Polycythemia causing posterior segment vascular occlusions.

A 44-year-old male patient presented with features suggestive of transient central retinal artery occlusion (CRAO) followed by permanent CRAO and lateral posterior ciliary artery occlusion. He had diagnostic features of polycythemia vera (PV). When presented for the first time, the patient had features of ocular ischemia such as ocular pain, conjunctival congestion, and retinal opacification but with normal arm-to-retina time and normal arteriovenous transit time. During the second presentation, he had ocular pain, congested conjunctiva, retinal opacification, cherry red spot with box-carrying of retinal vessels, and choroidal infarct (Amalric's sign). He had lost light perception in that eye. Patients with polycythemia are prone to multifocal vascular occlusions and this can be the presenting feature in PV. A timely diagnosis and prompt management can prevent these repeated thromboembolic occlusive episodes.

Introduction

Amalric sign is a rare clinical finding that indicates choroidal ischemia and may be associated with central retinal artery occlusion (CRAO).[1] Amalric sign is a wedge-shaped choroidal infarct caused by the occlusion of the posterior ciliary artery (PCA). We report a case of recurrent vascular occlusions in the eye as a presenting feature of polycythemia vera (PV) causing monocular blindness. To our knowledge, this is the first reported case of the lateral PCA (LPCA) occlusion with CRAO in PV.

Case Report

A 44-year-old man reported with complaints of redness, pain, and reduced vision, in the right eye, for the past 3 days. He was a chronic smoker with no known systemic illness. His visual acuity was reduced to counting finger close to face in the right eye. There was generalized conjunctival congestion in the right eye. Intraocular pressure was 10 mmHg in both eyes. Fundus examination revealed areas of retinal opacification around the macula [Figure 1a and b]. The retinal vessels appeared normal with a healthy disc and with no visible embolus. Fundus fluorescein angiography showed an arm-to-retina time of 28 s and an arteriovenous transit time of 8 s with late hyperfluorescence in the perifoveal capillary area [Figure 2]. Optical coherence tomography showed increased reflectivity and thickness of the inner retina layers [Figure 1c]. The patient was advised to undergo hematologic investigations and evaluation by a cardiologist. He next reported after 10 days with complaints of redness and pain in the right eye. He had no perception of light in the right eye. The anterior segment revealed diffuse conjunctival congestion and afferent pupillary defect in the right eye. The intraocular pressure was 12 mmHg and 16 mmHg in the right and left eye, respectively. Fundus examination showed hyperemic disc, retinal opacification, cherry red spot, box-carrying of vessels with triangular hypopigmented whitish subretinal lesions with apex toward the macula [Figure 3].

Figure 1

(a-c) Fundus and optical coherence tomography changes at 1st presentation

Figure 2

(a-c) Fundus fluorescein angiography at 1st presentation showed an arm-to-retina time of 28 s and an arteriovenous transit time of 8 s with late hyperfluorescence in the perifoveal capillary area

Figure 3

Montaged fundus image at day 10, retinal pigment epithelial changes in the posterior pole and in the triangular wedge-shaped are

Blood parameters were suggestive of polycythemia-hemoglobin 19.0 g%, packed cell volume 57.1%, red blood cell (RBC) 7.80 millions/mm3, mean corpuscular volume 73.0/µm3, total white blood cell count 14,200/mm3, platelets 673,000/mm3, erythrocyte sedimentation rate 4 mm at the end of 1 h. The peripheral smear showed a dense spread of normocytic normochromic RBC's with leukocytosis and thrombocytosis. The electrocardiogram, echocardiogram, and color Doppler of carotid arteries were normal. Patient was referred to hematologist. Bone marrow aspirate cytology showed mild trilineal hyperplasia with reduced iron stores, and the bone marrow biopsy revealed trilineal hematopoiesis with focal minimal paratrabecular fibrosis. He was diagnosed as a case of polycythemia rubra vera and was treated by venesection and was also administered hydroxyurea and aspirin.

On his follow-up, after 23 days, his blood count was normal. He had no light perception in the right eye, but the ocular pain and conjunctival congestion had subsided. Retinal examination showed pale disc, arterial narrowing, and retinal pigment epithelial changes in the posterior pole and in the triangular wedge-shaped area [Figure 4a]. During the follow-up visit at 3 months, the visual acuity and anterior segment findings remained the same. The fundus picture showed optic disc atrophy, narrowed arteries, and a more prominent segmental chorioretinal atrophic patch temporal to fovea with the apex toward the macula (triangular sign of Amalric) [Figure 4b].

Figure 4

(a and b) Day 23 and 3-month fundus photograph showing the segmental chorioretinal atrophic patch (triangular sign of Amalric)

Discussion

PV affects the hematopoietic stem cells and is characterized as a neoplastic marrow disorder.[2] It is associated with excessive proliferation of erythrocytes, leukocytes, and thrombocytes. The prevalence of PV was estimated in the United States to be 22/100,000.[3] Ocular complications are secondary to hyperviscosity and thrombosis.[4] Thrombotic events are present in 20%–50% of patients with PV at diagnosis and involve major vessels and the microcirculation.[5]

Isolated monocular blindness as the presenting feature of polycythemia has been presented only four times indicating the rarity of presentation.[6] Repeated occlusions in the same eye were postulated to be due to hyperviscosity. In our patient, smoking could have caused an additive effect. The most interesting feature was the presence of ocular pain and congestion before both episodes of monocular blindness indicating the severity of ischemia. These features subsided only after the treatment was initiated by the hematologist in the form of phlebotomy, oral hydroxyurea, and aspirin.

Amalric was the first to describe an unusual triangular pigmented disturbance in the fundi of patients with ischemic ocular disorders.[7] The same sign is described in vasculitides such as polyarteritis nodosa.[8] On the basis of his experimental studies, Hayreh reported the presence of one to five PCAs arising from the ophthalmic artery. Of the eyes studied, one PCA was seen in 3%, two in 48%, three in 39%, four in 8%, and five in 2% of the eyes. Accordingly, he named them lateral, medial, and superior PCAs, respectively.[9] Hayreh and Baines produced similar lesions in rhesus monkeys by cutting the medial and LPCA. He noted that these whitish subretinal lesions occurred at 18–24 h of PCA occlusion and became depigmented after 2–3 weeks. They were located in the periphery, with bases toward the equator and apices toward the posterior pole.[10]

In this case, there was a transient CRAO followed by a permanent CRAO along with LPCA occlusion and anterior ischemic optic neuropathy. The lateral posterior ciliary occlusion was shown by the triangular hypopigmented subretinal patches with apex temporal to fovea and base extending anterior to equator. One needs to look carefully for the choroidal infarcts when there is a combined CRAO and LPCA occlusion as most often they can be missed, amidst the intense retinal opacification. This case report documents the evolution of the vascular occlusion and highlights the fact that recurrent vascular occlusion in the eye can be a presenting feature of polycythemia. The devastating outcome of such vascular occlusions warrants a close follow-up in patients with polycythemia to prevent visual loss.

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Conflicts of interest

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