[Fuchs heterochromic cyclitis: current concepts]

The clinical features of Fuchs' heterochromic cyclitis (F.H.C.) were described thoroughly by him in 1906. Supplementary data was then supplied by Amsler and Verrey with respect to the vascular characteristics of this disease. Fuchs' disease is not a frequent affection and accounts for no more than 1-2% of the total cases of uveitis. The diagnosis is very difficult to establish at an early stage of the disease. Incomplete or atypical forms are frequent and differential diagnosis is difficult from other cases of cyclitis and/or intermediate uveitis. Furthermore, heterochromia is recognized with difficulty in brown-eyed people. The time of onset of the 3 main symptoms (cataract, heterochromia and cyclitis) varies considerably and the possibility that each of the symptoms follows an individual course at least for a certain period, cannot be excluded. Paraclinical and biological methods for investigating the disease are still limited. However immunological techniques have established the frequent incidence of immune complexes in the aqueous, while some anomalies in the vascular system have been detected on fluoroangiography of the iris. A congenital predisposition to this disease may explain the fact that F.H.C. is generally unilateral. Additionally it might explain Amsler's findings. The way to establish a link both in time and space between all these findings (so as to build up a unique theory which could explain different symptoms) is still unknown, but the so-called sympathetic theory and its theoretical consequences could be rejected permanently in the future.