Choroidal and Sub-Retinal Pigment Epithelium Caverns: Multimodal Imaging and Correspondence with Friedman Lipid Globules

Multicolor imaging: Current clinical applications

Multicolor (MC) imaging is an innovative pseudocolor fundus imaging modality based on confocal scanning laser ophthalmoscopy. It effectively scans the retina at different depths to create a composite image. The green reflectance image depicts the middle retinal while blue reflectance image provides images of the retinal surface. The infrared reflectance image depicts retinal structures at the level of outer retina and choroid. We systematically analyze published case reports, case series, and original articles on MC imaging where it has helped in discovering additional clinical features of retinal diseases not readily apparent on conventional color fundus photography and played a role in monitoring the response to treatment.

Subretinal hyporeflective globule: A novel OCT finding in central serous chorioretinopathy

PURPOSE

To describe the subretinal hyporeflective globule in cases of central serous chorioretinopathy (CSC).

METHODS

A retrospective analysis of consecutive cases of CSC presenting to a tertiary eye care center in eastern India was conducted. Subretinal hyporeflective globules were identified as small globular lesions below the external limiting membrane/ellipsoid zone, but above the RPE layer. They had a hyperreflective border with a hyporeflective core and a clear posterior tail of hyper-transmission.

RESULTS

The present study analyzed 137 eyes of 137 patients. Eighty (58.4%) eyes had acute disease at presentation, 48 (35%) eyes had chronic disease, and eight (5.8%) eyes had resolved CSC. Subretinal hyporeflective globules were seen in 27 (21.8%) eyes, of which choroidal caverns were seen in seven (5.1%) eyes. Twenty-five eyes with chronic CSC and only two eyes with acute CSC had subretinal hyporeflective globules. Three eyes with resolved CSC had subretinal hyporeflective globules.

CONCLUSION

We describe subretinal hyporeflective globule as a novel optical coherence tomography (OCT) finding in cases of CSC and describe its clinical correlates.

Extensive Macular Atrophy with Pseudodrusen-like appearance: Progression Kinetics and Late-Stage Findings

PURPOSE

To describe the clinical outcome and late-stage findings of extensive macular atrophy with pseudodrusen-like appearance (EMAP).

DESIGN

Retrospective cohort study.

PARTICIPANTS

Seventy-eight patients (156 eyes) affected by EMAP.

METHODS

We collected data on best-corrected visual acuity, kinetic perimetry, OCT, short-wavelength autofluorescence, and near-infrared autofluorescence findings. Genetic testing for the TIMP3 and C1QTNF5 genes was performed via Sanger sequencing for 58 patients, with no pathogenic variants identified.

MAIN OUTCOME MEASURES

The primary outcomes were best-corrected visual acuity at the last examination, visual field at the last examination, and incidence rates and time-to-event curves for blindness with the United States Social Security Administration and World Health Organization (WHO) criteria, foveal involvement, and atrophy enlargement beyond the 30° and 55° field of view. Imaging findings at the last examination were secondary outcomes.

RESULTS

At the most recent visit, mean age was 70.9 ± 5.2 years. Using United States criteria, 58.1% of the patients were blind, and 25.8% were blind according to WHO criteria. All eyes showed large central scotomas, which were associated with visual field constriction in 22.2% of eyes. We detected focal openings or large dehiscences of Bruch's membrane (BM) in 25.4% of eyes. Near-infrared autofluorescence showed increased visibility of the choroidal vessels beyond the atrophy in 87.2% of eyes. The incidence rates for blindness were 3.95 per 100 patient-years with United States criteria and 1.54 per 100 patient-years according to WHO criteria. The incidence rates were 22.8 per 100 eye-years for foveal involvement, 12.0 per 100 eye-years for atrophy enlargement beyond 30°, and 6.6 per 100 eye-years for atrophy enlargement beyond 55°. The estimates were not influenced by the age at onset.

CONCLUSIONS

We identified characteristic imaging findings, including BM ruptures, in elder patients with EMAP and calculated incidence rates for different functional and anatomic outcomes.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Chronic Central Serous Chorioretinopathy in Elderly Subjects: Structure and Blood Flow Characteristics of Retina and Choroid

INTRODUCTION

With advancements in imaging technology, researchers have been able to identify more distinctive imaging features of central serous chorioretinopathy (CSC). However, existing research primarily concentrates on young patients aged 50 years and below, leaving a dearth of studies on elderly CSC patients. Previous studies indicate that elderly CSC patients may exhibit unique imaging characteristics and have a clinical prognosis that significantly differs from younger patients. This study aimed to evaluate the characteristics of retina, choroid structure, and blood flow in elderly patients with chronic CSC (cCSC) examined multimode imaging and try to find new pathogenesis information of it.

METHODS

Using a cut-off age of 50 years, patients with chronic central serous chorioretinopathy were divided into two groups: older and younger. The control group consisted of 40 healthy individuals, with their right eyes assigned. Various clinical features were recorded, including the incidence of ellipsoid zone rupture (EZ-), fibrin in the subretinal fluid (SRF), pachydrusen, subretinal drusenoid deposits (SDD), pigment epithelial detachment (PED), double-layer sign (DLS), and choroidal lipid globule cavern. Measurements were taken for the thickness of the outer nuclear layer (ONL), the length of the extended outer photoreceptor segment (POS), the height and width of SRF, the vascular density of each layer of the retinal capillary plexus, the central macular thickness (CMT), and the subfoveal choroidal thickness (SFCT).

RESULTS

The proportion of females in the elderly group (43.75%) was significantly higher than that in the youth group (22.41%) (p = 0.034). The degree of hyperopia in the elderly group (1.03 ± 0.73) was higher than that in the youth group (0.26 ± 1.06), with a significant difference in BCVA (p = 0.05). The thickness of SFCT, CMT, ONL in the elderly group, and the length of photoreceptor outer segment in the elderly group were thinner than those in the youth group (p < 0.05). Choroidal capillary perfusion area (CCPA), macular area, and paramacular area were lower in the elderly group than those in the youth group in the full scan range (p < 0.05). The blood flow densities of deep capillary plexus (DCP), intermediate capillary plexus (ICP), and superficial capillary plexus (SCP) in the whole scan range, macular area, and paramacular area were lower in the elderly group than in the youth group, but the differences were not statistically significant.

