Prognostic factors of trans-ethmosphenoid optic canal decompression for indirect traumatic optic neuropathy

AIM： To investigate a possible correlation between visual acuity（VA） prognosis and the presence at baseline of various orbital and ocular signs in patients affected by indirect traumatic optic neuropathy（ITON）. METHODS： From July 1 st, 2012 to July 1 st, 2015, 224 adults diagnosed with ITON who underwent endoscopic transethmosphenoid optic canal decompression（ETOCD） were reviewed. Visual outcome before and after treatment were taken into comparison. RESULTS： Accompanied older in age, longer time to medical treatment and existence of optic canal fracture（OCF） were the independent predictors for poor postoperative VA and lower improvement degree of visual acuity（IDVA）, while worse preoperative VA was predictive factor for poor postoperative VA only. Mean value of IDVA in patients with OCF was 0.19±0.30. Mean value of IDVA in patients without OCF was 0.29±0.35. IDVA in cases without OCF was significant higher than those with OCF（t=2.272, P〈0.05）. CONCLUSION： Patients suffered from ITON without OCF before ETOCD have better surgical outcome than those with OCF. Older in age, longer time to medical treatment and existence of OCF are independent factors for poor VA prognosis and lower IDVA. Preoperative VA is independent factor for VA prognosis only.

Newly onset indirect traumatic optic neuropathy-surgical treatment first versus steroid treatment first

AIM: To investigate the efficacy and safety of the treatment of endoscopic trans-ethmosphenoid optic canal decompression(ETOCD) with combination of steroid in patients with newly onset indirect traumatic optic neuropathy(ITON) and compare the outcome between immediate ETOCD treatment and ETOCD with preoperative steroid treatment. METHODS: Patients presented as newly onset ITON(suffered trauma within 3 d) at a tertiary medical center between Mar 1 st, 2016 and Mar 1 st, 2018 were enrolled in this study. All patients were equally and randomly divided into 2 groups. Cases in group A were performed ETOCD immediately after admition while cases in group B were prescribed by methylprednisolone(20 mg/kg · d) for 3 d before ETOCD. Methylprednisolone(20 mg/kg · d) was used after surgery for 6 d in group A and 3 d in group B. Follow-up was up to 3 mo in all cases. Visual acuity(VA) before and after treatment between the two groups were taken into comparison. RESULTS: Complete postoperative data were acquired from 34 patients in group A and from 32 patients in group B. Group A had significantly higher effective rate in VA than group B(χ~2 =4.905, P=0.027).CONCLUSION: For patients with newly onset ITON, combination treatment of ETOCD with high-dose steroid is an effective and safe way. Immediate surgery will lead to better prognosis for these cases.

Analysis of retinal vasculature changes in indirect traumatic optic neuropathy using optic coherence tomography angiography

AIM:To assess the retinal vasculature alterations in indirect traumatic optic neuropathy(ITON)patients following craniofacial trauma by optic coherence tomography angiography(OCTA).METHODS:Patients diagnosed of monocular ITON were recruited from August 2016 to May 2020.OCTA was performed using the Angio Vue OCT-A system for two cube scans centered at the optic nerve head and fovea.OCTA data included thicknesses of peripapillary retinal nerve fiber layer(RNFL)and macular ganglion cell complex(GCC),as well as proportion of capillary perfusion and data were analyzed for correlation with post-injury timepoints:within 7,8-30,31-90,and 91-365d.RESULTS:A total of 73 ITON patients were studied.Significant thinning of RNFL and GCC layers and attenuation of microvascular perfusion were observed in ITON eyes as compared to contralateral unaffected eyes(for most of the analyzed sectors and quadrants,P<0.05).Without respect to surgical intervention and vision recovery,the decrease in retinal layer thicknesses and microvascular perfusion was time-dependent,and most significant within three months(P<0.001).CONCLUSION:ITON presents with time-dependent thinning of retinal layers and attenuation of microvasculature,indicating possible degeneration of retinal ganglion cells due to reduced retinal blood supply.

Axonal loss and blood flow disturbances in the natural course of indirect traumatic optic neuropathy

Background Indirect traumatic optic neuropathy （TON） is an acute injury of the optic nerve associated with severe visual dysfunction, which may be a result of secondary mechanical injury and vascular disorder of the optic nerve due to trauma. We analyzed the natural course of axonal loss and blood flow disturbances in patients with indirect TON to find a possible therapeutic window. Methods A cohort of 54 patients with indirect TON recruited between October 2008 and October 2010 at Beijing Tongren Hospital was retrospectively analyzed. The patients were divided into no light perception group （NLP） and better than NLP （btNLP） group. Specifically, the thickness of the retinal nerve fiber layer （RNFL） measured by spectral domain optical coherence tomography （SD-OCT）, and hemodynamic parameters of the ophthalmic artery （OA）, central retinal artery （CRA） and posterior ciliary artery （PCA） were determined. Results Two weeks after injury, there was a statistically significant decrease in the thickness of RNFL in the btNLP group as compared with the fellow control eyes （P 〈0.05）. In contrast, in the NLP group, RNFL thickness slightly increased for 2 weeks following injury, then overtly reduced after 4 weeks （P 〈0.05）. Peak systolic velocity （PSV） of CRA was significantly decreased 4 weeks after injury （P 〈0.05） in both the NLP group and btNLP group （P 〈0.05）. The thickness of RNFL in the NLP group was negatively correlated with PSV of CRA after 1 week of injury （P 〈0.05, r=-0.962）. Conclusions SD-OCT is a useful supplement in detecting the axonal loss in TON. The dynamic change of the thickness of RNFL appears to correlate with the hemodynamic disturbances in the natural course of TON. The first 2 weeks following an injury is critical and should be considered as the therapeutic window for TON patients.