2Department of Ophthalmology, Carl R. Darnall Army Medical Center, Fort Hood, TX
Multimodal imaging techniques (i.e. fundus color photographs, OCT), were used to confirm the diagnosis of branch retinal artery occlusion (BRAO). OCT angiography was performed on the day of presentation using the prototype AngioVue OCT angiography (OCTA) system on the commercially-available Avanti SD-OCT device (Optovue, Inc, Fremont, CA), which used a SSADA software algorithm to generate OCT angiograms. The AngioVue OCTA system operated at 70,000 A-scans per second to acquire OCTA volumes consisting of 304x304 A-scans in approximately 2.6 seconds. Orthogonal registration and merging of two consecutive scan volumes were used to obtain optic disc angiography of the affected eye.
En-face sectioning was performed to visualize the various levels of ischemia; decreased perfusion was noted and can be seen superficial to the nerve head, within the peripapillary capillaries, and angio choroid (Figure 1). Increased retinal thickening corresponding to areas of ischemia is noted within the inner retinal layers (Figure 2).
Upon completion of his ophthalmic exam, the patient was admitted to the stroke service of the hospital were a complete stroke work up was completed to include echocardiography, neuro-imaging, and systemic labs all of which were unremarkable.
Yu, et al. studied SD-OCT in 35 acute BRAO and 38 chronic BRAO. Acute findings included:
1. Thickening and hyperreflectivity of inner retinal layers, including NFL/GCL
2. Acute middle maculopathy d/t ischemia of the intermediate and deep retinal capillary plexuses
3. Diffuse thickening and hyper reflectivity of both inner and middle retinal layers d/t ischemia of inner and superficial, intermediate, and deep capillary plexuses.
Chronic BRAO finding include thinning and atrophy of retinal layers corresponding to acute lesions when present. Overall superficial and deep capillary ischemia occurred in 78% of eyes, isolated deep capillary ischemia or paracentral acute middle maculopathy occurred in 22%.
Ahmed, et al. characterized emboli on SD-OCT in 11 cases of acute BRAO. Findings include flake of highly reflective, yet transparent material, oriented with its edge towards the direction of flow and positioned in the middle of the artery was seen in 3 cases. Reflectivity profile of the blood above and below the flake on SD-OCT and FA were normal.
This paper is the first published case report of OCT angiographic findings in acute branch retinal artery occlusion. These findings can be correlated with previously described findings on OCT. The OCT of the affected area showed thickening of the inner retinal layers consistent with previous descriptions. En face OCT angiogram of the nerve head revealed diffuse ischemia in the areas corresponding to intraluminal plaques. In the future we anticipate that OCT angiography could replace fluorescein angiography as the gold standard diagnostic test and might be more quickly and easily performed as part of routine clinical care. Future studies should directly compare OCT angiography to fluorescein angiography, enroll a large number of patients, and further examine OCT angiography findings as a potential to guide prognosis and therapy.
- Ahmed Hassan J, Oliver NK, Anne Willerslev, Inger C, Michael Larsen. Embolus characterization in branch retinal artery occlusion by optical coherence tomography. Actaophthalmologica. 2014;93(1):95-96.
- Hayreh, Sohan Singh, PA Podhajsky, MB Zimmerman. Branch retinal artery occlusion: natural history of visual outcome. Ophthalmology. 2009;116(6):1188-1194. doi:10.1016/j.ophtha.2009.01.015.
- Karapetyan, Anushavan, Tang LS, Zeng J, Ying MD. Detection of under diagnosed concurrent branch retinal artery occlusion in a patient with central retinal vein occlusion using spectral domain optical coherence tomography. BMC ophthalmology 2014;14(1):1-5. doi:10.1186/1471-2415-14-91.
- Ritter Markus, Stefan Sacu, Gábor G Deák, Karl Kircher, Ramzi G Sayegh, Christian Pruente, et al. In vivo identification of alteration of inner neurosensory layers in branch retinal artery occlusion. British Journal of Ophthalmology. 2012;96(2):201-207. doi:10.1136/bjo.2010.198937.
- Royster AJ, Nanda SK, Hatchell DL, Tiedeman JS, Dutton JJ, Hatchell MC. Photochemical initiation of thrombosis: fluorescein angiographic, histologic, and ultrastructural alterations in the choroid, retinal pigment epithelium, and retina. Archives of ophthalmology. 1988;106(11):1608-1614.
- Shah Vinay A, Billi Wallace, Nelson RS. Spectral domain optical coherence tomography findings of acute branch retinal artery occlusion from calcific embolus. Indian journal of ophthalmology. 2010;58(6):523. doi:10.4103/0301-4738.71703
- Yu Suqin, Claudine E Pang, Yuanyuan Gong, K Bailey Freund, Lawrence A Yannuzzi, Ehsan Rahimy, et al. The Spectrum of Superficial and Deep Capillary Ischemia in Retinal Artery Occlusion. American journal of ophthalmology. 2015;159(1):53-63. doi:10.1016/j.ajo.2014.09.027.