Yellow subconjunctival deposits

Conjunctival Amyloidosis: A Report of Two Cases with Review of Literature - 2000-2020

Amyloidosis is a complex multisystem disorder characterized by deposition of an aberrant protein in tissues and results in disruption of the normal organ function. Localized amyloidosis is a rare disorder. It commonly affects the head-and-neck region, and only 4% of these lesions are encountered in the orbital region. Hence, conjunctival amyloidosis is a very rare entity. It is thought to be a manifestation of local immunologic disorders. Amyloidosis of conjunctiva is more often localized with no other systemic features. Here, we present two cases of unilateral conjunctival amyloidosis, one with extensive calcification. Conjunctival amyloidosis must be considered in the differential diagnosis of conjunctival neoplasms. Histopathological examination and apple-green birefringence on polarized microscopy with Congo red stain remain the gold standard for diagnosing this entity.

Ocular Involvement in Hereditary Amyloidosis

The term amyloidosis describes a group of rare diseases caused by protein conformation abnormalities resulting in extracellular deposition and accumulation of insoluble fibrillar aggregates. So far, 36 amyloid precursor proteins have been identified, and each one is responsible for a specific disease entity. Transthyretin amyloidosis (ATTRv) is one of the most common forms of systemic and ocular amyloidosis, due to the deposition of transthyretin (TTR), which is a transport protein mainly synthesized in the liver but also in the retinal pigment epithelial cells. ATTRv amyloidosis may be misdiagnosed with several other conditions, resulting in a significant diagnostic delay. Gelsolin and keratoepithelin are other proteins that, when mutated, are responsible for a systemic amyloid disease with significant ocular manifestations that not infrequently appear before systemic involvement. The main signs of ocular amyloid deposition are in the cornea, irido-corneal angle and vitreous, causing complications related to vasculopathy and neuropathy at the local level. This review aims at describing the main biochemical, histopathological and clinical features of systemic amyloidosis associated with eye involvement, with particular emphasis on the inherited forms. We discuss currently available treatments, focusing on ocular involvement and specific ophthalmologic management and highlighting the importance of a prompt treatment for the potential sight-threatening complications derived from amyloid deposition in ocular tissues.