied, from low gradients when the filling was slow to higher gradients when the filling was faster. The vessels violated the physiological watershed zone and seem to function as anastomoses between the ordinarily segmented venous drainage of the choroid. The dilated segments may result in pooling of venous blood as part of venous outflow abnormalities that may be operative in these diseases.

Deep phenotype unsupervised machine learning revealed the significance of pachychoroid features in etiology and visual prognosis of age-related macular degeneration

Unsupervised machine learning has received increased attention in clinical research because it allows researchers to identify novel and objective viewpoints for diseases with complex clinical characteristics. In this study, we applied a deep phenotyping method to classify Japanese patients with age-related macular degeneration (AMD), the leading cause of blindness in developed countries, showing high phenotypic heterogeneity. By applying unsupervised deep phenotype clustering, patients with AMD were classified into two groups. One of the groups had typical AMD features, whereas the other one showed the pachychoroid-related features that were recently identified as a potentially important factor in AMD pathogenesis. Based on these results, a scoring system for classification was established; a higher score was significantly associated with a rapid improvement in visual acuity after specific treatment. This needs to be validated in other datasets in the future. In conclusion, the current study demonstrates the usefulness of unsupervised classification and provides important knowledge for future AMD studies.

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

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

Pachychoroid: current concepts on clinical features and pathogenesis

PURPOSE

The term "pachychoroid" refers to a newly described phenotype in which functional and structural choroidal changes are thought to play a key pathogenic role in a spectrum of related retinal disorders. A more detailed understanding of how the choroid is involved within this spectrum and a better knowledge of the most relevant clinical signs of the pachychoroid phenotype are important to differentiate these disorders from other retinal conditions. Our objectives are to provide a literature review of pachychoroid and the commonalities that may be present across pathologies included in the spectrum, and to provide details on the examination, monitoring, and management of these disorders.

METHODS

We searched the PubMed web platform to identify relevant studies using the following keywords: pachychoroid, pachychoroid pigment epitheliopathy, pachychoroid neovasculopathy, aneurysmal type 1 neovascularization, focal choroidal excavation, peripapillary pachychoroid syndrome, vasculopathy pachysclera, pachychoroid geographic atrophy, and pachydrusen. We selected 157 publications and identified the most important features related to pachychoroid.

RESULTS

The presence of hypertrophic or congested vessels in the choroid, not thickened choroid per se, under an area of reduced or absent choriocapillaris in the posterior pole seems to be the most salient feature of pachychoroid. However, other qualitative/quantitative features are needed to differentiate the uncomplicated pachychoroid from the pathological pachychoroid clinical spectrum, which may be associated with exudation, neovascularization, and/or retinal pigment epithelium and photoreceptor atrophy.

CONCLUSIONS

The most salient feature of pachychoroid appears to be the presence of large vessels under an area of reduced or absent choriocapillaris. Knowledge of the features and pathogenesis of the different disorders in the pachychoroid spectrum may assist in the management of patients.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

Association between pachychoroid and long-term treatment outcomes of photodynamic therapy with intravitreal ranibizumab for polypoidal choroidal vasculopathy

We investigated long-term treatment responses in patients with treatment-naïve polypoidal choroidal vasculopathy (PCV) undergoing photodynamic therapy (PDT) with intravitreal ranibizumab (IVR). The medical charts of 14 patients with treatment-naïve PCV who underwent PDT with IVR were retrospectively reviewed. Patients were followed up and treated with additional IVR for ≥3 years. Best-corrected visual acuity (BCVA), central foveal thickness (CFT), greatest linear dimension (GLD) on angiography, polyp regression and central choroidal thickness (CCT) were assessed. Associations between these functional or anatomic outcomes with age, baseline CCT, baseline GLD or choroidal vascular hyperpermeability (CVH) were investigated using univariate and multivariate analysis. Mean logMAR BCVA improved significantly at 3 years (0.34 ± 0.24 to 0.12 ± 0.29, p = 0.003). Greater BCVA improvement and longer time to first recurrence was significantly associated with CVH. Fewer number of IVR retreatment within 3 years was associated with thicker baseline CCT. Mean CCT significantly decreased at 3 years (217 ± 33 µm to 197 ± 48 µm, p = 0.003). Greater decrease of CCT was significantly associated both with greater number of IVR retreatment within 3 years and absence of CVH. These results showed that pachychoroid characteristics at baseline was associated long-term functional and anatomic outcomes in patients with treatment-naïve PCV who had undergone combination PDT and IVR.