CONCLUSIONS

In conclusion, our data suggest that elderly patients with cCSC may experience different disease outcomes. Elderly cCSC patients exhibit less gender bias, poorer vision, more severe structural damage and ischemia in the choroid and retina, and have a higher risk of developing choroidal neovascularization.

Imaging Histology Correlations of Intraretinal Fluid in Neovascular Age-Related Macular Degeneration

Purpose

Fluid presence and dynamism is central to the diagnosis and management of neovascular age-related macular degeneration. On optical coherence tomography (OCT), some hyporeflective spaces arise through vascular permeability (exudation) and others arise through degeneration (transudation). Herein we determined whether the histological appearance of fluid manifested this heterogeneity.

Methods

Two eyes of a White woman in her 90s with anti-vascular endothelial growth factor treated bilateral type 3 neovascularization secondary to age-related macular degeneration were osmicated, prepared for submicrometer epoxy resin sections, and correlated to eye-tracked spectral domain OCT. Examples of intraretinal tissue fluid were sought among similarly prepared donor eyes with fibrovascular scars, in a web-based age-related macular degeneration histopathology resource. Fluid stain intensity was quantified in reference to Bruch's membrane and the empty glass slide.

Results

Exudative fluid by OCT was slightly reflective and dynamically responded to anti-vascular endothelial growth factor. On histology, this fluid stained moderately, possessed a smooth and homogenous texture, and contained blood cells and fibrin. Nonexudative fluid in degenerative cysts and in outer retinal tubulation was minimally reflective on OCT and did not respond to anti-vascular endothelial growth factor. By histology, this fluid stained lightly, possessed a finely granular texture, and contained mainly tissue debris. Quantification supported the qualitative impressions of fluid stain density. Cells containing retinal pigment epithelium organelles localized to both fluid types.

Conclusions

High-resolution histology of osmicated tissue can distinguish between exudative and nonexudative fluid, some of which is transudative.

Translational Relevance

OCT and histological features of different fluid types can inform clinical decision-making and assist in the interpretation of newly available automated fluid detection algorithms.

SUBRETINAL LIPID GLOBULES AN EARLY BIOMARKER OF MACULAR NEOVASCULARIZATION IN EYES WITH INTERMEDIATE AGE-RELATED MACULAR DEGENERATION

PURPOSE

To explore the association between subretinal lipid globules (SLGs) detected in eyes with intermediate age-related macular degeneration with the presence of nonexudative macular neovascularization.

METHODS

This was a retrospective analysis of 113 consecutive patients with bilateral intermediate age-related macular degeneration (226 eyes) followed for a least 6 months. All eyes underwent multimodal imaging with fundus autofluorescence, spectral-domain optical coherence tomography, and optical coherence tomography angiography. Subretinal lipid globules were identified on spectral-domain optical coherence tomography as round hyporeflective lesions measuring 31 to 157 µ m located between the ellipsoid zone and the retinal pigment epithelium/Bruch membrane complex. Nonexudative macular neovascularization was detected with optical coherence tomography angiography. The features of NE-MNV lesions detected in eyes with SLGs were compared with those in eyes without SLGs.

RESULTS

Subretinal lipid globules were identified in 15 eyes of which 14 eyes (93.3%) demonstrated NE-MNV on optical coherence tomography angiography. In the remaining 98 eyes without SLGs, 18 (18.4%) displayed NE-AMD on optical coherence tomography angiography. The macular neovascularization area was larger in the SLG subgroup (+0.38 vs. +0.21 mm 2 , P = 0.008) and showed faster horizontal growth (+727 µ m, CI 95% 250.4, 1,205.4) than MNV in eyes without SLGs (+64.9 µ m, CI 95%, 24.3, 154) on optical coherence tomography B-scans. After a mean of 11.6 months, the conversion rate to exudative MNV was similar between eyes with SLGs and those without SLGs [8/26 (38.5%) versus 3/13 (27.3%), P = 0.56)].

CONCLUSION

The detection of SLGs in eyes with intermediate age-related macular degeneration was strongly correlated with the presence of NE-MNV. Although these MNV lesions were larger and grew faster than NE-MNV detected in eyes lacking SLGs, the rates of conversion to exudative MNV appeared similar.

Presence of Choroidal Caverns in Patients with Posterior and Panuveitis

Choroidal caverns (CCs) have been described in association with age-related macular degeneration and pachychoroid disease. However, it is unknown if caverns are found in patients with chronic non-infectious uveitis (NIU). Herein, we evaluated patients with NIU who had optical coherence tomography and indocyanine green angiography for CCs. Clinical and demographic characteristics were extracted from the chart review. Univariate and multivariate mixed-effects logistical models were used to assess the association between clinical and demographic factors and the presence of CCs. One hundred thirty-five patients (251 eyes) met the inclusion criteria: 1 eye had anterior uveitis, 5 had intermediate uveitis, 194 had posterior uveitis, and 51 had panuveitis. The prevalence of CCs was 10%. CCs were only observed in patients with posterior and panuveitis, with a prevalence of 10.8% and 7.8%, respectively. Multifocal choroiditis (MFC) was the type of uveitis where CCs were most frequently observed, with 40% of eyes with MFC having CCs. In addition, male sex (p = 0.024) was associated with CCs. There was no significant difference in the degree of intraocular inflammation or mean subfoveal choroidal thickness between CC+ and CC- eyes. This is the first study to describe CCs in uveitis. Overall, these findings suggest that caverns may be a sequela of structural and/or vascular perturbations in the choroid from uveitis.

Quantitative multimodal imaging of extensive macular atrophy with pseudodrusen and geographic atrophy with diffuse trickling pattern

To compare clinical and imaging characteristics of extensive macular atrophy with pseudodrusen-like appearance (EMAP) versus diffuse-trickling geographic atrophy (DTGA) and non-diffuse-trickling geographic atrophy (nDTGA) phenotypes of age-related macular degeneration. Prospective, observational study performed in the Ophthalmology Department of IRCCS San Raffaele Hospital between January 2015 and January 2021. Patients examination included fundus autofluorescence (FAF) and optical coherence tomography at baseline and follow-up visits. We measured subfoveal choroidal thickness (SCT), Sattler/choroid ratio (SCR), choroidal vascularity index and ellipsoid zone disruption distance on OCT scans. We calculated progression rates and circularity of the atrophic lesions on FAF images. These variables were compared between the three groups and correlations with progression rates and visual acuity were assessed. Sixty-three eyes from 63 patients were included: 18 with EMAP, 18 with DTGA and 27 with nDTGA. Mean follow-up was 3.73 ± 2.12 years. EMAP and DTGA shared a faster progression, lower circularity and SCR, and higher EZ disruption distance than nDTGA, while SCT and CVI were similar between the three groups. Baseline circularity and SCR correlated with progression rates. EMAP and DTGA show similar OCT and FAF characteristics, which differ from nDTGA.

