Efficacy And Predictive Factors Of Orbital Decompression In The Treatment Of Dysthyroid Optic Neuropathy

Objective: To Make clear the clinical characteristics of dysthyroid optic neuropathy(DON)through the analysis of the clinical symptoms,signs and imaging examination of the patients with DON,which helps to early diagnosis,judge the DON condition and grasp the timing of DON treatment.Methods: This study is retrospective.The medical records of 75 patients(118 eyes)affected by DON and treated with orbital decompression performed at Department of Ophthalmology,Union Hospital,Tongji Medical College,Huazhong University of Science and Technology between January 2013 and December 2019 were evaluated.The general condition of patients was recorded,including age,sex,smoking status,history of thyroid dysfunction,previous treatment of TAO,and the course of DON.Evaluating patient's clinical characteristics,including clinical activity score(CAS),proptosis,best-corrected visual acuity(BCVA),color vision,relative afferent pupillary defect(RAPD),color vision,visual field,pattern-reversed visual evoked potential(PVEP),optic disc,eye movement,diplopia,strabismus,cornea,orbital computed tomography(CT).Collate the above clinical data and carry out statistical analysis.Results: 1.A total of 75 DON patients(118 eyes)were included in this study.Of these,thirtyfive patients(47%)were women and 40 patients(53%)were males.The average age of DON patients was 49.21±10.01 years(range 21-71 years).The course of DON were 6 months(range 0.2-50 months).Twenty-eight patients(37%)were smokers,eighteen patients(24%)had hypertension,and one patient(1%)had diabetes.There were 62 cases(83%)of hyperthyroidism,11 cases(15%)of normal thyroid function and 2 cases(2%)of hypothyroidism when first visit ophthalmology.Previous treatments for thyroid disease as follows: radioiodine therapy was used in 24 patients(32%),oral antithyroid therapy in 56patients(75%)and thyroidectomy in 11 patients(15%).Previous treatments for TAO as follows: twenty-one patients(28%)were treated with oral low-dose glucocorticoid,thirty-seven patients(49%)were treated with peribulbar injection of triamcinolone acetonide,42 patients(56%)underwent systemic glucocorticoid shock therapy,two patients(3%)received orbital radiotherapy,two patients(3%)were treated with oral immunosuppressive drugs,and one patient(1%)underwent orbital decompression surgery.2.Of the 75 patients included in this study,43 cases(57%)had bilateral DON,and 32 cases(43%)with unilateral DON.Sixty-six eyes(56%)were active(CAS?3/7),and 52 eyes(44%)were inactive(CAS<3/7).The average CAS was 2.64±1.23.There were 35 eyes(30%)whose proptosis >21 mm,and the mean proptosis was 20.43±10.01 mm.All DON eyes had preoperative visual impairment(100%),PVEP abnormalities(100%),ocular motor disorders(100%)and orbital apex crowding(100%).Most DON eyes have some degree of visual field defect(81%),color vision abnormality(92%),subjective diplopia(65%),and strabismus(55%).A few DON eyes had RAPD(44%),and exposed keratitis(13%).Preoperative optic disc was normal in 61eyes(52%),edema in 43 eyes(36%),and pale in 14 eyes(12%).Conclusions: Middle aged,male,smoking history,I131 treatment and hyperthyroidism are important risk factors for DON.Visual acuity decline,visual field defect,PVEP abnormality,RAPD,color vision loss and optic disc edema,paleness are DON characteristic clinical signs.Orbital apex crowding is DON characteristic imaging sign.Objective: To evaluate the changes of clinical indexes after orbital decompression in patients with dysthyroid optic neuropathy(DON),to analyze the related factors of visual recovery after orbital decompression in DON,and to compare the recovery of visual function in patients with DON after two-wall and three-wall orbital decompression.Methods: This study is retrospective.The medical records of 37 patients(52 eyes)affected by DON and treated with orbital decompression performed at Department of Ophthalmology,Union Hospital,Tongji Medical College,Huazhong University of Science and Technology between January 2013 and December 2019 were evaluated.Collect and record ophthalmic examination data for all patients,including clinical activity score(CAS),proptosis,eye movement,diplopia,strabismus,cornea,best-corrected visual acuity(BCVA),color vision,relative afferent pupillary defect(RAPD),intraocular pressure(IOP),fundoscopy,visual field for mean deviation(MD)and pattern standard