Evidence of outer retinal changes in glaucoma patients as revealed by ultrahigh-resolution in vivo retinal imaging
Stacey S Choi1, Robert J Zawadzki, Michele C Lim
1Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, California, USA. chois@neco.edu
Unlabelled:
AIMS; It is well established that glaucoma results in a thinning of the inner retina. To investigate whether the outer retina is also involved, ultrahigh-resolution retinal imaging techniques were utilised.
Methods:
Eyes from 10 glaucoma patients (25-78 years old), were imaged using three research-grade instruments: (1) ultrahigh-resolution Fourier-domain optical coherence tomography (UHR-FD-OCT), (2) adaptive optics (AO) UHR-FD-OCT and (3) AO-flood illuminated fundus camera (AO-FC). UHR-FD-OCT and AO-UHR-FD-OCT B-scans were examined for any abnormalities in the retinal layers. On some patients, cone density measurements were made from the AO-FC en face images. Correlations between retinal structure and visual sensitivity were measured by Humphrey visual-field (VF) testing made at the corresponding retinal locations.
Results:
All three in vivo imaging modalities revealed evidence of outer retinal changes along with the expected thinning of the inner retina in glaucomatous eyes with VF loss. AO-UHR-FD-OCT images identified the exact location of structural changes within the cone photoreceptor layer with the AO-FC en face images showing dark areas in the cone mosaic at the same retinal locations with reduced visual sensitivity.
Conclusion:
Losses in cone density along with expected inner retinal changes were demonstrated in well-characterised glaucoma patients with VF loss.