Clinical implications of pachyvessels in polypoidal choroidal vasculopathy

Background

Polypoidal choroidal vasculopathy (PCV) is one of the disorders within the pachychoroid spectrum diseases. The presence of pachyvessels is one of the characteristics of pachychoroid disorders. However, the relationship between the presence of pachyvessels and the clinical characteristics of PCV eyes has not been determined. The purpose of this study was to determine the relationship between the presence of choroidal pachyvessels and the clinical characteristics of eyes with PCV.

Methods

The medical records of patients who were diagnosed with PCV and were treatment-naïve were reviewed. Fluorescein and indocyanine green angiography, fundus photography, spectral domain optical coherence tomography (SD-OCT), and enhanced depth imaging OCT (EDI-OCT) were used to obtain images of the choroid. The presence of pathologically dilated outer choroidal vessels, pachyvessels, was determined by ICGA images. These pachyvessels were confirmed to correspond with the large choroidal vessels in the EDI OCT images. The PCV eyes were divided into two groups based on the presence or absence of pachyvessels and clinical features and subfoveal choroidal thickness (SFCT) were evaluated between the two groups.

Results

Eighty-six eyes of 84 patients with PCV were evaluated. Pachyvessels were detected in 48 eyes (55.8%). The mean SFCT was 203.9 ± 83.9 μm in all 86 eyes, and it was significantly thinner in eyes with pachyvessels (+) than without pachyvessels (−) (183.2 ± 58.4 μm vs 230.2 ± 103.1 μm; P = 0.01). The differences in the incidence of subretinal fluid, pigment epithelial detachments, and hemorrhages between the two groups were not significant. However, the PCV eyes in pachyvessels (+) group with hemorrhage had the thinnest choroid (P = 0.047). The choroidal features of the fellow eyes were similar to those of the PCV affected eyes, that is, the fellow eyes in pachyvessels (+) group had pachyvessels and the fellow eyes in pachyvessels (−) group did not have pachyvessels.

Conclusions

Pachyvessels were presented 55.8% in eyes with PCV, and these eyes had the thin SFCT. The presence of pachyvessels and attenuation of the inner choroid were probably due to the pathological changes in the eyes with PCV.

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.

Association of imaging factors derived from convolutional neural network with visual outcomes in age-related macular degeneration and polypoidal choroidal vasculopathy

We investigated the association of visual outcome in typical neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV) with or without pachychoroid with lesion areas on optical coherence tomography (OCT) quantified by convolutional neural network (CNN) analysis. Treatment-naïve 132 nAMD and 45 PCV eyes treated with ranibizumab or aflibercept for at least 12 months were retrospectively reviewed. Significant factors, including intraretinal fluid (IRF), subretinal fluid (SRF), pigment epithelial detachment (PED) and subretinal hyperreflective material (SHRM) area quantified by CNN at baseline and 12 months, were analyzed by logistic regression analyses for 3-line visual gain or maintenance of 20/30 Snellen vision. Visual gain at the final visit in nAMD was associated with a smaller SHRM at baseline (OR 0.167, P = 0.03), greater decrease in SRF and SHRM from baseline to month 12 (OR 1.564, P = 0.02; OR 12.877, P = 0.01, respectively). Visual gain in nAMD without pachychoroid was associated with a greater decrease in SRF and SHRM (OR 1.574, P = 0.03, OR 1.775, P = 0.04). No association was found in nAMD with pachychoroid and any type of PCV. Greater decrease in SRF and SHRM from baseline to month 12 was associated with favorable visual outcomes in nAMD without pachychoroid but not in nAMD with pachychoroid and PCV.

Associations of systemic, serum lipid and lipoprotein metabolic pathway gene variations with polypoidal choroidal vasculopathy in China

BACKGROUND

To investigate the association of systemic, serum lipids and genetic variants in the high-density lipoprotein (HDL) metabolic pathway with polypoidal choroidal vasculopathy (PCV) in China.

METHODS

The case-control study was included 150 controls and 66 cases with PCV. Serum levels of total cholesterol (TC), low-density lipoprotein (LDL), HDL, triglycerides (TG), apolipoprotein A1 (APOA1), apolipoprotein B (APOB) together with systemic risk factors including gender, hyperlipidemia, diabetes mellitus (DM), hypertension, coronary artery disease (CAD) and asthma were identified. All subjects were genotyped for four single nucleotide polymorphisms (SNPs) from three genes in the HDL metabolic pathway: rs10468017 of hepatic lipase (LIPC), rs12678919 of lipoprotein lipase (LPL), rs3764261 and rs173539 of cholesterol ester transfer protein (CETP) with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Student's t-tests, chi-square tests, anova and logistic regression were used to evaluate associations.

