PURPOSE To investigate ultrahigh speed, swept source optical coherence tomography (SSOCT) angiography for visualizing vascular changes in eyes with non-exudative age-related macular degeneration (AMD) with geographic atrophy (GA). DESIGN Observational, prospective, cross-sectional study. PARTICIPANTS A total of 63 eyes from 32 normal subjects and 12 eyes from 7 patients with non-exudative AMD with GA. METHODS A 1050 nm, 400 kHz A-scan rate SSOCT system was used to perform volumetric optical coherence tomography angiography (OCTA) of the retinal and choriocapillaris (CC) vasculatures in normal subjects and patients with non-exudative AMD with GA. OCTA using variable interscan time analysis (VISTA) was performed to assess CC alteration and differentiate varying degrees of CC flow impairment. MAIN OUTCOME MEASURES Qualitative comparison of retinal and CC vasculatures in normal subjects versus those in patients with a clinical diagnosis of non-exudative AMD with GA. RESULTS In all 12 eyes with GA, OCTA showed pronounced CC flow impairment within the region of GA. In 10 of the 12 eyes with GA, OCTA with VISTA showed milder CC flow impairment extending beyond the margin of GA. Of the 5 eyes exhibiting foveal sparing GA, OCTA showed CC flow within the region of foveal sparing in 4 of the eyes. CONCLUSIONS The ability of ultrahigh speed, swept source OCTA to visualize alterations in the retinal and CC vasculatures noninvasively makes it a promising tool for assessing non-exudative AMD with GA. OCTA using VISTA can distinguish varying degrees of CC alteration and flow impairment and may be useful for elucidating disease pathogenesis, progression, and response to therapy.
Background and Objective To investigate the potential of ultrahigh-speed swept-source optical coherence tomography angiography (OCTA) to visualize retinal and choroidal vascular changes in patients with exudative age-related macular degeneration (AMD). Patients and Methods Observational, prospective cross-sectional study. An ultrahigh-speed swept-source prototype was used to perform OCTA of the retinal and choriocapillaris microvasculature in 63 eyes of 32 healthy controls and 19 eyes of 15 patients with exudative AMD. Main outcome measure: qualitative comparison of the retinal and choriocapillaris microvasculature in the two groups. Results Choroidal neovascularization (CNV) was clearly visualized in 16 of the 19 eyes with exudative AMD, located above regions of severe choriocapillaris alteration. In 14 of these eyes, the CNV lesions were surrounded by regions of choriocapillaris alteration. Conclusion OCTA may offer noninvasive monitoring of the retinal and choriocapillaris microvasculature in patients with CNV, which may assist in diagnosis and monitoring.
Mechanical properties of cells have been shown to have a significant role in disease as in many instances cell stiffness changes when a cell is no longer healthy. We present a high throughput microfluidics based approach that exploits the connection between travel time of a cell through a narrow passage and cell stiffness. The system resolves both cell travel time and relative cell diameter while retaining information on the cell level. We show that stiffer cells have longer transit times than less stiff ones and that cell size significantly influences travel times. Experiments with untreated HeLa cells and cells made compliant with Latrunculin A and Cytochalasin B further demonstrate that travel time is influenced by cell stiffness, with the compliant cells having faster transit time.
Structured Abstract PURPOSE To investigate the utility of ultrahigh speed, swept source optical coherence tomography (SSOCT) angiography in visualizing retinal microvascular and choriocapillaris (CC) changes in diabetic patients. METHODS The study was prospective and cross-sectional. A 1050 nm wavelength, 400 kHz A-scan rate SSOCT prototype was used to perform volumetric optical coherence tomography angiography (OCTA) of the retinal and CC vasculatures in diabetic patients and normal subjects. 63 eyes from 32 normal subjects, 9 eyes from 7 PDR patients, 29 eyes from 16 NPDR patients, and 51 eyes from 28 diabetic patients without retinopathy were imaged. RESULTS Retinal and CC microvascular abnormalities were observed in all stages of diabetic retinopathy. In NPDR and PDR, OCTA visualized a variety of vascular abnormalities including: clustered capillaries, dilated capillary segments, tortuous capillaries, regions of capillary dropout, reduced capillary density, abnormal capillary loops, and foveal avascular zone enlargement. In PDR, retinal neovascularization above the inner limiting membrane was visualized. Regions of CC flow impairment in patients with PDR and NPDR were also observed. In 18 of the 51 of eyes from diabetic patients without retinopathy, retinal mircrovascular abnormalities were observed and CC flow impairment was found in 24 of the 51 diabetic eyes without retinopathy. CONCLUSIONS The ability of OCTA to visualize retinal and CC microvascular abnormalities suggests OCTA may be a useful tool for understanding pathogenesis, evaluating treatment response, and earlier detection of vascular abnormalities in patients with diabetes.
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