Transthyretin-related vitreous amyloidosis in different endemic areas

Abstract

Background. To investigate the vitreous opacity in patients with familial amyloidotic polyneuropathy (FAP) in two major endemic areas, Japan and Sweden.

Methods. We obtained clinical data for 90 patients with vitreous opacity that was associated with FAP amyloidogenic transthyretin (ATTR) Val30Met; 18 Japanese patients and 72 Swedish patients. We reviewed medical records at Kumamoto University Hospital in Japan and Umeå University Hospital in Sweden. We evaluated the characteristics of the patients, systemic and ocular histories, clinical findings and treatment.

Results. Swedish patients were significantly older at the onset of vitreous opacity (mean age 67.8 years) than were Japanese patients (47.6 years). A similar age difference was found for the onset of polyneuropathy. In addition, Swedish patients without polyneuropathy were significantly older (74.1 years) at the onset of vitreous opacity than those with polyneuropathy (64.6 years). A significant difference in the occurrence of vitreous opacity as the only manifestation of FAP was seen for Swedish patients (35%) compared with Japanese patients (6%).

Conclusions. Swedish FAP ATTR Val30Met patients appeared to develop vitreous opacity later and more frequently compared with Japanese patients.

Keywords:

• Familial amyloidotic polyneuropathy
• ocular manifestations
• vitreous opacity
• genetic heterogeneity
• transthyretin

Acknowledgements

The authors work was supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture, Japan, and from the Ministry of Health and Welfare, Japan.