Swept-source optical coherence tomography features of choroidal nevi

CAVITARY CHOROIDAL NEVUS SHOWING THICKNESS FLUCTUATIONS IN RESPONSE TO ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR THERAPY FOR DIABETIC MACULAR EDEMA: A CASE REPORT

PURPOSE

The purpose of this study was to report the multimodal imaging features of a cavitary choroidal nevus showing thickness fluctuations that mirrored the response of diabetic macular edema (DME) to intravitreal antivascular endothelial growth factor (VEGF) therapy.

METHODS

This is a retrospective case report. Multimodal imaging findings including fundus photography, optical coherence tomography (OCT), fluorescein and indocyanine green angiography, OCT-angiography (OCTA), and B-scan ultrasonography were analyzed.

RESULTS

A woman in her 80s with a cavitary choroidal nevus and DME was treated with intravitreal anti-VEGF therapy using a pro re nata regimen over 5 years. The choroidal nevus showed thickness fluctuations paralleling the response of DME to anti-VEGF therapy. Worsening of the DME was associated with marked increased choroidal lesion thickness on OCT. Conversely, resolution of DME after intravitreal anti-VEGF injections was followed by choroidal lesion flattening on OCT. Variations of the choroidal lesion thickness were mainly dependent on changes of intralesional hyporeflective caverns on OCT.

CONCLUSION

Our report shows thickness variations of a cavitary choroidal nevus that paralleled the clinical course of DME treated with intravitreal anti-VEGF therapy. To the best of our knowledge, this is the first report on volume variations of a cavitary choroidal nevus after anti-VEGF therapy.

Multispectral Fundus Photography of Choroidal Nevi With Trans-Palpebral Illumination

Purpose

The purpose of this study was to investigate the spectral characteristics of choroidal nevi and assess the feasibility of quantifying the basal diameter of choroidal nevi using multispectral fundus images captured with trans-palpebral illumination.

Methods

The study used a widefield fundus camera with multispectral (625 nm, 780 nm, 850 nm, and 970 nm) trans-palpebral illumination to examine eight subjects diagnosed with choroidal nevi. Geometric features of nevi, including border clarity, overlying drusen, and lesion basal diameter, were characterized. Clinical imagers, including scanning laser ophthalmoscopy (SLO), autofluorescence (AF), and optical coherence tomography (OCT), were utilized for comparative assessment.

Results

Fundus images depicted nevi as dark regions with high contrast against the background. Near-infrared (NIR) fundus images provided enhanced visibility of lesion borders compared to visible fundus images and SLO images. Lesion-background contrast measurements revealed 635 nm SLO at 11% and 625 nm fundus at 42%. Significantly enhanced contrasts were observed in NIR fundus images at 780 nm (73%), 850 nm (63%), and 970 nm (67%). For quantifying the diameter of nevi, NIR fundus images at 780 nm and 850 nm yielded a deviation of less than 10% when compared to OCT measurements.

Conclusions

NIR fundus photography with trans-palpebral illumination enhances nevi visibility and boundary definition compared to SLO. Agreement in diameter measurements with OCT validates the accuracy and reliability of this method for choroidal nevi assessment.

Translational Relevance

Multispectral fundus imaging with trans-palpebral illumination improves choroidal nevi visibility and accurately measures basal diameter, promising to enhance clinical practices in screening, diagnosis, and monitoring of choroidal nevi.

Multispectral Fundus Photography of Choroidal Nevi with Trans-Palpebral Illumination

Purpose

To investigate the spectral characteristics of choroidal nevi and assess the feasibility of quantifying the basal diameter of choroidal nevi using multispectral fundus images captured with trans-palpebral illumination.

Methods

The study employed a widefield fundus camera with multispectral (625 nm, 780 nm, 850 nm, and 970 nm) trans-palpebral illumination. Geometric features of choroidal nevi, including border clarity, overlying drusen, and lesion basal diameter, were characterized. Clinical imagers, including scanning laser ophthalmoscopy (SLO), autofluorescence (AF), and optical coherence tomography (OCT), were utilized for comparative assessment.

Results

Fundus images captured with trans-palpebral illumination depicted nevi as dark regions with high contrast against the background. Near-infrared (NIR) fundus images provided enhanced visibility of lesion borders compared to visible light fundus images and SLO images. Lesion-background contrast measurements revealed 635 nm SLO at 11% and 625 nm fundus at 42%. Significantly enhanced contrasts were observed in NIR fundus images at 780 nm (73%), 850 nm (63%), and 970 nm (67%). For quantifying the basal diameter of nevi, NIR fundus images at 780 nm and 850 nm yielded a deviation of less than 10% when compared to OCT B-scan measurements.

Conclusion

NIR fundus photography with trans-palpebral illumination enhances nevi visibility and boundary definition compared to SLO. Agreement in basal diameter measurements with OCT validates the accuracy and reliability of this method for choroidal nevi assessment.

