Anna Brouwer

3 71 ERG abnormalities in non-infectious uveitis often persist Introduction Uveitis comprises of a group of multiple diseases with an inflammation of the uvea and its adjacent structures, including the retina. 1 If this inflammation is severe, it can be treated with immune-modulating drugs. However, despite intensive treatment strategies with these medicines, vision loss can still develop. 2 This vision loss can be the result of several complications of intraocular inflammation. Well-known complications are macular oedema, cataract and glaucoma. 3 However, retinal atrophy and loss of retinal function may also occur. Recently, we described a characteristic type of ERG abnormality in uveitis: a prolonged cone b-wave, which was seen in all anatomic subtypes including anterior uveitis. This prolonged cone b-wave was associated with a more severe inflammation of both present and past. 4 So far it is unknown to what extent ERG abnormalities in uveitis are reversible. We found that the prolonged cone b-wave could still be present in eyes in which inflammation had become inactive at the time of ERG recording. However, there are reports of ERG abnormalities that improve in uveitis. For instance, in birdshot chorioretinitis (BSCR) the ERG can normalize after treatment. 5,6 On the other hand, in Behçet disease, the ERG does not improve, even when the inflammation becomes quiet. 7 In other uveitis entities, such as in AMPPE, MEWDS and AZOOR, the ERG may either improve or deteriorate over time. 8–10 To gain more insights into factors that may contribute to either an improvement, or a worsening of retinal function in uveitis patients, we investigated changes in the ERG over time in relation to clinical factors such as anatomical localization and diagnosis, severity of inflammation and treatment. Methods Design and patient population This is a one-year follow-up study of a prospective cohort study which describes the retinal function of uveitis patients by using the ERG. 4 Inclusion criteria for this follow-up study were as follows: a non-infectious uveitis and a disease duration of less than 1 year at the time of inclusion for the previous study. The results of the first ERGs were part of a larger cohort study which was previously described. 4 The diagnoses which were included are as follows: Behçet disease, birdshot, chorioretinitis, human leukocyte antigen (HLA)-B27 associated uveitis, Vogt–Koyanagi–Harada disease, sarcoidosis, and uveitis of unknown cause.