Successful use of intravitreal bevacizumab and pascal laser photocoagulation in the management of adult Coats' disease.

Traditional methods of managing exudative retinal detachment secondary to Coats' disease have been associated with varying degrees of success. We describe a case of a 34 year-old male who presented with a sub-total exudative retinal detachment of the right eye that encroached upon the macula, associated with a vasoproliferative tumor secondary to Coats' disease. The patient under-went successful treatment with two intravitreal injections of bevacizumab (Avastin, Genetech Inc., San Francisco, CA, USA) combined with targeted laser photocoagulation with a 532 nm Pascal laser (Topcon Corp., Tokyo, Japan). The visual acuity improved 5 days after the second intravitreal injection from 6/18 to 6/5, with no residual macular edema and complete regression of the vasoproliferative tumor. The improvement in visual acuity was maintained at 12 months post-treatment. We believe this is the first case report describing the successful use of Pascal laser photocoagulation with intravitreal bevacizumab in the treatment of Coats' disease. Our aim was to defer laser treatment until 'near total' retinal reattachment and regression of the vasoproliferative tumor was achieved. There are, however, reports of vitreous fibrosis in patients with Coats' disease treated with intravitreal bevacizumab. This suggests further long-term follow-up studies are required in patients treated with this approach.

INTRODUCTION

Traditional methods of managing exudative retinal detachment secondary to Coats’ disease have been associated with varying degrees of success. We present the first case report describing the successful use of Pascal laser (Topcon Corp., Tokyo, Japan) photocoagulation with intravitreal bevacizumab, in the treatment of Coats’ disease, with complete resolution and no signs of disease recurrence at 12 months.

CASE REPORT

A 34 year-old male was referred to our department with rapidly reducing vision in the right eye over a 3-4 week period. He was otherwise medically healthy, with no relevant past ophthalmic history.

At presentation, his visual acuities were 6/18 and 6/5 in the right and left eyes, respectively. The intraocular pressures were 12 mmHg in each eye and slit-lamp examination of the anterior segment was unremarkable. Fundus examination revealed a subtotal temporal exudative retinal detachment of the right eye, with large intraretinal and subretinal exudates, encroaching the macula; with an associated large retinal vasoproliferative tumor affecting the temporal mid-periphery [Figure 1]. The left eye was clinically and angiographically normal.

Figure 1

Composite color fundus photograph of patient's right eye at presentation, showing subtotal exudative retinal detachment encroaching on macula and vasoproliferative tumor in the temporal periphery

Spectralis optical coherence tomography image to show macular involvement in the subtotal exudative retinal detachment

Fluorescein angiography confirmed a profusely leaking temporal vasoproliferative tumor in the right eye with widespread telangiectatic vessels and aneurysmal dilatation of the capillary bed, in addition to diffuse areas of capillary non-perfusion of the right peripheral fundus [Figure 2]. Based on the features of the ophthalmic workup, the patient was diagnosed with vasoproliferative tumor of the retina (VPTR) with exudative retinal detachment secondary to Coats’ disease.

Figure 2

Early venous phase fluorescein angiogram image, showing the vasoproliferative tumor and adjacent zone of capillary dropout, with retinal telangiectasia

Late phase wide field fundus fluorescein angiogram, showing widespread peripheral retinal telangiectasia, aneurysmal change, retinal ischemia and leakage from the temporally located vasoproliferative tumor of the retina

The patient was treated with two intravitreal Avastin (Genetech Inc., San Francisco, CA, USA) injections (1.25 mg), 4 weeks apart. Five days following the second injection, when he presented for laser treatment, the visual acuity of the right eye had improved to 6/5 unaided with no residual macular edema and complete regression of the VPTR. Panretinal photocoagulation was targeted towards areas of telangiectasia and peripheral ischemia, in addition to direct treatment of the VPTR using a 532 nm Pascal laser photocoagulator. A 3 × 3 square array pattern with pulse duration set at 20 ms and 200 micron spot size was used [Figure 3]. At the last follow-up, 12 months after initial intervention, visual acuity was maintained at 6/5, with no signs of recurrence.

Figure 3

Composite color fundus photograph showing complete resolution of the subtotal exudative retinal detachment and regression of vasoproliferative tumor. Targeted laser burns were applied to the vasoproliferative tumor, while scattered burns were applied to areas of retinal ischemia

Spectralis optical coherence tomography image to show complete resolution of submacular edema

DISCUSSION

Sun et al.1 demonstrated elevated levels of vascular endothelial growth factor (VEGF) in Coats’ disease, which rapidly reduced following an injection of pegaptanib sodium. VEGF levels reduced from a pre-treatment level of 908 pg/ml to 167 pg/ml (normal–100 pg/ml), with an improvement in exudation and near complete reattachment of the retina.1 The authors suggested the vascular changes commonly found in Coats’ disease may be secondary to dysregulated VEGF-mediated angiogenesis.1

In our case, two bevacizumab injections combined with laser photocoagulation produced significant and permanent reductions in exudation and edema with marked improvement in visual acuity. There has been no recurrence of exudation to date. Our therapeutic rationale for the case was to use an anti-VEGF agent as adjunctive therapy to conventional laser, deferring laser until ‘near total’ retinal reattachment and regression of the vasoproliferative tumor was achieved. We felt this approach would be preferable as it would enhance subsequent laser uptake and efficacy of treatment, in addition to reducing the total energy of laser delivery. Although complete resolution of the exudative retinal detachment was achieved with two injections of bevacizumab, we felt it was worthwhile to apply laser treatment in order to decrease the chances of disease recurrence.

While there are a handful of other case reports that describe the use of intravitreal bevacizumab in the management of exudative retinal detachment secondary to Coats’ disease, either as the sole treatment2 or as an adjunctive treatment,34 our case is the first report of the successful use of Pascal laser photocoagulation in conjunction with bevacizumab, using short duration laser burns. However, experience with bevacizumab in Coats’ disease remains limited. Ramasubramanian and Shields5 report the development of vitreous fibrosis in four pediatric patients with exudative retinal detachment secondary to Coats’ disease treated with intra-vitreal bevacizumab and warn of inducing vitreoretinal traction with this treatment. Based on this observation, we feel further long term follow-up studies of this therapeutic approach are warranted.