Secondary Coats' response to retinal vasculitis managed with bevacizumab.

We report a case of 22-year-old young male who presented with a 3-month history of gradual and painless decrease of vision in his right eye (RE). On ophthalmological examination, best-corrected visual acuity in his RE was counting finger close to the face. Left eye ophthalmic examination was unremarkable. RE indirect ophthalmoscopy revealed multiple telangiectatic vessels, aneurysmal dilations, extensive yellow (lipid) exudation over the posterior pole along with perivascular exudation, and multiple sclerosed vessels in peripheral retina. Fluorescein angiography also revealed progressive leakage from telangiectasias, multiple aneurysmal outpouchings, extensive capillary dropouts, and vascular communicating channels in all quadrants. Spectral-domain-optical coherence tomography of macula demonstrated marked intraretinal fluid. Based on the above findings, a diagnosis of healed retinal vasculitis with Coats'-like response was made. The patient received 4-weekly two intravitreal bevacizumab injections which resulted in stabilization of the retinal findings and improvement in visual acuity.

Coats’ disease describe a specific clinical picture of abnormal congenital telangiectatic retinal vessels accompanied by yellow subretinal exudates, with or without retinal detachment in the absence of any vitreal traction.[1] Coats’-like response refers to a fundus with the similar clinical appearance of Coats’ disease in the setting of other ocular or systemic disease.[2] Till date, it has been described in various ocular disorders such as pars planitis, senile retinoschisis, pigmented paravenous retinochoroidal atrophy, retinitis pigmentosa, chronic ischemic branch retinal vein obstruction, and retinopathy of prematurity, as well as systemic diseases including muscular dystrophy, Senior–Loken syndrome (renal retinal dystrophy), Turner's syndrome, linear En Coup De Sabre scleroderma, and Leber's congenital amaurosis.[23456] Retinal vasculitis is a sight-threatening intraocular inflammation affecting the retinal vasculature. To our knowledge, this is the first reported case of Coats’-like response in retinal vasculitis with its management.

Case Report

A 22-year-old young male presented with a 3-month history of gradual and painless reduced vision in his right eye (RE). There were no systemic complaints. On initial ophthalmologic examination, the patient's best-corrected visual acuity (BCVA) was counting finger close to the face in the RE, while the left eye (LE) was emmetropic. Anterior-segment examination was normal for both eyes with an intraocular pressure of 14 mmHg and 16 mmHg in the RE and LE, respectively, by applanation tonometry. RE fundoscopy revealed clear vitreous with multiple telangiectatic vessels and aneurysmal dilations along with extensive yellow (lipid) exudation over the posterior pole. Diffuse perivascular exudation along with multiple sclerosed vessels were also noted at the posterior pole and peripheral retina [Fig. 1a and b]. LE fundus examination was unremarkable [Fig, 1c and d]. Fundus fluorescein angiography (FFA) revealed progressive and intense leakage from telangiectasias at the posterior pole and late disc staining [Fig. 2 a–c]. Retinal capillary bed showed marked dilation and tortuosity with multiple aneurysmal outpouchings and numerous vascular communicating channels in all quadrants suggesting their response to ischemia. There were extensive areas of capillary nonperfusion in midperiphery with no active neovascularization [Fig. 3]. Spectral-domain-optical coherence tomography (SD-OCT) of macula demonstrated marked intraretinal fluid [Fig. 4a]. Based on the above findings, a diagnosis of healed retinal vasculitis with Coats’-like response was made. The patient underwent a thorough vasculitis workup for etiology including erythrocyte sedimentation rate, complete blood count, urine analysis, Mantoux test, chest X-ray, antinuclear antibody, serology for human immunodeficiency virus type, and treponemal antibody test, which was unremarkable. The patient received 4-weekly two intravitreal injections of 1.25 mg/0.05 ml bevacizumab. Bevacizumab is an off-label drug which is used for the treatment of macular edema in various retinal vascular disorders. Four weeks after the second injection, there was a remarkable decrease in the amount of lipid exudation along with scarring and obliteration of telangiectatic vessels [Fig. 1b]. Repeat FFA demonstrated reduced retinal vasculature anomalies with no evidence of peripheral neovascularization [Fig. 2d–f]. Postoperatively, there was reduction in macular edema along with epiretinal membrane as demonstrated by SD-OCT [Fig. 4b], and BCVA improved to 20/400 which remained stable during the follow-up with no further deterioration.

Figure 1

Fundus photograph (a) montage showing multiple telangiectatic vessels, yellow exudates over the posterior pole along with perivascular exudation and sclerosed vessels in periphery; (b) postoperatively with residual macular exudates and obliterated telangiectatic vessels. (c) Left eye posterior pole showing normal fundus. (d) Left eye montage showing normal fundus

Figure 2

Fundus fluorescein angiography of the right eye at presentation showing progressive and intense leakage from telangiectasias in early (a), mid (b), and late (c) phases of angiogram and late disc staining. (d-f) early, mid, and late phases of angiograms postintravitreal bevacizumab showing decrease in leakage from telangiectasias

Figure 3

Multiple aneurysmal outpouchings, numerous vascular communicating channels, and extensive capillary nonperfusion areas in the nasal quadrant

Figure 4

Spectral-domain-optical coherence tomography showing (a) marked intraretinal fluid at macula and (b) minimal fluid with epiretinal membrane and retinal folds 4 weeks after intravitreal bevacizumab injection

Discussion

Coats’-like response refers to a vascular alteration (telangiectasia and aneurysmal dilatation) with lipid exudation in the setting of some ocular or systemic diseases. Retinal vasculitis may occur as an isolated idiopathic condition or secondary to some infective, neoplastic, or autoimmune disorder. Active vascular disease is characterized by white sheathing or cuffing of the affected vessels with or without macular edema followed by sclerosis of these vessels in healed stages. Late changes include telangiectasias, microaneurysms, and ischemia-induced neovascularization, and complications such as recurrent vitreous hemorrhage, traction retinal detachment, macular scarring, rubeosis iridis, and neovascular glaucoma,[78] but Coats’-like response has never been reported as a cause of vision loss. The exact pathology of congenital or secondary retinal telangiectasia is not clear, but histopathological specimens show functional or structural loss of the blood–retinal barrier, microvascular atresia, and occlusion, which leads to vascular ectasia and collateral vessels. Possible etiology could be any vaso-occlusive event, autoimmune vasculopathy, or chronic inflammation causing structural damage to vasculature which may precede the development of retinal telangiectasias.[6] The Coats’-like response in our patient occurred because of damage to the retinal vasculature secondary to inflammation. The clinical significance of this entity arises from the fact that such an exudative response adds to the visual disability of the preexisting illness because of involvement of posterior pole with the ensuing macular edema. Hence, in such cases, treating the Coats’-like response and neovascular drive may help in improving the visual acuity as in our case. It has been suggested that massive vascular endothelial growth factor (VEGF) expression occurs due to retinal ischemia in chronic inflammation such as retinal vasculitis. Bevacizumab has been shown to be effective in reducing neovascular drive and stabilizing blood–retinal barrier secondary to vasculitis, if given 4 weekly, thereby hastening the process of resolution of subretinal exudation and macular edema.[9] Moreover, it also reduces the need for vitrectomy in the future. Our patient responded well to bevacizumab with marked resolution of subretinal exudates and edema. Although a small amount of macular exudation remained, it was stable thereafter and the patient's visual acuity improved. To conclude, this is the first reported case of Coats’-like response in retinal vasculitis. Use of anti-VEGF such as bevacizumab could lead to the stabilization of the retinal findings and preserve a good visual acuity in such cases.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.