Apolipoprotein AI-Derived Vitreous Amyloidosis: An Elusive Diagnosis

A 56-year-old female presented with vitreous opacity with gradual visual disturbance in her right eye of 1-year duration. A Non-Hodgkin's lymphoma had been treated 15 years before. Presenting best-corrected visual acuity (BCVA) was 20/200 in her right eye and 20/25 in her left eye. Intraocular pressure was 18 mm Hg bilaterally. Slit-lamp examination revealed no abnormal findings in the anterior segment of both eyes, including the absence of cells and flare. Fundoscopic examination indicated hazy media with the typical glass-wool-like appearance in her right eye. B-scan ultrasound demonstrated that the vitreous was full of middle-echo spots, vitreous opacities, and posterior vitreous detachment occurred. The patient underwent vitreous biopsy and a standard 25-gauge pars plana vitrectomy (diagnostic and therapeutic). Intraoperatively, the eye was noted to have severe diffuse debris and very strong vitreoretinal adhesions. Cytospin smears prepared from the vitreous aspirate indicated amorphous acellular material that stained positively with Congo Red and showed apple green birefringence on polarized microscopy, consistent with the diagnosis of amyloidosis. A genetic evaluation of tongue tissue demonstrated apolipoprotein AI-derived amyloidosis. The BCVA was 20/25 OU at 3 months postoperatively.