Characteristics and Classification of Choroidal Caverns in Patients with Various Retinal and Chorioretinal Diseases

PURPOSE

To investigate the features of choroidal caverns in diverse retinal diseases with swept-source optical coherence tomography (SS-OCT).

METHODS

Subjects with normal eyes, retinitis pigmentosa (RP), wet age-related macular degeneration (wAMD), acute central serous chorioretinopathy (CSC), or chronic CSC were enrolled. The characteristics of choroidal caverns were evaluated with SS-OCT. The prevalence of choroidal caverns in retinal diseases and the correlations between the number, width and depth of choroidal caverns with the thickness of choroid were analyzed.

RESULTS

Among 315 eyes of 220 subjects, choroidal caverns were found in 110 eyes (34.9%). Choroidal caverns were divided into two categories based on their location and size. Type I was small and usually lobulated, presented in the choroidal capillary and Sattler's layers. Type II was larger, usually isolated, and presented in the Sattler's and Haller's layers. The prevalence of type I in subjects with normal eyes, RP, wAMD, acute CSC, or chronic CSC was 17.4%, 19.6%, 1.6%, 32.8%, and 85.2%, respectively, while that of type II was 0%, 0%, 21.3%, 13.8%, and 53.7%, respectively. The number, width, and thickness of type II choroidal caverns correlated positively with macular choroidal thickness.

CONCLUSIONS

Choroidal caverns could be divided into two categories. Type II choroidal caverns appeared associated with the pachychoroid spectrum and RPE atrophic diseases.

MULTIMODAL IMAGING OF A CHOROIDAL NEVUS WITH CAVERNS IN THE SETTING OF PACHYCHOROID DISEASE

PURPOSE

To describe the multimodal imaging findings of extensive choroidal caverns within a choroidal nevus in an eye with pachychoroid spectrum disease.

METHODS

A 69-year-old woman was referred with a known history of branch retinal vein occlusion in the right eye and choroidal nevus in the left eye. Fundus examination of both eyes revealed subretinal yellow deposits, suggestive of pachydrusen. Retinal venous collaterals were noted in the temporal macular of the right eye. A lightly pigmented choroidal lesion with nearly confluent overlying drusen and retinal pigment epithelial alterations, consistent with chronic choroidal nevus, was noted in the macula of the left eye.

RESULTS

Optical coherence tomography B-scans revealed thickened choroid (pachychoroid) with subfoveal choroidal thickness of 504 µ m and 580 µ m with large hyporeflective spaces suggestive of pachyvessels in both eyes. In the region of the choroidal nevus, the choroidal vascular spaces appeared comparatively large and were classified as "caverns" measuring up to 480 µ m in diameter. Optical coherence tomography angiography and indocyanine green angiography demonstrated the absence of flow within the caverns. Indocyanine green angiography further illustrated choroidal vascular hyperpermeability with patchy hyperfluorescent areas in both eyes. Wide-field swept-source optical coherence tomography showed mild posterior scleral bowing, a feature occasionally documented with choroidal nevus, and highlighted greater hyporeflectivity and hypertransmission on optical coherence tomography within the caverns compared with the noncavernous choroidal vessels.

CONCLUSION

Choroidal caverns can occur within choroidal nevus in the setting of pachychoroid disease.

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.

Bilateral choroidal caverns in a child with pachychoroid and anxious personality

Purpose

To report a case of a 7-year-old male patient with bilateral choroidal caverns (CC) and pachychoroid.

Observations

During the Italian COVID-19 lockdown, a 7-year old boy presented with bilateral vision decline that had started two weeks before. Structural optical coherence tomography revealed pachychoroid and CC bilaterally. Other ocular examinations were negative. The patient had an apprehensive personality and symptoms quickly resolved when he was provided with non-prescription glasses; his visual disturbances were thus considered to be functional and factitious.

Conclusions and Importance

Our patient's symptoms remind us that the distress imposed upon psychologically frail subjects by the COVID-19 pandemic may have multifaceted manifestations. The discovery of CC in a pediatric patient with healthy eyes presents us with new questions about the processes of degeneration thought to be the cause for CC. Further studies are needed to estimate the prevalence of CC in the general adult and pediatric populations, as well as in patients with chorioretinal diseases.

Findings of uncertain significance by optical coherence tomography (OCT) as prognostic factors in neovascular age-related macular degeneration (nAMD) treated with ranibizumab

Background

Biomarkers hold great promise for personalized medicine as information gained from diagnostic or progression markers can be used to tailor treatment to the individual for highly effective intervention in the disease process.

Methods

The aim of this retrospective study was to evaluate the association between visual outcome and the presence of findings of uncertain significance by optical coherence tomography (OCT) pre and post loading dose in patients with neovascular age-related macular degeneration (nAMD) treated with ranibizumab.

Results

Univariate analysis revealed a higher letter gain in those with presence of onion sign (+ 5.6 ETDRS letters, p = 0.04) absence of prechoroidal cleft (+ 3.7 ETDRS letters, p = 0.04), intraretinal pseudocysts (+4.8 ETDRS letters, p = 0.002), subretinal pseudocysts (+ 4.6 ETDRS letters, p = 0.005) and choroidal caverns (+ 4.4 ETDRS, letters p = 0.0065).

Conclusions

The presence of prechoroidal cleft, intraretinal and subretinal pseudocysts and choroidal caverns were associated with lower visual gains. Moreover, we found that the onion sign is related as a biomarker of good prognostics.

Trial registration Registration number: 2021R13B2. Date of registration: 01/05/2020

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.

Choroidal Caverns in Stargardt Disease

Purpose

To report choroidal caverns in patients affected by recessive Stargardt disease (STGD1) and to investigate its clinical features.

