Título

Comparing anterior segment optical coherence tomography with gonioscopy performed by glaucoma expert and general ophthalmologist in angle closure suspects

Introdução

Assessment of angle configuration is an essential part of the diagnosis and management of individuals with angle closure. The reference standard for diagnostic angle status is visualization of angle structures by indirect gonioscopy. An anterior segment optical coherence tomography (AS­OCT) may provide reproducible images of the anterior chamber angle. The aim of this study is to compare the ability of AS­OCT to detect angle closure with gonioscopy performed by glaucoma experts (GE) and general ophthalmologist (GO)

Método

Gonioscopy in dark conditions was performed by GE and GO in 44 patients with Van Herick anterior chamber depth grade (VH) I or II. Indentation gonioscopy was also performed. An angle quadrant was classified as closed on gonioscopy if posterior trabecular meshwork was not visible. Images of the same evaluated eye were obtained using both Visante (Carl Zeiss Meditec Inc., Dublin, CA, USA) and Triton AS­ OCT (Topcon Inc, Tokyo, Japan). Angle scans obtained by both AS­OCT devices were evaluated for the presence of iridocorneal contact anterior to the scleral spur. Axial length (AXL) and anterior chamber depth (ACD) were obtained by optic biometry. The kappa (k) statistic was used to assess the agreement between categorical variables.

Resultados

Of the 44 patients included 84% were female. The mean age was 65.84±9.25 years. The anterior chamber was classified as VH I in 28 eyes (59%) and VH II in 18 eyes (41%). The mean AXL was 22.40±0.89 mm and ACD was 2.56±0.29 mm. The agreement between GE and GO for identification of closed angle quadrant was 77.27% (k=0.43), 70.45% (k=0.27), 59.09% (k=0.20) and 70.45% (k=0.33) in superior, nasal, inferior and temporal quadrants, respectively. Similar evaluation was performed in indentation gonioscopy, and the agreement was 65.91% (k=0.23), 54.55% (k=0.02), 72.73% (k=0.16) and 54.55% (k=0.09), respectively.

Conclusões

Gonioscopy is a subjective method that demands an extensive training to be correctly performed. There was a moderate agreement between angle status acquired by gonioscopy performed by GE and GO, and AS­OCT images in angle closure suspects.