Secondary Glaucoma in transthyretin (TTR)-related Familial Amyloid Polyneuropathy

Abstract

Purpose: To describe the clinical features of secondary glaucoma associated with transthyretin (TTR)-related Familial Amyloid Polyneuropathy (FAP).

Methods: In this retrospective monocentric study, five patients with FAP associated secondary glaucoma were seen at the ophtalmologic consultation of the french national center for FAP between november 2011 and november 2012. The exact mutation of the amyloidogenic TTR variants was analysed for all patients. All patients had a comprehensive ophthalmic examination including Best corrected Visual acuity (BCVA), ocular pressure, slit lamp photographs, gonioscopy, fundus examination with optic disc photography, ultrasound pathymetry, automated perimetry, and OCT RNFL. Glaucomatous optic neuropathy was diagnosed based on the presence of visual field abnormalities, neuroretinal rim thining, excavation or RNFL defects. Medical and surgical treatments were analysed for all patients.

Results: All cases had bilateral involvement except two monophtalmic patients (1 case of traumatism, and one case of Phtisis bulbi following multiple retinal detachment surgical procedures). All patients were of portuguese origin. Molecular biological examination showed Val30Met mutation in all patients. There were 4 women and one man with a mean age of 52±8 years. Mean BCVA was 0.83±0.9 LogMAR. Three eyes had a BCVA below 20/400. Mean ocular pressure was 27±3mmHg. Mean deviation was -17.6±11.2dB. Amyloid deposition at the pupillary border, fringed pupil and pigmented deposition in the irido-corneal angle were noted in all affected eyes. One patient had bilateral amyloid deposition on the lens anterior capsule. Three patients had concomitent vitreous involvement. Patients were treated with 2.4±2.1 ocular hypotensive drugs. Four eyes had been treated with at least one filtrating surgery.

Conclusions: Although limited by the small size of the sample, our results are comparable to those available in previously published reports : FAP-associated secondary glaucoma is a very severe disease, associated with amyloid deposits in the anterior chamber and characteristic pupil deformation. Systematic and comprehensive eye examination should be performed in all patients affected with FAP in order to improve early detection of glaucoma.

Keywords: 735 trabecular meshwork • 539 genetics