Frequency of photographically apparent optic disc and parapapillary nerve fiber layer drusen in Usher syndrome
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A Edwards1, S Grover, G A Fishman
1Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago 60612, USA.
Purpose And Design:
Using a retrospective case series, the authors determine the frequency and clinical features of optic disc and parapapillary nerve fiber layer drusen in type I and type II Usher syndrome (congenital deafness and retinitis pigmentosa).
Methods:
Color fundus photographs available on 43 patients with type I and 108 patients with type II Usher syndrome were analyzed for the presence of optic disc or parapapillary nerve fiber layer drusen.
Results:
Optic disc and/or parapapillary nerve fiber layer drusen were observed in 15 (35%) of 43 patients with type I Usher syndrome and 9 (8%) of 108 patients with type II Usher syndrome for whom color photographs were available. Bilateral drusen were observed in 11 patients (73%) with type I and 3 patients (33%) with type II Usher syndrome. In 3 (20%) of the 15 patients with type I and in 5 (56%) of the 9 patients with type II, only an isolated druse was seen. Six of the 15 patients with type I Usher syndrome showed parapapillary nerve fiber layer drusen, whereas the drusen were within the optic disc in all 9 patients with type II.
Conclusions:
Drusen of the optic disc and parapapillary nerve fiber layer tended to occur more frequently in type I than type II Usher patients and also were more often bilateral and multiple, with a tendency to occur in the parapapillary region and within the optic disc.