STELLATE MULTIFORM AMELANOTIC CHOROIDOPATHY: Clinical and Multimodal Imaging Features

PURPOSE

To describe the clinical and multimodal imaging features of stellate multiform amelanotic choroidopathy (SMACH; also known as serous maculopathy due to aspecific choroidopathy).

METHODS

Retrospective observational case series of eyes presenting with SMACH. Multimodal imaging including fundus photography, optical coherence tomography (OCT), OCT angiography (OCTA), and indocyanine green angiography (ICGA) was analyzed.

RESULTS

Eighteen eyes from 18 patients (mean age: 28 ± 19 years) were included. The mean follow-up duration was 9 years. Ophthalmoscopy showed a yellowish orange, dendriform choroidal lesion. At presentation, subretinal fluid (SRF) was seen in 10 of 18 cases (56%). Eight patients (44%) showed no evidence of SRF during a mean follow-up of 6 years. Cross-sectional OCT showed hyperreflective fibrous-like changes within the inner choroid with choriocapillaris flow preservation on OCTA. En face OCT showed a hyperreflective choroidal lesion with finger-like projections oriented in a stellate configuration. On ICGA, SMACH showed early and late hypofluorescence. None of the cases showed lesion growth.

CONCLUSION

SMACH seems to be a unilateral choroidopathy characterized by distinctive multimodal imaging features. As SRF was absent in some cases, while a dendriform pattern was a consistent finding in all eyes, the authors propose renaming this entity "stellate multiform amelanotic choroidopathy," a name that retains its previous abbreviation "SMACH."

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.

CAVITARY CHOROIDAL NEVUS: A CASE REPORT

PURPOSE

To describe a case of choroidal nevus with intralesional cavitations detected with enhanced depth imaging optical coherence tomography and to show its changes during an 8-year follow-up.

METHODS

A case report.

RESULTS

A 55-year-old male patient was found to have a pigmented lesion at the posterior pole of his right eye, just temporal to the fovea. A complete multiimaging examination was obtained and showed a lesion of about 4 mm of diameter with a small amount of subretinal fluid and chronic changes in the retina overlying the lesion. Based on clinical examination, a diagnosis of choroidal nevus was made, but interestingly the enhanced depth imaging optical coherence tomography revealed the presence of intralesional cavitations. Close follow-up with no intervention was planned, and over 8 years of observation, the lesion remained stable in size, with a gradual increase of the central necrosis.

CONCLUSION

Benign pigmented choroidal lesions can show internal cavitations likely secondary to internal necrosis. This feature does not represent a sign of malignancy of the lesion. Enhanced depth imaging optical coherence tomography is a feasible imaging tool for the visualization of the internal cavitations and to follow their evolution over time.

Choriocapillaris: Fundamentals and advancements

The choriocapillaris is the innermost structure of the choroid that directly nourishes the retinal pigment epithelium and photoreceptors. This article provides an overview of its hemovasculogenesis development to achieve its final architecture as a lobular vasculature, and also summarizes the current histological and molecular knowledge about choriocapillaris and its dysfunction. After describing the existing state-of-the-art tools to image the choriocapillaris, we report the findings in the choriocapillaris encountered in the most frequent retinochoroidal diseases including vascular diseases, inflammatory diseases, myopia, pachychoroid disease spectrum disorders, and glaucoma. The final section focuses on the development of imaging technology to optimize visualization of the choriocapillaris as well as current treatments of retinochoroidal disorders that specifically target the choriocapillaris. We conclude the article with pertinent unanswered questions and future directions in research for the choriocapillaris.

Application of Multimodal and Molecular Imaging Techniques in the Detection of Choroidal Melanomas

Choroidal melanomas are the most common ocular malignant tumors worldwide. The onset of such tumors is insidious, such that affected patients often have no pain or obvious discomfort during early stages. Notably, enucleation is required for patients with a severe choroidal melanoma, which can seriously impact their quality of life. Moreover, choroidal melanomas metastasize early, often to the liver; this eventually causes affected patients to die of liver failure. Therefore, early diagnosis of choroidal melanomas is extremely important. Unfortunately, an early choroidal melanoma is easily confused with a choroidal nevus, which is the most common benign tumor of the eye and does not often require surgical treatment. This review discusses recent advances in the use of multimodal and molecular imaging to identify choroidal melanomas and choroidal nevi, detect early metastasis, and diagnose patients with choroidal melanomas.

Retinal applications of swept source optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA)

The advent of optical coherence tomography (OCT) revolutionized both clinical assessment and research of vitreoretinal conditions. Since then, extraordinary advances have been made in this imaging technology, including the relatively recent development of swept-source OCT (SS-OCT). SS-OCT enables a fast scan rate and utilizes a tunable swept laser, thus enabling the incorporation of longer wavelengths than conventional spectral-domain devices. These features enable imaging of larger areas with reduced motion artifact, and a better visualization of the choroidal vasculature, respectively. Building on the principles of OCT, swept-source OCT has also been applied to OCT angiography (SS-OCTA), thus enabling a non-invasive in depth-resolved imaging of the retinal and choroidal microvasculature. Despite their advantages, the widespread use of SS-OCT and SS-OCTA remains relatively limited. In this review, we summarize the technical details, advantages and limitations of SS-OCT and SS-OCTA, with a particular emphasis on their relevance for the study of retinal conditions. Additionally, we comprehensively review relevant studies performed to date to the study of retinal health and disease, and highlight current gaps in knowledge and opportunities to take advantage of swept source technology to improve our current understanding of many medical and surgical chorioretinal conditions. We anticipate that SS-OCT and SS-OCTA will continue to evolve rapidly, contributing to a paradigm shift to more widespread adoption of new imaging technology to clinical practice.

