COATS’ DISEASE
Coats’ disease is usually unilateral and is characterized by exudative retinal detachment in young males.[19][
20][
21] Telangiectatic blood vessels have been identified in this disorder and presumably are the basis for the retinal exudates and exudative detachment of the retina (Figure 7-3).[
22][
23] Coats’ disease may produce leukocoria in children and can be confused clinically with retinoblastoma. In such cases, a fine needle aspiration may be obtained to differentiate these two entities. In addition, a vitrectomy may be employed to repair the retinal detachment.[
24][
25][
26] In either case, the specimens are extremely hypocellular with occasional macrophages containing cytoplasmic vacuoles (Figure 7-4).[
27] Histologically, there is massive subretinal exudates and retinal detachment. Telangiectasis of the retinal blood vessels or the extraretinal blood vessels can be identified (Figure 7-5).
DIABETIC RETINOPATHY
Diabetic retinopathy is the single most common source of intraocular washing specimens processed by our cytology laboratory. Retinopathy occurs in about 70% of patients who have had diabetes mellitus beyond 20 years. Diabetic retinopathy manifests as a microangiopathy with thickening of vascular basement membrane, loss of endothelium, and degeneration of capillary pericytes.[
28][
29][
30][
31][
32] In the early stages, venous dilatation, capillary microaneurysms, and exudates are observed.[
33][
34] Vascular disease leads to ischemia of the retina and neovascularization is stimulated (proliferative diabetic retinopathy) (Figure 7-6).[
35][
36] Vitrectomy may be performed in this disease for several reasons, including vitreous hemorrhage secondary to neovascularization and tractional retinal detachment with removal of fibrovascular membrane.[
37][
38][39]
Neovascularization is identified in vitrectomy specimens as well-defined blood vessels lined by a single layer of endothelium (Figure 7-7).
PROLIFERATIVE VITREORETINPATHY
The leading cause of failure in retinal detachment surgery is proliferative vitreoretinopathy (PVR).[40][41][
42][
43] It is characterized by a proliferation of cellular membranes on both sides of the detached retina and in the vitreous cavity.[44] Fibrovascular proliferation that extends anterior to the posterior border of the vitreous base has been termed anterior PVR.[
45] Traction induced from the membranes on the posterior lens surface, ciliary body, and iris may produce a peripheral retinal detachment.[
46] Epiretinal membranes are composed of retinal pigment epithelial cells, glial cells, fibrocytes, and macrophages.[
47][
48][49][
50][
51][
52][
53][
54][55][
56] Surgically removed epiretinal membranes may be sent for cytologic examination. Cell buttons or cytospin preparations reveal a thin fragment composed of spindle cells and oval cells, some of which may contain pigment (Figure 7-8).
Epiretinal membranes composed mainly of spindle cells have been associated with photocoagulation, trauma, and inflammatory disease.[57] However, most simple epiretinal membranes are idiopathic.[
58]
References:
19. Coats G. Royal London Ophthal Hosp Rep 1908;17:440-525.
20.
Fox KR. Metabol Pediatr Syst Ophthalmol 1980;4:121-124.
21.
Reese AB. Am J Ophthalmol 1956;42:1-8.
22.
Chang M, McLean IW, Merritt JC. J Pediatr Opthalmol Strabismus 1984;21:163-168.
23.
Egbert PR, Chan CC, Winter FC. J Pediatr Ophthalmol 1977;13:336-339.
24.
Jaffe MS, Shields JA, Canny CLB, Eagle RC, Fry RL. Ann Ophthalmol 1977;9:863-868.
25.
Pe'er J. Am J Opthalmsol 1988;106:742-743.
26.
Laqua H, Wessing A. Ophthalmology 1983;90:1284-1291.
27.
Haik BG, Koizumi J, Smith ME, Ellsworth, RM. Am J Opthalmol 1985;100:327-328.
28.
