Abstract
Purpose::
Although heterogeneity of clinical symptoms is recognized even for the same amyloidogenic transthyretin (TTR) mutation, ocular amyloidosis had never fully been evaluated. We investigated the clinical characteristics of vitreous opacity in patients with familial amyloidotic polyneuropathy (FAP) ATTR Val30Met in two major endemic areas, Arao, Japan and the northern part of Sweden.
Methods::
Patients included in our study were 90 patients, 18 patients in Japan and 72 patients in Sweden, with vitreous opacity associated with FAP ATTR Val30Met. All patients had a definite diagnosis of FAP on the basis of genetic investigations. The clinical data of the patients were obtained from medical records.
Results::
The mean age at the onset of vitreous opacity was significantly older in Swedish patients (67.8 year-old) than in Japanese patients (47.6 year-old; P<0.05) as same as the onset of polyneuropathy. The prevalence of vitreous opacity as the initial symptom of FAP, as the only manifestation of FAP and vitreous surgery was significantly greater in Swedish patients (51%, 35%, and 88%, respectively) than in Japanese patients (17%, 6%, and 39%, respectively; each P<0.05).
Conclusions::
Vitreous opacity in Swedish patients developed much older and more aggressive compared to that of Japanese patients. These findings point to the possibilities that aging changes in the eye, in addition to environmental factors, may facilitate amyloid formation mechanism in FAP.