Transient reduction in the retinal microvascular network following implantation surgery of implantable collamer lens: An OCT angiography study.

Purpose: To evaluate changes in the retinal microvascular network after posterior chamber phakic implantable collamer lens (ICL) surgery using optical coherence tomography angiography (OCTA) in patients with high myopia. Methods: Patients with high myopia who underwent ICL surgery were enrolled in this study. All patients underwent comprehensive ophthalmologic exams preoperatively and 1 week, 1 month, and 3 months postoperatively. The vascular densities (VDs) in the retina and the superficial and deep capillary plexuses of different annular and quadrantal areas were evaluated from OCTA images (Zeiss Cirrus 5000). Correlations between the variations in microvascular density and possible factors were further analyzed. Results: The study comprised 32 eyes of 32 patients. The mean age of the patients was 26.91±7.610 years (15 men and 17 women). A statistically significant reduction in microvascular density in the retina and the superficial plexus was found 1 week and 1 month postoperatively (p<0.05, repeated-measures ANOVA). Further fractal analysis found that the VD of the outer ring declined statistically significantly (p<0.05). A statistically significant decrease was also found in the inferior nasal sector 1 week postoperatively, with an overall decrease in all four quadrants 1 month postoperatively. The microvascular density recovered toward the baseline level 3 months postoperatively. No correlations were observed between the variation in microvascular density and the spherical equivalent (SE), axial length (AL), intraocular pressure (IOP), amplitude of accommodation (AA), or contrast sensitivity. Conclusions: Retinal microvascular density was decreased postoperatively and then recovered toward the baseline level after 3 months. ICL surgery may have a transient influence on the retinal microvascular network without affecting visual function.