In vivo retinal optical coherence tomography at 1040 nm - enhanced penetration into the choroid.

Optics Express (Impact Factor: 3.53). 06/2005; 13(9):3252-8. DOI: 10.1364/OPEX.13.003252
Source: PubMed

ABSTRACT For the first time in vivo retinal imaging has been performed with a new compact, low noise Yb-based ASE source operating in the 1 microm range (NP Photonics, lambdac = 1040 nm, Deltalambda = 50 nm, Pout = 30 mW) at the dispersion minimum of water with ~7 microm axial resolution. OCT tomograms acquired at 800 nm are compared to those achieved at 1040 nm showing about 200 microm deeper penetration into the choroid below the retinal pigment epithelium. Retinal OCT at longer wavelengths significantly improves the visualization of the retinal pigment epithelium/choriocapillaris/choroids interface and superficial choroidal layers as well as reduces the scattering through turbid media and therefore might provide a better diagnosis tool for early stages of retinal pathologies such as age related macular degeneration which is accompanied by choroidal neovascularization, i.e., extensive growth of new blood vessels in the choroid and retina.

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    ABSTRACT: We directly demonstrated the revascularization in a free retinal pigment epithelium (RPE)-choroid graft with direct blood flow detection by experimental phase-resolved Doppler optical coherence tomography (PRD-OCT). Seven patients with age-related macular degeneration underwent an RPE-choroid graft translocation in a prospective institutional cohort study. Spectral domain optical coherence tomography (SD-OCT) was used to measure the revascularization stage. With PRD-OCT the presence of flow was imaged postoperatively. The PRD-OCT confirmed flow in three patients when SD-OCT indicated the afferent vessel ingrowth stage, and in all seven patients when the SD-OCT indicated the efferent vessel ingrowth stage. The PRD-OCT study was able to detect the presence of blood flow in a free RPE-choroid graft. The PRD-OCT findings directly confirmed the revascularization that was otherwise based on the more circumstantial evidence provided by SD-OCT images and angiography. The use of both techniques to monitor the revascularization process in a free graft in patients are an interesting example of replacing more invasive by noninvasive techniques. There is potential future use of PRD-OCT for the visualization of vascularization patterns in other pathologies.
    01/2015; 4(1):2. DOI:10.1167/tvst.4.1.2
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    ABSTRACT: Amaç: Sağlıklı kadınlarda menstrüel siklusun subfoveal koroid kalınlığı üzerindeki etkilerinin değerlendirilmesi. Gereç ve Yöntem: Çalışmaya 28-30 gün arasında düzenli menstrüel siklusu olan, 18 kadının 18 sağ gözü dahil edildi. Koroid dokusunun görüntülenmesi spectral domain optik koherans tomografi (3D OCT-2000, Topcon Corp. Tokyo, Japan) ile artırılmış derinlikli görüntüleme modu kullanılarak menstrüel siklusun erken folliküler, mid-folliküler, ovulatuar ve mid-luteal fazlarında (1., 7., 14. ve 21. günlerde) yapıldı. Subfoveal koroid kalınlığı ölçümü birbirinden habersiz iki kişi tarafından yapılarak istatistiksel analiz için ortalama değer kullanıldı. Erken folliküler fazdaki görüntüler referans alınarak istatistiksel analiz yapıldı. Verilerin analizi için SPSS 11,6 (SPSS Inc., Chicago, IL, USA) paket programında Wilcoxon signed rank testi kullanıldı. İstatistiksel anlamlılık için p değeri 0,05 olarak kabul edildi. Bulgular: Çalışmaya alınan kadınların ortalama yaşı 23,4±2,8 yıl ve yaş aralığı 20-27 yıl idi. Ortalama subfoveal koroid kalınlığı menstrüel siklusun erken folliküler fazında 300,9±18,8μm, mid-folliküler fazında 323,3±26,1 μm, ovulatuar fazında 312,1±24,7 μm ve mid-luteal fazlarında 306,5±28,9μm bulundu. Mid-folliküler, ovulatuar ve mid-luteal fazlardaki subfoveal koroid kalınlığı anlamlı olarak erken folliküler fazdan yüksek idi (p=0,000, p=0,001 ve p=0,004, sırasıyla). Sonuç: Subfoveal koroid kalınlığı sağlıklı kadınlarda menstrüel siklus boyunca değişim göstermektedir. Koroid kalınlığı ölçümleri yapılırken üreme çağındaki sağlıklı kadınlarda menstrüel siklus boyunca koroid kalınlığının değişebileceği akılda tutulmalıdır. Anahtar Kelimeler: Menstrüel siklus, Subfoveal koroid kalınlığı
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    ABSTRACT: We present a noninvasive phase-variance (pv)-based motion contrast method for depth-resolved imaging of the human chorioretinal complex microcirculation with a newly developed phase-stabilized high speed (100-kHz A-scans/s) 1-mu m swept-source optical coherence tomography (SSOCT) system. Compared to our previous spectral-domain (spectrometer based) pv-spectral domain OCT (SDOCT) system, this system has the advantages of higher sensitivity, reduced fringe wash-out for high blood flow speeds and deeper penetration in choroid. High phase stability SSOCT imaging was achieved by using a computationally efficient phase stabilization approach. This process does not require additional calibration hardware and complex numerical procedures. Our phase stabilization method is simple and can be employed in a variety of SSOCT systems. Examples of vasculature in the chorioretinal complex imaged by pv-SSOCT from normal as well as diseased eyes are presented and compared to retinal images of the same subjects acquired with fluorescein angiography and indocyanine green angiography. Observations of morphology of vascular perfusion in chorioretinal complex visualized by our method are listed. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License.
    Journal of Biomedical Optics 12/2014; 19(12):126010. DOI:10.1117/1.JBO.19.12.126010 · 2.75 Impact Factor

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