Three-dimensional High-speed Optical Coherence Tomography Imaging of Lamina Cribrosa in Glaucoma
Presented in part at: American Academy of Ophthalmology Annual Meeting, November 2006, Las Vegas, Nevada.
Received 9 January 2008; received in revised form 21 May 2008; accepted 4 September 2008. published online 16 December 2008.
Objective
To evaluate the appearance of the optic nerve head and lamina cribrosa in patients with glaucoma using spectral/Fourier-domain optical coherence tomography (SD-OCT) and to test for a correlation between lamina cribrosa thickness measured on SD-OCT images and visual field loss.
Design
Observational case series.
Participants
We evaluated 52 eyes of 30 patients with glaucoma or ocular hypertension.
Methods
The high-speed SD-OCT equipment used was a prototype system developed for 3-dimensional (3D) imaging. It had a sensitivity of 98 decibels (dB), a tissue axial resolution of 4.3 μm, and an acquisition rate of ∼18,700 axial scans per second. For 3D analyses, a raster scan protocol of 256 × 256 axial scans covering a 2.8 × 2.8 mm disc area was used. Lamina cribrosa thickness was measured on 3D images using 3D image processing software. Correlation between lamina cribrosa thickness and mean deviation (MD) values obtained using static automatic perimetry were tested for statistical significance.
Main Outcome Measures
Clarity of lamina cribrosa features, lamina cribrosa thickness, and MD values on static automatic perimetry.
Results
On 3D images, the lamina cribrosa appeared clearly as a highly reflective plate that was bowed posteriorly and contained many circular areas of low reflectivity. The dots of low reflectivity visible just beneath the anterior surface of the lamina cribrosa in en face cross-sections corresponded with dots representing lamina pores in color fundus photographs. The mean (±1 standard deviation) thickness of the lamina cribrosa was 190.5±52.7 μm (range, 80.5–329.0). Spearman rank testing and linear regression analysis showed that lamina cribrosa thickness correlated significantly with MD (Spearman σ = 0.744; P<0.001; r2 = 0.493; P<0.001). Different observers performed measurements of the lamina cribrosa thickness in SD-OCT cross-sectional images with high reproducibility (intraclass correlation coefficient = 0.784).
Conclusions
These 3D SD-OCT imaging clearly demonstrated the 3D structure of the lamina cribrosa and allowed measurement of its thickness, which correlated significantly with visual field loss, in living patients with glaucoma. This noninvasive imaging technique should facilitate investigations of structural changes in the optic nerve head lamina cribrosa in eyes with optic nerve damage due to glaucoma.
Financial Disclosure(s)
The authors have no proprietary or commercial interest in any materials discussed in this article.
Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
Correspondence: Masanori Hangai, MD, Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, 54 Shougoin Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan. Fax: (81) 75-752-0933
Manuscript no. 2008-53.
Available online: December 16, 2008.
Finanacial Disclosure(s): The authors have no proprietary or commercial interest in any materials discussed in this article.
Supported in part by a Grant-in-Aid for Scientific Research (18591917) from the Japan Society for the Promotion of Science (JSPS).
ABSTRACT