Evaluation of Optical Coherence Tomography-Angiography Findings in Keratoconus Patients Treated With Accelerated...

To examine the impact of an accelerated cross-linking (A-CXL) protocol on retinal microvascularization in the treatment of keratoconus using optical coherence tomography-angiography (OCT-A).

The trial included 49 eyes receiving A-CXL therapy for keratoconus. Retinal and optic nerve head parameters were evaluated using OCT-A. OCT-A measurements were conducted preoperatively and at 1 week, 1 month, and 6 months postoperatively.

Forty-nine keratoconus patients undergoing A-CXL were evaluated. Superficial capillary plexus vessel density (SCP-VD) showed significant decreases in the foveal and parafoveal regions at 1 week and 1 month. Although most SCP-VD parameters showed a trend toward recovery by 6 months, some quadrants remained below baseline. Deep capillary plexus vessel density (DCP-VD) showed significant reductions across all quadrants in the foveal, parafoveal, and perifoveal regions at 1 week ( P <0.05 for all), and several of these changes persisted through 6 months. Central macular thickness (CMT) decreased at all time points ( P <0.05). Persistent reductions in parafoveal DCP-VD, retinal deep capillary blood flow area, CMT, and choriocapillaris blood flow area were still evident at the final follow-up ( P <0.05 for all).

In keratoconic eyes successfully treated with A-CXL, significant changes in the vascular density of both the superficial and deep retinal plexuses were observed in the early postoperative period. Although alterations in the superficial plexus seemed to be mostly reversible, sustained changes in deep retinal microcirculation and perfusion parameters suggest a more prolonged and possibly subclinical effect of A-CXL on the outer retina.