Details

Autor(en) / Beteiligte

• Ang, Marcus, FRCSEd
• Sim, Dawn A., FRCOphth
• Keane, Pearse A., FRCOphth
• Sng, Chelvin C.A., FRCSEd
• Egan, Catherine A., FRCOphth
• Tufail, Adnan, FRCOphth
• Wilkins, Mark R., FRCOphth

Titel

Optical Coherence Tomography Angiography for Anterior Segment Vasculature Imaging

Ist Teil von

• Ophthalmology (Rochester, Minn.), 2015-09, Vol.122 (9), p.1740-1747

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2015

Quelle

MEDLINE

Beschreibungen/Notizen

• Purpose To evaluate the application of an optical coherence tomography angiography (OCTA) system adapted for the assessment of anterior segment vasculature. Design Cross-sectional, observational study. Participants Consecutive subjects with normal eyes on slit-lamp clinical examination and patients with abnormal corneal neovascularization. Methods All scans were performed using a commercially available AngioVue OCTA system (Optovue, Inc., Fremont, CA) using an anterior segment lens adapter and the split-spectrum amplitude decorrelation angiography algorithm. Each subject underwent scans from 4 quadrants (superior, inferior, nasal, and temporal) in each eye by 2 trained, independent operators. Main Outcome Measures Analysis of signal strength, image quality, and reproducibility of corneal vascular measurements was performed. Results In our study of 20 normal subjects (10 men, 10 women; mean age, 25.3±7.8 years), we found good repeatability (κ coefficient, 0.76) for image quality score and good interobserver agreement for vasculature measurements (intraclass coefficient, 0.94). After optimization of the angiography scan protocol, vascular measurements within the regions of interest were compared in the superior versus inferior quadrants (mean vascular loops, 3.34±1.16 vs. 3.12 ± 0.90 [ P  = 0.768]; segment-to-loop ratio, 4.18±0.71 vs. 4.32±0.87 [ P  = 0.129]; fractal dimension [Df ] value, 1.78±0.06 vs. 1.78±0.06 [ P  = 0.94]; vascular loop area, 25.9±14.5 vs. 25.9±10.7 × 10−3 mm2 [ P  = 0.21]) and nasal versus temporal quadrant (mean vascular loops, 2.89±0.98 vs. 3.57±0.99 [ P < 0.001]; segment-to-loop ratio, 3.94±0.69 vs. 4.55±0.78 [ P  = 0.897]; Df value, 1.78±0.06 vs. 1.77±0.06 [ P  = 0.14]; vascular loop area, 29.7±15.7 vs. 22.1±7.1 × 10−3 mm2 [ P  = 0.38]. We then used the established OCTA scanning protocol to visualize abnormal vasculature successfully in 5 patients with various corneal pathologic features, including graft-associated neovascularization, postherpetic keratitis scarring, lipid keratopathy, and limbal stem cell deficiency. Conclusions This preliminary study describes a method for acquiring OCTA images of the cornea and limbal vasculature with substantial consistency. This technique may be useful for the objective evaluation of corneal neovascularization in the future.