Amyloidosis, Silicone Vitreoretinopathy, pg2

AMYLOIDOSIS

Vitreous amyloidosis is usually associated with primary familial amyloidosis. It is important to recognize vitreous amyloidosis because it may be the presenting sign or symptom of both systemic and ocular lesions, including proptosis, ocular palsies, internal ophthalmoplegia, neuroparalytic keratitis, glaucoma, and conjunctival involvement. [18, 19, 20, 21, 22, 23, 24]
Amyloidosis in the vitreous is causally linked with retinal blood vessel involvement. Vitreous amyloid may be dense enough to obscure vision or may be misinterpreted clinically as vitreous hemorrhage. [25] Biomicroscopically, the opacities may appear yellow-white and have a membranous veil-like quality (Figure 6-7). Some authors have described a central white dot associated with vertically oriented yellow strands. [26]
Vitrectomy may be done as a diagnostic or therapeutic maneuver. [27, 28, 29, 30] Intraocular washings reveal amorphous birefringent deposits that are enhanced with Congo red stain (Figure 6-8). Red-green dichroism may be observed in specimens stained with Congo red and illuminated with polarized light (Figure 6-9). Amyloid fluoresces with thioflavin T stain. It has been demonstrated that vitreous amyloid reacts immunocytochemically with antibody to prealbumin. [31] Familial amyloidosis of the neuropathic type has been associated with homozygosity for the transthyretin methionine-30 gene. [32]

SILICONE VITREORETINOPATHY

Silicone oil is used retinal detachment surgery as a means to tamponade retinal breaks and reattach the retina. [33, 34, 35] It is often reserved for cases of recurrent retinal detachments and advanced proliferative vitreoretinopathy. [36] There is experimental and clinical evidence to suggest that silicone oil may stimulate fibrous proliferation and recurrent membrane formation. [37, 38, 39, 40] Histologic studies have demonstrated glial or pigment epithelial tissue containing vacuoles as well as extracellular clear spaces. [41] Cytologic preparations show intracellular vacuoles that presumably represent silicone oil engulfed by glial cells and macrophages (Figure 6-10).

HEALON-LADEN MACROPHAGES

The differential diagnosis of clear vacuoles within macrophages includes residual healon (hyaluronic acid polymer). This viscoelastic substance is used mainly during cataract surgery to keep the ocular chambers formed so instruments glide smoothly through incisions and the corneal endothelium is protected from damage. Cytologic specimens show macrophages with cytoplasmic clear spaces (Figure 6-11). A proliferative reaction has not been reported with healon.

REFERENCES:
18. Lieberman TW, Ferry AP. Trans Am Ophthalmol Soc 1974;72:302-325
19. Kaufman HE. Arch Ophthalmol 1958;60:1036-2043
20. Crawford JB. Arch Ophthalmol 1967;78:214-216
21. Wong VG, McFarlin DE. Arch Opththalmol 1967;78:208-213
22. Legrand J. Guenel J, Dubigeon P. Bull Soc Ophtalmol Fr 1968;68:13-20
23. Hamburg A. Ophthalmologica 1971;162:173-177
24. Franceschetti AT, Rabinowicz T. J Genet Hum 1969;17:349-366
25. Schwartz MF, Green WR, Michels RG, Kincaid MC, Fogle J. Ophthalmology 1982;89:394-401
26. Mieler WF, Williams DF, Levin M. Arch Ophthalmol 1988;106:881-883
27. Paton D, Duke JR. AJO 1966;51:736-747
28. Kasner D, Miller GR, Taylor WH, Sever RJ, Norton EW, et al Trans Am Acad Ophthalmol Otolaryngol 1968;72:410-418
29. Matsui M, Tashiro T, Asai Y. Acta Soc Ophthalmol Jpn 1976;80:142-146
30. Irvine AR. Char DH. AJO 1976;82:705-708
31. Doft BH, Rubinow A, Cohen AS. AJO 1984;97:296-300
32. Sandgren O, Holmgrem G, Lundgren E. Arch Ophthalmol 1990;108:1584-1586
33. Cibis PA, Becker B, Okun E, Canaan S. Arch Ophthalmol 1962;68:590-599
34. Grey RHB, Leaver PK. BF J Ophthalmol 1979;92:1029-1034
35. McCuen BW II, Landers MB III, Machemer R. Ophthalmology 1985;92:1029-1034
36. Cox MS, Trese MT, Murphy PL. Ophthalmology 1986;93:646-650
37. Fastenberg DM, Diddie KR, Delmage JM, Dorey K. AJO 1983;95:663-667
38. Gonvers M, ThresherR. Graefes Arch Clin Exp Ophthalmol 1983;221:46-53
39. Watzke RC. Arch Ophthalmol 1967;77:185-196
40. Cockerham WD, Schepens CL, Freeman HM. Arch Ophthalmol 1970;83:704-712
41. Lewis H, Burke JM, Abrams GW, Aaberg TM. Ophthalmology 1988; 95:583-591

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