Ocular amyloidosis and secondary glaucoma

Objective: To report the clinical and histopathologic findings in two cases of secondary glaucoma associated with amyloidosis. Design: Two case reports. Methods: Retrospective review of clinical findings, course, and treatment of the two patients. The histopathologic findings from available biopsy material were also reviewed. Main Outcome Measures: Intraocular pressure (IOP), visual field changes, and surgical outcome. Results: The first case describes a 76-year-old woman with orbital amyloidosis who developed gradual unilateral elevation of IOP that was poorly responsive to medical therapy and underwent filtration surgery. Episcleral venous pressure was elevated on the affected side, and histopathologic analysis of the conjunctival tissue confirmed perivascular amyloid deposits, further suggesting raised episcleral venous pressure to be a possible mechanism of glaucoma. The second case describes a 47-year-old white woman with familial amyloid neuropathy with a transthyretin cys-114 mutation. The association of glaucoma with this mutation has not been described previously. Persisting elevation of IOP in one eye was initially responsive to topical antiglaucoma medications but eventually required filtration surgery. Amyloid particles were found in the aqueous and on the lens surface. Histopathologic analysis of the aqueous and sclerectomy specimens demonstrated amyloid, suggesting outflow obstruction as a possible mechanism of glaucoma. Conjunctival buttonholing complicated filtration surgery in both cases, and the leaks eventually resolved with good control of IOP. Conclusions: Amyloid associated with glaucoma may involve different pathophysiologic mechanisms. The elevated IOP may not respond well to medical therapy. Cautious surgical manipulation of the conjunctiva is warranted in these cases.