Assessment of corneal vessels activity through the 'Barcode sign' of corneal OCT.

Abstract

Background/objectives: Anterior segment optical Coherence Tomography (AS-OCT) is used extensively in imaging the cornea in health and disease. Our objective was to analyse and monitor corneal vascularisation (CVas) through the corresponding back-shadows visible on AS-OCT.

Subjects/methods: AS-OCT scans were obtained from 26 consecutive patients (eyes) with CVas of different aetiologies. AS-OCT horizontal line scans showing the back shadows cast by the vessels were analysed and correlated with findings seen on slit lamp examination. Vessels were graded clinically as active, partially regressed, and regressed. The density of back shadow in the patient samples before and after treatment was analysed using Image-J software.

Results: AS-OCT demonstrated a dense back shadow in all the 26 active vessels studied. When multiple vessels were present, the barcode sign was apparent. The back shadows absent in 22 (84.62%) at the regressed (healed) stage. The intensity of the backshadow had reduced in regressing vessels 4 (15.38%). The integrated density of the backshadow on AS-OCT in the active stage (pre-treatment) and corresponding healed (post-treatment, partially regressed or ghost vessels) scans was statistically significantly different (P < 0.0001).

Conclusion: This study demonstrates that AS-OCT provides additional important information in patients with CVas enabling distinction between active and regressing/regressed vessels. Semiquantitative assessment can be made by measuring the integrated density of the back shadows produced by the vessels.