what is Difference between Diffuse Optical Tomography and Optical Tomography?

optical coherence tomography

• why optical coherence tomography vs. fluorescein angiogram?

• Answer:

  Hello again, pru-ga, I'm glad you were able to find -- and reply to -- my earlier comment. Google Answers is a great service, but it can be a bit tricky at times, especially for first-time users. As I had mentioned, I found three studies that directly relate to your question. I found these by searching the very useful, very comprehensive medical database known as PubMed, which is maintained by the federal National Institutes of Health in the U.S. The main PubMed search page can be found at: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi where I conducted a search on the terms: "optical coherence tomography" "fluorescein angiogram" (I also varied the search strategy, looking, e.g. for [ tomography angiogram ] but did not find additional relevant studies.) I excerpted the citations and some text from the three study abstracts below. You can view the full abstracts at the links provided with each citation. If anything in this answer is not clear -- or if you need additional information -- just let me know by posting a Request for Clarification. Please do not rate this answer until you are satisified that you have all the information you need. Let me know how I can help, and I'll be happy to assist you further. All the best. pafalafa-ga ========== [This study demonstrates the superiority of OCT over FA for detecting cystoid macular edema] http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12049577 Arch Ophthalmol. 2002 Jun;120(6):731-7. Decreased visual acuity associated with cystoid macular edema in neovascular age-related macular degeneration. Ting TD, Oh M, Cox TA, Meyer CH, Toth CA. Department of Ophthalmology, Duke University Medical Center, Box 3802, Erwin Road, Durham, NC 27710, USA. OBJECTIVE: To determine the prevalence and visual significance of cystoid macular edema (CME) in eyes with subfoveal neovascular age-related macular degeneration using optical coherence tomography (OCT). MATERIALS AND METHODS: The medical records of 61 ... patients...with nondisciform subfoveal neovascular age-related macular degeneration were... reviewed. All patients underwent fluorescein angiography and OCT imaging... CONCLUSIONS: ...Cystoid macular edema is more common with horoidal neovascularization containing classic component. The OCT is a useful test to detect the presence of CME in these patients since CME may be difficult to identify on fluorescein angiogram. ========== [Another study showing OCT successfully identifying CME when FA was not able to] http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11193945 Nippon Ganka Gakkai Zasshi. 2000 Dec;104(12):943-59. [Macular diseases--application of automated static perimetry and optical coherence tomography] Iijima H. Department of Ophthalmology, Yamanashi Medical University. The usefulness of automated static perimetry and optical coherence tomography in the management of macular diseases has been described... ......The highly protrusive nature of the orange-red nodule in eyes with idiopathic polypoidal choroidal vasculopathy was demonstrated with dimensional measurementwith OCT... Parafoveal retinal sensitivity obtained with automatedstaticperimetry was studied in correlation with retinal thickness measured usingOCT ineyes with branch retinal vein occlusion showing macular edema without macularnon-perfusion or massive retinal hemorrhages. The increased retinal thickness dueto macular edema is closely correlated with retinal sensitivity both at the fovea and in theparafoveal area. ...Eighty-nine phakic eyes of 46 patients with retinitis pigmentosa patients were studied to detect cystoid macular edema using OCT. Cystoid lesions were observed in the macula in 12 eyes in 6 (13%) of 46 patients. Some eyes with OCT-proven cystoid macular edema did not show dye pooling in the fluorescein angiogram... ========== [And here's the third study, also involving CME, and the detection benefits of OCT over FA] http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10458174 Am J Ophthalmol. 1999 Aug;128(2):185-91. Optical coherence tomography of cystoid macular edema associated with retinitis pigmentosa. Hirakawa H, Iijima H, Gohdo T, Tsukahara S. Department of Ophthalmology, Yamanashi Medical University, Tamaho, Japan. PURPOSE: To detect cystoid macular edema in consecutive eyes with retinitis pigmentosa by means of optical coherence tomography and to study the correlation between cross-sectional structures and angiographic findings in cystoid macular edema. METHODS: In a prospective study, cross-sectional images through the fovea were evaluated by means of optical coherence tomography...Eyes showing cystoid appearance in the macula in the optical coherence tomographic images were further studied with measurement of the dimensions of cystoid lesions and with a fluorescein angiogram... CONCLUSION: Cystoid macular edema in eyes with retinitis pigmentosa could easily be detected with the use of optical coherence tomography independent of the angiographic degree of dye leakage. The size of cystoid lesions demonstrated in the optical coherence tomographic images...was not necessarily correlated with the angiographic grading of dye leakage.... ========== Again, if you have any questions about accessing the full abstracts, just let me know.