Structural and vascular retinal changes and visual outcomes after treatment of compressive anterior visual pathway...

There is limited evidence regarding longitudinal postoperative changes in retinal vascular density in patients with compressive anterior visual pathway lesions. In this study, we aimed to investigate the changes in retinal vasculature after decompression surgery based on optical coherence tomography (OCT) and OCT angiography (OCTA) and the predictive utility of OCT and OCTA parameters for postoperative visual outcomes. This prospective study included 22 eyes (15 patients) with a compressive anterior visual pathway lesion, which were assessed preoperatively as well as at 1, 3, and 6 postoperative months. Preoperative and postoperative visual acuity (VA), mean deviation on standard automated perimetry, and OCT and OCTA parameters (e.g., retinal nerve fiber layer, macular ganglion cell complex [GCC] thickness, vessel densities of radial peripapillary capillaries, parafoveal and perifoveal superficial vessel densities, and deep vessel densities) were evaluated. At 1 month postoperatively, the average VA and mean deviation were significantly improved (P = .001, P < .001, respectively), while the average values of retinal nerve fiber layer, GCC, and vessel densities of the radial peripapillary capillaries were significantly reduced (P = .027, P < .001, P < .001, respectively), with these trends continuing until 6 postoperative months. Moreover, the average parafoveal superficial vessel densities was significantly reduced at 6 postoperative months (P = .016). Preoperative GCC thickness was a significant predictive factor for VA improvement over the follow-up period (P = .008), while an average GCC thickness of < 70 μm was associated with significantly worse visual outcomes (P = .003). Following decompressive surgery, OCT and OCTA can detect further regression of retinal structure and vasculature over 6 months as a result of retrograde degeneration of the compressed optic nerve with subsequent axonal loss and secondary superficial retinal vascular remodeling. Despite these structural changes, functional visual outcomes improved due to restored nerve transmission in surviving axons. Our findings indicate that average GCC thickness may serve as a predictor associated with visual prognosis and thus should be routinely evaluated.