Swept-source optical coherence tomography angiography findings in choroidal and retinal tumors

OBJECTIVES

To report the swept-source optical coherence tomography angiography (SS-OCTA) findings in choroidal and retinal tumors.

METHODS

A retrospective noncomparative interventional case series of 60 eyes having various choroidal and retinal tumors imaged with SS-OCTA (Topcon DR1 Triton Plus, Tokyo, Japan) between September 2018 and February 2020 was conducted. Inclusion criteria were tumor thickness <4 mm, tumor base diameter <10 mm, and tumor location at the posterior pole.

RESULTS

Choroidal nevi usually demonstrated well-defined borders, hyperreflective internal structure, and no outer retinal involvement on SS-OCTA. Choroidal melanoma, in contrast to nevi, usually had ill-defined borders (p = 0.018), mixed hyperreflective-hyporeflective or hyperreflective internal structure (p = 0.014), and demonstrated outer retinal involvement (p < 0.001). Circumscribed choroidal hemangioma usually presented with well-defined borders, a hyperreflective internal tumor structure with multiple dilated interconnected tumor vessels intermixed with signal void areas representing connective tissue. Optic disc melanocytomas showed a hyporeflective plexus related to blocking of signal by the pigment and an intact radial peripapillary capillary network. There was flow on the surface and slightly deeper within the lesion on B-scan angiography overlay. Retinal astrocytic hamartomas had well-defined borders and a hyperreflective vascular plexus in the superficial and deep retina. Outer retina and choriocapillaris showed hyporeflective change due to shadowing/masking from calcium or high blood flow in the lesion.

CONCLUSIONS

Each of the different retinal and choroidal tumors studied in this series presented with different SS-OCTA features to aid in the differential diagnosis of these conditions. Good quality images are obtained in patients with good fixation and tumors <3 mm in thickness located at the posterior pole.

Ultra-wide-field imaging assessment of small choroidal pigmented lesions using red and green colour channels

BACKGROUND

Diagnosis of small choroidal melanoma is mainly based on tumour thickness, subretinal fluid, or lipofuscin pigment. Ultra-wide-field imaging (UWF) allows depiction of choroidal lesions through a red (RC) and a green channel (GC). Aim of the study was to determine the utility of this tool in the detection of small choroidal melanoma.

METHODS

Retrospective cross-sectional study of patients with small choroidal pigmented lesions up to 3 mm in thickness. All patients underwent clinical and imaging assessment including UWF. Lesions were subcategorized based on thickness and lesion type. A qualitative assessment ensued using the red and green channels feature.

RESULTS

A total of 152 patients were included. Melanotic naevi (76/152,50%) and small choroidal melanomas (55/152,36%) were the predominant types. Thickness was <1 mm in 30% (46/152), 1-2 mm in 46% (70/152) and 2-3 mm in 24% (36/152) of cases. Two distinct imaging patterns were noted: dark on RC/undetectable on GC and dark on RC/light on GC. In melanotic naevi the dark on RC/light on GC pattern was significantly associated with increased tumour thickness (p = 0.006) and the presence of lipofuscin (p < 0.001) suggesting a potential prognostic significance. In small melanomas such an association was not established. The majority of small melanomas manifested a dark on RC/undetectable on GC pattern despite the presence of subretinal fluid and lipofuscin.

CONCLUSIONS

UWF imaging of choroidal pigmented tumours with red-green channels revealed two distinct patterns. The dark on RC/light on GC pattern was more common in suspicious melanotic naevi, but not in small melanomas. The use of red-green channels is not a reliable diagnostic tool in the early detection of small melanomas.

Integrated bioinformatics analysis of aberrantly-methylated differentially-expressed genes and pathways in age-related macular degeneration

Background

Age-related macular degeneration (AMD) represents the leading cause of visual impairment in the aging population. The goal of this study was to identify aberrantly-methylated, differentially-expressed genes (MDEGs) in AMD and explore the involved pathways via integrated bioinformatics analysis.

Methods

Data from expression profile GSE29801 and methylation profile GSE102952 were obtained from the Gene Expression Omnibus database. We analyzed differentially-methylated genes and differentially-expressed genes using R software. Functional enrichment and protein–protein interaction (PPI) network analysis were performed using the R package and Search Tool for the Retrieval of Interacting Genes online database. Hub genes were identified using Cytoscape.