deviation(PSD),pattern-reversed visual evoked potential(PVEP)for P100 latency and amplitude at 60 and 15 arcmin stimulation checkerboard size,optical coherence tomography(OCT)for retinal nerve fiber layer(RNFL),central retinal thickness(CRT)and cup/plate ratio(C/D).Preoperative orbital imaging to guide the design of orbital decompression surgery.After long-term follow-up(at least 3 months)until visual acuity was no longer improved,BCVA results were recorded.According to the different operation methods,the included DON eyes were divided into two groups: two wall(medial wall and lateral wall)orbital decompression group and three wall(medial wall,lateral wall and inferior wall)orbital decompression group.The above clinical data were collated for difference analysis,spearman correlation analysis.Results: 1.This study included 52 eyes,of which 48 eyes BCVA improved,1 eye BCVA decreased and 3 eyes BCVA no change after surgery.The postoperative mean Log MAR value decreased(from 0.84±0.55 to 0.21±0.43).The visual field also improved significantly after surgery.The average postoperative MD increased(from-12.00±8.56 d B to-5.53±5.99 d B),and the average PSD decreased(from 5.65±2.62 d B to 3.01±1.66 d B).The postoperative PVEP improved.The postoperative average P100 latency at 60 arcmin and15 arcmin were shortened(from 117.26±13.63 ms to 110.72±8.97 ms and from 123.65±16.70 ms to 116.41±15.53 ms,respectively).The postoperative average P100 amplitude at 60 arcmin and 15 arcmin increased(from 4.40±2.72?V to 7.84±3.34?V and from 4.47±2.67?V to 7.81±2.47?V,respectively).The postoperative average RNFL thickness decreased(from 101.54±17.73?m to 92.85±12.67?m).The postoperative mean C/D increased(from 0.44±0.15 to 0.50±0.15).The average proptosis decreased(from 20.13±3.34 mm to 14.02±1.37 mm).The postoperative average IOP decreased(from 19.71±4.95 mm Hg to 15.25±1.77 mm Hg).All the above evaluation indexes were statistically different(all P<0.05).There was no significant change in CRT before and after surgery(P=0.963).2.Postoperative BCVA(Log MAR)and ?BCVA(Log MAR)(?,postoperative-preoperative)were positively correlated with preoperative BCVA(Log MAR)(all P<0.05).That is,the better the preoperative vision,the better the recovery of postoperative vision.Postoperative BCVA(Log MAR)and ?BCVA(Log MAR)were negatively correlated with preoperative MD(all P<0.05),and ?BCVA(Log MAR)was positively correlated with preoperative PSD(P=0.002),That is,the smaller the preoperative visual field defect,the better the recovery of postoperative vision.Postoperative BCVA(Log MAR)was negatively correlated with preoperative CRT(P=0.004),and there was no significant correlation between ?BCVA(Log MAR)and CRT(P=0.951),That is,the greater the preoperative CRT,the better the postoperative visual acuity.?BCVA(Log MAR)was negatively correlated with mean preoperative RNFL thickness(P=0.001),and there was no significant correlation between postoperative BCVA(Log MAR)and preoperative mean RNFL(P=0.923).That is,the greater the average preoperative RNFL thickness,the obvious the improvement of postoperative vision.There was no significant correlation between the improvement of postoperative visual acuity and age,DON course,CAS,preoperative IOP,preoperative exophthalmos,preoperative PVEP(P100 latency and amplitude at 60' and 15'),and preoperative C/D(all P>0.05).3.The improvement of exophthalmos(P=0.011)and P100 amplitude at 60' and 15'(P=0.046 and 0.020)in three-wall orbital decompression group were more obvious than those in twowall orbital decompression group.There was no significant difference in BCVA?IOP?CAS?MD?PSD?RNFL thickness,CRT and P100 latency between the two groups(all P>0.05).Six cases(66.67%)had continuous diplopia and 1 case(20%)had new-onset diplopia after operation in three-wall orbital decompression group,while 6 cases(46.15%)had persistent diplopia and no new-onset diplopia after operation in two-wall orbital decompression group.4.Main postoperative complications after orbital decompression surgery were periorbital sensory loss(3 patient/5 eyes),local hyperesthesia(1patient/1eye),temporal hollowing(1patient/2eyes),oscillopsia(1patient/2eyes),and cerebrospinal fluid leak(2patients/2eyes).Conclusions: 1.Orbital decompression could effectively improve visual acuity,visual field(MD and PSD),and PVEP(P100 amplitude and latency)of DON patients,and significantly reduce the proptosis,intraocular pressure,and average RNFL thickness,but the impact on the