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Abstract #27761 Published in IGR 13-1
Longitudinal change detected by spectral domain optical coherence tomography in the optic nerve head and peripapillary retina in experimental glaucoma
Strouthidis NG; Fortune B; Yang H; Sigal IA; Burgoyne CFInvestigative Ophthalmology and Visual Science 2011; 52: 1206-1219
See also comment(s) by Linda Zangwill •
Purpose. To investigate whether longitudinal changes deep within the optic nerve head (ONH) are detectable by spectral domain optical coherence tomography (SDOCT) in experimental glaucoma (EG) and whether these changes are detectable at the onset of Heidelberg Retina Tomography (HRT; Heidelberg Engineering, Heidelberg, Germany)-defined surface topography depression. Methods. Longitudinal SDOCT imaging (Spectralis; Heidelberg Engineering) was performed in both eyes of nine rhesus macaques every 1 to 3 weeks. One eye of each underwent trabecular laser-induced IOP elevation. Four masked operators delineated internal limiting membrane (ILM), retinal nerve fiber layer (RNFL), Bruch's membrane/retinal pigment epithelium (BM/RPE), neural canal opening (NCO), and anterior lamina cribrosa surface (ALCS) by using custom software. Longitudinal changes were assessed and compared between the EG and control (nonlasered) eyes at the onset of HRT-detected surface depression (follow-up 1; [FU1]) and at the most recent image (follow-up 2; [FU2]). Results. Mean IOP in EG eyes was 7.1 to 24.6 mm Hg at FU1 and 13.5 to 31.9 mm Hg at FU2. In control eyes, the mean IOP was 7.2 to 12.6 mm Hg (FU1) and 8.9 to 16.0 mm Hg (FU2). At FU1, neuroretinal rim decreased and ALCS depth increased significantly (paired t-test, P < 0.01); no change in RNFL thickness was detected. At FU2, however, significant prelaminar tissue thinning, posterior displacement of NCO, and RNFL thinning were observed. Conclusions. Longitudinal SDOCT imaging can detect deep ONH changes in EG eyes, the earliest of which are present at the onset of HRT-detected ONH surface height depression. These parameters represent realistic targets for SDOCT detection of glaucomatous progression in human subjects.
Classification:
6.9.2.2 Posterior (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis > 6.9.2 Optical coherence tomography)
6.9.1.1 Confocal Scanning Laser Ophthalmoscopy (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis > 6.9.1 Laser scanning)
2.13 Retina and retinal nerve fibre layer (Part of: 2 Anatomical structures in glaucoma)
2.14 Optic disc (Part of: 2 Anatomical structures in glaucoma)
