ULTRASOUND BIOMICROSCOPY OF THE ANTERIOR SEGMENT IN FUCHS UVEITIS SYNDROME

To evaluate changes in anterior chamber parameters in Fuchs’ uveitis syndrome (FUS) based on ultrasound biomicroscopy (UBM)

Department of Ophthalmology of the Military Hospital, Tunis, Tunisia.

A prospective, cross-sectional comparative study was carried out from January 2021 to September 2021. We examined twenty eyes of 10 patients with unilateral FUS. The fellow eyes served as controls.The diagnosis of FUS was made based on clinical signs including unilateral chronic anterior uveitis: typical starry keratic precipitates, low cellularity and flare in the anterior chamber, iris atrophy, and absence of any posterior synechia. Excluded were any associated immune-mediated systemic or infectious diseases by laboratory testing and medical history. Previous ophthalmic diseases were also exclusion criteria.We noted the patients' best-corrected visual acuity (BCVA), the intraocular pressure (IOP), gonioscopy, and fundus examination. Anterior segment imaging was performed on each eye using UBM (Aviso Lin-50; Quantel Medical). The following biometric parameters of the anterior segment were measured: lens vault (LV), iris Thickness (IT), angle opening distance (AOD 500), angle recess area (ARA 750), and trabecular iris space area (TISA 750). We compared all parameters between the two eyes of each patient.

The mean age of the FUS patients was 38,7 ± 5.3 years (six female and four male). The BCVA was significantly lower in eyes with FUS than in fellow eyes (0.73 ± 0.21; 1.0 respectively; p<0.05). We found Iris nodules (Koeppe nodules) in three patients, heterochromia iritis in four and glaucoma in five. IOP of fellow eyes was normal without anti-glaucoma treatment in all cases. All fellow eyes had normal ophthalmologic examination findings. All iridocorneal angle parameters (AOD 500, ARA 750, TISA750) were significantly larger in eyes with FUS than in healthy eyes (all p<0,05). The iris was thinner in FUS eyes than in healthy fellow eyes (IT=0.47 ± 0.07; 0.53 ± 0.07 respectively; p=0,036). Besides, the LV was significantly greater in FUS eyes than in fellow eyes (0.91±0.24; 0.50±0.29 respectively; p=0,012).

The iridocorneal angle is wider in eyes with FUS. The atrophy and configuration changes in the iris may be responsible for the angle widening. The UBM is a great tool to analyze the anterior segment parameters in FUS. These innovative findings could provide the background for further studies related to the association between glaucoma and FUS.