Monthly Archives: June 2020

OCT-RNFL-Discordance – page 20 of 29

RTVue Inner vs Outer Retinal Thickness Accurate segmentation of the inner and outer retinal layers is supported by the devastating impact to the inner retina, which suffered an arterial occlusion, and the relative sparing of the outer retina, which receives its vascular supply primarily from the choroid.

OCT-RNFL-Discordance – page 20 of 292021-03-29T21:07:06+00:00

OCT-RNFL-Discordance – page 19 of 29

RTVue Inner Retinal Thickness RTVue can measure the inner retinal thickness (equivalent to the GCC) as well. Note the dramatic decrease in thickness of the inner, inferior retina as depicted in blue. Since the inferior branch of the CRA supplies the inner retina only, this finding is anticipated.

OCT-RNFL-Discordance – page 19 of 292021-03-29T21:07:22+00:00

OCT-RNFL-Discordance – page 18 of 29

Significance Map Explanation A Significance Map is provided that shows the regions on the Deviation Map where the percent loss is statistically significant. The Significance Map shows normal areas as green, borderline areas as yellow, and outside normal areas as red (see figure below). These are based on probability values of p < 5%

OCT-RNFL-Discordance – page 18 of 292021-03-29T21:07:33+00:00

OCT-RNFL-Discordance – page 17 of 29

Introduction to GCC Map The GCC map for a normal eye shows a bright circular band surrounding the macula representing a thick GCC from healthy ganglion cells (figure A). The center of the macula is thinner because there are no ganglion cells in this area, as demonstrated on page 13. In glaucoma, as

OCT-RNFL-Discordance – page 17 of 292021-03-29T21:07:46+00:00

OCT-RNFL-Discordance – page 16 of 29

RTVue Outer Retinal Thickness With the Optovue RTVue, We can measure the thickness of the outer retinal layers. Note that the thickness map is essentially normal as depicted by the primarily green thickness map.

OCT-RNFL-Discordance – page 16 of 292021-03-29T21:07:59+00:00

OCT-RNFL-Discordance – page 15 of 29

Introduction to GCC Excerpt from "Direct Ganglion Cell Assessment with the RTVue by Optovue: The Ganglion Cell Complex Analysis" by Mike Sinai, Ph.D. Retinal ganglion cells encompass three layers in the retina: 1) The retinal nerve fiber layer (RNFL) is made up of the ganglion cell axons. 2) The ganglion cell layer (GCL)

OCT-RNFL-Discordance – page 15 of 292021-03-29T21:08:25+00:00

OCT-RNFL-Discordance – page 14 of 29

Comparison of Cirrus vertical OCT scan with RTVue GCC Topcon, Cirrus, and iVue vertical scans through the fovea in the right eye all demonstrate that the inner retina is thinner inferiorly than superiorly as predicted in an occlusion of the inferior branch of the CRA. Shown on the left is the Cirrus vertical

OCT-RNFL-Discordance – page 14 of 292021-03-29T21:08:43+00:00

OCT-RNFL-Discordance – page 13 of 29

GDx vs Zeiss Cirrus- Comparison of Three Examinations OD Although the (circumpapillary) GDx RNFL does demonstrate a dramatic change and loss inferiorly, the Cirrus (circumpapillary) RNFL is essentially normal following the inferior artery occlusion. Note that GDx is measuring the polarization or birefringence of the RNFL but the OCT is measuring optical reflectivity. Does

OCT-RNFL-Discordance – page 13 of 292021-03-29T21:08:59+00:00

OCT-RNFL-Discordance – page 12 of 29

Comparison of Cirrus, iVue, and Topcon SD OCT All three show some minor inferior thinning, relative to the superior thickness maps. However, the Cirrus OCT, as shown on page 8, does not find statistically significant RNFL loss on either the Quadrant or Clock Hour Analysis

OCT-RNFL-Discordance – page 12 of 292021-03-29T21:09:15+00:00