RESULTS

Hyperlipidemia was a risk factor (odds ratio (OR) = 1.19, P = 0.001) for PCV. HDL, LDL and APOB levels were associated with PCV (OR = 0.001, P = 0.004; OR = 0.099, P = 0.010; OR = 0.839, P = 0.018). Higher level of TC was potently associated with increased risk of PCV (OR = 109.8, P = 0.000). LIPC rs10468017 was a risk factor for PCV (OR = 11.68, P = 0.000). CETP rs3764261 conferred a decreased risk for PCV (OR = 0.08, P = 0.000). No associations of LPL rs12678919 or CETP rs173539 with PCV were found. Mean level of HDL increased with T allele of the CETP gene (p = 0.026): 1.24 mmol/L (±0.31) for the GG genotype and 1.66 mmol/L (±0.54) for the TT genotype. Additionally, T allele was associated with the following increase in APOA1: 136.78 mg/dl (±20.53) for the CC genotype and 149.57 mg/dl (±22.67) for the TT genotype of LIPC and 137.91 mg/dl (±20.36) for the GG genotype and 162.67 mg/dl (±22.50) for the TT genotype of CETP gene.

CONCLUSION

Our study suggested that the significant association was found between hyperlipidemia, the serum levels of TC, HDL, LDL and APOB and PCV. The result of present study also showed that the association of LIPC rs10468017 and CETP rs3764261 with PCV.

Efficacy of Photodynamic Therapy for Polypoidal Choroidal Vasculopathy Associated with and without Pachychoroid Phenotypes

PURPOSE

To compare the efficacy of photodynamic therapy (PDT) in eyes with polypoidal choroidal vasculopathy (PCV) associated with and without pachychoroid phenotypes (pachychoroid PCV and nonpachychoroid PCV, respectively).

DESIGN

Retrospective chart review.

PARTICIPANTS

Patients previously diagnosed with PCV and initially treated with PDT.

METHODS

Patients were classified as having pachychoroid- or nonpachychoroid-driven conditions. The long-term visual outcome and its associated factors were investigated.

MAIN OUTCOME MEASURES

Visual acuity (VA) outcomes at 1, 2, 3, 4, and 5 years after initial PDT in pachychoroid and nonpachychoroid PCV.

RESULTS

Of the 158 eyes, 88 (55.7%) met the criteria for pachychoroid PCV; 70 (44.3%) did not (nonpachychoroid PCV). In cases of pachychoroid PCV, VA improved significantly at 1 year (P = 0.042) and maintained baseline level at 5 years (P = 0.38). By contrast, VA continued to deteriorate in the nonpachychoroid PCV group during the follow-up period and had already declined significantly by the second year (P = 0.022, compared with baseline). Despite no difference in baseline VA between pachychoroid and nonpachychoroid PCV groups (P = 0.11), the VA at 5 years was significantly better in the pachychoroid PCV group compared with the nonpachychoroid PCV group (0.54±0.47 vs. 0.93±0.63, respectively; P = 0.23 × 10^-3). The incidence of massive submacular hemorrhage (SMH) or vitreous hemorrhage (VH) was not different between groups at 5 years (P = 0.67), and their occurrence was associated with decreased VA in both the nonpachychoroid and pachychoroid PCV groups (coefficient β, 0.361 and 0.481; P = 0.59 × 10^-3 and P < 1.0 × 10^-5, respectively).

CONCLUSIONS

Five years after PDT treatment, VA was maintained at the baseline level in the pachychoroid PCV group but not in the nonpachychoroid PCV group. Massive SMH or VH during the follow-up period affected the final visual outcomes in both conditions.

Different imaging characteristics between unilateral and bilateral polypoidal choroidal vasculopathy

PURPOSE

To investigate the different imaging characteristics between unilateral and bilateral polypoidal choroidal vasculopathy (PCV) cases, based on confocal scanning laser ophthalmoscope assessment.

METHODS

For this retrospective case series study, diagnostic indocyanine green angiography (ICGA) and spectral domain optical coherence tomography (SD-OCT) were performed to assess the eligible PCV eyes.

RESULTS

Among the 53 patients at baseline, 14 showed bilateral PCV lesions, including two cases of branching vessel network (BVN) without leakage. Concerning the subfoveal choroidal thickness (SFCT), unilateral PCV eyes (326 [155-547] μm) were statistically comparable to their fellow eyes (330 [163-477] μm) (p = 0.257). However, the SFCT (228[141-273] μm) from the bilateral PCV group was significantly lower compared with both the PCV (p = 0.002) and fellow eyes (p < 0.001) from the unilateral group. Moreover, ICGA related hyperfluorescent spots were shown to have a significant positive correlation with SFCT in the unilateral PCV eyes and their fellow eyes, other than bilateral PCV cases. In addition, the drusens tended to prevail in the fellow eyes of the unilateral PCV group (46.2%), compared with bilateral cases.