Robison WG Jr. Kador PF, Kinoshita JH. Science 1983;221:1177.
29.
Kalebic T, Garbisa S, Glaser B, Liotta LA.Science 1983;221:281.
30.
Kuwabara T, Cogan DG. Arch Ophthalmol 1963;69:492-502.
31.
Toussaint D, Dustin P. Arch Ophthalmol 1963;70:96-108.
32.
Yanoff M. N Engl J Med 1966;274:1344-1349.
33.
De Venecia G, Davis M, Engerman R. Arch Ophthalmol 1976;94:1766-1773.
34.
Addison DJ, Garner A, Ashton N. Br Med J 1970;1:264-266.
35.
Niki T, Muraoka K, Shimizu K. Ophthalmology 1984;91:1440.
36.
Miller H, Miller B, Zonis S, Nir I. Invest Ophthalmol Vis Sci 1984;25:1338-1342.
37.
Thompson JT, de Bustros S, Michels RG, Rice TA. Arch Ophthalmol 1987;105:503-507.
38.
Thompson JT, de Buustros Michels RG, Rice TA. Arch Ophthalmol 1987; 105:191-195.
39. Blankenship GW. St Louis: C.V. Mosby, 1989;3:515-539.
40. The Retinal Society Terminology Committee. Ophthalmology 1983;90:121-125.
41. Claes C, Freeman HM, Tolentino FI. New York: Springer-Verlag, 1988:3-11.
42.
Lewis H, Aaberg TM, Abrams GW. Am J Ophthalmol 1991;111:8-14. 43.
Schwartz D, De la Cruz ZC, Green WR, Michels RG. Retina 1988;8:275-281. 44. Glaser BM. Pathobiology of PVR. New York: Springer-Verlag, 1988:12-21.
45.
Lewis H, Aaberg T. Am J Ophthalmol 1988; 105:277. 46.
Lewis H, Abrams GW, Foos RY. Am J Ophthalmol 1987;104:614-618. 47.
Machemer R, Laqua H. Am J Ophthalmol 1975;80:1-23.48.
Clarkson JG, Green WR, Massoff D. Am J Ophthalmol 1977;84:1-17. 49. Daicker B, Guggenheim R. Albrecht Von Graefes Arch Klin Exp Ophthalmol 1979;210:109-110
50.
Van Horn DL, Aaberg TM, Machemer R. Am J Ophthalmol 1977;84:383-393. 51.
Kampik A, Kenyon KR, Michels RG, Green WR, de Cruz ZC, Epiretinal and vitreous membranes: comparative study of 56 cases. Arch Ophthalmol 1981;198199:1445-1454. 52.
Kampik A, Green WR, Michels Rg, Nase PK. Ultrastructure of progressive idiopathic epiretinal membrane removed by vitreous surgery. Am J Ophthalmol 1980:90:797-809. 53.
Hiscott PS, Grierson I, McLeod D. Natural history of fibrocellular epiretinal membranes: a quanative, autoradiographic and immunohistochemical study. Br J Ophthalmol 1985;69:810-823.
54.
Michels RG. A clinical and hisopathical study of epiretinal membranes affecting the macula and removed bu vitreous surgery. Trans Am Ophthalmol Soc 1982;80:580-656. 55. Foos RY. Spectrum of nonvasular proliferative extraretinopathies. In: Nicholson DH, ed. Ocular pathology update. New York: Masson Publishing, 1980:107-114.
56.
Foos RY. Nonvascular proliferative extraretinopathies. Am J Ophthalmol1978;86:723-725.
57. Kampik A, Green WR, Michels RG, Rice TA. Epiretinale membranen nack photokoagulation (postkoagulative maculopathie). Ber Dtsch Ophthalmol Ges 1981;78:593-598.
58. Roth AM, Foos RY. Surface wrinking retinopath in eyes enucleated at autotopsy. Trans AM Acad Ophthalmol Otolaryngol 1971;75:1047-1058.