54 I RETINA TODAY I APRIL 2011

RETINAL ONCOLOGY CASE REPORTS IN OCULAR ONCOLOGY

SECTION EDITOR: CAROL L. SHIELDS, MD

Coats disease is a condition characterized by

idiopathic retinal telangiectasia and aneurysmal

vessels, often with intraretinal and subretinal

exudation.1 Described in 1908, the exact etiolo-

gy of Coats disease remains unknown; however, muta-

tions in retinal proteins encoded by CRB1 and NDP may

be shedding light on possible causes.1

Coats disease usually presents in childhood; it has a 3:1

male predominance and is unilateral in 95% of cases.2,3

Patients present with poor vision, strabismus, or leukoco-

ria.3 Fundus evaluation often reveals peripheral retinal

telangiectasia, aneurysms (light bulbs), and subretinal

fluid and exudation, often tracking back to the macula.1

As the disease further progresses, complications include

secondary glaucoma, anterior chamber cholesterolosis,

corneal edema, cataract, lens dislocation, macular fibro-

sis, and amblyopia.3,4 In some cases, enucleation is neces-

sary for intractable pain from secondary neovascular

glaucoma. We hereby report a case of Coats disease with

dramatic resolution of exudation following treatment.

CA SE

A 24-month old Hispanic male was noticed by his parents

to have a white pupil and lazy eye. On examination, the visu-

al acuity of the right eye was fix and follow, but the left eye

showed no fix or follow. There was left esotropia of 35 prism

diopters. Intraocular pressure was 16 mm Hg in both eyes.

On evaluation, the right eye was unremarkable and find-

ings were limited to the left eye. The OS displayed xantho-

coria from a shallow total retinal detachment (RD) and sub-

retinal exudates around the optic disc inferiorly and extend-

ing temporally, emanating from a mass of telangiectasia in

the nasal retina (Figure 1 A). Flourescein angiography (FA)

showed peripheral retinal nonperfusion for 360° immediate-

ly anterior to leaking telangiectasia and aneurysms. (Figure 1

B-D). The clinical findings and FA suggested the diagnosis of

Coats disease stage 3B.2 Treatment involved closure of all

leaking telangiectasia with three sessions of cryotherapy and

one session of laser photocoagulation delivered over 2 to 3

months. The exudation and RD resolved completely by 19

months; however, subfoveal gliosis resulted along the

superotemporal arcade. At 24 months, the eye remained

stable and the reduced visual acuity was attributed to

chronic scarring from the RD and Coats disease com-

pounded by amblyopia (Figure 2). The child was advised to

undergo amblyopia occlusion therapy.

DISCUSSION

Coats first described unilateral exudative retinopathy in

young males and divided it into three groups depending

on the presence of exudation and abnormal retinal vascu-

lature. In 2001, Shields and associates proposed a classifica-

tion of Coats disease based on disease course and progno-

Coats Disease:Classification and

TreatmentBY RISHAV KANSAL, BS; KIRAN TURAKA, MD; AND CAROL L. SHIELDS, MD

Figure 1. Twenty-four–month old Hispanic boy with unilater-

al Coats disease stage 3B before and after treatment with

complete regression of telangiectasia and subretinal fluid

and active exudation. At presentation before treatment, the

left eye shows extensive subretinal fluid with exudation (A);

fluorescein angiogram depicts telangiectasia superiorly (B)

and nasally (C) with peripheral capillary nonperfusion and

leakage in the late phases (D).

