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Central retinal venous occlusion in a child with hyperhomocysteinemia

Abstract Rationale: To report a rare case of 8-year-old girl patient with central retinal venous occlusion (CRVO) with hyperhomocysteinemia. Patient concerns: The patient had a 2-year history on painless visual loss in the left eye. Diagnoses: All examination results were within normal limits except plasma homocysteine (HCY). Fluorescein angiography (FA) confirmed peripheral capillary non-perfusion (CNP) in the left eye, and OCT showed macular edema. The girl patient was diagnosed as CRVO. Interventions: Based on all of the test results, laser photocoagulation was performed at peripheral capillary non-perfusion (NP). Ranibizumab was injected into virtreous cavity to reduce the macular edema. Oral folic acid, vitamin B12, and vitamin B6 were performed to the girl. Outcomes: After 13 months, the girl visual acuity recovered to 20/100 in the left eye. Lessons: All eye examinations should be performed in young patients, and they should undergo treatments immediately after is diagnosed as CRVO.


Introduction
Central retinal venous occlusion (CRVO) is an uncommon cause of visual loss in young people. The pathogenesis and risk factors of CRVO are poorly understood in younger people. The percentage of CRVO cases with systemic disease is greater in the older (74%) than in younger patients (40%-67%). [1] Elevated homocysteine (HCY), which is associated with venous thrombosis, has been considered as an important risk factor for RVO. [2] HCY could directly damage the vascular endothelium if it accumulates. [3] Associated medical conditions in younger patients include hyperhomocysteinemia. [4] In the case reported herein, an 8-year-old girl patient presented a CRVO with hyperhomocysteinemia in the left eye.

Case presentation
An 8-year-old girl patient presented to our hospital because of a 2-year history on painless visual loss in the left eye. Upon examination, the visual acuity (VA) in the right eye was 20/25 which was 20/20 with À0.75DS, the presenting VA in the left eye was 20/1000 which was helpless with +0.25DS/À1.75DC Â 170, both of the intraocular pressures by applanation tonometry were 14 mmHg. The examinations of the right eye were normal ( Fig. 1A and B). Anterior segment findings in the left eye showed normal except the presence of afferent papillary defect. On indirect fundus examination, the optic disc had abnormal vessels and blush, and there was presence of dilated and tortuous retinal veins (Fig. 1C). Fluorescein angiography (FA) confirmed peripheral capillary non-perfusion (CNP) in the left eye (Fig. 1D), and optical coherence tomography (OCT) showed macular edema ( Fig. 2A). FA also showed that normal choroidal filling, but there was a variable delay in retinal vascular ( Fig. 1E-F). High fluorescence accumulated at the posterior pole in the late time (Fig. 2B). Finally, the girl patient was diagnosed as CRVO.
Editor: N/A. Informed written consent was obtained from the patient for publication of this case report and accompanying images.  For her retinovascular disease, laser photocoagulation was performed at peripheral CNP area and 0.05 ml intravitreal ranibizumab (Lucentis, Novatis) injection for alleviating the level of edema. For her HCY, oral folic acid, vitamin B12, and vitamin B6 were carried out according to the specialist physician.
After 13 months, NP area covered with laser spot (Fig. 3B), FA showed generally normal retinal vascular filling (Fig. 3C-D), and the macular recovered to normal (Fig. 2C), a small amount of fluorescence leakage at the macular (Fig. 2D). The VA recovered to 20/100 in the left eye. Her HCY was 6.5 mmol/L.

Discussion
Hyperhomocysteinemia is increasingly considered an important risk factor for retinal vascular diseases. [2] Clinic-based studies showed an association of hyperhomocysteinemia with CRVO. [5,6] In univariate analyses, participants with HCY > 15 mmol/l were three times more likely to have RVO. [2] In addition, mean HCY levels were significantly higher in the RVO groups than the control group. [7] In the present case, the girl patient was diagnosed as CRVO with hyperhomocysteinemia in the left eye after comprehensive eye examination. Many studies have shown that vitamin supplementation with folic acid or combined with vitamin B6, and vitamin B12 reduces HCY levels in patients with venous thrombosis and in healthy volunteer, regardless of the underlying cause. [7] Further, the www.md-journal.com symptomatic treatment was carried out for the girl patient. And, 3 vitamins, including folic acid, vitamin B12, and vitamin B6, were used to regulate the level of HCY in the blood. There was no presence of intraretinal hemorrhages because the girl had a 2-years history visual loss, possible the hemorrhages has been absorbed (Fig. 1C). Treatment options for CRVO until recently have been limited to largely laser for the neovascular complications of retinal ischemia. [8] Furthermore, laser photocoagulation was used to treat retinal ischemia. Macular edema is a significant cause of vision loss in patients with CRVO. Vascular endothelial growth factor (VEGF) is known to be upregulated in CRVO. [9] Anti-VEGF therapy, such as intravitreal ranibizumab provides an effective treatment against vision-threatening macular edema [10] and help repair the breakdown in the blood-retinal barrier. [10] Considering the abovementioned case, the girl patient was received ranibizumab injection to treat macular edema. Visual prognosis was poor in most patients despite treatment with CRVO. [4] After 13 months, the VA of the girl recovered to 20/ 100 in the left eye. However, the macular in the fundus photograph does not change ( Fig. 1C and Fig. 3A), it may be too long after CRVO which did not treat result in the formation of scar.
As we can see, the ophthalmologist should take into account thorough examination in the diagnostic evaluation of all young patients with RVO disease. The patients should undergo treatments immediately after CRVO.