Anterior Segment Optical Coherence Tomography Angiography Assessment of Corneal Vascularisation After Combined Fine-Needle Diathermy with Subconjunctival Ranibizumab: A Pilot Study.

Abstract

To describe anterior segment optical coherence tomography angiography (AS-OCTA) imaging to monitor corneal vascularisation (CoNV) and scar reduction after combined fine-needle diathermy (FND) with subconjunctival ranibizumab. Prospective clinical study of six eyes from six subjects with corneal scar and CoNV which underwent combined FND with subconjunctival ranibizumab. All eyes were imaged using slit-lamp photography (SLP) and AS-OCTA (Optovue, Inc., Fremont, CA, wavelength: 840nm) before and after the operation, with two independent masked assessors analysing all images. Main outcome measures were changes in median corneal scar area and vessel density (AS-OCTA) comparing pre- and postoperative imaging up to month 3 and 6. The mean age of the subjects was 60 ± 23years, with three males and three females. CoNV and corneal scarring involving the visual axis were present in all eyes, secondary to previous infective keratitis (n = 3), severe blepharokeratoconjunctivitis (n = 2), or chemical injury (n = 1). Follow-up time frame ranged from 2 to 6months postoperation. There was a reduction in median corneal scar area from 30.2 mm2 (IQR 18.7-38.5) before surgery to 14.8 mm2 (IQR 7.1-19.6) after surgery, with a median reduction of 37.1% (IQR = -3.1-86.9, p = 0.046). There was also a reduction in median cornea vessel density (AS-OCTA) from 20.8% (IQR 16.1-20.8) before surgery to 17.6% (IQR 14.0-17.6) after surgery, with a median reduction of 15.1% (IQR 13.2-15.1, p < 0.001). Combined imaging of SLP and AS-OCTA is useful for monitoring treatment response of corneal scarring and CoNV after combined FND with subconjunctival Ranibizumab.