CRT is small.2.Postoperative visual acuity and the improvement of postoperative visual acuity were significantly related to preoperative BCVA,MD,PSD,and RNFL thickness,that is,the better the preoperative visual acuity,the smaller the visual field defect and the thicker the RNFL,the better the postoperative visual acuity recovery.But age,DON course,CAS,IOP,proptosis and PVEP did not affect the recovery of postoperative visual acuity.3.Both 2-wall and 3-wall decompression could effectively improve visual function of patients with DON.Three-wall decompression provided better improvement in P100 amplitude and proptosis,however new-onset diplopia was more common with this surgical technique.4.The possible complications after orbital decompression surgery,such as periorbital sensory loss,local hyperesthesia,temporal hollowing,oscillopsia,and cerebrospinal fluid leak,could generally heal itself without special treatment.Objective: To observe the changes of retinal nerve fiber layer(RNFL)thickness after orbital decompression and its predictive value for postoperative visual function recovery.Methods: This study is retrospective.The medical records of 37 patients(52 eyes)affected by DON and treated with orbital decompression performed at Department of Ophthalmology,Union Hospital,Tongji Medical College,Huazhong University of Science and Technology between January 2013 and December 2019 were evaluated.The evaluation indexes mainly include each quadrant RNFL thickness around the optic papilla measured by optical coherence tomography(OCT)(including the average,superior,inferior,nasal and temporal quadrants),clinical activity score(CAS),proptosis,eye movement,diplopia,strabismus,cornea,best-corrected visual acuity(BCVA),visual field for mean deviation(MD)and pattern standard deviation(PSD),pattern-reversed visual evoked potential(PVEP)for P100 latency and amplitude at 60 and 15 arcmin stimulation checkerboard size.The above clinical data were collated for difference analysis,spearman correlation analysis,logistic regression analysis and ROC curve analysis.Results: 1.There was significant reduction in RNFL thickness of all DON patients in global average and all quadrants except nasal quadrant.Peripapillary RNFL thickness was measured in 19 patients(26 eyes)within 6 months and beyond 6 months in our follow-up after surgery,respectively.When peripapillary RNFL thickness was compared preoperatively versus within 6 months postoperatively,significant differences were observed in superior and inferior peripapillary RNFL thickness(all P = 0.001).When peripapillary RNFL thickness was compared between preoperatively versus beyond 6 months postoperatively,significant differences were observed in global average and all quadrants(all P<0.05).2.The preoperative RNFL thickness in global average,nasal,superior and inferior quadrant was correlated with postoperative improvement of BCVA,MD,PSD(all P<0.05).Similarly,significant correlation between the preoperative RNFL thickness in global average and all quadrants and postoperative improvement of P100 amplitude,either at 60 or 15 arcmin(all P<0.05),was observed except P100 amplitude changes at 15 arcmin in temporal quadrant(P=0.125).However,a correlation between the preoperative RNFL thickness in global average and all quadrants and postoperative improvement of P100 latency at 60 or 15 arcmin was not significant(all P>0.05).3.The nasal RNFL thickness was an excellent predictor for improvement in BCVA by 20/25 or better(sensitivity 80% and specificity 62%)and in MD by 10 d B or more(sensitivity 85% and specificity 67%)after surgery,whose cutoff value was 73.50 ?m,while the inferior and superior RNFL thickness could act as a predictor for improvement in P100 amplitude by 5 ?V or more at 60 arcmin(sensitivity 89% and specificity 97%)and at 15 arcmin(sensitivity 67% and specificity 90%),respectively,whose cutoff value were respectively 143.00 ?m and 130.50 ?m(all P<0.05).Conclusions: 1.The RNFL thickness of DON patients after orbital decompression decreased significantly,and they decreased gradually with the prolongation of postoperative time.2.The baseline RNFL thickness measured by OCT was significantly correlated with the recovery of visual acuity,visual field and PVEP after orbital decompression.3.The baseline RNFL thickness of the nasal quadrant,superior quadrant and inferior quadrant before surgery can be used as predictors of visual function recovery after orbital decompression.