Methods

Retrospective analysis of STGD1 patients recruited at the Regional Reference Center for Hereditary Retinal Degenerations at the Eye Clinic in Florence from 2012 to 2017. Patients included in the study underwent a complete ophthalmic examination including best-corrected visual acuity, color fundus photography, fundus autofluorescence, optical coherence tomography (OCT) and OCT angiography.

Results

Eighty-six patients (172 eyes) were included in the study. Twenty-three eyes (13.3%) of 21 patients presented choroidal caverns. The total number of detected choroidal caverns was 63. Choroidal caverns were only present in patients with stage III and IV STGD. Interestingly, patients with choroidal caverns presented larger macular atrophy (20.53 ± 16.9 mm² vs. 18.11 ± 20.39 mm²), worse visual acuity (1.03 ± 0.29 vs. 0.83 ± 0.26), and a thinner choroidal thickness (245.9 ± 88.7 vs. 266.0 ± 110.5 µm).

Conclusions

Choroidal caverns are present only in the advanced stage of STGD1, and a possible degenerative origin of the finding has been hypothesized.

Choroidal caverns in pachychoroid neovasculopathy

Background. Choroid plays an important role in the pathogenesis of retinal pathology. Choroidal cavern, a recently identifi ed fi nding of optical coherent tomography (OCT), has been described in some degenerative and atrophic forms of retinal pathology. In the literature, there are only a few studies of choroidal cavers in pachychoroid neovasculopathy, newly described form of age related macular degeneration.The aim: to perform a detailed analysis of choroidal structure on OCT scans of patients with pachychoroid neovasculopathy and to reveal the frequency of choroidal caverns identifi cation.Material and methods. The data of 30 patients (30 eyes) aged 64.4 ± 5.6 years with pachychoroid neovascularization were retrospectively analyzed. The patients underwent spectral OCT and OCT-angiography (OCTA) using a Spectralis device (Heidelberg Engineering, Germany). The protocol was “Posterior Pole”, consisting of 61 scans. To assess the structure of the choroid, an enhanced image depth (EDI) module was used. OCT angiography was performed with a scan area of 6 × 6 mm. These methods were compared to identify choroidal caverns.Results. On OCT subretinal type 1 neovascularization was revealed as a fl at detachment of the pigment epithelium and visualization of blood flow on OCTA in the lesion as angled vessels (21 eyes) or a seafan (9 eyes). On OCT-EDI scans, there was diffuse or local choroidal thickening of choroid with an increase in the vessels of the Haller’s layer and thinning of the choriocapillaries. Choroidal caverns appeared on OCT and en-face OCT as areas with low optical density, round or irregular, located in different layers of the chorioid, without hyperrefl ective boundaries. A typical sign of choroidal cavern is the tail of hypertransmission after the cavern toward the sclera. Choroidal caverns were found in 4 of 30 eyes (13.3 %) and were located both near the choroidal neovascularization lesion and beyond this area.Conclusion. The prevalence of choroidal cavities, a new choroidal biomarker, in pachychoroid neovasculopathy was 13.3 %. Identification of these changes is possible with the use of modern diagnostic techniques (OCT-EDI, OCTA and en-face OCT) that allow visualization the state of the choroid. The prognostic signifi cance of choroidal cavities requires further study.

RESOLUTION OF A SUBFOVEAL CHOROIDAL CAVERN AFTER HALF-DOSE PHOTODYNAMIC THERAPY FOR CENTRAL SEROUS CHORIORETINOPATHY

PURPOSE

To describe resolution of a subfoveal choroidal cavern after half-dose verteporfin photodynamic therapy for persistent central serous chorioretinopathy.

METHODS

Case report.

RESULTS

A 43-year-old man was referred for treatment of chorioretinopathy in his left eye. On presentation, swept-source optical coherence tomography demonstrated a serous retinal detachment and a 161-μm-thick subfoveal choroidal cavern showing a characteristic tail of hypertransmission extending posteriorly. Subfoveal choroidal thickness measured 456 μm in the affected eye. Complete resolution of subretinal fluid and the subfoveal choroidal cavern were observed 3 months after half-dose verteporfin photodynamic therapy. Twelve months after treatment, subfoveal choroidal thickness had decreased further to 276 μm, and visual acuity had improved to 20/15.

CONCLUSION

After half-dose verteporfin photodynamic therapy for chorioretinopathy, resolution of subretinal fluid was accompanied by resolution of a subfoveal choroidal cavern at 3 months and a 39.5% reduction in subfoveal choroidal thickness at 1 year.

COVID-19 Associated Choroidopathy

The aim of the study is to report on the indocyanine green angiography (ICGA) and OCT findings in patients hospitalized for severe COVID infection. In this observational prospective monocentric cohort study, we included patients hospitalized for severe COVID infection. The main outcomes were ICGA and OCT findings. A total of 14 patients with a mean age of 58.2 ± 11.4 years and a male predominance (9/14 patients; 64%) were included. The main ICGA findings included hypofluorescent spots in 19 eyes (68%), intervortex shunts in 10 eyes (36%), and characteristic "hemangioma-like" lesions in five eyes (18%). "Hemangioma-like" lesions were both unique and unilateral, and showed no washout on the late phase of the angiogram. The main OCT findings included focal choroidal thickening in seven eyes (25%), caverns in six eyes (21%) and paracentral acute middle maculopathy lesions in one eye (4%). All patients hospitalized for severe COVID infection had anomalies on ICGA and OCT. Lesions to both retinal and choroidal vasculature were found. These anomalies could be secondary to vascular involvement related directly or indirectly to the SARS-CoV2 virus.

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.

