Posters

Retinal segmentation of the macula in normal and glaucomatous eyes

Poster Details

First Author: M.Pazos SPAIN

Co Author(s):    A. Dyrda   A. Gomez   C. Martin   A. Anton-Lopez           

Abstract Details

Purpose:

To evaluate thickness of the different retinal layers in the macular area in normal and glaucomatous eyes using the automated layer by layer retinal segmentation software of Spectralis Spectral-Domain Optical Coherence Tomograph (SD-OCT).

Setting:

1. Ophthalmology, Hospital de l'Esperança-Parc de Salut Mar, Barcelona, Barcelona, Spain. 2. Institut de la Macula i la Retina, Centre mèdic Quirón-Teknon, Barcelona, Spain. 3. Institut Català de la Retina., Barcelona, Spain.

Methods:

Sixty-four eyes (24 normal, 20 mild glaucoma and 20 moderate glaucoma) were prospectively studied. Ophthalmological examination was done, including reliable 24-2 Humphrey Visual Field (HFV), Intraocular Pressure (IOP), optic disc evaluation by glaucoma specialists and a good quality (Q≥20) SPECTRALIS posterior pole imaging with the automated retinal layers segmentation software. A thickness map of 9 regions using the ETDRS circle (1-3-4 mm rings centered on the fovea) was obtained for each layer/group of layers including Retinal Nerve Fiber Layer (RNFL), Ganglion cell complex (GCCx) and Ganglion Cell layer (GCL). Differences among groups were assessed with ANOVA at p<0.01

Results:

RNFL volume was 0.99±0.1 mm3 for the normal group, 0.84±0.1 mm3 for the mild, and 0.76±0.1 mm3 for the moderate glaucoma, and inferior quadrants showed the highest thickness difference (42±5, 32.4±8 and 24.9±4.6 µm, respectively)(p<0.001). GCCx volumes were 2.11±0.2, 1.74±0.2 and 1.54±0.2 mm3 for the normal, mild and moderate glaucoma, respectively (p<0.001). Both for GCCx and GCL, 8 regions in the mild glaucoma group (except the central area) and all 9 regions studied in the moderate glaucoma group, showed a significant thickness reduction when compared to normal eyes; when comparing mild vs moderate glaucoma, Significant thinning was found in the inferior and temporal quadrants.

Conclusions:

1. The Automated segmentation of the SD-OCT Spectralis allows visualization and quantification of the different retinal layers in the macula including isolated GCL (without Inner Plexiform Layer). 2. This segmentation showed significant thinning of RNFL, GCCx and GCL in glaucomatous eyes when compared to normal eyes. 3. GCCx and GCL thickness were found to be significantly thinner in the temporal and inferior areas of moderate glaucoma when compared to mild glaucoma.

Financial Disclosure:

One or more of the authors receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented, One or more of the authors receives non-monetary benefits from a company producing, developing or supplying the product or procedure presented.