SCIENTIFIC POSTER_Ines Casal_1

Familial amyloid polyneuropathy (FAP) is a group of autosomal dominant inherited diseases whose most frequent causative mutation is TTR V30M (a substitution of methionine for valine at position 30 in transthyretin). Transthyretin (TTR) is a normal serum protein which is mainly synthesized in the liver, but also in other tissues such as the choroid plexus and the retinal pigmented epithelium. This disorder is characterized by an extracellular amyloid deposition in multiple organs, nerves and the eye. The present study aims to describe and the manifestations of this disorder in the posterior segment of the eye. Medical records of 513 patients from the Ophthalmology service of Centro Hospitalar do Porto were reviewed. Ocular manifestations relating to the posterior segment of the eye were vitreous opacities and retinal amyloid angiopathy. These manifestations are still present after liver transplantation due to TTR production by the retinal pigmented epithelium. Amyloid deposits in the vitreous body causing vitreous opacification is a well-known clinical manifestation of FAP that usually occur late in the course of the disease and go along with floaters and progressive decrease in visual acuity. Vitrectomy is the only treatment available. Surgery can be performed as complete vitrectomy (extensive vitreous removal, with indentation) or subtotal vitrectomy (without indentation, leaving some peripheral vitreous). Some authors have reported secondary surgery after incomplete vitrectomy, because amyloid continued to deposit in the residual vitreous with visual impairment. Further late manifestation in the posterior segment is retinal amyloid angiopathy, characterized by deposits in the wall of the retinal vessels, sheathing of retinal vessels, microaneurysms and scattered retinal haemorrhages. Fluorescein angiography shows focal staining, microaneurysms and vascular occlusion. Indocyanine green angiography reveals multiple sites of hyperfluorescence along the choroidal vessels. We also observed a correlation between the vitreous opacities and retinal angiopathy and that progression of retinal amyloid angiopathy may be faster after vitrectomy. Conclusion : posterior segment manifestations usually occur in a late course of the disease and the prevalence increases with time. With increased survival of transplanted patients these changes become more frequent. Ophthalmologists should pay attention to them and offer patients adequate treatment and continuous follow-up.