Download Coats Disease: Classification and Treatment

RETINAL ONCOLOGY CASE REPORTS IN OCULAR ONCOLOGY
SECTION EDITOR: CAROL L. SHIELDS, MD
Coats Disease:
Classification and
Treatment
BY RISHAV KANSAL, BS; KIRAN TURAKA, MD; AND CAROL L. SHIELDS, MD
oats disease is a condition characterized by
idiopathic retinal telangiectasia and aneurysmal
vessels, often with intraretinal and subretinal
exudation.1 Described in 1908, the exact etiology of Coats disease remains unknown; however, mutations 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 leukocoria.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 fibrosis, and amblyopia.3,4 In some cases, enucleation is necessary for intractable pain from secondary neovascular
glaucoma. We hereby report a case of Coats disease with
dramatic resolution of exudation following treatment.
C
C A SE
A 24-month old Hispanic male was noticed by his parents
to have a white pupil and lazy eye. On examination, the visual 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 findings were limited to the left eye. The OS displayed xanthocoria from a shallow total retinal detachment (RD) and subretinal exudates around the optic disc inferiorly and extending temporally, emanating from a mass of telangiectasia in
the nasal retina (Figure 1 A). Flourescein angiography (FA)
showed peripheral retinal nonperfusion for 360° immediately 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
54 I RETINA TODAY I APRIL 2011
A
B
C
D
Figure 1. Twenty-four–month old Hispanic boy with unilateral 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).
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 compounded by amblyopia (Figure 2). The child was advised to
undergo amblyopia occlusion therapy.
DISCUSSI ON
Coats first described unilateral exudative retinopathy in
young males and divided it into three groups depending
on the presence of exudation and abnormal retinal vasculature. In 2001, Shields and associates proposed a classification of Coats disease based on disease course and progno-
RETINAL ONCOLOGY CASE REPORTS IN OCULAR ONCOLOGY
A
B
Figure 2. At 24 months’ follow-up, the retina was flat (A), but there were residual subretinal fibrosis and cholesterol deposits (B).
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 endstage 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
Stage
and vision. Treatment options include cryotherapy applied
transconjuctivally to the telangiectatic areas and/or photocoagulation.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, subretinal 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
TABLE 1: CLASSIFICATION OF COATS DISEASE BASED
ON CLINICAL FINDINGS AND RECOMMENDED TREATMENT.2
Clinical Finding
Number of Eyes Treatment (%)
Observation
Photocoagulation
Cryotherapy Enucleation
100
0
0
0
40
10
50
0
Stage 1
Retinal telangiectasia
1
Stage 2
Telangiectasia and
exudation
Extrafoveal exudation
Foveal exudation
17
Stage 3
3A
3A.1
3A.2
3B
Exudative RD
Subtotal RD
Extrafoveal RD
Foveal RD
Total RD
87
24
24
37
17
8
10
42
50
10
58
63
84
4
4
11
Stage 4
Total RD and
glaucoma
18
0
0
22
78
Stage 5
Advanced end-stage
disease
3
100
0
0
0
2A
2B
10
7
APRIL 2011 I RETINA TODAY I 55
RETINAL ONCOLOGY CASE REPORTS IN OCULAR ONCOLOGY
TABLE 2. SIMPLIFIED CLASSIFICATION OF
COATS DISEASE.5
Stage Finding
Remember % patients in each
with
group based on
Shields and
coworkers5
1
Telangiectasia
T
1%
2
T+ Exudation
TE
14%
3
69%
4
T+E+Subretinal
TES
fluid
T+E+S+Glaucoma TESG
5
T+E+S+G+Phthisis TESGP
2%
14%
patients and detected dense macular fibrosis in 11 (23%)
patients.4 Various treatment modalites were used, including laser photocoagulation, cryotherapy, and vitrectomy.4
Macular fibrosis resulted in 23% of patients, all of whom
had temporal retinal telangiectasias.4 The authors proposed that the etiology for macular fibrosis was neovascularization 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 photocoagulation 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 earlier diagnosis and treatment could preserve vision and prevent 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 treatment 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
56 I RETINA TODAY I APRIL 2011
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 resolution 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 [email protected].
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 of
Coats 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 repetitive aggressive laser ablation therapy. Retina. 2008;28:S38-S41.
7. Yoshizumi MO, Kreiger AE, Lewis H, et al. Vitrectomy techniques in late-stage Coats’-like
exudative retinal detachment. Doc Ophthalmol. 1995;90:387–394.
8. Black GC, Perveen R, Bonshek R, et al. Coats’ disease of the retina (unilateral retinal
telangiectasis) caused by somatic mutation in the NDP gene: a role for norrin in retinal
angiogenesis. Hum Mol Genet. 1999;11:2031-2035.
9. den Hollander AI, Davis J, van der Velde-Visser SD, et al. CRB1 mutation spectrum in
inherited 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 injection in a child with Coats disease. J AAPOS. 2008;12:309-311.