SCIENTIFIC POSTER_Minchul Shin

Purpose:

To present the en face images of human choroid with depth by 3D scans and reconstruction using Spectralis OCT, RTVue OCT and their own 3D softwares.

Patients and methods:

Forty healthy volunteers were included in this study. We used Heidelberg Spectralis OCT for 20 subjects and RTVue OCT for the other 20 subjects. 1. Spectralis OCT Scan area was horizontal 15 degree (384 A-scan), vertical 10 degree (261 B-scan) with macula center. Two B-scans were performed at the same line for averaging. Enhanced depth imaging (EDI) and eyetracking were used. After 3D scan, we made 3D reconstruction using its own software and got en face images of choroid with respect to its depth. We used a plane perpendicular to visual axis as a reference. 2. RTVue Scan area was horizontal 7.0 mm (388 A-scan), vertical 7.0 mm (144 B-scan) with macula center. Two B-scans were performed at the same line for averaging. After 3D scan, we made 3D reconstruction using its own software and got en face images of choroid with respect to its depth. We chose retinal pigment epithelium (RPE) surface for a reference. Results 1. Spectralis In healthy volunteers, below the very bright RPE layer, choriocapillary layer, Sattler’s layer and Haller’s layer were well recognized. Choriocapillary was capillary network. Larger diameter vessels began to appear in Sattler’s layer, Haller’s layer. Because the reference of Spectralis was a just plane, the center and periphery of scan area could not show same choroidal layer. 2. RTVue Although the resolution of RTVue was lower than that of Spectralis OCT, choriocapillary layer, Sattler’s layer, Haller’s layer were well recognized. Because RTVue recognize RPE surface automatically, whole scan area showed same choroidal layer.

Conclusion:

We could get en face image of choroid by 3D scans using Spectralis OCT, RTVue OCT and their own 3D software. These novel methods can be used in clinics and research for choroidal diseases.