Tutorial
Introduction
Materials and Methods
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Discussion
Conclusion
References
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Management of Traumatic Hyphema: Therapeutic Options
Earl R. Crouch Jr, MD, FACS · Eric R. Crouch, MD
Shields JA, Shields CL. Differentiation of coats' disease and retinoblastoma. J Pediatr Ophthalmol Strabismus. 2001;38(5):262-266.
Coats' disease is a well-known ocular disorder characterized by congenital retinal telangiectasia, retinal exudation, and exudative retinal detachment.1-3 Clinical variations and methods of treatment for Coats' disease have been reported in the literature.2-5 Retinoblastoma is a well-known malignant intraocular tumor of childhood that requires prompt diagnosis and early treatment.6,7 The treatments for Coats' disease and retinoblastoma are different. Therefore, it is important to correctly diagnose these entities and initiate appropriate treatment.
Coats' disease often is confused clinically with retinoblastoma.8-10 Both diseases occur mainly in young children and can produce retinal detachment and leukokoria. Failure to differentiate Coats' disease and retinoblastoma can have serious consequences. This article reviews the clinical features of patients with Coats' disease and retinoblastoma and describes the characteristics that may serve to differentiate them.
From February 1974 through January 2000, approximately 150 patients with Coats' disease and 1000 patients with retinoblastoma were evaluated by the Oncology Service at Wills Eye Hospital. Prospective data were collected including detailed fundus drawings, anterior segment photography, fundus photography, and ultrasonography. Particular attention was given to age at diagnosis, patient gender, laterality of the disease, anterior segment findings, status of the vitreous, macular changes, presence of yellow intraretinal and subretinal exudation, and characteristics and distribution of retinal blood vessels.
The relative salient features that differentiate Coats' disease from retinoblastoma are summarized in Table. The two conditions usually differ with regard to demographics, clinical findings on ocular examination, and results of imaging studies such as ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI).
There are a number of conditions that can simulate retinoblastoma clinically. Lesions that present the greatest problems in diagnosis are Coats' disease, persistent hyperplastic primary vitreous, and presumed ocular toxocariasis.8-10 In our experience, Coats' disease is the condition that most often simulates retinoblastoma. There are several cases in which the clinician misdiagnosed retinoblastoma as Coats' disease and serious consequences ensued. Our observations suggest these two conditions almost always have distinguishable features and knowledge of their differences should minimize the problem of erroneous diagnosis and misdirected therapy.
History can be different in patients with Coats' disease and
retinoblastoma. Patients with Coats' disease usually have a negative medical
and family history. Patients with retinoblastoma occasionally have a positive
family history for retinoblastoma. Children with Coats' disease are generally
older than those with retinoblastoma, with median ages of 5 years and 1.5
years, respectively. However, 8% of patients with retinoblastoma present in
children .5 years and some present initially as teenagers.11
The anterior chamber usually is clear in both Coats' disease and retinoblastoma. However, in rare instances, Coats' disease can be associated with anterior chamber cholesterolosis,12 a finding that has not been described with untreated retinoblastoma (Slide 1A). In some cases of diffuse or endophytic retinoblastoma, clumps of white cells can gain access to the anterior chamber and produce a pseudohypopyon (Slide 1B).13,14 Both Coats' disease and retinoblastoma can present with neovascular glaucoma.15
Posterior segment changes are the most important and
consistent findings that serve to differentiate Coats' disease from
retinoblastoma. The most helpful differentiating features are related to the
status of the vitreous, retinal vessels, exudation, subretinal fluid, and the
presence of a visible mass. In Coats' disease, the vitreous is almost always
clear. In endophytic retinoblastoma, the vitreous typically shows white cells
that resemble snow in a diffuse or clumping arrangement.
Retinal exudation is a highly reliable and consistent feature. By definition, Coats' disease is characterized by distinct yellow exudation in the sensory retina sometimes with glistening yellow cholesterol crystals (Slide 2A). Significant yellow intraretinal exudation is almost never seen with untreated retinoblastoma (Slide 2B).
The caliber and distribution of retinal blood vessels help
differentiate Coats' disease from retinoblastoma. Coats' disease shows
telangiectasia of small blood vessels, usually in the peripheral retina. The
dilated blood vessels in Coats' disease are irregular, forming distinct
aneurysms or sausage-like configurations. In retinoblastoma, the larger blood
vessels are more uniformly dilated and often tortuous, and they often feed and
drain a distinct retinal mass. The blood vessels in Coats' disease tend to stay
visible throughout their course, whereas the blood vessels in retinoblastoma
tend to dip into the retina and disappear from view (Slide 3A) and (Slide 3B).
