Monitoring the Effectiveness of High-Fluence Peripheral Crosslinking for Corneal Neovascularization with Anterior Segment Optical Coherence Tomography Angiography

Abstract

Background/Aims: To investigate the effectiveness of an accelerated high-fluence peripheral crosslinking (pCXL) treatment protocol for corneal neovascularization (cNV) and the viability of optical coherence tomography angiography (OCTA) to monitor cNV dynamics. Methods: This pilot study included six eyes of six adult patients with cNV in at least one corneal quadrant who were treated with pCXL (7.2 J/cm2, 9 mW). The degree of cNV regression was monitored with slit lamp photography and anterior segment OCTA. The main outcome measure was total vessel area one and four weeks after treatment. Results: OCTA allowed for the objective monitoring of vascular metrics: The total vessel area declined from an average of 1025.4 mm2 (min: 0.13 mm2; max: 3637 mm2) at the baseline evaluation to 382.4 mm2 (min: 0.08 mm2; max: 1528 mm2) (p = 0.096). The total vessel length lessened from an average of 107.1 mm (min: 2.8 mm; max: 321.1 mm) to 47 mm (min: 2.6 mm; max: 156.5 mm) (p= 0.27). The average number of junctions at baseline decreased from 46.67 (min: 3; max: 166) to 26.5 (min: 0; max: 50) (p = 0.23). The junction density decreased from an average of 10.75/mm2 (min: 0.0002 /mm2; max: 36.5056/mm2) to 7.37/mm2 (avg.) (min: 0; max 18.7356/mm2) (p = 0.24). PCXL was performed safely without adverse effects, but vascular occlusion was not complete in all eyes. Conclusions: High-fluence pCXL may represent a valuable treatment option to achieve cNV regression, whilst the optimal fluence dose still remains to be defined. Anterior segment OCTA is an innovative tool for non-invasive, objective, and quantitative cNV monitoring.