OCT Biomarkers in Neovascular Age-Related Macular Degeneration: A Narrative Review

Age-related macular degeneration (AMD) is the leading cause of legal blindness in elderly people. Neovascular AMD (nAMD) is responsible for the majority of cases of severe visual loss in eyes with AMD. Optical coherence tomography (OCT) is the most widely used technology for the diagnosis and follow-up of nAMD patients, which is widely used to study and guide the clinical approach, as well as to predict and evaluate treatment response. The aim of this review is to describe and analyze various structural OCT-based biomarkers, which have practical value during both initial assessment and treatment follow-up of nAMD patients. While central retinal thickness has been the most common and one of the first OCT identified biomarkers, today, other qualitative and quantitative biomarkers provide novel insight into disease activity and offer superior prognostic value and better guidance for tailored therapeutic management. The key importance of retinal fluid compartmentalization (intraretinal fluid, subretinal fluid, and subretinal pigment epithelium (RPE) fluid) will be discussed firstly. In the second part, the structural alterations of different retinal layers in various stages of the disease (photoreceptors layer integrity, hyperreflective dots, outer retinal tubulations, subretinal hyperreflective material, and retinal pigment epithelial tears) will be analyzed in detail. The last part of the review will focus on how alterations of the vitreoretinal interface (vitreomacular adhesion and traction) and of the choroid (sub-RPE hyperreflective columns, prechoroidal clefts, choroidal caverns, choroidal thickness and choroidal volume, and choroidal vascular index) interact with nAMD progression. OCT technology is evolving very quickly, and new retinal biomarkers are continuously described. This up-to-date review article provides a comprehensive description on how structural OCT-based biomarkers provide a valuable tool to monitor the progression of the disease and the treatment response in nAMD patients. Thus, in this perspective, clinicians will be able to allocate hospital resources in the best possible way and tailor treatment to the individual patient's needs.

SUBRETINAL DRUSENOID DEPOSIT IN AGE-RELATED MACULAR DEGENERATION: Histologic Insights Into Initiation, Progression to Atrophy, and Imaging

PURPOSE

To clarify the role of subretinal drusenoid deposits (SDD; pseudodrusen) in the progression of age-related macular degeneration through high-resolution histology.

METHODS

In 33 eyes of 32 donors (early age-related macular degeneration, n = 15; geographic atrophy, n = 9; neovascular age-related macular degeneration, n = 7; unremarkable, n = 2), and 2 eyes of 2 donors with in vivo multimodal imaging including optical coherence tomography, examples of SDD contacting photoreceptors were assessed.

RESULTS

Subretinal drusenoid deposits were granular extracellular deposits at the apical retinal pigment epithelium (RPE); the smallest were 4-µm wide. Outer segment (OS) fragments and RPE organelles appeared in some larger deposits. A continuum of photoreceptor degeneration included OS disruption, intrusion into inner segments, and disturbance of neurosensory retina. In a transition to outer retinal atrophy, SDD appeared to shrink, OS disappeared, inner segment shortened, and the outer nuclear layer thinned and became gliotic. Stage 1 SDD on optical coherence tomography correlated with displaced OS. Confluent and disintegrating Stage 2 to 3 SDD on optical coherence tomography and dot pseudodrusen by color fundus photography correlated with confluent deposits and ectopic RPE.

CONCLUSION

Subretinal drusenoid deposits may start at the RPE as granular, extracellular deposits. Photoreceptor OS, RPE organelles, and cell bodies may appear in some advanced deposits. A progression to atrophy associated with deposit diminution was confirmed. Findings support a biogenesis hypothesis of outer retinal lipid cycling.

Progression of Atrophy and Visual Outcomes in Extensive Macular Atrophy with Pseudodrusen-like Appearance

Purpose

Design

Participants

Methods

Main Outcome Measures

Results

Conclusions

Multimodal Imaging Features and Clinical Relevance of Subretinal Lipid Globules

PURPOSE

To describe the presence of subretinal lipid globules (SLG), analyze the multimodal imaging features inherent in their optical properties, and provide a means to distinguish them from other retinal structures and clinical signs.

DESIGN

Retrospective cohort study.

METHODS

The clinical data and multimodal imaging features of 39 patients (49 eyes) showing SLG were evaluated. Patients underwent color fundus photography, near-infrared reflectance (NIR), spectral-domain (SD) and swept-source (SS) optical coherence tomography (OCT) and OCT angiography. In vitro phantom models were used to model OCT optical properties of water, mineral oil, and intralipid droplets and to investigate the optical mechanisms producing hypertransmission tails beneath SLG.

RESULTS

The SLG were not visible in color fundus photographs or in NIR images. With both SD- and SS-OCT B-scans, SLG appeared as 31-157 μm, round, hyporeflective structures demonstrating a characteristic hypertransmission tail previously described with lipid globules found in the choroid and in neovascular membranes. Similarly, with en face OCT, SLG appeared as small, round, hyporeflective structures. SLG were encountered most often in eyes with neovascular age-related macular degeneration (AMD) that had type 1 macular neovascularization (MNV) (91.1%). Of those eyes, 93.3% were receiving intravitreal antivascular endothelial growth factor (VEGF) therapy (median of 15 injections) with a mean follow-up of 52.6 months. The number of prior injections positively correlated with the number of SLG. The detection of MNV preceded the presence of SLG in 66.7% of cases. En face OCT showed that, in many eyes (49%), SLG appeared in clusters of >10. In 38.8% of eyes, SLG were found overlying type 1 MNV, and in 44.9% of eyes, often those with more numerous SLG, the SLG were located near the lesion border. In 2 eyes with AMD followed for nonexudative type 1 MNV, SLG were detected prior to the detection of other imaging signs of exudation. SLG were observed in several other exudative macular diseases. Phantom models demonstrated that the hypertransmission tail beneath SLG is related to a lensing effect produced by these hyporeflective spherical structures.

CONCLUSIONS

SLG are a newly recognized OCT feature frequently seen in eyes receiving intravitreal anti-VEGF therapy for type 1 MNV due to AMD. OCT B-scans show SLG as small, round, hyporeflective structures with a characteristic hypertransmission tail. This OCT signature is influenced by the OCT focal plane, and it relates to reduced signal attenuation through oil and a lensing effect created by a higher refractive index compared to surrounding tissue.

Biometrics, Impact, and Significance of Basal Linear Deposit and Subretinal Drusenoid Deposit in Age-Related Macular Degeneration

Purpose

Basal linear deposit (BLinD) is a thin layer of soft drusen material. To elucidate the biology of extracellular deposits conferring age-related macular degeneration (AMD) progression risk and inform multimodal clinical imaging based on optical coherence tomography (OCT), we examined lipid content and regional prevalence of BLinD, soft drusen, pre-BLinD, and subretinal drusenoid deposit (SDD) in AMD and non-AMD aged eyes. We estimated BLinD volume and illustrated its relation to type 1 macular neovascularization (MNV).

Methods

Donor eyes were classified as early to intermediate AMD (n = 25) and age-matched controls (n = 54). In high-resolution histology, we assessed BLinD/soft drusen thickness at 836 and 1716 locations in AMD and control eyes, respectively. BLinD volume was estimated using solid geometry in donor eyes, one clinically characterized.

