A 39-year-old female with a history of recurrent pregnancy losses for which investigation was not available presented with acute vision loss in the RE.
On examination, BCVA was counting fingers, with associated relative afferent pupillary defect, in the RE and 20/20 in the LE. Slit-lamp examination showed quiet anterior segment and vitreous and a normal intraocular pressure in both eyes. Funduscopic examination of the RE revealed a few superficial and deep intraretinal haemorrhages, cotton-wool spots, and dilated tortuous veins. There was also optic disc swelling and ischaemic retinal whitening in the posterior pole inferotemporally along a cilioretinal artery and in the superonasal quadrant (Fig. 1). The LE fundus was normal. Fluorescein angiography of the RE showed delayed filling of the cilioretinal artery and of the superonasal branch retinal artery (Fig. 2A, B). There was also a filling defect in the inferior part of the optic disc at the early phase, with late staining at the late phase (Fig. 2A, C). Swept source optical coherence tomography (SS-OCT) showed perifoveal band-like hyperreflective lesions at the level of the inner nuclear layer corresponding to retinal whitening seen clinically (Fig. 3). Imaging findings in the LE were unremarkable. Clinical and multimodal imaging in the RE were consistent with a diagnosis of combined impending CRVO, cilioretinal artery occlusion, BRAO, and AION.
The results of physical examination, cardiologic evaluation, including carotid artery echocardiography, and standard laboratory investigations were normal or negative. The results of the hypercoagulability workup, including prothrombin time/partial prothrombin time (PT/PTT), plasma homocysteine, antiphospholipid antibodies (lupus anticoagulant, anticardiolipin), protein C, protein S, the prothrombin G20210A mutation, and antithrombin, were negative. However, testing for FVL mutations, which was not routinely available in our hospital, was not performed in our patient at initial presentation. The patient was treated with acetylsalicylic acid.
Nine months later, she presented with mild blurry vision in the LE. Visual acuity was 20/400 in the RE and 20/25 in the LE. The anterior segment and intraocular pressure were normal in both eyes. Fundus examination of the RE showed the presence of diffuse optic disc pallor and the resolution of acute retinal changes with diffuse attenuation of the cilioretinal artery and retinal arterioles (Fig. 4A). In the LE, there was diffuse tortuosity and dilatation of retinal veins consistent with impending CRVO (Fig. 4B).
SS-OCT of the RE showed thinning and atrophy of the inner nuclear layer (Fig. 4C). SS-OCTA of the RE showed marked vascular alterations with visibility of superficial retinal vessels seen as projection artefacts on the attenuated deep retinal capillary plexus (Fig. 4D).
Eight weeks later, the visual acuity of the LE was 20/40, and the impending CRVO had progressed to complete CRVO (Fig. 5). A repeated hypercoagulability workup revealed abnormal resistance to activated protein C, and the patient was then tested for the FVL mutation. The patient was found to be heterozygous for the FVL mutation. The patient was treated with acenocoumarol. At the last follow-up visit, the BCVA was 20/400 in the RE and 20/20 in the LE. Fundus examination of the LE showed resolution of retinal haemorrhages and retinal vein tortuosity and dilatation (Fig. 6). There were no further changes in the right fundus.