A B

C D

RETINAL ONCOLOGY CASE REPORTS IN OCULAR ONCOLOGY

APRIL 2011 I RETINA TODAY I 55

sis (Table 1).5 A simplified classification has been extracted

(Table 2). Stage 1 is characterized by telangiectasia only.2,5

Stage 2 demonstrates telangiectasias and exudation and is

further subcategorized depending on involvement of the

fovea.2,5 Stage 3 demonstrates subtotal retinal detachment,

also subcategorized based on foveal involvement, while

stage 4 exhibits total RD with glaucoma.2,5 Stage 5 is end-

stage disease with a blind, painless eye and total RD, often

with cataract and eventual phthisis bulbi.2,5

Current management aims to preserve patient comfort

and vision. Treatment options include cryotherapy applied

transconjuctivally to the telangiectatic areas and/or photo-

coagulation.1 Schefler and associates used repeated diode

laser treatment in 17 patients with advanced Coats

disease.6 The telangiectasia and exudates resolved in 14

cases (82%), with globe salvage in 16 (94%) and poor visual

acuity in 7 (47%).6 In more advanced cases with RD, sub-

retinal fluid drainage and pars plana vitrectomy combined

with scleral buckling have been successful.7 Jumper and

associates used multiple sessions of laser treatment in 47

Figure 2. At 24 months’ follow-up, the retina was flat (A), but there were residual subretinal fibrosis and cholesterol deposits (B).

TABLE 1: CLASSIFICATION OF COATS DISEASE BASED ON CLINICAL FINDINGS AND RECOMMENDED TREATMENT.2

Stage Clinical Finding Number of Eyes Treatment (%)

Observation Photocoagulation Cryotherapy Enucleation

Stage 1 Retinal telangiectasia 1 100 0 0 0

Stage 2

2A2B

Telangiectasia and exudationExtrafoveal exudationFoveal exudation

17

107

40 10 50 0

Stage 33A3A.13A.23B

Exudative RDSubtotal RDExtrafoveal RDFoveal RDTotal RD

87

242437

17810

425010

586384

4411

Stage 4 Total RD and glaucoma

18 0 0 22 78

Stage 5 Advanced end-stage disease

3 100 0 0 0

A B

RETINAL ONCOLOGY CASE REPORTS IN OCULAR ONCOLOGY

56 I RETINA TODAY I APRIL 2011

patients and detected dense macular fibrosis in 11 (23%)

patients.4 Various treatment modalites were used, includ-

ing laser photocoagulation, cryotherapy, and vitrectomy.4

Macular fibrosis resulted in 23% of patients, all of whom

had temporal retinal telangiectasias.4 The authors pro-

posed that the etiology for macular fibrosis was neovascu-

larization secondary to lipid exudation, concluding that the

macular fibrosis contributed to poor vision.4

Shields and coworkers reported on management of

158 eyes based on Coats disease staging (Table 1).2 Stage 1

patients were managed generally with observation as there

was no leakage from the telangiectasia.2 Stages 2 and 3

eyes were treated with cryotherapy or laser photocoagula-

tion to reverse retinal leakage. Stage 4 eyes usually require

enucleation for intractable ocular pain from secondary

neovascular glaucoma.2 Stage 5 eyes were observed, as

these end-stage eyes had very poor visual acuity with no

hope for return of vision.2 The authors concluded that ear-

lier diagnosis and treatment could preserve vision and pre-

vent complications such as secondary glaucoma.2

Studies of gene mutations are shedding some light on

the possible pathogenesis of Coats disease. In 1999,

Norrie disease pseudoglioma (NDP) gene was shown to

carry a somatic missense mutation in nine enucleated

eyes in male children with Coats disease.8 The authors of

this report concluded that the somatic mutations in the

NDP gene during the development of the retina led to

formation of telangiectasia in Coats disease.8 In animal

studies, den Hollander and associates have implicated

Crumbs homologue 1 (CRB1) gene as being abnormal in

exudative retinopathies including Coats disease, and they

proposed that heterozygous CRB1 mutations may be a

risk factor for development of classic Coats disease.9

The use of bevacizumab (Avastin, Genentech) in the treat-

ment of Coats disease is currently an area of research. It has

been shown that vascular endothelial growth factor (VEGF)

levels in Coats disease eyes are considerably elevated in stages

2 and 3.10 Several case reports have been published with

bevacizumab as a treatment modality. In a recent case study

by Cakir and associates, a 14-year-old boy with stage 3A

Coats disease was treated with intravitreal bevacizumab and

intravitreal triamcinolone acetonide after being unresponsive

to laser treatment.11 Following treatment, there was resolu-

tion of the superior bullous exudative retinal detachment

and subfoveal serous fluid. Visual acuity improved from

20/400 to 20/125 and remained stable at 6 months.11

In summary, we present a case of stage 3B Coats disease

treated with cryotherapy and laser photocoagulation,

which resulted in complete resolution of subretinal fluid

with residual chronic subretinal exudation and gliosis.