Results

In total, 827 and 592 genes showed high and low expression, respectively, in GSE29801; 4117 hyper-methylated genes and 511 hypo-methylated genes were detected in GSE102952. Based on overlap, we categorized 153 genes as hyper-methylated, low-expression genes (Hyper-LGs) and 24 genes as hypo-methylated, high-expression genes (Hypo-HGs). Four Hyper-LGs (CKB, PPP3CA, TGFB2, SOCS2) overlapped with AMD risk genes in the Public Health Genomics and Precision Health Knowledge Base. KEGG pathway enrichment analysis indicated that Hypo-HGs were enriched in the calcium signaling pathway, whereas Hyper-LGs were enriched in sphingolipid metabolism. In GO analysis, Hypo-HGs were enriched in fibroblast migration, membrane raft, and coenzyme binding, among others. Hyper-LGs were enriched in mRNA transport, nuclear speck, and DNA binding, among others. In PPI network analysis, 23 nodes and two edges were established from Hypo-HGs, and 151 nodes and 73 edges were established from Hyper-LGs. Hub genes (DHX9, MAPT, PAX6) showed the greatest overlap.

Conclusion

This study revealed potentially aberrantly MDEGs and pathways in AMD, which might improve the understanding of this disease.

Objective Evaluation of Proliferative Diabetic Retinopathy Using OCT

PURPOSE

To present the routine use of OCT and OCT angiography (OCTA) for the objective diagnosis and monitoring of proliferative diabetic retinopathy (PDR).

DESIGN

Retrospective, observational case series.

PARTICIPANTS

Patients with diabetic retinopathy imaged using a standardized PDR protocol.

METHODS

Patients routinely imaged with a standardized PDR protocol between March 2017 and January 2019 were included. This included a 12×9-mm structural OCT volume centered on the macula and a 6×6-mm OCTA scan centered on the optic nerve head obtained using a Topcon swept-source system (DRI OCT-1 Triton, Topcon, Tokyo, Japan). Ultra-widefield fluorescein angiography (FA) was also performed when clinically indicated. The ground truth for each case was determined by merging the findings from biomicroscopy and imaging modalities to generate the maximum level of detection for each finding.

MAIN OUTCOME MEASURES

Detection rates of new-onset, regression, and reactivation of neovascularization of the disc (NVD) and neovascularization elsewhere (NVE) using different modalities (biomicroscopy/color photography, structural OCT, B-scan OCTA, en face OCTA). Detection of progression of tractional retinal detachment (TRD).

RESULTS

A total of 383 eyes of 204 patients were evaluated. After excluding patients without PDR or with insufficient image quality, 47 eyes of 35 patients were included. For the detection of new-onset NVD and NVE, structural OCT had the highest detection rate (100%) of all modalities. However, for the detection of regression or reactivation of neovascularization (NV), B-scan OCTA had the highest detection rate (100%). Structural OCT detected regression only in 45.5% of cases, resulting in a low detection rate of reactivation (12.5%). Among 10 eyes with TRD, OCT detected fovea-threatening TRD during follow-up in 7 eyes, resulting in vitrectomy.

CONCLUSIONS

This study demonstrates the utility of novel multimodal imaging in the daily management of patients with PDR. Posterior pole structural OCT had the best detection rate for NV, and B-scan OCTA showed the most potential for objective monitoring of disease after treatment.

Is optical coherence tomography angiography helpful in the differential diagnosis of choroidal nevus versus melanoma?

PURPOSE

To describe the imaging features of choroidal nevus and melanoma using optical coherence tomography angiography, and evaluate the ability of this technique to establish the differential diagnosis based on the display of the tumor's intrinsic vasculature.

METHODS

Comparative analysis of optical coherence tomography angiography findings in consecutive patients diagnosed with choroidal nevus or choroidal melanoma following a complete ophthalmic evaluation, including best-corrected visual acuity and several imaging studies: color fundus photography, B-scan ultrasound, spectral-domain optical coherence tomography, and optical coherence tomography angiography. Optical coherence tomography angiography was used to investigate qualitative differences in the tumor vasculature.

RESULTS

Thirty-six eyes (18 cases of choroidal nevus and 18 cases of choroidal melanoma) from 36 consecutive patients were included in the study. Only cases located posterior to equator were included to enable performance of all tests. On optical coherence tomography angiography, choroidal nevus showed well-delimited margins (78%), hyperreflective choroid capillary vasculature (83%), fewer avascular areas (17%), and neovascular membrane in one case (6%). Choroidal melanoma showed imprecise margins (72%), hyporeflective choroidal capillary vasculature (72%), multiple avascular areas (78%), and choroidal vascular changes (e.g. thick vascular networks or vascular loops; 45%).

CONCLUSION

Optical coherence tomography angiography can provide useful information for assessing and differentiating between choroidal nevi and small melanomas. Significant differences between these conditions were found for the pattern of reflectivity, and presence/absence of avascular zones and vascular anomalies, which could be helpful for supporting the diagnosis.

