advertisement
Selections of the 3rd international symposium on optical coherence tomography
April 25-28, 2001, Longboat Key, Florida, USA
Joel Schuman
The 3rd International Symposium on Optical Coherence Tomography (OCT) was held April 25-28, 2001 in Longboat Key, Florida at the Colony Beach and Tennis Resort. The meeting featured 27 papers on OCT topics ranging from basic technology and software development to clinical applications including corneal, retinal and glaucoma imaging. The setting was ideal, with ample time for collegial interaction, and a good mix of didactics, hands-on opportunities, and sand and sea time.
The nature of the meeting was such that presentations were more about the technology and its applications than disease processes; however, several presentations introduced new clinical concepts, and used OCT to assess outcomes. One such example was Adam Martidis' discussion, "Treatment of refractory diabetic macular edema with intravitreal triamcinalone acetonide." In this case series, Martidis demonstrated a reduction in macular thickness and improvement in visual acuity through the use of intravitreal steroids. Quantitative assessment of macular thickness using OCT was a primary outcome measure.
Similarly, Carmen Puliafito demonstrated a reduction in macular thickness
following photodynamic therapy in, "Optical Coherence Tomography in the
management of photodynamic therapy." Puliafito proposed an OCT based staging
of macular degeneration following photodynamic therapy treatment as follows:
| · Stage | I: Acute Inflammatory Response | · Stage | II: Resolution of Subretinal Fluid | · Stage | III: Reaccumulation of Subretinal Fluid with Fibrosis | IIIa: fluid > fibrosis; probable retreatment | IIIb: fibrosis > fluid; natural progression to stage IV | · Stage | IV: Increasing Fibrosis with Persistent Fluid | · Stage | V:
Subretinal Fibrosis with Retinal Atrophy
Alain Gaudric, in "OCT characteristics of cystoid macular edema of various origins," demonstrated the ability of OCT to differentiate between macular edemas of different etiologies. This discriminatory ability may have potential clinical utility in patient care. In another staging presentation, Michael Ip presented, "Comparison of macular hole staging by manual grading of stereoscopic fundus photography and optical coherence tomography." Ip showed the ability of OCT to objectively stage macular holes and their development. A highlight of the meeting was a pair of presentations on OCT technology by two of its inventors, and leaders in the field. James G. Fujimoto, in "Ultrahigh resolution and spectroscopic optical coherence tomography," demonstrated some of the current and future potential of the device, showing the highest resolution in vivo images to date, at 2-3 microns axial resolution. Fujimoto showed the benefits of Doppler and spectroscopic imaging in detecting blood flow and adding discriminative information to OCT images. Joseph Izatt, in "Noninvasive imaging of human retinal hemodynamics using color Doppler optical coherence tomography," presented an exciting array of OCT advances, and showed that color Doppler OCT is superior to existing techniques for retinal blood flow detection, showing the depth, diameter and blood flow in vessels with heretofore unattainable spatial resolution. Izatt's talk was complimented by Radhakrishnan's, "Measurement of anterior segment parameters in normal eyes using real-time optical coherence tomography and comparison with standard clinical techniques." Radhakrishnan showed the utility of a specialized hand-held probe in real-time anterior segment imaging, and the dramatic possibilities this approach affords in the assessment of the anterior eye and the angle. Joel S. Schuman, in "Nerve fiber layer thickness and the likelihood of a visual field defect," introduced a new parameter, the NFL50, defined as that NFL thickness at which there is a 50% likelihood of a visual field defect. Schuman explained that this parameter might be useful in clinical glaucoma assessment as well as screening, in order to predict functional loss using a quantifiable, objective structural parameter. Hiroshi Ishikawa in, "Improved OCT software for RNFL analysis in glaucoma," and Alexey Chestakov, in "Corneal tomogram analyze with particularized software," each presented new advances in OCT analysis. Ishikawa's software utilized a new parameter, the retinal index (retinal thickness times (NFL reflectivity/99% maximal total reflectivity)), and demonstrated superior correlation with disease as compared to the standard OCT software. |