Results

BLinD, drusen, type 1 MNV, and fluid occupy the sub-RPE-basal laminar space. BLinD volume in a 3-mm diameter circle may be as much as 0.0315 mm3. Osmophilic lipid was more concentrated in BLinD/drusen than SDD. In the fovea, BLinD/drusen was prevalent in AMD eyes; pre-BLinD was prevalent in control eyes. SDD was low in the fovea and high in perifovea, especially in AMD eyes.

Conclusions

Although invisible, BLinD may presage type 1 MNV. BLinD volume approaches the criterion OCT drusen volume of 0.03 mm3 for AMD progression risk. BLinD culminates years of subfoveal lipid accumulation. SDD is detected relatively late in life, with currently unknown precursors. Deposit topography suggests one outer retinal lipid recycling system serving specialized cone and rod physiology, and its dysregulation in AMD is due to impaired transfer to the circulation.

Focal choroidal excavation and giant choroidal cavern in an eye with pachychoroid

Focal choroidal excavation (FCE) is a localized excavation of the choroid, which can be diagnosed by enhanced depth optical coherence tomography (OCT). Choroidal caverns are focal cavitation areas in the choroid which appear hyporeflective on OCT. These are angular or round, empty spaces with posterior tail of hypertransmission. A 47-year-old female presented to us for a routine eye check-up. The best-corrected visual acuity was 20/20 in both the eyes. On fundus examination, a localized pigmented lesion was seen in the right eye inferior to the optic disc, while the fundus of the left eye was normal. Spectral-domain OCT scan through the lesion showed an FCE and a giant cavern with a posterior tail of hypertransmission. The diameter of the cavern was 977 μ ×264 μ, with a subfoveal choroidal thickness (SFCT) of 360 μ. The SFCT of the other eye was 300 μ. Coexistence of FCE and cavern in an eye with thickened choroid is not yet reported in the literature, and their coexistence provides possible insight into the formation of FCE and caverns in the setting of thickened choroid.

Choroidal Patterns in Retinitis Pigmentosa: Correlation with Visual Acuity and Disease Progression

Purpose

The main aim was to identify different choroidal patterns in retinitis pigmentosa (RP) and to assess their clinical and anatomical meanings after 1 year of follow-up.

Methods

Forty-five patients with RP (29 men; mean age 44.5 ± 11.7 years) and 45 healthy controls (29 men; mean age 44.2 ± 9.8 years) were recruited. Optical coherence tomography (OCT) and OCT angiography (OCTA) images were obtained. By means of structural OCT, the following three choroidal patterns were identified: normal-appearing choroid (pattern 1), reduced Haller and Sattler layers (pattern 2), and pattern 2 + choroidal caverns (pattern 3). Main outcome measures were best-corrected visual acuity (BCVA), central macular thickness (CMT), choroidal thickness (CT), vessel density, vessel tortuosity, vessel dispersion, vessel rarefaction, and choroidal stromal index (CSI).

Results

Mean BCVA was 0.27 ± 0.30 LogMAR for patients with RP and 0.0 ± 0.0 LogMAR for controls (P < 0.01). CMT, CT, CSI, and OCTA parameters were statistically different between patients with RP and controls (P < 0.01). Choroidal patterns 1, 2, and 3 were identified in 20 (44%), 15 (33%), and 10 (23%) patients with RP, respectively. Several statistically significant correlations were also found. Interestingly, after 1 year of follow-up, only the pattern 3 subgroup showed significant worsening of BCVA, CMT, and OCTA parameters (P < 0.01).

Conclusions

Choroidal patterns were associated with different RP clinical forms as well as with different progression after 1 year.

Translational Relevance

Choroidal patterns evaluation may provide useful clinical information for patients with RP.

Choroidal Rift: A New OCT Finding in Eyes with Central Serous Chorioretinopathy

Central serous chorioretinopathy (CSC) is a complex and not entirely understood retinal disease. The aim of our research was to describe a novel optical coherence tomography (OCT) finding named “choroidal rift”, which may be identified in the choroid of eyes with CSC. We collected data from 357 patients (488 eyes) with CSC who had structural OCT and OCT angiography (OCTA) scans obtained. Choroidal rifts were identified as polygonal (and not round-shaped) hyporeflective lesions without hyperreflective margins. Choroidal rifts had to be characterized by a size superior to that of the largest choroidal vessel. Finally, hyporeflective lesions were graded as choroidal rifts only if these lesions had a main development perpendicular to the retinal pigment epithelium. OCT analysis allowed the identification of choroidal rifts in ten eyes from nine patients, all with chronic CSC, with an estimated prevalence rate of 2.1%. In three out of ten cases with choroidal rifts, these lesions spanned all the choroidal layers. In the remaining cases, choroidal rifts only partially spanned the choroidal thickness. In OCTA, choroidal rifts were characterized by the absence of flow. Combining structural OCT and OCTA information, we hypothesized that choroidal rifts may represent interruptions of the choroidal stroma in correspondence of fragile regions (in between expanded larger-sized choroidal vessels). Choroidal rift represents a novel OCT feature, which may characterize eyes with chronic CSC and may have a role in the development of irreversible chorio-retinal changes.

Recognizing Atrophy and Mixed-Type Neovascularization in Age-Related Macular Degeneration Via Clinicopathologic Correlation

Purpose

We explored via multimodal imaging and histology an eye with mixed-types 1 and 2 macular neovascularization (MNV) and complete retinal pigment epithelium (RPE) and outer retinal atrophy (cRORA) in age-related macular degeneration.

Methods

An 82-year-old white man was followed 7 years by optical coherence tomography and treated with intravitreal anti-vascular endothelial growth factor for 3 years. At the last clinic visit, visual acuity was stable at 20/50. Two months later the patient died, and eyes were preserved at 8.33 hours after death. Submicrometer epoxy resin sections of osmicated tissue were stained with toluidine blue and evaluated by oil immersion microscopy.

