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

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.