Nonglaucomatous localized retinal nerve fiber layer defects in Behçet uveitis

To describe nonglaucomatous retinal nerve fiber layer (RNFL) defects in patients with Behçet uveitis.

Cross-sectional study and observational case series.

We reviewed the clinical photographs of patients with Behçet uveitis (n = 259), ocular toxoplasmosis (n = 120), and multiple sclerosis (MS)-associated uveitis (n = 40) for the presence of localized RNFL defects. Behçet patients with localized RNFL defects were invited to participate in a prospective evaluation including standard automated perimetry, spectral-domain optical coherence tomography (SD OCT), and RNFL thickness analysis. Main outcome measures were the prevalence of localized RNFL defects, perimetric and SD OCT findings, and RNFL thickness analysis.

Sixty-two patients with Behçet uveitis (24%) had localized RNFL defect(s) without any visible scar. Twenty patients (17%) with ocular toxoplasmosis had a localized RNFL defect associated with a retinochoroidal scar in all. None of the MS patients had a localized RNFL defect. Of the 19 patients (24 eyes) with RNFL defect associated with Behçet uveitis who returned for follow-up, there was a corollary thinning on SD OCT B-scan in all and a corresponding visual field defect in 83%. RNFL thickness analysis was within normal limits in 54%, but revealed thinning in the thickness profile scale in 46% and in the pie chart in 21%.

In Behçet uveitis, localized RNFL defects may be caused by microvascular ischemia at the optic nerve head and/or at the posterior pole and may serve as a helpful ocular diagnostic clue and an indicator of posterior pole involvement, a risk factor for poor visual prognosis.