Results

A shallow irregular RPE elevation on optical coherence tomography correlated with type 1 MNV with fibrocellular scar and neocapillaries (close to RPE), at a density similar to underlying native choriocapillaris (0.37 vs. 0.42). Type 2 MNV covered the native RPE and was enveloped at the margins by RPE, without neocapillaries. Native RPE cells transdifferentiated from age-normal to melanotic and entered type 1 MNV and choroid. Some photoreceptors persisted over MNV. The cRORA initiated at a collapsed druse, expanded during follow-up, and exhibited low choriocapillaris density (0.05).

Conclusions

An eye with maintained vision on 3 years of anti-vascular endothelial growth factor therapy had type 1 MNV sustaining RPE. Type 2 MNV enveloped by RPE was visible in optical coherence tomography and histology. Persistence of photoreceptors and RPE over MNV contrasted with drusen-associated cRORA.

Translational Relevance

Vision during long-term anti-vascular endothelial growth factor treatment persists by MNV partially preserving outer retinal cells and by RPE enveloping type 2 MNV.

Hyperreflective Foci and Specks Are Associated with Delayed Rod-Mediated Dark Adaptation in Nonneovascular Age-Related Macular Degeneration

PURPOSE

Hyperreflective foci (HRF) are OCT biomarkers for the progression of nonneovascular age-related macular degeneration (AMD) attributed to anteriorly migrated retinal pigment epithelial cells. We examined associations between rod- and cone-mediated vision and HRF plus smaller hyperreflective specks (HRS); we identified a histologic candidate for HRS.

DESIGN

Cross-sectional study and histologic survey.

PARTICIPANTS

Patients with healthy maculae (n = 34), early AMD (n = 26), and intermediate AMD (n = 41).

METHODS

AMD severity was determined by color fundus photography. In OCT scans, HRF and HRS were counted manually. Vision tests probed cones (best-corrected visual acuity [VA], contrast sensitivity), mixed cones and rods (low-luminance VA, low-luminance deficit, mesopic light sensitivity), or rods (scotopic light sensitivity, rod-mediated dark adaptation [RMDA]). An online AMD histopathologic resource was reviewed.

MAIN OUTCOME MEASURES

Vision in eyes assessed for HRF and HRS; histologic candidate for HRS.

RESULTS

In 101 eyes of 101 patients, HRF and HRS were identified in 25 and 95 eyes, respectively, with good reliability. Hyperreflective foci were present but sparse in healthy eyes, infrequent in early AMD eyes, and frequent but highly variable among intermediate AMD eyes (mean±standard deviation [SD] number per eye, 0.1 ± 0.2, 0.2 ± 0.5, and 1.9 ± 3.4 for healthy, early AMD, and intermediate AMD eyes, respectively). Hyperreflective specks outnumbered HRF in all groups (mean±SD, 4.5 ± 3.2, 6.3 ± 5.8, and 19.4 ± 22.4, respectively). Delayed RMDA was associated strongly with more HRF and HRS (P < 0.0001). Hyperreflective foci also were associated with worse low-luminance VA (P = 0.0117). Hyperreflective specks were associated with worse contrast sensitivity (P = 0.0278), low-luminance VA (P = 0.0010), low-luminance deficit (P = 0.0031), and mesopic (P = 0.0018) and scotopic (P < 0.0001) sensitivity. By histologic analysis, cone lipofuscin was found in outer retinal layers of 25% of healthy aged eyes.

CONCLUSIONS

Hyperreflective foci and HRS are markers of cellular activity associated with visual dysfunction, especially delayed RMDA, an AMD risk indicator assessing efficiency of retinoid resupply. Hyperreflective specks may represent lipofuscin translocating inwardly within cones. HRF and HRS may serve as structural end points in clinical trials targeting AMD stages earlier than atrophy expansion. These results should be confirmed in a larger sample.

CLINICOPATHOLOGIC CORRELATION OF GEOGRAPHIC ATROPHY SECONDARY TO AGE-RELATED MACULAR DEGENERATION

Supplemental Digital Content is Available in the Text.

Direct clinicopathologic correlation of an eye with geographic atrophy secondary to age-related macular degeneration provides histologic correlates of features commonly seen by optical coherence tomography, such as end-stages of drusen, subretinal drusenoid deposit, plaques near the Bruch membrane, and hyporeflective wedge.

Purpose:

In an eye with geographic atrophy (GA) secondary to age-related macular degeneration, we correlated ex vivo histologic features with findings recorded in vivo using optical coherence tomography (OCT), near-infrared reflectance imaging, and fundus autofluorescence.

Methods:

In the left eye of an 86-year-old white woman, in vivo near-infrared reflectance and eye-tracked OCT B-scans at each of 6 clinic visits and a baseline fundus autofluorescence image were correlated with high-resolution histologic images of the preserved donor eye.

Results:

Clinical imaging showed a small parafoveal multilobular area of GA, subfoveal soft drusen, refractile drusen, hyperreflective lines near the Bruch membrane, subretinal drusenoid deposit (reticular pseudodrusen), and absence of hyperautofluorescent foci at the GA margin. By histology, soft drusen end-stages included avascular fibrosis with highly reflective cholesterol crystals. These accounted for hyperreflective lines near the Bruch membrane in OCT and plaques in near-infrared reflectance imaging. Subretinal drusenoid deposit was thick, continuous, extracellular, extensive outside the fovea, and associated with distinctive retinal pigment epithelium dysmorphia and photoreceptor degeneration. A hyporeflective wedge corresponded to ordered Henle fibers without cellular infiltration. The external limiting membrane descent, which delimits GA, was best visualized in high-quality OCT B-scans. Retinal pigment epithelium and photoreceptor changes at the external limiting membrane descent were consistent with our recent histologic survey of donor eyes.

Conclusion:

This case informs on the extent, topography, and lifecycle of extracellular deposits. High-quality OCT scans are required to reveal all tissue features relevant to age-related macular degeneration progression to GA, especially the external limiting membrane descent. Histologically validated signatures of structural OCT B-scans can serve as references for other imaging modalities.

Unique optical coherence tomographic features in age-related macular degeneration

Age-related macular degeneration is a major cause of blindness worldwide characterized by the presence of drusen and leading to retinal pigment epithelium and outer retinal changes in advanced stages. Approximately 10% of eyes with age-related macular degeneration develop neovascular complications and present with retinal or sub-retinal pigment epithelium exudation, hemorrhage, or both. Recent advances in imaging techniques, especially optical coherence tomography (OCT), help in early identification of disease and guide various treatment decisions; however, not all signs are suggestive of ongoing exudation or neovascular activity. Although uncommon, multiple OCT-based signs are reported that may be difficult to appreciate clinically. Prompt identification of these signs such as outer retinal tubulation, cystoid degeneration, or pseudocysts may avoid unnecessary interventions. Moreover, certain OCT-based features involving the choroid, such as prechoridal cleft and choroidal cavern, have also been found in eyes with age-related macular degeneration. We discuss these unique OCT-based signs, their pathogenesis, clinical relevance, and management.

