ULTRAHIGH RESOLUTION OPTICAL
COHERENCE TOMOGRAPHY

J.G Fujimoto, W. Drexler, I. Hartl, T. Ko, R. Ghanta, J. Schuman and
S. Bursell

Massachusets Institute of Technology, MIT and U. Vienna., MIT, New England Eye Center, Joslin Diabetes Center, USA

Introduction.  We demonstrate a third generation ultrahigh resolution ophthalmologic optical coherence tomography (OCT) system that enables unprecedented in vivo visualization of retinal architectural morphology, and assess its potential for imaging retinal diseases.  Methods. Ultrahigh resolution OCT is performed using a new broadband laser light source.  Preliminary imaging studies were performed in patients with normal eyes, diabetic retinopathy, and glaucoma.  Results:  OCT imaging with axial resolutions of less than 3 µm has been achieved.  OCT tomograms have been correlated with standard ophthalmic examination techniques.  Ultrahigh resolution OCT achieves the highest in vivo OCT resolu­tions to date with an axial resolution improvement by a factor of ~4-5 over standard OCT retinal imaging.  Ultrahigh resolution enables visualization of internal retinal morphology which is not resolvable with standard OCT.  Image processing techniques permit quantitative measurement of the different retinal layers including the ganglion cell layer, the photoreceptor layer, as well as the retinal nerve fiber layer and total retinal thickness.  Conclusion.  Ultrahigh resolution ophthalmic OCT enables improved visu­alization of in­ternal retinal architectural mor­phology as well as increased accuracy of quantitative measurment.