The aforementioned features are helpful in differentiating
Coats' disease from retinoblastoma in the majority of cases. In occasional
instances, exophytic retinoblastoma produces an elevated retinal detachment
immediately posterior to the lens and a distinct mass cannot be visualized with
slit-lamp biomicroscopy or ophthalmoscopy (Slide 4A),
(Slide 4B), (Slide 5A), and
(Slide 5B). In such cases, ultrasonography can be a
valuable diagnostic procedure for differentiating Coats' disease from
retinoblastoma. With the B-scan technique, Coats' disease reveals a linear
intraocular echo characteristic of a retinal detachment with an acoustically
empty area corresponding to the subretinal space (Slide
6A) and (Slide 6B). In severe cases, there may be
a few fine echoes in the subretinal space, corresponding to dense accumulation
of cholesterol. In contrast, exophytic retinoblastoma usually shows a mass
pattern beneath the retinal detachment. More dense echoes, compatible with
calcium, can be visualized in the majority of such cases.
Computed tomography and MRI may be useful in atypical cases to
more clearly define a mass or calcium. It should be realized that advanced
Coats' disease could induce osseous metaplasia of the retinal pigment
epithelium. In such cases, calcification can be visualized with ultrasonography
or CT. However, the calcium in osseous metaplasia of the retinal pigment
epithelium is linear and at the level of the pigment epithelium, whereas in
retinoblastoma it is confined to the area of the intraocular tumor.
Coats' disease and retinoblastoma have some clinical similarities, but they have sufficient differences to allow their differentiation on office examination in most cases. Parents can be counseled in the office, and when examination under anesthesia is subsequently performed, the clinician is prepared to proceed with the preplanned treatment. Familiarity with the classic features of Coats' disease should allow accurate diagnosis and exclude the possibility of retinoblastoma so that appropriate treatment can be given. Consultation with a retinoblastoma specialist is advised in cases in which differentiation is more difficult.
- Reese AB. Telangiectasis of the retina and Coats' disease. Am J Ophthalmol. 1956;42:1-8.
- Shields JA, Shields CL, Honavar S, Demirci H. Clinical variations and complications of Coats disease in 150 cases: The 2000 Sanford Gifford Memorial Lecture. Am J Ophthalmol. 2001;131:561-571.
- Shields JA, Shields CL, Honavar SG, Demirci H, Cater J. Classification and management of Coats disease: The 2000 Proctor Lecture. Am J Ophthalmol. 2001;131:572-583.
- Mandava N, Yannuzzi LA. Coats' disease. In: Guyer DR, Yannuzzi LA, Chang S, Shields JA, Green WR, eds. Retina-Vitreous-Macula. Philadelphia, Pa: WB Saunders Co; 1999:390-397.
- Haller JA. Coats' disease. In: Ryan SJ, ed. Retina. Vol 2. 3rd ed. St Louis, Mo: CV Mosby Co; 2001:1441-1448.
- Shields JA, Shields CL. Retinoblastoma: clinical and pathologic features. In: Shields JA, Shields CL. Intraocular Tumors. A Text and Atlas. Philadelphia, Pa: WB Saunders Co; 1992:305-332.
- Shields JA, Shields CL. Retinoblastoma. In: Shields JA, Shields CL, eds. Atlas of Intraocular Tumors. Philadelphia, Pa: Lippincott Williams & Wilkins; 1999:208-231.
- Howard GM, Ellsworth RM. Differential diagnosis of retinoblastoma. A statistical survey of 500 children. I. Relative frequency of the lesions which simulate retinoblastoma. Am J Ophthalmol. 1965;60:610-618.
- Shields JA, Shields CL, Parsons HM. Differential diagnosis of retinoblastoma. Retina. 1991;11:232-243.
- Shields JA, Parsons HM, Shields CL, Shah P. Lesions simulating retinoblastoma. J Pediatr Ophthalmol Strabismus. 1991;28:338-340.
- Shields CL, Shields JA, Shah P. Retinoblastoma in older children. Ophthalmology. 1991;98:395-399.
- Shields JA, Eagle RC Jr, Fammartino J, Shields CL, De Potter P. Coats' disease as a cause of anterior chamber cholesterolosis. Arch Ophthalmol. 1995;113:975-977.
- Shields JA, Shields CL, Eagle RC, Blair CJ. Spontaneous pseudohypopyon secondary to diffuse infiltrating retinoblastoma. Arch Ophthalmol. 1988;106:1301-1302.
- Nicholson DO, Norton EW. Diffuse infiltrating retinoblastoma. Trans Am Ophthalmol Soc. 1980;78:265-289.
- Shields CL, Shields JA, Shields MB, Augsburger JJ. Prevalence and mechanisms of secondary intraocular pressure elevation in eyes with intraocular tumors. Ophthalmology. 1987;94:839-846.