Choroidal cleft simulating choroidal caverns in neovascular age-related macular degeneration

The authors report a case of a female patient affected by neovascular age-related macular degeneration (AMD). In particular, multiple sub-retinal hyperreflective infiltrates were found on optical coherence tomography. Optical coherence tomography examination of her right eye displayed the presence of sub-retinal pigment epithelium hyporeflective spaces located beneath a hyperreflective fibrotic neovascularization. This case highlights the importance of differentiating choroidal clefts from choroidal caverns.

ASSOCIATION BETWEEN CHOROIDAL CAVERNS AND CHOROIDAL VASCULAR HYPERPERMEABILITY IN EYES WITH PACHYCHOROID DISEASES

PURPOSE

To investigate the association between choroidal caverns, choroidal vascular hyperpermeability (CVH), and pachyvessels in eyes with pachychoroid disease.

METHODS

This was a retrospective review of swept-source optical coherence tomography and indocyanine green angiography imaging performed on eyes with pachychoroid disease.

RESULTS

Imaging from 21 eyes with pachychoroid disease entities (8 eyes with pachychoroid pigment epitheliopathy, 11 eyes with central serous chorioretinopathy, and 3 eyes with pachychoroid neovasculopathy) from 11 patients (mean 49.5 years, male/female: 10/1, all white) was available for review. In all study eyes, pachyvessels traversed the areas of CVH visible in mid- and late-phase indocyanine green angiography. A total of 504 choroidal caverns were identified in 11 study eyes (52%). Of the 504 choroidal caverns, 445 (88%) were seen within the areas of CVH compared with 59 (12%), which were detected outside the areas of CVH (P < 0.001). Eyes with multiple caverns had an increased choroidal thickness when compared with eyes with ≤1 cavern (P < 0.001).

CONCLUSION

Choroidal caverns, found primarily in the areas of indocyanine green angiography CVH traversed by pachyvessels, were detected in 52% of eyes with pachychoroid disease. The presence of choroidal caverns in these cases may indicate a loss of normal choroidal architecture associated with dilated Haller layer veins and increased choroidal thickness.

Ultrastructural analysis of submacular choriocapillaris and its transport systems in AMD and aged control eyes

The choriocapillaris is the source of nutrients and oxygen for photoreceptors, which consume more oxygen per gram of tissue than any other cell in the body. The purpose of this study was to evaluate and compare the ultrastructure of the choriocapillaris and its transport systems in patients with and without age-related macular degeneration (AMD). Ultrastructural changes were also evaluated in subjects that were homozygous for polymorphisms in high risk CFH alleles (Pure 1) only or homozygous only for high risk ARMS2/HTRA1 (Pure 10) alleles. Tissue samples were obtained from the macular region of forty male (n = 24) and female (n = 16) donor eyes and prepared for ultrastructural studies with transmission electron microscopy (TEM). The average age of the aged donors was 74 ± 7.2 (n = 30) and the young donors 31.7 ± 11.25 (n = 10). There was no significant difference in average ages between the adult groups. TEM images of the capillaries in the choriocapillaris (CC) were taken at 4,000X and 25,000X and used to measure the area of endothelial cell somas, the number of fenestrations, and area of caveolae within the endothelial cells per length of Bruchs membrane (BrMb). The Student t-test and Wilcoxon sum rank test were used to determine significant differences. There was no significant difference between young subjects and aged controls in any of the morphological criteria assessed. There was a significant decrease in the number of fenestrations/mm of BrMb in atrophic areas of GA eyes (p = 0.007) when compared with aged control eyes. A significant increase was found in the caveolae area as a percent of the endothelial cell soma of capillaries from GA subjects as compared with the controls (p = 0.03). Loss of capillary segments in choriocapillaris was also evident, especially in areas of geographic atrophy and CNV. In eyes from patients with sequence variations, the capillary endothelial cells often appeared degenerative and exhibited atypical fenestrations and pericytes covering the blood vessels. Subjects that were homozygous for polymorphisms in high risk CFH alleles only had more fenestrations/mm of BrMb than subjects that were homozygous only for high risk ARMS2/HTRA1 alleles (p = 0.04), while the latter had greater caveolae area/endothelial cell area than the former (p = 0.007). This study demonstrated an attenuation of CC and a significant decline in the two major transport systems in CC endothelial cells in AMD. This may contribute to drusen deposition, nutrient transport, and vision loss in AMD subjects.

Antecedents of Soft Drusen, the Specific Deposits of Age-Related Macular Degeneration, in the Biology of Human Macula

AMD pathobiology was irreversibly changed by the recent discovery of extracellular cholesterol-containing deposits in the subretinal space, between the photoreceptors and retinal pigment epithelium (RPE), called subretinal drusenoid deposits (SDDs). SDDs strikingly mirror the topography of rod photoreceptors in human macula, raising the question of whether an equivalent process results in a deposition related to foveal cones. Herein we propose that AMD's pathognomonic lesion-soft drusen and basal linear deposit (BLinD, same material, diffusely distributed)-is the leading candidate. Epidemiologic, clinical, and histologic data suggest that these deposits are most abundant in the central macula, under the fovea. Strong evidence presented in a companion article supports the idea that the dominant ultrastructural component is large apolipoprotein B,E-containing lipoproteins, constitutively secreted by RPE. Lipoprotein fatty acids are dominated by linoleate (implicating diet) rather than docosahexaenoate (implicating photoreceptors); we seek within the retina cellular relationships and dietary drivers to explain soft druse topography. The delivery of xanthophyll pigments to highly evolved and numerous Müller cells in the human fovea, through RPE, is one strong candidate, because Müller cells are the main reservoir of these pigments, which replenish from diet. We propose that the evolution of neuroglial relations and xanthophyll delivery that underlie exquisite human foveal vision came with a price, that is, soft drusen and sequela, long after our reproductive years.