coats

Coats Disease

Min Lee, MD, and LaTanya Love, MD
University of Texas Health Science Center at Houston

A 9-month-old boy presented with a 2-month history of a small white dot in the center of his right eye that had progressively increased in size.

The patient had been born without complications at 36 weeks’ gestation, was up to date on immunizations, was developmentally appropriate for his age, and had had no previous medical problems. The mother reported observing a white drainage from the boy’s right eye and a weight loss of 6 pounds over the last 2 weeks. The mother also felt that his right eye was causing him pain and photophobia. She denied any trauma in the boy.

The patient’s vital signs and the physical examination findings were normal, with the exception of the right eye, which had an 8-mm white opacity, located centrally, with a yellowish, irregular border and no drainage or erythema. Ophthalmology was consulted, and a diagnosis of Coats disease was made.

Magnetic resonance imaging (MRI) of the brain and orbit showed right retinal detachment, no tumoral enhancement in the right globe, and no intracranial abnormality. Results of left eye ultrasonography and fluorescein angiography were largely normal, except for several areas of mild ischemia in the periphery. Ultrasonography of right eye showed total retinal detachment, a thickened retina, and no solid subretinal masses. Right eye fluorescein angiography could not be performed because of a completely hazy and edematous cornea. Right eye pressure was 41 mmHg; left eye pressure was 12 mm Hg.

coats

Coats disease is a progressive ophthalmic condition characterized by retinal telangiectasia, hemorrhage, and exudation that can lead to total retinal detachment and glaucoma. It is most often seen in male children and young adults. Coats disease is thought to be a disease of retinal vessels, caused by abnormal pericytes and endothelial cells and the breakdown of the blood-retina barrier, leading to leakage, aneurysm, ischemia, and retinal detachment.1 The presenting signs can include strabismus, leukocoria, pain, heterochromia, nystagmus, and decreased or loss of vision.1,2 When patients present with such symptoms, the most important condition to rule out in the differential diagnosis is retinoblastoma, which is the most common primary ocular malignancy in children and can be fatal if untreated. Retinopathy of prematurity, familial exudative vitreoretinopathy, ocular toxocariasis, and persistent fetal vasculature also be should in the differential diagnosis.1-3

Diagnosis can be made using fundoscopic examination, which shows differing findings depending on the stage of disease, such as retinal telangiectasia and aneurysmal dilation of the retinal vasculature (usually at the temporal and inferior quadrants), subretinal deposits, macular fibrosis, subfoveal nodules, retinal detachment, and vitreous hemorrhage. Fluorescein angiography, ultrasonography, computed tomography (CT), and MRI can help in making the diagnosis or assessing disease progression. Fluorescein angiography allows for the visualization of vascular changes, ultrasonography can show subretinal opacities due to cholesterolosis and retinal detachment, and CT and MRI can be used to rule out retinoblastoma.1,3

Treatment for Coats’ disease includes the ablation of abnormal retinal vasculatures, laser photocoagulation, and cryotherapy in mild to moderate disease; vitreoretinal surgery in more advanced disease; and enucleation in the most severe cases.1,4 Recently, anti–vascular endothelial growth factor medications have been studied as a potential treatment, but with variable and conflicting results.5,6

Our patient likely presented in the late stage of Coats disease, and it was deemed that enucleation was necessary due to the pain, the high intraocular pressure in the right eye, the absence of potential for future vision, and the unlikely but remote chance of the presence of retinoblastoma. He underwent enucleation, after which pathology results showed no evidence of retinoblastoma or other malignancy.

References

1. Ghorbanian S, Jaulim A, Chatziralli IP. Diagnosis and treatment of Coats’ disease: a review of the literature. Ophthalmologica. 2012;227(4):175-182.

2. Reichstein DA, Recchia FM. Coats disease and exudative retinopathy. Int Ophthalmol Clin. 2011;51(1):93-112.

3. Zhang Z, Shi J-T, Wang N-L, Ma J-M. Retinoblastoma in a young adult mimicking Coats’ disease. Int J Ophthalmol. 2012;5(5):625-629.

4. Rubin MP, Mukai S. Coats’ disease. Int Ophthalmol Clin. 2008;48(2):149-158.

5. Ray R, Barañano DE, Hubbard GB. Treatment of Coats’ disease with intravitreal bevacizumab. Br J Ophthalmol. 2013;97(3):272-277.

6. Zhao Q, Peng X-Y, Chen F-H, et al. Vascular endothelial growth factor in Coats’ disease [published online ahead of print June 13, 2013]. Acta Ophthalmol. doi:10.1111/aos.12158.