Anna Brouwer

Summary, discussion & future perspectives We observed a prolonged cone b-IT frequently in non-anterior childhood uveitis but the 30 Hz flicker response was often affected in these patients as well ( Chapter 5 ). Most of the included patients had an intermediate uveitis. A frequent complication of intermediate uveitis is cystoid macular edema (CME), 3 which is associated with an abnormal 30 Hz flicker response and a prolonged cone b-IT in patients with a retinal vein occlusion. 4 Therefore, it may be that this combination of an abnormal 30 Hz flicker response and a prolonged cone b-IT was more frequently affected in childhood uveitis due to the higher prevalence of CME. The 30 Hz flicker response may be more affected due to the intraretinal edema which could reduce the phototransmission. Similar to adults, a prolonged cone b-IT and an abnormal 30 Hz flicker response in childhood uveitis was associated with a more severe inflammation; specifically the presence of vitritis and CME. In Chapter 6 we describe that in a typical form of anterior uveitis, juvenile idiopathic arthritis (JIA) associated uveitis, the ERG can be abnormal as well. But in this case series the type of ERG abnormalities varied amongst patients. We observed abnormalities in all parts of the ERG. The cone b-IT was often abnormal, but we could not conclude that this was the most pronounced ERG abnormality in JIA uveitis. The only ERG parameter which showed no abnormalities was the implicit time of the rod b-wave. All JIA associated uveitis eyes that had an active uveitis, had an abnormal ERG, which may indicate that there is an association between an abnormal ERG and an active inflammation, comparable to our other studies. However, we also observed ERG abnormalities in eyes with an inactive inflammation. Future studies should investigate if there is an association between an abnormal ERG in JIA associated uveitis and a more severe inflammation in the past, similar to our findings in the adult cohort. Does the ERG improve? Fortunately, the ERG can improve in some cases, as we observed in Chapter 3 . In our adult uveitis cohort, we measured a second ERG in patients that had an uveitis duration of < 1 year at the time of the first ERG. An improvement of the cone b-IT was most often seen in eyes where the inflammation became less active, particularly in eyes were the inflammation in the anterior chamber due to a panuveitis became inactive. However, in most eyes we did not observe an improvement in the cone b-IT when the inflammation became inactive, and other ERG abnormalities persisted as well. We did not expect that all ERG abnormalities would improve in all cases, because in Chapter 2 we observed quite some ERG abnormalities in inactive uveitis eyes in the group of patients with a uveitis duration of > 5 years. 161 8