Perivenular Macular Whitening During Acute Central Retinal Vein Occlusion

We report a particular manifestation of presumed acute retinal ischemia, ie, the presence of perivenular macular whitening, in 3 cases of acute central retinal vein occlusion (CRVO). This aspect, which is most clearly evident on blue filter photographs, was associated with significant but transient loss of vision.

Case 1 A 54-year-old man complained of loss of vision in the right eye, which had started 4 days previously. His medical history included chronic lymphoid leukemia in remission. At the initial examination, visual acuity was 20/60 OD and 20/20 OS. Findings from anterior segment slitlamp biomicroscopy were unremarkable in both eyes. Intraocular pressure was 16mmHg OD, and 18 mmHg OU. Fundus examination of the right eye revealed the presence of dilated veins and scattered hemorrhages (Figure 1A). Blue filter photographs indicated the presence of patchy areas of inner macular whitening affecting perivenular spaces in the median raphe (Figure 1B). The fundus of the left eye was normal. Fluorescein angiography of the right eye showed impaired filling of retinal arteries; the temporal arteries were filled with dye 5.8 seconds after the appearance of dye in the central retinal artery. Middle- and late-phase angiograms did not reveal breakdown of the blood-retinal barrier or capillary closure (Figure 2). The patient was not given any specific treatment. One month later, an ophthalmologic examination showed complete resolution of symptoms and 20/20 visual acuity. Funduscopic examination showed improvement of the fundus aspect with normalization of vein calibers and few residual hemorrhages.

Case 2. A 45-year-old man sought treatment for sudden visual loss in the left eye on waking that day. His medical and ophthalmologic histories were unremarkable. Initial examination in our department showed visual acuity of 20/20 OD and counting fingers OS. Findings from anterior segment slitlamp biomicroscopy were normal in both eyes. Intraocular pressure was 15 mmHg OD and 16 mmHg OS. The right fundus was normal. The left fundus had a few scattered hemorrhages and mild retinal vein dilation (Figure 3A). A blue filter photograph revealed areas of inner retinal whitening surrounding the venules in the macula (Figure 3B), which were not visible on the red-free photograph. On fluorescein angiography, retinal perfusion was markedly delayed, with slow progression of the dye in arteries, but there was no capillary closure or blood-retinal barrier rupture. Infusion of urokinase in the ophthalmic artery was performed on the day of the initial visit. The next day, visual acuity was 20/20 OU. Three months later, visual acuity was still 20/20 OU, and results of a funduscopic examination were normal, except for generalized mild vessel narrowing. A standard medical workup, including coagulation testing, complete blood cell count, and echo Doppler examination of the carotid artery and intracranial vessels, did not reveal any underlying disease.

Case 3. A 35-year-old woman who was 6 months pregnant complained of paracentral scotoma in the left eye which had begun 3 days previously. On initial examination, visual acuity was 20/20 OD and 20/160 OS. Findings from a fundus examination of the right eye were normal. In the left fundus, there were mild venous dilation and hemorrhages in the fovea and in the periphery (Figure 4A). Blue filter fundus photography revealed the presence of inner retinal whitening temporal to the macula in the left eye (Figure 4B). Fluorescein angiography was not performed because of the patient's pregnancy. No specific treatment was given. Two months later, visual acuity was 20/40 OS, and an examination showed partial resolution of fundus hemorrhages and vein dilation and complete resolution of inner retinal whitening. The patient had no arterial hypertension. Results of a complete blood cell count, coagulation test results, sedimentation rate, and antiphospholipid antibody levels were within normal limits.

In patients with acute CRVO, we report the presence of perivenular retinal whitening with a fernlike appearance that was most clearly visible on blue-field photographs. This was observed in patients with mild funduscopic symptoms of recent-onset CRVO, which contrasted with the presence of marked visual loss. This retinal whitening was easily differentiated from soft exudates, which are a discrete accumulation of axoplasmic material and which are usually located along the temporal vascular arcades. The ischemic nature of the retinal whitening was suggested by the presence of arterial flow impairment in 2 cases; the third patient did not undergo fluorescein angiography. A similar arterial flow impairment has been previously reported in patients with recent-onset CRVO.^1,2 The loss of vision in our patients was most likely owing to macular ischemia itself because there was no blood-retinal barrier rupture detected by fluorescein angiography. Because these patients were relatively young and had mild funduscopic changes that resolved within days, this manifestation may be defined as impending CRVO.³

To our knowledge, acute macular ischemia affecting perivenular spaces during CRVO has not been previously reported. The cause of arterial flow impairment during acute CRVO may be due either to retrograde transmission of elevated venous pressure or constriction of retinal arteries, which has been shown to occur shortly after experimental branch retinal vein occlusion.⁴ The perivenular location of ischemia may be explained by the fact that decreased arterial flow leads to preferential oxygenation of the periarterial retina, which uptakes the available oxygen and subsequently desaturates hemoglobin before it can reach the perivenular spaces.⁵ The prognostic value of this manifestation on long-term visual outcomes needs to be assessed in a larger series.

The authors have no relevant financial interest in this article.

Corresponding author: Michel Paques, MD, PhD, Department of Ophthalmology, Fondation Ophtalmologique Rothschild, 25 Rue Manin, 75019 Paris, France (e-mail: michel.paques@laposte.net).