POSTERIOR SCLERAL MELANOCYTOSIS: A NOVEL FUNDUS FINDING MASQUERADING AS A CHOROIDAL NEVUS

PURPOSE

To report a case of "posterior scleral melanocytosis," a pigmented lesion of the posterior sclera that clinically resembles a flat choroidal nevus.

METHODS

Case report of a patient with posterior scleral melanocytosis. Multimodal imaging, including swept source optical coherence tomography, was used to demonstrate the scleral location of the pigmented lesion and to distinguish its features from a typical choroidal nevus present in the same eye.

RESULTS

An 86-year-old woman was seen for regular follow-up for neovascular age-related macular degeneration in her right eye and 2 pigmented lesions in her left eye, both presumed to be choroidal nevi. Anterior segment examination showed no evidence of ocular or dermal melanocytosis. Optical coherence tomography of the pigmented lesion in the left eye showed two distinct patterns. One lesion showed hyperreflectivity within the choroidal tissue associated with posterior shadowing, whereas the second lesion showed normal choroidal reflectivity with hyperreflectivity confined to the inner sclera associated with marked posterior shadowing.

CONCLUSION

To the authors' knowledge, this is the first report of posterior scleral melanocytosis, a pigmented fundus lesion confined to the inner sclera. The need for high-penetrance optical coherence tomography to differentiate these lesions from a typical choroidal nevus may explain why this entity has not been previously described. The true nature of this entity will ultimately require histopathologic study.

Soft Drusen in Age-Related Macular Degeneration: Biology and Targeting Via the Oil Spill Strategies

AMD is a major cause of legal blindness in older adults approachable through multidisciplinary research involving human tissues and patients. AMD is a vascular-metabolic-inflammatory disease, in which two sets of extracellular deposits, soft drusen/basal linear deposit (BLinD) and subretinal drusenoid deposit (SDD), confer risk for end-stages of atrophy and neovascularization. Understanding how deposits form can lead to insights for new preventions and therapy. The topographic correspondence of BLinD and SDD with cones and rods, respectively, suggest newly realized exchange pathways among outer retinal cells and across Bruch's membrane and the subretinal space, in service of highly evolved, eye-specific physiology. This review focuses on soft drusen/BLinD, summarizing evidence that a major ultrastructural component is large apolipoprotein B,E-containing, cholesterol-rich lipoproteins secreted by the retinal pigment epithelium (RPE) that offload unneeded lipids of dietary and outer segment origin to create an atherosclerosis-like progression in the subRPE-basal lamina space. Clinical observations and an RPE cell culture system combine to suggest that soft drusen/BLinD form when secretions of functional RPE back up in the subRPE-basal lamina space by impaired egress across aged Bruch's membrane-choriocapillary endothelium. The soft drusen lifecycle includes growth, anterior migration of RPE atop drusen, then collapse, and atrophy. Proof-of-concept studies in humans and animal models suggest that targeting the “Oil Spill in Bruch's membrane” offers promise of treating a process in early AMD that underlies progression to both end-stages. A companion article addresses the antecedents of soft drusen within the biology of the macula.

Enhanced Depth Imaging OCT of Ultrasonographically Flat Choroidal Nevi Demonstrates 5 Distinct Patterns

PURPOSE

To characterize the enhanced depth imaging (EDI) OCT features of ultrasonographically flat choroidal nevi.

DESIGN

Retrospective observational study.

PARTICIPANTS

Patients with ultrasonographically flat choroidal nevi identified over a 3-year period.

METHODS

Comprehensive eye examinations and multimodal imaging were performed every 6 to 12 months.

MAIN OUTCOME MEASURES

Lesion thickness and features, EDI-OCT findings.

RESULTS

A total of 102 nevi (98 patients) were included. Median follow-up was 9 months (range 0-144 months) and 1 to 8 (mean 2.1) OCTs were performed. On OCT, nevi were classified into 5 subtypes: 3.2% were "not visible," 37.2% had "hyperreflectivity confined within normal choroidal thickness," 16.0% had characteristic anteriorly bowed hyperreflectivity with "discrete" borders and cascading edges, 14.9% were "flat with posterior bowing," and 28.7% were "elevated." One nevus of the "elevated" type demonstrated clinically insignificant growth (<10% in thickness) after 22 months of follow-up.

CONCLUSIONS

Five distinct EDI-OCT patterns of choroidal nevi seemed flat on ultrasonography, and many demonstrated thickness and elevation not measurable on B-scan ultrasonography. Lesion thickness can be measured using EDI-OCT.

Polypoidal lesions associated to choroidal naevus: spectrum of pachychoroid disease?

A 78-year-old woman was referred by an optician for an incidental finding of peripapillary naevus in the absence of visual symptoms. On examination, the right eye showed a choroidal naevus of around 1.5 disc diameter, adjacent to the optic disc. Optical coherence tomography detected the presence of pigment epithelium detachment and subretinal fluid within the context of the naevus. Fundus fluorescein angiography and indocyanine green showed multiple polypoidal lesions (Polypoidal Choroidal Vasculopathy, PCV) in the choroid within the spectrum of a pachychoroid, without any sign of malignancy related to neovascularisation. The patient underwent a follow-up of 6 months, showing stability of the lesions over this timeframe. No treatment has been required since the polypoidal lesions were outside the fovea and visual acuity remained stable. The association between choroidal naevi and polypoidal lesions is rare1; however, this seems to confirm that these findings are part of the spectrum of pachychoroid disease.

