Endoscopic Transnasal Optic Canal Decompression For Traumatic Optic Neuropathy: Efficacy And Prognosis Analysis Of 72 Cases

Objective:Traumatic optic neuropathy(TON)is a pathological state of acute visual function impairment caused by external force impacting the optic nerve.Endoscopic transnasal optic canal decompression(ETOCD)surgery plays a positive role in the prognosis of TON patients'visual function.This study aimed to analyze the clinical outcome of this surgery,identify the relevant prognostic factors,and investigate the therapeutic efficacy under different initial vision,different surgical timing,and a combination of the both.Methods:This study retrospectively analyzed the clinical data of 72 TON patients who received ETOCD surgery at the Second Affiliated Hospital,Zhejiang University School of Medicine from August 2017 to May 2019.Visual acuity was compared before and after surgery,prognostic risk factors of visual acuity and improvement degree of visual acuity(IDVA)were identified by multiple linear regression analysis,and the improvement rates of visual acuity was compared under different initial vision,different surgical timing,and a combination of the both.Results:Among all the TON patients experienced ETOCD involved,the Log MAR visual acuity after surgery(-2.87±0.19)was higher than Log MAR visual acuity before surgery(-3.92±0.13)(P<0.01).The total visual acuity improvement rates of ETOCD were 54.2%.There were 83.3%and 33.3%improvement rates in patients with residual vision and no light perception,respectively,and the difference was statistically significant(~2=17.622,P<0.0001).The visual acuity improvement rates of TON patients underwent ETOCD within 3 days,within 7 days and beyond 7 days were 60.9%,61.5%and 35.0%,respectively.There was a statistically significant difference between improvement rates within 7 days and beyond 7 days(~2=4.098,P=0.043).For patients with no light perception,visual acuity was improved in 50.0%were treated within 3 days,37.5%were treated 3-7 days,and 0.0%were treated beyond 7 days.The improvement rates of blindness patients managed within 3 days(P=0.008)and 3-7days(P=0.035)was significantly higher than that for patients managed beyond 7 days.For patients with residual vision,visual acuity was improved in 85.7%were treated within 3 days,92.3%were treated 3-7 days,and 70.0%were treated beyond 7 days,no statistically significant difference was found between each group.Multiple linear regression analysis models displayed that initial visual acuity and time to received surgery were both independent risk factors for visual acuity prognosis(P<0.05),but only surgical timing was significantly associated with the IDVA(P<0.05).Optic canal fracture,orbital fracture,and hemorrhage within the ethmoid and/or sphenoid sinus were not significantly correlated with IDVA and visual acuity prognosis(P>0.05).Conclusion:ETOCD surgery is conducive to the improvement of impaired vision after TON.A better initial visual acuity indicates better final visual acuity outcomes after surgery,shorter time to surgery after TON implies better visual acuity prognosis and higher IDVA.ETOCD surgery should be performed as soon as possible to salvage the patient's visual acuity,particularly within the first 7 days following TON.For blindness patients,it is necessary to carry out the surgery within 3 days.