The retinal riddle: Arterial macroaneurysm or vein occlusion?

An 81-year-old hypertensive female presented with sudden diminution of vision to hand movements (N36) in the left eye (OS) since a week. Fundus revealed localized intraretinal hemorrhages (IRHs) within the superotemporal arcade with hard exudates and macular edema [Fig. 1a]. Optical coherence tomography (OCT) macula showed neurosensory detachment and intraretinal fluid [Fig. 1b]. These features closely resembled macular branch retinal vein occlusion; however, IRH near the retinal artery with focal saccular dilatation unraveled retinal arterial macroaneurysm (RAM) in the hemorrhagic stage [Fig. 1c]. OCT through the lesion revealed an enlarged retinal vessel under the internal limiting membrane [Fig. 1d]. The current case had RAM lesions located well away from the veins, and OCT angiography (OCTA) did not demonstrate nicking, compression of adjacent veins, or capillary nonperfusion [Fig. 2a-d].Figure 1: (a) Fundus photograph of OS with localized intraretinal hemorrhages and hard exudates within the superotemporal arcade and macular edema. (b) OCT of OS revealing altered foveal contour, multiple cystoid hypo reflective spaces in the inner retinal layer (yellow asterisk) suggestive of cystoid macular edema, hyper-reflective dots with back shadowing in inner retinal layers suggestive of hard exudates, and neurosensory detachment (yellow arrowhead) suggestive of subretinal fluid accumulation. (c) Fundus photograph of OS showing arteriovenous crossing changes (black arrow) and three focal saccular dilatations of the retinal artery (white arrows) suggestive of RAMs. (d) OCT through the RAM lesion showing an enlarged retinal vessel (white arrowhead) under the internal limiting membraneFigure 2: Enface OCT angiography image scanning the proximal (a) and distal (c) retinal arterial macroaneurysms with corresponding B scan OCT (b) and (d) showing increased flow signals [red areas]Discussion RAM is an acquired, focal dilatation of a retinal artery first described by Robertson in 1973, typically occurring within the first three bifurcations.[1] The majority of patients have either a solitary (86%) or two macroaneurysms (12%).[2] Association between RAM and BRVO is well known. Usually, a BRVO may precede the development of a RAM; however, rupture of a RAM close to an arteriovenous crossing can also result in a BRVO.[3-5] The current case presented with three macroaneurysms, which is rare, and OCTA aided us to identify that the macular edema, hard exudates and hemorrhages, and associated vision loss were attributable to RAM with no evidence of any adjacent macular BRVO. Although the primary treatment with intravitreal anti-VEGF injections remains the same for both BRVO and macular edema subsequent to RAM, subretinal hemorrhage, breakthrough vitreous hemorrhage, and extensive exudative changes leading to photoreceptor layer deterioration can occur in RAM and the patients must be appropriately counseled for this. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship: Nil. Conflicts of interest: There are no conflicts of interest.