Evaluation of choroidal lesions with swept-source optical coherence tomography

AIMS

The aim of our study was to image choroidal lesions with swept-source optical coherence tomography (SS-OCT) and to identify the morphological characteristics associated with optimal visualisation.

METHODS

This was a prospective, cross-sectional study. Patients with choroidal melanocytic lesions <3 mm in thickness on B-scan ultrasonography were recruited. All participants underwent SS-OCT. On SS-OCT we evaluated qualitative (eg, lesion outline, detection of scleral-choroidal interface and quality of the image) and quantitative (measurement of maximum lesion thickness and the largest basal diameter) parameters. Probability of optimal image quality was examined using ordered logistic regression models. The main outcome measure was quality of the choroidal lesion images on SS-OCT, defined as: optimal, suboptimal or poor.

RESULTS

We included 85 choroidal lesions of 82 patients. There were 24 choroidal lesions (29%) for which image quality was classified as optimal, 31 lesions (37%) as suboptimal and 30 lesions (36%) as poor. The factors associated with optimal image quality were distance closer to the fovea (OR 0.76, p<0.001), posterior pole location (OR 3.87, p=0.05), lower ultrasonography thickness (OR 0.44, p=0.04), lighter lesion pigmentation (OR 0.12, p=0.003) and smaller lesion diameter (OR 0.73, p<0.001). In the multivariable analysis, closer distance to the fovea (OR 0.81, p=0.005), lighter lesion pigmentation (OR 0.11, p=0.01) and smaller lesion diameter (OR 0.76, p=0.006) remained statistically significant.

CONCLUSION

SS-OCT is useful in imaging most choroidal melanocytic lesions. Image quality is best when the choroidal lesion is closer to the fovea, has a smaller diameter and a lighter choroidal pigmentation.

Swept-source optical coherence tomographic findings in eyes with metastatic choroidal tumor

Purpose

To report the swept-source optical coherence tomographic (OCT) findings in two eyes with choroidal metastases.

Observations

Two patients with choroidal metastasis were studied. The metastasis was from a breast cancer in Case 1 and from a lung cancer in Case 2. In Case 1, swept-source OCT showed a highly reflective solid tumor with low optical reflective tissues that had replaced the choroidal tissue. Swept-source OCT was able to image the choroidal mass where other fundus imaging methods such as fluorescein angiography did not show the mass. Ophthalmoscopy of Case 2 showed hemorrhages in the inner retina, on the tumor, and in the vitreous. Swept-source OCT showed a subretinal mass with a steeple-crowned cap and a ruptured Bruch's membrane on the tumor.

Conclusion and importance

Swept-source OCT imaging can detect the inner structure of a choroidal mass and retina around it in good detail.

En Face Optical Coherence Tomography Angiography Imaging Versus Fundus Photography in the Measurement of Choroidal Nevi

BACKGROUND AND OBJECTIVES

Choroidal nevi are common benign intraocular tumors with a small risk of malignant transformation. This retrospective study investigates the use of en face spectral-domain optical coherence tomography angiography (SD-OCTA) in determining the clinical features and measurement of choroidal nevi.

PATIENTS AND METHODS

Patients with choroidal nevi were imaged with both OCTA and a fundus photography device. Greatest longitudinal dimension (GLD), perpendicular dimension (PD), and the GLD/PD ratio were assessed on each device. Inter-device variation and intra- and inter-rater reliability analyses were performed.

RESULTS

Fourteen patients with choroidal nevi were included. No significant difference between the GLD/PD ratio as measured by all three devices was found (Chi-square = 2.8, 2 df, P = .247). Intraclass correlation coefficients were greater than 0.7 for repeated measures on all devices, suggesting good repeatability and reproducibility.

CONCLUSION

This study demonstrated inter-device consistency and high intra- and inter-rater reliability when measuring choroidal nevi. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:741-747.].

Choroidal Nevus-Associated Neovascular Membrane Demonstrated by OCT Angiography

We present a case of choroidal nevus, complicated by a choroidal neovascular membrane (CNV) that was detected by OCT angiography. Choroidal nevi are relatively common intraocular tumors. The presence of subretinal and intraretinal fluids can indicate that a CNV has occurred as a complication, warranting prompt management. However, subretinal and intraretinal fluids are also documented in nevi without CNV. OCT angiography may be of great help in determining whether those fluids are associated or not with a CNV, therefore guiding therapy.

