The retinal vasculature pathophysiological changes in vision recovery after treatment for indirect traumatic optic neuropathy patients

Abstract

Purpose To evaluate the retinal vasculature pathophysiological changes of indirect traumatic optic neuropathy (ITON) patients after effective surgery. Methods Monocular ITON patients who underwent endoscopic trans-ethmosphenoid optic canal decompression (ETOCD) or conservative treatments in Zhongshan Ophthalmic Center from January 2017 to June 2020 were recruited. Visual acuity (VA), visual evoked potential (VEP), oxygen saturation of retinal blood vessels (SO2), and optical coherence tomography angiography (OCT-A) were measured. All patients were followed up at least 3 months after treatments. Results A total of 95 ITON patients were recruited, including 77 patients who underwent ETOCD and 18 patients who underwent conservative treatments. After treatments, more patients received ETOCD (59/77 = 76.6%) presented with improved VA compared with the patients with conservative treatments (6/18 = 33.3%). Compared with the pre-therapeutic measurements, VEP were significantly improved after surgery in ETOCD-treated patients (P < 0.05). Latent periods of P1 and N2, as well as amplitude of P2 of VEP parameters, showed more sensitive to vision recovery (P < 0.05). Retinal artery SO2 and the differences between arteries and veins were improved in ETOCD-treated patients (P < 0.05). Meanwhile, with OCT-A examination, the retinal thickness and retinal vessel density were notably better in ETOCD-treated patients after surgery than that in patients received conservative treatments (P < 0.05). Conclusions Vision recovery after effective treatment of ITON patients was associated with the increased oxygen saturation of retinal vessels, better availability of oxygen in the retina, greater vessel density, and thicker retinas, which might further underlie the vasculature mechanism of vision recovery in ITON patients.

The outcome of surgical and non-surgical treatments for traumatic optic neuropathy: a comparative study of 685 cases

“…In theory, optic canal decompression is beneficial to relieve constriction of the osseous structure to the optic nerve, especially in cases of optic nerve swelling due to edema, hematoma, or swelling of the nerve or nerve sheath. The VA could improve due to the amelioration of the secondary injuries such as inflammatory reaction, and degeneration, and regeneration of retinal ganglion cells (RGCs) after TON (18,19).…”

Retinal peripapillary microvasculature in indirect traumatic optic neuropathy predicted prognosis of endoscopic trans‐ethmosphenoid optic canal decompression

“…Most studies considered that after trauma, the contusion necrosis of nerve fibre in ITON was the result of vasospasm and swelling within the optic canal (Allon et al, 2014; O'Hare Doig et al, 2014; Sarkies, 2004). The impaired circulation of the related area would occur theoretically, whereas little attention had been paid to the alteration of intraocular blood flow in ITON patients (Gao et al, 2021). The decreased retinal blood of the ITON had been reported with the ultrasound doppler.…”

“…Although the retinal blood flow only made up 2% ~ 10% of total ocular circulation, it was essential for the health of the eyes (Ustymowicz et al, 2009). The abnormal hemodynamics affected the visual impairment of ITON (Gao et al, 2021). The reduced RPC density was an important factor to indicate the severity of visual impairment in several optic neuropathies (Zhang et al, 2019).…”

“…The ETOCD was accepted widely for the treatment of ITON (Lai & Liao, 2018; Ma et al, 2018; Yang et al, 2004; Yu et al, 2016). The disparity of visual alteration in ITON patients after treatment might depend on various factors such as microvascular health (Gao et al, 2021; Guy et al, 2014). One underlying theory of ETOCD treatment was to improve retinal microvasculature (Gao et al, 2021; McClenaghan et al, 2011).…”

“…The disparity of visual alteration in ITON patients after treatment might depend on various factors such as microvascular health (Gao et al, 2021; Guy et al, 2014). One underlying theory of ETOCD treatment was to improve retinal microvasculature (Gao et al, 2021; McClenaghan et al, 2011). It had been reported that after the ETOCD, the oxygen saturation of retinal arteries was improved (Gao et al, 2021).…”