Intraocular amyloidosis presenting with secondary glaucoma: a clinical-pathologic report and literature review

Purpose We describe a case of intraocular amyloidosis presenting as secondary glaucoma, highlighting the clinical presentation and pathologic correlates. We also review the medical literature on all prior reported cases and discuss the diagnostic challenges pertinent to this particular case. Observations We report the case of a 72-year-old man presenting with medically intractable elevations of intraocular pressure. On clinical examination, the anterior segment was unremarkable, but there were significant vitreous opacities. The patient underwent tube shunt surgery, and a simultaneous aqueous humor biopsy was acellular and nondiagnostic. A subsequent pars plana vitrectomy demonstrated amyloid aggregates on histology. Mass spectrometric analysis revealed that this was transthyretin-type amyloid (ATTR), which is associated with a hereditary mutation in the transthyretin (TTR) gene, yet systemic evaluation was unremarkable, and our patient has not yet chosen to pursue genetic testing. Conclusions and importance Amyloid can deposit in nearly all ocular tissues, and it should be suspected when common ophthalmological presentations do not respond appropriately to standard medical therapies. The challenge in this case was that the anterior segment examination was unremarkable, which is a relatively uncommon presentation for secondary glaucoma in the setting of intraocular amyloidosis. Furthermore, unlike the vast majority of cases of glaucoma associated with intraocular amyloidosis reported to date, our patient had no family history of amyloidosis, nor was any evidence of systemic amyloidosis found upon screening. Literature review, however, establishes that vitreous amyloidosis is invariably associated with a hereditary transthyretin (TTR) mutation, even in the relatively uncommon cases presenting without any known family history and without any systemic symptoms. In the appropriate circumstances, a low threshold to biopsy is appropriate.