放射性视神经病变的临床和影像学特征分析

Analysis of clinical and imaging characteristics of radiation-induced optic neuritis

目的观察放射性视神经病变(RION)的临床及影像学特征。方法回顾性临床研究。2010年至2021年于解放军总医院眼科检查确诊的RION患者43例69只眼纳入研究。其中,男性23例36只眼;女性20例33只眼。放射治疗(以下简称为放疗)时年龄(49.54±13.14)岁。放疗实体病灶中心剂量(59.83±14.12)Gy。联合化学药物治疗(以下简称为化疗)16例。所有患者均行最佳矫正视力(BCVA)、眼底彩色照相检查;同时行光相干断层扫描(OCT)检查46只眼;视野检查30只眼;眼部核磁共振成像(MRI)检查40只眼。BCVA检查采用Snellen视力表进行,记录时换算为最小分辨角对数(logMAR)视力。行腰椎穿刺脑脊液检查12例。行高压氧治疗(HBOT)10例13只眼;静脉滴注甲基强的松龙(IVMP)治疗9例12只眼;HBOT联合IVMP治疗12例23只眼;仅行基础治疗12例21只眼。并据此分为HBOT组、IVMP组、HBOT联合IVMP组及对照组。观察患眼发病时、恢复时、最终的BCVA和视盘周围神经纤维层(RNFL)、黄斑区内界膜-视网膜色素上皮(ILM-RPE)层厚度变化,以及不同治疗方式BCVA最终结局。不同病程者以及不同治疗方案组RNFL、ILM-RPE层厚度比较采用独立样本t检验。结果43例患者中,单眼、双眼分别为17(39.53%,17/43)、26(60.47%,26/43)例。完成放疗至出现视力下降的时间为(36.33±30.48)个月。RION病程1周~10年,其中病程≤2个月者37只眼。亚急性视力下降41只眼。logMAR BCVA<1.0、1.0~0.3、>0.3分别为45、15、9只眼。RION病程2个月内视盘苍白、水肿分别为10(27.03%,10/37)、3(8.11%,3/37)只眼。与病程<1个月时比较,病程1个月时,视盘上方RNFL[95%可信区间(CI)2.08~66.56,P=0.038]、黄斑区外环上方ILM-RPE层(95%CI 4.37~45.39,P=0.021)厚度明显变薄;病程2个月时,黄斑中心区ILMRPE层明显增厚(95%CI-32.95~-4.20,P=0.015);病程3~6个月时,黄斑区内环颞侧ILM-RPE层明显增厚(95%CI-42.22~-3.83,P=0.022);病程>6个月时,视盘RNFL除颞侧外均明显变薄,黄斑区平均、内环上方、外环ILM-RPE层明显变薄(P<0.05)。行MRI检查的40只眼中,受累视神经T1强化33只眼(82.50%,33/40),其中颅内段23只眼(69.70%,23/33);伴增粗和长T2信号12只眼(36.36%,12/33)。治疗后BCVA恢复17只眼(24.64%,17/69);最终BCVA提高9只眼(13.04%,9/69)。与对照组比较,HBOT组、IVMP组、HBOT联合IVMP组患眼恢复时BCVA、最终BCVA差异均无统计学意义(t=-1.04、0.61、1.31、-1.47、-0.42、0.46,P>0.05)。结论RION患眼病程1个月内视盘RNFL和黄斑区ILM-RPE层同时出现结构性损伤,RNFL表现为持续变薄,ILM-RPE表现为变薄-增厚-变薄的特点;MRI可见视交叉和视神经各节段出现T1强化,强化节段通常伴增粗和长T2信号;HBOT、IVMP治疗RION无明显疗效。

Objective To observe the clinical and imaging characteristics of radiation optic neuropathy(RION).Methods A retrospective clinical study.A total of 43 patients(69 eyes)who were diagnosed with RION at the Chinese PLA General Hospital from 2010 to 2021 were included in this study.There were 23 males(36 eyes)and 20 females(33 eyes).The age of patients at the time of radiation therapy was 49.54±13.14 years.The main dose of radiotherapy for lesions was 59.83±14.12 Gy.Sixteen patients were treated with combined chemotherapeutic agents.The clinical details of best corrected visual acuity(BCVA)and color photography of the fundus were collected.Forty-six eyes underwent optical coherence tomography(OCT),visual field were examined in 30 eyes,magnetic resonance imaging(MRI)were performed in 40 eyes.The BCVA examination was performed using Snellen visual acuity chart,which was converted to minimum resolution angle logarithm(logMAR)visual acuity during recording.Hyperbaric oxygen therapy(HBOT)was performed in 10 patients(13 eyes),9 patients(12 eyes)were treated with intravenous methylprednisolone(IVMP),12 patients(23 eyes)were treated with HBOT combined with IVMP and control group of 12 patients(21 eyes)were only treated with basal treatment.And grouped accordingly.To observe the changes in onset,recovery,and final BCVA of the affected eye as well as thickness changes of the retinal nerve fiber layer(RNFL)of the optic disc and inner limiting membrane-retinal pigment epithelium(ILM-RPE)layer of the macular area,and final outcome of BCVA with different treatment modalities in affected eyes.The RNFL and ILM-RPE layer thicknesses were compared between patients with different disease duration as well as between treatment regimens using independent samples t-test.Results Of the 43 cases,vision loss was monocular in 17 patients(39.53%,17/43)and binocular in 26 patients(60.47%,26/43).The latency from radiotherapy to onset of visual loss was 36.33±30.48 months.The duration of RION ranged from 1 week to 10 years,in which the disease duration of 37 eyes≤2 months.Subacute visual acuity loss was present in 41 eyes.logMAR BCVA<1.0,1.0-0.3,>0.3 were 45,15,and 9 eyes,respectively.Optic disc pallor and optic disc edema were found in 10(27.03%,10/37),3(8.11%,3/37)eyes,respectively,within 2 months.The superior RNFL[95%confidence interval(CI)2.08-66.56,P=0.038]and the outer circle of the inner limiting membrane to retinal pigment epithelium(ILM-RPE)(95%CI 4.37-45.39,P=0.021)layer thinned significantly during the first month.The center of the ILM-RPE layer thickened(95%CI-32.95--4.20,P=0.015)significantly during the first two months.The inner circle temporal quadrant of the ILM-RPE layer thickened(95%CI-42.22--3.83,P=0.022)significantly from the third to sixth month,and the RNFL except for the temporal quadrants and the average RNFL,inner circle superior quadrant and outer circle of the ILM-RPE layer thinned significantly after 6 months(P<0.05).Among the 40 eyes that underwent MRI examination,33 eyes(82.50%,33/40)were affected by T1 enhancement of optic nerve,including 23 eyes(69.70%,23/33)in intracranial segment;12 eyes with thickening and long T2 signal(36.36%,12/33).After treatment,BCVA was restored in 17 eyes(24.6%,17/69)and final BCVA improved in 9 eyes(13.0%,9/69).There was no significant difference between HBOT,IVMP and HBOT combined with IVMP therapy in improving BCVA recovery or final BCVA compared with the control group,respectively(t=-1.04,0.61,1.31,-1.47,-0.42,0.46;P>0.05).Conclusions The structural damage of the RNFL and ILM-RPE layer occurred during the first month,the RNFL showed progressive thinning during the follow-up period,while the ILM-RPE layer showed thinning-thickening-thinning.MRI shows T1 enhancement of the optic chiasma and segments of the optic nerve,and the enhanced segments are usually accompanied by thickening and long T2.HBOT and IVMP have no obvious effect on RION.