Abstract
Purpose
To illustrate the spectrum of clinical and imaging features in patients with unilateral Coats’ disease at baseline and in response to treatment with laser, intravitreal bevacizumab, and regional steroids.
Observations
Telangiectasias, macular exudates, and vascular leakage were present in all 3 patients included in this series. After treatment with laser and bevacizumab, OCT angiography findings included an anomalous foveal vascular loop and chorioretinal anastomoses. Choroidal flow voids appeared to improve after intravitreal bevaziumab and laser treatment in 2 patients with OCT angiography obtained at follow up. A-scan axial lengths in affected eyes were 1.5–1.8 mm smaller than fellow eyes.
Conclusions and importance
OCT angiography is a non-invasive tool that can be a useful adjunct to multimodal imaging studies in the management of Coats’ disease. Improved vascular density following anti-VEGF injection suggests a possible role of the choroidal vasculature in this retinal vascular pathology.
1
Introduction
Coats’ disease is an idiopathic, non-hereditary condition defined by telangiectasias of the small-to medium-sized retinal vessels, causing intra- and sub-retinal exudation in the absence of vitreoretinal traction , It affects males in their first two decades of life and may present with xanthocoria or strabismus. A predominantly unilateral disease (95–100%), subtle angiographic contralateral findings occur in 50–78% of cases. The pathophysiology of Coats’ disease involves plasma protein leakage through a compromised blood retinal barrier, secondary to abnormal pericytes and damaged vascular endothelial tissue. Aneurysmal dilation of vessels and telangiectasia formation occurs. , In early Coats’ disease, preventing disease progression involves destroying abnormal vessels using cryotherapy, laser, anti-vascular endothelial growth factor (VEGF) injections, and/or regional steroids. ,
Coats’ disease presents heterogeneously and often requires multiple imaging modalities to confirm diagnosis and monitor treatment response. Fundus photography, fundus fluorescein angiography (FFA), optical coherence tomography (OCT), and recently, OCT angiography (OCTA), have revolutionized the approach to managing Coats’ disease. , While FFA shows small areas of vascular leakage throughout the fundus, OCTA non-invasively delineates flow patterns at various retinal and choroidal layers. ,
The purpose of this series is to report the spectrum of imaging features in patients with Coats’ disease, at baseline and in response to treatment. We used Spectralis HRA+OCTA (Heidelberg Engineering, Heidelberg, Germany) in three children with Coats’ disease. We add to the general body of literature and show that changes in flow voids following treatment may be difficult to assess using OCTA technology.
2
Methods
Three non-consecutive cases of Coats’ disease undergoing examination under anesthesia with multimodal imaging including Spectralis HRA+OCTA (Heidelberg, Heidelberg Spectalis, Germany) were retrospectively reviewed. OCTA slabs were selected for superficial vascular plexus [retinal nerve fiber layer to internal limiting membrane], deep vascular plexus [inner plexiform layer to outer plexiform layer], choriocapillaris [Bruch’s membrane to 10 μm below], and choroid [10 to 60 μm below Bruch’s membrane]. Segmentation was automated but individually reviewed to correlate for structural changes. Smooth segmentation was selected, and projection artifacts were removed. Standard OCTA contrast settings were selected 1:2 for the retinal slabs and 1:4 for the choroidal slabs.
3
Findings
3.1
Case 1
A 9-year-old male presented with two years of decreased vision in the right eye. Snellen visual acuity was 20/30 in the right eye and 20/25 in the left eye. The intraocular pressure was 12 in the right eye and 14 in the left eye. The axial length by A-scan was 22.3 mm and 24.0 mm in the right and left eyes, respectively. Indirect ophthalmoscopy revealed a ridge of exudates and telangiectatic vessels in the right eye. The left eye was normal. FFA revealed extensive late leakage of temporal telangiectatic vessels with peripheral nonperfusion ( Fig. 1 A) . The patient was diagnosed with Coats’ disease. An examination under anesthesia (EUA) performed after 3 months showed stable posterior segment and fluorescein angiography findings. OCTA at this time point demonstrated irregular vascular flow around the foveal avascular zone (FAZ), choriocapillaris, and choroid ( Fig. 1 B) .
The patient underwent treatment with intravitreal bevacizumab (Avastin, Genentech, USA), subtenon’s triamcinolone acetonide (TA), and diode laser to the areas of nonperfusion. EUA 6 weeks later showed persistent crescentic lipid exudation. FFA highlighted light bulb telangiectasias and peripheral vascular leakage. OCT showed hard exudates without macular edema ( Fig. 1 C) . An OCTA performed 6 weeks following initial treatment showed relatively stable retinal blood flow in the macula, with possible improvement of flow voids in the choriocapillaris, and choroid ( Fig. 1 D) .
3.2
Case 2
A 5-year old male presented with a two-day history of subjective vision loss in the right eye. Visual acuity was 20/40 in the right eye and 20/30 in the left eye. Intraocular pressure was 17 and 12, in the right and left eyes, respectively. Fundus examination revealed peripheral exudation and telangiectatic vessels in the right eye. The left eye was normal. EUA two weeks later revealed echographic axial lengths of 20.8 mm and 22.3 mm in the right and left eyes, respectively. In the right eye, there were multiple areas of exudation, with a small area of exudative elevation temporally. FFA showed peripheral telangiectasias with incomplete peripheral perfusion and late leakage ( Fig. 2 A) . Macular OCT was without macular edema. The patient was treated with intravitreal bevacizumab and indirect diode laser to the avascular retina.