Adaptive Optics of Small Choroidal Melanoma

The authors report the use of an adaptive optics (AO) system in an asymptomatic patient with small choroidal melanoma. A noninvasive, novel assessment that detected potential photoreceptor abnormalities in the retina overlying the choroidal lesion and adjacent retina is presented. These findings may help current clinical evaluation to monitor structural damage to the outer retina and possibly justify earlier intervention in borderline cases. Future research is warranted to recognize full potential of this imaging modality. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:354-357.].

Choroidal vasculature characteristics based choroid segmentation for enhanced depth imaging optical coherence tomography images

PURPOSE

In clinical research, it is important to measure choroidal thickness when eyes are affected by various diseases. The main purpose is to automatically segment choroid for enhanced depth imaging optical coherence tomography (EDI-OCT) images with five B-scans averaging.

METHODS

The authors present an automated choroid segmentation method based on choroidal vasculature characteristics for EDI-OCT images with five B-scans averaging. By considering the large vascular of the Haller's layer neighbor with the choroid-sclera junction (CSJ), the authors measured the intensity ascending distance and a maximum intensity image in the axial direction from a smoothed and normalized EDI-OCT image. Then, based on generated choroidal vessel image, the authors constructed the CSJ cost and constrain the CSJ search neighborhood. Finally, graph search with smooth constraints was utilized to obtain the CSJ boundary.

RESULTS

Experimental results with 49 images from 10 eyes in 8 normal persons and 270 images from 57 eyes in 44 patients with several stages of diabetic retinopathy and age-related macular degeneration demonstrate that the proposed method can accurately segment the choroid of EDI-OCT images with five B-scans averaging. The mean choroid thickness difference and overlap ratio between the authors' proposed method and manual segmentation drawn by experts were -11.43 μm and 86.29%, respectively.

CONCLUSIONS

Good performance was achieved for normal and pathologic eyes, which proves that the authors' method is effective for the automated choroid segmentation of the EDI-OCT images with five B-scans averaging.

Swept Source optical coherence tomography of choroidal nevi

OBJECTIVE

The aim of this article is to report on retinal and choroidal morphology in choroidal nevi documented with Swept Source optical coherence tomography (SS-OCT).

DESIGN

This is a retrospective, observational study.

PARTICIPANTS

We included 27 consecutive patients with choroidal nevi. Mean age was 66.3 years (21-95 years).

METHODS

The SS-OCT scanning protocol consisted of a single line scan through the centre of the nevi with a resolution of 3 µm, built from 1024 A-scans, with a length of 12 mm. We attempted to visualize the outer choroidoscleral boundary and suprachoroidal layer (SCL) below the choroidal nevus and to observe any other defects of retinal or choroidal morphology.

RESULTS

In all cases, we observed that the inner margin of benign tumours was separated from the retinal pigment epithelium with a hyporeflective band. Melanotic nevi cast partial (41%) or complete shadow (41%) on the underlying structures. The outer choroidoscleral boundary was visible under the tumour in 8 eyes (25%). SCL and suprachoroidal space were noted in 40% of eyes in close proximity to the lesion, but in no case were these lines visible directly below the lesion. Thinning of the choriocapillaries was observed in 8 eyes (25%) and thinning of the choroid in 5 eyes (15.6%).

CONCLUSIONS

Using SS-OCT, we observed that the inner border of benign choroidal lesions was always situated below a hyporeflective band, possibly corresponding to the choriocapillaries. A new finding was that we observed the SCL in 40% of cases. This was always visible in close proximity to the nevus, never directly below it.

A pilot study to compartmentalize small melanocytic choroidal tumors and choroidal vessels with speckle-noise free 1050 nm swept source optical coherence tomography (OCT choroidal "tumoropsy")

PURPOSE

The purpose was to illustrate small melanocytic choroidal tumors with speckle-noise free swept-source optical coherence tomography (SSOCT).

METHODS

Twenty-five small melanocytic choroidal tumors in 24 eyes underwent 1050 nm OCT. All tumors were measured manually with the built-in caliper tool and compared to data derived from a semiautomated algorithm that removed speckle noise but preserved the structure of the tumors from the SSOCT data.

RESULTS

The average manual measurements for the horizontal, vertical, and axial diameters were 1535.28 μm (range, 547-2807 μm), 1713.8 μm (range, 574-3921 μm), and 227.28 μm (range, 115-489 μm), respectively. The measured average volumes of the tumors were 835,248,212 μm(3) (range, 48,818,700 to 4,567,401,810 μm(3)) and 228,588,535 μm(3) (range, 22,879,641 to 787,668,886 μm(3)) for caliper measurements, respectively, for the extracted volumes. The average volume variation between the two methods was 66.16 % (range, 46.5 % to 82.75 %). The average ratio between the caliper and extracted volumes was 3.402 (range, 1.346-8.198, SD 1.681), 2.367 (range, 1.346-3.258, SD 0.618), 2.321 (range, 1.346-3.258, SD 0.611), 2.402 (range, 1.518-3.258, SD 0.591), and 1.749 (range, 1.518-1.733, SD 0.239) for all tumors, all tumors with the exclusion of extreme parameters, tumor <3 mm, tumor <2 mm, and tumor <1 mm, respectively. The average ratio (tumor index) between the tumor volume and the choroidal vessel volume was 12.539 (range, 0.489-73.701).

