Choroidal macrovessel (CM) is a rare, mostly unilateral vascular anomaly of the choroidal circulation.
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These abnormally large vessels may cause disturbances in the overlying retinal pigment epithelium (RPE) and the development of subretinal fluid. Some CMs can even masquerade as a choroidal tumour or parasitic infestation.1
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Reports showing early filling of CMs during indocyanine green angiography (ICGA) suggest that most CMs are arterial in nature.1
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The short posterior ciliary circulation is comprised of a medial and lateral posterior choroidal artery (PCA)5
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; the latter may represent the origin of most CMs and may explain why almost all previously reported CMs arise in the macula. An extramacular origin for CM is rare, and to our knowledge, there are only 2 cases described in the literature. Of these 2 cases, only 1 was illustrated with retinal imaging, which appears to show an origin of the anomalous vessel within the macula.1
In this correspondence, we describe and illustrate an extramacular CM that clearly originates in an extramacular location superior to the optic disc, as shown with ultra-wide-field (UWF) ICGA. This work was completed at the retinal disorders and ophthalmic genetics division at the Stein Eye Institute, University of California–Los Angeles.
A 58-year-old patient was referred for an evaluation of floaters and photopsia in the left eye for 5 days. Past medical history included hypertension and hypothyroidism secondary to thyroidectomy to treat thyroid cancer 8 years prior. Ocular history was remarkable for anisometropic myopia with a spherical equivalent of –2.25 D in the right eye and –6.50 D in the left eye.
On examination, visual acuity was 20/25 OD and 20/20 OS with normal anterior segments OU. Ophthalmoscopy demonstrated RPE mottling superior to the optic disc OS (Fig. 1A). UWF fundus autofluorescence showed a corresponding area of hyperautofluorescence (Fig. 1B). Optical coherence tomography B-scans through this region showed a large (380 µm in height) choroidal vessel with overlying subretinal fluid, focal elevation of the RPE–Bruch membrane complex, and elongated photoreceptor outer segments (Fig. 2). UWF ICGA revealed early arterial filling of a large dilated and tortuous extramacular CM originating superior to the optic disc and extending into the superior periphery without late leakage or staining (Fig. 3A). There was marked asymmetry of choroidal venous drainage, with reduced venous drainage directed toward the inferonasal vortex ampulla (Fig. 3B).
Fig. 1(A) Ultra-wide-field colour image of the left eye illustrating retinal pigment epithelium mottling (red circle) superior to the optic disc. (B) Ultra-wide-field fundus autofluorescence showing the corresponding area, which is hyperautofluorescent (red circle).
Fig. 2Near-infrared reflectance (left) and spectral-domain optical coherence tomography (OCT) B-scans (right). The OCT B-scans show the choroidal macrovessel to measure 380 μm in greatest vertical diameter and 932 μm in greatest horizontal diameter. There are areas of overlying subretinal fluid, focal elevation of the retinal pigment epithelium–Bruch membrane complex, and elongated photoreceptor outer segments. The green lines in the near-infrared reflectance show the location of the OCT B-scans.
Fig. 3(A) Ultra-wide-field indocyanine green angiography showing filling of the dilated and tortuous extramacular choroidal macrovessel originating superior to the optic disc and extending into the superior periphery without late leakage or staining. Note the lateral and medial distal short posterior ciliary arteries (white arrows) and the long posterior ciliary arteries (black arrows), which all exhibit a triangular distribution. The paraoptic vessels represent the short posterior ciliary arteries that originate around the optic disc (red asterisk). (B) There is marked asymmetry of the choroidal venous drainage, with reduced venous drainage directed toward the inferonasal vortex ampulla.
Otero-Marquez et al.
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reported a possible association of CM with myopia. They reviewed the fundus images of 13 cases of CM and identified features of high myopia, including fundus tessellation and peripapillary atrophy in 11 of these patients. The patient reported herein exhibited high myopia with a refraction of –6.50 D OS. Of interest, retinal arterial tortuosity was identified only in this subject’s left eye. The coexistence of CM with retinal arterial tortuosity may be coincidental or may be related to an underlying vascular disorder involving both systems.The presence of RPE mottling and subretinal fluid can be associated with CM.
