INVISIBLE, HONEYCOMB-LIKE, CAVITARY RETINAL ASTROCYTIC HAMARTOMA

Role of optical coherence tomography angiography in retinal tumors: A narrative review

Intraocular tumors constitute a small subset of cases in ophthalmologic practice. Proper diagnosis of intraocular tumors is crucial because some pose threat to vision and life, while others may indicate underlying systemic disorders. Intraocular tumors comprise benign and malignant lesions affecting the retina, choroid, optic disc, iris, and ciliary body. Retinal tumors can be classified as vascular, neural, glial, and retinal pigment epithelial tumors. Optical coherence tomography angiography (OCTA) is a noninvasive imaging modality employed in diagnosis and management of retinal and choroidal vascular diseases, and has enhanced our knowledge in better understanding of the vascular physiology and pathology. Multiple case reports and small series evaluating the role of OCTA in retinal tumors are published in literature. OCTA helps in better understanding of the vascularity of intraocular tumors. In addition to this, OCTA has its role in clinical practice. It helps in identification of small retinal capillary hemangioblastoma (RCH), assessment of treatment response, and identification of tumor recurrence in RCH. It aids in identification of retinal astrocytic hamartoma missed on clinical examination and differentiating retinal astrocytic hamartoma and presumed solitary circumscribed retinal astrocytic proliferation. It helps in assessment of risk of tumor recurrence in retinoblastoma. It helps in differentiating tumors of retinal pigment epithelium (RPE) origin from pigmented tumors of the choroid. It also helps in detection of choroidal neovascular membrane in combined hamartoma of the retina and RPE.

The role of near-infrared reflectance imaging in retinal disease: A systematic review

Near-infrared reflectance (NIR) retinal imaging aids in a better visualization of structures at the level of outer retina, retinal pigment epithelium, and choroid. It has multiple advantages, including easy acquisition in association with structural spectral domain optical coherence tomography, more comfort for patients, and enhanced contrast and spatial resolution. It helps in the diagnosis of chorioretinal diseases that present with minimal funduscopic findings and can be used to follow up many chorioretinal conditions. We describe the chorioretinal NIR imaging appearance and the clinical role of NIR imaging in ocular inflammatory disease, vascular and acquired disease, degenerative disease, tumors, associated systemic condition, toxic and traumatic disease, optic nerve head conditions, and physiological findings.

Near-Infrared Reflectance Imaging in Retinal Diseases Affecting Young Patients

Near-infrared reflectance (NIR) is a noninvasive, contactless, and rapid in vivo imaging technique for visualizing subretinal alterations in the photoreceptor layer, retinal pigment epithelium, and choroid. The present report describes the application of this imaging method in retinal and choroidal pathologies affecting young patients where scarce cooperation, poor fixation, and intense glare sensation can result in a challenging clinical examination. A literature search of the MEDLINE database was performed using the terms "near-infrared reflectance" and "spectral-domain optical coherence tomography." Articles were selected if they described the diagnostic use of NIR in children or young adults. Of 700 publications, 42 manuscripts published between 2005 and 2020 were inherent to children or young adults and were considered in this narrative literature review. The first disease category is the phakomatoses where NIR is essential in visualizing choroidal alterations recognized as cardinal biomarkers in neurofibromatosis type 1, microvascular retinal alterations, and retinal astrocytic hamartomas. Another diagnostic application is the accurate visualization of crystals of various nature, including the glistening crystals that characterize Bietti crystalline dystrophy. Acute macular neuropathy and paracentral acute middle maculopathy represent a further disease category with young adulthood onset where NIR is not only diagnostic but also essential to monitor disease progression. A further interesting clinical application is to facilitate the detection of laser-induced maculopathy where funduscopic examination can be normal or subnormal. In conclusion, NIR imaging has a noninterchangeable role in diagnosing certain retinal diseases, especially in children and young adults where there is scarce collaboration and a lack of evident clinical findings. Moreover, this technique can reveal unique retinal and choroidal biomarkers highly specific to rare conditions.

Long-term follow-up of adult patient with neurofibromatosis type 1 with retinal astrocytic hamartoma using spectral-domain optical coherence tomography: a review of the literature and a report of a case

Background: Retinal astrocytic hamartoma (RAH) is a tumor that can be sporadic or in the context of tuberous sclerosis complex (TSC) and has been reported to be associated with neurofibromatosis type 1 (NF1) in a few cases.Patient and methods: A 65-year-old male patient with NF1 was referred for ophthalmological evaluation. Comprehensive examination, near-infrared reflectance (NIR), spectral-domain optical coherence tomography (SDOCT), fluorescein angiography (FFA), and indocyanine green angiography (ICGA) were carried out. The follow-up of the patient was at 4 and 7 years.Results: Best-corrected visual acuity (BCVA) was 20/20 in both eyes. Anterior segment examination revealed bilateral Lisch nodules. Fundus examination was unremarkable but at NIR and SDOCT the patient presented choroidal hamartoma, microvascular retinal alterations, and enlarged choroidal vessels in both eyes. NIR also revealed an unusual area of peripapillary hyporeflectivity in the right eye. On SDOCT, this corresponded to an elevated peripapillary mass characterized by intralesional optically empty cavities in the retinal nerve fiber layer (RNFL) and ganglion cell layer-inner plexiform layer (GCL-IPL), diagnosed as a RAH. Four years later, BCVA was 20/25 with a retinal schisis departing from the lesion to the macula. At 7 years, BCVA was stable at 20/25, the lesion was smaller, and there was a slight reduction of the schisis.Conclusion: RAH is a rare finding in NF1 and the translucent type has not been previously reported. RAH in NF1 has a peripapillary location and demonstrates clinically unpredictable behavior; thus, close monitoring with multimodal imaging is advisable.

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.