CONCLUSION

Speckle-noise free swept-source OCT may be an illustrative OCT imaging technology. OCT may be useful for describing and monitoring small melanocytic choroidal tumors and the choroidal vessels.

Wide field of view swept-source optical coherence tomography for peripheral retinal disease

BACKGROUND/AIMS

To assess peripheral retinal lesions and the posterior pole in single widefield optical coherence tomography (OCT) volumes.

METHODS

A wide field of view (FOV) swept-source OCT (WFOV SSOCT) system was developed using a commercial swept-source laser and a custom sample arm consisting of two indirect ophthalmic lenses. Twenty-seven subjects with peripheral lesions (choroidal melanomas, choroidal naevi, sclerochoroidal calcification, retinitis pigmentosa, diabetic retinopathy, retinoschisis and uveitis) were imaged with the WFOV SSOCT. Volumes were taken in primary gaze. Using the optic nerve to fovea distance as a reference measurement, comparisons were made between the lateral FOV of the WFOV SSOCT, current generation spectral-domain OCT (SDOCT) and widefield scanning laser ophthalmoscopy (SLO) of the same eyes.

RESULTS

Peripheral pathologies were captured with WFOV SSOCT in 26 of the 27 subjects. The one not captured was in the far nasal periphery and was not seen in the primary gaze volume. Posterior pole associated pathologies were captured in all subjects. Current generation SDOCT had a mean lateral FOV of 2.08±0.21 optic nerve to fovea distance units, WFOV SSOCT had an FOV of 4.62±0.62 units and SLO had an FOV of 9.35±1.02 units.

CONCLUSIONS

WFOV OCT can be used to examine both peripheral retinal pathology and the posterior pole within a single volume acquisition. SLO had the greatest FOV, but does not provide depth information. Future studies using widefield OCT systems will help further delineate the role of WFOV OCT to quantitatively assess and monitor peripheral retinal disease in three dimensions.

Advanced Clinical Imaging and Tissue-based Biomarkers of the Eye for Toxicology Studies in Minipigs

There is increased interest to use minipigs in ocular toxicology studies due to their anatomical similarities with human eyes and as a substitute for nonhuman primates. This requires adaptation of enhanced optical coherence tomography (OCT) techniques and of ocular relevant immunohistochemistry (IHC) or in situ hybridization (ISH) markers to porcine eyes. In this study, OCT and OCT angiography (AngioOCT) were performed on adult Göttingen minipigs. To increase structural information on retinal and choroidal vasculature, OCT data were speckle denoized and choroidal blood vessels were segmented with threshold filtering. In addition, we established a set of IHC and ISH markers on Davidson's fixed paraffin-embedded minipig eyes: neurofilament-160, neuronal nuclei, calretinin, protein kinase C-α, vimentin, glial fibrillary acidic protein, glutamine synthetase, ionized calcium-binding adaptor molecule-1, rhodopsin, synaptophysin, postsynaptic density protein-95, retinal pigment epithelium (RPE)-specific protein-65, von Willebrand factor, α-smooth muscle actin, desmin, and Ki-67, thus enabling visualization of retinal neuronal and glial cells, photoreceptors, synapses, RPE, blood vessels, myocytes, macrophages, or cell proliferation. Using ISH, transcripts of vascular endothelial growth factor A, angiopoietin-2, and endothelial tyrosine kinase were visualized. This article describes for the first time in minipig eyes speckle noise-free OCT, AngioOCT, and a set of IHC/ISH markers on Davidson's fixed paraffin-embedded tissues and helps to establish the minipig for ocular toxicology and pharmacology studies.

Detection and Intraretinal Localization of an 'Invisible' Retinoblastoma Using Optical Coherence Tomography

PURPOSE

To report the use of handheld spectral-domain optical coherence tomography (HHSD OCT) to identify and define the intraretinal location of a small retinoblastoma that was not detectable by indirect ophthalmoscopy.

METHODS

This is a retrospective case report of a tumor identified with HHSD OCT in a single patient.

RESULTS

A 7-week-old male was diagnosed with unilateral group E retinoblastoma in the right eye. An enucleation was completed successfully with histopathologic confirmation of the diagnosis. The normal left eye was monitored for the development of retinoblastoma, and 10 weeks after diagnosis, three new small retinoblastomas were noted in the posterior pole. Identification of the smallest of the three tumors was facilitated by HHSD OCT; it was adjacent to the optic nerve head, and involved the outer nuclear layer, outer plexiform layer, and inner nuclear layer, with the inner retina draping over the tumor.

CONCLUSION

HHSD OCT can aid the ocular oncologist in the identification of very small retinoblastomas before they are visible to the eye, which allows for earlier and potentially vision-sparing treatment of these lesions. Additionally, the ability to identify these very small tumors and to localize them anatomically within the retinal layers may aid in our understanding of retinoblastoma tumorigenesis.