Measurement of Deep Optic Nerve Complex Structures with Two Spectral Domain Optical Coherence Tomography Instruments

ABSTRACT

PURPOSE: To assess the usefulness of two spectral domain optical coherence tomography (SD-OCT) instruments (Cirrus(R), Spectralis(R)) for evaluating optic nerve head and peripapillary structures. METHODS: Images of optic nerve complex were obtained from 136 eyes of 136 patients using enhanced depth imaging technique of 2 SD-OCT instruments. Optic nerve head and peripapillary structures were investigated for their visibility and morphological features in total eyes and glaucomatous eyes. Effect factors for laminar thickness measurement were evaluated and the reproducibility of the lamina cribrosa thickness measured by the 2 OCT instruments was analyzed. RESULTS: Lamina cribrosa thickness was better identified using Spectralis(R) OCT in total and glaucomatous eyes. Short posterior ciliary artery (in total eyes) and peripapillary choroid (in total and glaucomatous eyes) were also better identified using Spectralis(R) OCT (p < 0.001). A cup-disc ratio < or = 0.6 was the significant effect factor for laminar thickness measurement (p < 0.05). Interobserver reproducibility was excellent using both OCT instruments. Intraobserver reproducibility was excellent using Spectralis(R) OCT and moderate using Cirrus(R) OCT. CONCLUSIONS: Spectralis(R) OCT was better for visualizing optic nerve head and peripapillary structures and showed better reproducibility than Cirrus(R) OCT. Thus, the Spectralis(R) may be helpful for detecting and understanding features of the optic nerve complex.