CONCLUSIONS

Our results indicate that SFCT, ICGA related hyperfluorescent spots, and drusen were the three main imaging characteristic differences between unilateral and bilateral PCV cases.

Age-Related Scattered Hypofluorescent Spots on Late-Phase Indocyanine Green Angiography as Precursor Lesions of Polypoidal Choroidal Vasculopathy

Purpose

Age-related scattered hypofluorescent spots on late-phase indocyanine green angiography (ASHS-LIA) might represent lipid accumulation in Bruch's membrane in the form of basal linear deposits (BlinD). The present study was conducted to describe the clinical characteristics of polypoidal choroidal vasculopathy (PCV) associated with ASHS-LIA.

Methods

Consecutive patients with treatment-naïve PCV who underwent color fundus photography (FP), fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), and spectral-domain optical coherence tomography (SD-OCT) at the Zhongshan Ophthalmic Center from June 2016 through May 2018, were reviewed. ASHS-LIA and choroidal vascular hyperpermeability (CVH) were evaluated by ICGA. Subfoveal choroidal thickness (SFCT) was assessed by SD-OCT.

Results

A total of 187 patients were eligible for inclusion in this study (mean, 63.2 ± 7.6 years; range, 41-85 years). Of these patients, 117 (62.6%) showed ASHS-LIA, 57 (30.5%) had bilateral lesions and 70 (37.4%) showed CVH. Moreover, compared with patients without ASHS-LIA, PCV patients with ASHS-LIA were older (P = 0.001), more frequently had bilateral lesions (P = 0.001), and less frequently showed CVH (P = 0.006). SFCT in eyes with ASHS-LIA was significantly greater than that in eyes without ASHS-LIA after adjusting for age, sex, and CVH (P = 0.026). Nevertheless, there was no significant difference in best-corrected visual acuity or lesion characteristics between the two groups.

Conclusions

ASHS-LIA, which is very common in PCV patients, might be involved in the pathogenesis of PCV. PCV with ASHS-LIA was more frequently associated with bilateral involvement, less CVH, and a thicker choroid than PCV without ASHS-LIA.

Polypoidal choroidal vasculopathy: a comprehensive clinical update

Polypoidal choroidal vasculopathy as a disease is yet to be comprehended completely. The clinical features consisting of huge serosanguineous retinal pigment epithelial and neurosensory layer detachments, although unique may closely mimick neovascular age-related macular degeneration and other counterparts. The investigative modalities starting from indocyanine angiography to optical coherence tomography angiography provide diagnostic challenges. The management strategies based on the available therapies are plenty and not vivid. A detailed review with clarifying images has been compiled with an aim to help the readers in getting a better understanding of the disease.

The association of choroidal structure and its response to anti-VEGF treatment with the short-time outcome in pachychoroid neovasculopathy

Pachychoroid neovasculopathy (PNV) shares some anatomical features with other pachychoroid spectrum diseases, but little is known about the characteristics on the treatment with anti-vascular endothelial growth factor (VEGF). We investigated the effect of choroidal structure and responses to anti-VEGF on the prognosis of pachychoroid neovasculopathy (PNV) and other types of neovascular age-related macular degeneration (non-PNV). Twenty-one eyes with PNV and 34 eyes with non-PNV who had anti-VEGF treatment were retrospectively reviewed. Choroidal neovascularization (CNV) area at baseline was measured with fluorescein angiography (FAG). The luminal and stromal area in the choroid was measured by enhanced-depth-imaging (EDI) OCT at baseline and 1 month. The association between dry macula or LogMAR VA (visual acuity, VA) at 1 month and baseline values or changes in the luminal or stromal area at 1 month, baseline CNV area, or anti-VEGF drugs were analyzed in patients with or without PNV. In non-PNV, change of luminal area (coefficient = 7.0×10-5, p = 0.0001), baseline CNV area (coefficient = 0.18, p = 0.033), and aflibercept vs. ranibizumab (coefficient = 0.29, p = 0.0048) were chosen as predictors for dry macula by the model selection. Similarly, in non-PNV, change of luminal area (coefficient = 6.1×10-6, p = 0.033), baseline CNV area (coefficient = 0.034, p = 0.022), and aflibercept vs. ranibizumab (coefficient = 0.056, p = 0.0020) were chosen as predictors for greater VA improvement. In PNV, however, none of these factors was chosen as predictors for dry macula or VA improvement by the model selection. The result of the present study implied that structural response after anti-VEGF might be different between non-PNV and PNV in the treatment with anti-VEGF agents.