Coats disease responds to destructive procedures, but the

future role of less invasive therapy has yet to be defined. ■

Support provided by the Retina Research Foundation of

the Retina Society in Capetown, South Africa (CLS), and the

Eye Tumor Research Foundation, Philadelphia, PA (CLS).

Rishav Kansal, BS, is a medical student at

Temple University in Philadelphia.

Kiran Turaka, MD, is an Ocular Oncology

Fellow at Wills Eye Institute, Thomas Jefferson

University in Philadelphia.

Carol L. Shields, MD, is the Co-Director of the

Ocular Oncology Service, Wills Eye Institute,

Thomas Jefferson University. She is a Retina

Today Editorial Board member. Dr. Shields can be

reached at +1 215 928 3105; fax: +1 215 928 1140;

or via e-mail at carol.shields@shieldsoncology.com.

The authors have no financial interest in the

devices or medications in this document.

1. Do DV, Haller JA. Coats Disease. in Ryan, SJ, ed. Retina. China: Elsevier Mosby, 2004:1417-23.2. Shields JA, Shields CL. Review. Coats Disease: The 2001 LuEsther T. Mertz Lecture.Retina. 2002;22:80-91.3. Shields JA, Shields CL, Honavar SG, Demirci H. Clinical variations and complications ofCoats disease in 150 cases: the 2000 Sanford Gifford Memorial Lecture. Am J Ophthalmo.l.2001;131:561-571. 4.Jumper JM, Pomerleau D, McDonald HR, et al. Macular fibrosis in Coats disease. Retina.2010; 30:S9-S14.5. Shields JA, Shields CL, Honavar S, et al. Classi?cation and management of Coats disease:The 2000 Proctor Lecture. Am J Ophthalmol. 2001;131:572-583.6. Schefler AC, Berrocal AM, Murray TG. Advanced Coats disease. Management with repeti-tive aggressive laser ablation therapy. Retina. 2008;28:S38-S41.7. Yoshizumi MO, Kreiger AE, Lewis H, et al. Vitrectomy techniques in late-stage Coats’-likeexudative retinal detachment. Doc Ophthalmol. 1995;90:387–394.8. Black GC, Perveen R, Bonshek R, et al. Coats’ disease of the retina (unilateral retinaltelangiectasis) caused by somatic mutation in the NDP gene: a role for norrin in retinalangiogenesis. Hum Mol Genet. 1999;11:2031-2035.9. den Hollander AI, Davis J, van der Velde-Visser SD, et al. CRB1 mutation spectrum ininherited retinal dystrophies. Hum Mutat. 2004;24:355-369.10. He Y, Wang H, Zhao B, et al. Elevated vascular endothelial growth factor level in Coats’disease and possible therapeutic role of bevacizumab. Graefes Arch Clin Exp Ophthalmol.2010;248(10):1519-21 11. Cakir M, Cekic O, Yilmaz F. Combined intravitreal bevacizumab and triamcinolone injec-tion in a child with Coats disease. J AAPOS. 2008;12:309-311.

TABLE 2. SIMPLIFIED CLASSIFICATION OF COATS DISEASE.5

Stage Finding Remember

with

% patients in each

group based on

Shields and

coworkers5

1 Telangiectasia T 1%

2 T+ Exudation TE 14%

3 T+E+Subretinalfluid

TES 69%

4 T+E+S+Glaucoma TESG 14%

5 T+E+S+G+Phthisis TESGP 2%