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These pathoanatomical complications may develop from compression of the overlying inner choroid leading to RPE dysfunction. A similar pathogenesis may explain the development of pigmentary changes and fluid in eyes with choroidal nevi or overlying dilated veins (pachyvessels) in eyes with pachychoroid disease.9
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Hayreh
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studied the PCA circulation and noted the presence of typically 1 to 5 PCAs. The lateral and medial PCAs (of the short posterior ciliary system) are most commonly identified (97%–100% of eyes), but the superior PCA is an uncommon branch that exists in 9% of eyes. The PCAs branch into short and long PCAs. The short PCAs pierce the sclera in 2 locations. The paraoptic short PCAs enter adjacent to the optic disc and the distal short PCAs enter nasal or temporal to the disc. In contrast, the long lateral PCA enters the sclera temporal to the macula. Use of UWF ICGA in our case clearly demonstrates the medial and lateral distal short PCAs as well as the long PCAs. Remarkably, a single superior PCA that is dilated and tortuous is also identified and represents the CM (Fig. 3). This anomalous pattern of circulation can be detected in less than 10% of normal subjects. Most previously reported CMs originate from the temporal distal short PCA, which may explain the remarkable macular predominance for this vascular entity.To our knowledge, this is the only reported case of a CM originating from the superior PCA and the only illustration of this uncommon vascular pattern with ICGA. The extramacular origin of the CM is rare and can be easily overlooked because of the peripheral location, which may explain the scarcity of reports describing this vascular anomaly. The novelty of this case is further underscored by the associated presence of unilateral retinal arterial tortuosity in the ipsilateral eye. Multimodal retinal imaging including UWF ICGA and fundus autofluorescence can facilitate identification of these abnormalities, which can be complicated by the development of pigmentary alterations and even serous retinal detachment with the potential to cause vision loss.
Footnotes and Disclosures
Meira Fogel-Levin: none. Alice Wong: none. SriniVas R. Sadda is a consultant for Amgen, Allergan, Novartis, Roche/Genentech, Regeneron, Bayer, 4DMT, Astellas, Apellis, Iveric, Centervue, Heidelberg, and Optos. He has received speaker fees from Carl Zeiss Meditec, Nidek, Topcon, Optos, Heidelberg Engineering, and Novartis. He has received research instruments from Carl Zeiss Meditec, Nidek, Topcon, Optos, Heidelberg Engineering, and Centervue.. K. Bailey Freund is a consultant for Heidelberg Engineering, Zeiss, Allergan, Bayer, Genentech, and Novartis and receives research support from Genentech/Roche. David Sarraf is an advisory board member (Optovue), consultant (Amgen, Bayer Healthcare, Genentech, Novartis, Optovue, and Iveric Bio), investigator (Amgen, Genentech, Heidelberg, Optovue, and Regeneron), receiver of grants/honoraria (Amgen, Bayer Healthcare, Genentech, Iveric Bio, Novartis, Optovue, and Regeneron), speaker (Optovue), equipment receiver (Heidelberg, Optovue, and Topcon), and stock owner (Optovue).
References
- Choroidal macrovessels: multimodal imaging findings and review of the literature.Br J Ophthalmol. 2021; (bjophthalmol-2020-318095 [online ahead of print])
- Choroidal macrovessel.Br J Ophthalmol. 2011; 95: 1333-1334
- Multimodal imaging of macular choroidal macrovessel: a report of two cases.Retin Cases Brief Rep. 2021; 15: 218-223
- Optical coherence tomographic angiography and ultra-widefield indocyanine green angiography of a choroidal macrovessel.Am J Ophthalmol Case Rep. 2020; 18100612
- Posterior ciliary artery circulation in health and disease: the Weisenfeld lecture.Invest Ophthalmol Vis Sci. 2004; 45: 749-757
- The ophthalmic artery: III. Branches.Br J Ophthalmol. 1962; 46: 212-247
- Non-invasive imaging of a choroidal macrovessel.Am J Ophthalmol Case Rep. 2020; 20100871
- Progression of age related macular degeneration overlying a large choroidal vessel.Retin Cases Brief Rep. 2016; 10: 22-25
- Eye (Lond). 2019; 33 (Pachychoroid disease.): 14-33
- Central serous chorioretinopathy.Ophthalmologica. 2014; 232: 65-76
Article Info
Publication History
Published online: October 19, 2021
Identification
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© 2021 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.
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