Ocular coherence tomography angiography features of congenital hypertrophy of retinal pigment epithelium

Advances in multimodal imaging for diagnosis of pigmented ocular fundus lesions

Pigmented ocular fundus lesions can range from benign to malignant. While observation is reasonable for asymptomatic benign lesions, early recognition of tumours that are vision or life threatening is critical for long-term prognosis. With recent advances and increased accessibility of multimodal imaging, it is important that providers understand how to best use these tools to detect tumours that require early referral to subspecialty centres. This review aims to provide an overview of pigmented ocular fundus lesions and their defining characteristics using multimodal imaging. We cover the spectrum of pigmented ocular fundus lesions, including freckle and focal aggregates of normal or near-normal uveal melanocytes, retinal pigment epithelium (RPE) hyperplasia, congenital hypertrophy of the RPE, RPE hamartoma associated with familial adenomatous polyposis, congenital simple hamartoma of the RPE, combined hamartoma of the retina and RPE (congenital hypertrophy of the RPE), choroidal nevus, melanocytosis, melanocytoma, melanoma, adenoma, and RPE adenocarcinoma. We describe key diagnostic features using multimodal imaging modalities of ultra-widefield fundus photography, fundus autofluorescence, optical coherence tomography (OCT), enhanced-depth imaging OCT, ultrasonography, fluorescein angiography, indocyanine green angiography, and OCT angiography (OCTA), with particular attention to diagnostic features that could be missed on fundus examination alone. Finally, we review what is on the horizon, including applications of artificial intelligence. Through skilled application of current and emerging imaging technologies, earlier detection of sight- and life-threatening melanocytic ocular fundus tumours can lead to improved patient prognosis.

Retinal Vascular Patterns and Capillary Plexus Reflectivity of Intraocular Tumors; an Optical Coherence Tomography Angiography Study

PURPOSE

To define the vascular characteristics of malignant and benign intraocular tumors by optical coherence tomography angiography (OCTA) and consequently to determine the advantages and disadvantages of the imaging technique in clinical practice.

MATERIALS AND METHODS

This prospective, descriptive study consisted of choroidal hemangioma, choroidal nevus, choroidal melanoma, ocular melanocytoma, congenital hypertrophy of retinal pigment epithelium (CHRPE), and choroidal osteoma. Retinal angiography images were taken by OCTA in a 6 × 6 mm HD scan protocol. OCTA characteristics were defined by considering different tumor types separately.

RESULTS

This study included 93 eyes of 90 patients diagnosed with benign or malignant intraocular tumors. The mean age of the patients was 48.9 ± 16.9 years in the hemangioma group, 55.3 ± 12.9 years in the nevus group, 48.2 ± 13.4 years in the melanoma group, 48 ± 18.9 years in the melanocytoma group, 45 ± 22.9 years in the CHRPE group, and 27.8 ± 7.8 years in the osteoma group. We showed four vascular patterns at the level of the choriocapillaris layer in circumscribed choroidal hemangiomas-the appearance of a 'bag of worms', club-like appearance, giant choroidal vessels and normal choriocapillaris. The rates of these vascular patterns were 40%, 30%, 10%, and 20% in treatment-naïve hemangiomas and were 46.1%, 30.8%, 7.7%, and 15.4% in photodynamic therapy-treated hemangiomas, respectively. There was no different vascular structure in the tumor associated with the lesion in the nevus group. There were three different patterns at the choriocapillaris level in the melanomas-a vascular network (10%), avascular areas (30%) and vascular loops (60%). There were some atypical and non-specific vascular changes demonstrated in the CHRPE and osteoma groups and a fine vascular network was observed in the melanocytoma group.

CONCLUSION

The different types of intraocular tumors had specific vascular characteristics which were easily demonstrated by the OCTA machine. This imaging technique can be a useful tool to differentiate these intraocular tumors non-invasively.

In vivo visualization of variable photoreceptor alteration in a case of peripapillary congenital hypertrophy of the retinal pigment epithelium using spectralis ® high magnification module

Purpose

To analyze using the high magnification module (HMM) a case of peripapillary congenital hypertrophy of retinal pigment epithelium (CHRPE) and to correlate the findings to multimodal imaging and swept-source optical coherence tomography angiography (SS-OCTA, PLEX® Elite 9000, Carl Zeiss Meditec, Dublin, California, USA) imaging.

Observations

A 57-year-old Caucasian woman presenting a peripapillary CHRPE of the left eye (LE) was examined using HMM and SS-OCTA, in addition to multimodal imaging. SS-OCTA disclosed the gradual changes, with four distinguishable zones: Zone 1 with complete outer retinal and retinal pigment epithelium (RPE) atrophy, Zones 2 and 3, corresponding to incomplete outer retinal (and RPE) atrophy presenting increased flow deficits, and normal choriocapillaris outside the lesion (Zone 4). High Magnification Module (HMM, Spectralis ®, Heidelberg Engineering) showed small polygonal hyperreflective outlines over the pigmented parts of the lesion (Zone 2), and partly over the narrow halo surrounding the lesion (Zone 3), with an absence of these outlines over the lacunae (Zone 1).

Conclusions and importance

HMM is a non-invasive imaging modality, allowing the in vivo visualization of a mosaic pattern, corresponding to the hyperreflective polygonal outlines, or absence thereof, in different zones of CHRPE.

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High magnification module (HMM) is a non-invasive imaging modality.

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HMM allows the visualization of a mosaic pattern/ absence thereof in congenital hypertrophy of retinal pigment epithelium

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This may help improve the understanding and diagnosis of photoreceptor alteration in CHRPE.

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.

In patients with a positive family history of familial adenomatous polyposis can the condition be diagnosed from the presence of congenital hypertrophy of the retinal pigment epithelium detected via an eye examination: A systematic review

In classic familial adenomatous polyposis (FAP) adenomas become malignant. Congenital hypertrophy of the retinal pigment epithelium (CHRPE) is a retinal pigmented lesion and is the earliest and most common potential extraintestinal manifestation of FAP. This review aims to summarize and analyse all of the published data on CHRPE in patients with classic FAP and then ascertain whether these patients should undergo a relatively cheap and non-invasive dilated fundus examination to screen for CHRPE. Adhering to Preferred Reporting Items for Systematic Reviews and Meta Analyses guidelines our database search identified 102 relevant articles of which 13 were selected for further analysis. The percentage of FAP patients with CHRPE was found to be 80.00%, whereas the percentage of at-risk patients with CHRPE was 31.12%. Despite various statistically significant findings, CHRPE alone cannot be used as a surrogate for diagnosing FAP in those with a positive family history. The authors advocate a combined approach of eye examinations, colonoscopy and genetic testing.