Session: Poster session A

Foveopapillary angle measured by fundus photography and optical coherence tomography. Are these methods interchangeable?

María ALARCÓN TOMÁS^1,2, Blanca ESLAVA-VALDIVIELSO¹, Rosa MARTIN-CARRIBERO¹, Yanira GÓMEZ- SANGIL¹

¹Hospital Universitario Puerta de Hierro. , Madrid, Spain
²Clinica Baviera., Madrid, Spain

Introduction

Although measurement of the foveopapillary angle (FPA) by fundus photography has been the traditional method for objective torsion measurement, optical coherence tomography has emerged as a popular alternative in the past few years. In some situations, as in high miopic patients, it is difficult to determine the exact localization of the fovea and thus the FPA. Concordance between fundus photography and OCT Spectralis has been previously evaluated finding that FPA with OCT Spectralis isn’t affected by poor foveal definition. Marking the center of the fovea using B-scan of the Swept Source OCT (SS-OCT) could also be useful for this purpose. The aim of this study is to evaluate the concordance of the FPA measured by fundus photography and SS-OCT.

Methods:

FPA was measured in 15 patients by 2 different methods: 1) Fundus photography using a non-mydriatic Retinography (Topcon Corporation, Tokio, Japan) and 2) Color retinography from SS-OCT Triton (Topcon Corporation, Tokio, Japan) with B- scan fovea identification. For FPA calculation Cyclocheck.com (developed by Piotr Loba and Justyna Simiera) was used. FPA and B-Scan identification was made by 2 independent observers to determine interobserver reproducibility. Intraclass correlation coefficient (ICC) was assessed to evaluate concordance between these methods.

Results

29 eyes were included in the study, 73% were male, median age 60,5 years (26-78). Mean FPA in fundus photography was 7.12±4.46 degrees while 6.05± 4.56 degrees in SS-OCT. Concordance in FPA between the two methods was fair with an overall ICC of 0.529 (p>0.01). The concordance between observers when measuring FPA was high with ICC of 0.83 for fundus photography and 0.85 for SS-OCT.

Conclusions

Although both methods are very reproducible in measuring FPA, with high levels of agreement between observers, the results obtained by these methods are not interchangeable.