A Study Of Visual Field Defect Of Optic Nerve Contusion

【Object】To research characteristics of visual field defects of the patients with traumatic optic neuropathy,and to discuss the clinic significance of visual field in diagnosis of traumatic optic neuropathy.【Method】Test 24 patients/48 eyes including 19 males/38 eyes and 5 females /10 eyes with optic nerve contusion,whose average of age is 38.38 years.They are divided into two teams named eyes on injured side and contralateral eyes for analysis. We test distance vision activity with logarithmic visual acuity chart,test visual field with the 30-2 threshold program of the HumphreyⅡ(750) Visual Field Analyzer of Carl Zeiss company,and test VEP with TAIK FEC-350T Electrophysiological Detector.We analyze the defect types,MD,PSD,quadrant distribution,distribution of points with the highest defected value,consistency of bilateral visual field,and compare them with visual activity and VEP.【Result】1.Average of visual activity of eyes on injured side declines more than that of contralateral eyes.Visual activity of 83.33 percent of eyes in injured side decline,and that of 41.67 percent of contralateral eyes decline.2.Visual field of eyes on injured side:5 cases with blindness(20.83%),5 cases with cocentral scotoma(20.83%),5 cases with general reduction of sensitivity (20.83%),4 cases with annular scotoma(16.67%),3 cases with arch scotoma and cocentral scotoma(12.5%),1 case with arch scotoma(4.17%),1 case with hemianopsia(4.17%).Visual field of eyes on injured side:8 cases with cocentral scotoma(33.33%),7 cases with no defect(29.17%),6 cases with general reduction of sensitivity(25%),2 cases with annular scotoma(8.33%),1 case with arch scotoma and cocentral scotoma(4.17%).3.Cumulative count of involved quadrants:that of eyes on injured side:22 cases with defect in superior temporal quadrant,21 cases with defect in superior nasal quadrant,20 cases with defect in infranasal quadrant,19 cases with defect in infratemporal quadrant,and 44 cases with defect on nasal side,41 cases with defect on temporal side,43 cases with defect on superior side,39 cases with defect on inferior side;that of contralateral eyes:12 cases with defect in superior temporal quadrant,13 cases with defect in superior nasal quadrant,12 cases with defect in infranasal quadrant,13 cases with defect in infratemporal quadrant,and 25 cases with defect on nasal,temporal,superior and inferior side separately.4.Cumulative count of quadrants with points with the highest defected value: that of eyes on injured side:5 cases in superior temporal quadrant,7 eases in superior nasal quadrant,11 cases in infranasal quadrant,4 cases in infratemporal quadrant,and 18 cases on nasal side,9 cases on temporal side,12 cases on superior side,15 cases on inferior side;that of contralateral eyes:7 cases in superior temporal quadrant,5 cases in superior nasal quadrant,3 cases in infranasal quadrant,2 cases in infratemporal quadrant,and 7 cases on nasal side,10 cases on temporal side,12 cases on superior side,5 cases on inferior side.5.To test consistency of bilateral visual field,there is no significant difference between the consistency of quadrants with defect and that of quadrants with points with the highest defected value(P=0.057＞0.05).The order of average of visual activity is:blindness＜hemianopsia＜annular scotoma＜arch scotoma and cocentral scotoma＜arch scotoma＜general reduction of sensitivity＜cocentral scotoma in eyes on injured side;but it is:annular scotoma＜arch scotoma and cocentral scotoma＜cocentral scotoma＜general reduction of sensitivity in contralateral eyes.6.Of eyes in injured side,MD is related with visual activity.AP100 and A/LT positively.And of contralateral eyes,visual activity is related with MD and PSD.and the former is more significant.【Conclusion】1.Visual field test is sensitive to optic nerve contusion.There is much value to test visual field for the patients with blunt trauma on head.2.Contralateral eyes maybe involved by blunt trauma on one side,and visual field test could show the injury more early before visual activity shows.3.Visual field defect may appear before visual activity reducing,so we can help the patients with blunt trauma on head except significant symptoms to get treatment early. 4.Visual field defect of optic nerve contusion is diverse.It shows that injury of optic nerve fibers is diverse in the same.But we can learn the situation of injury of optic nerve fibers from visual field defect generally.5.In visual field defect of patients with optic nerve contusion,gcncral reduction of sensitivity is the most common type,second one is cocentral scotoma.Blindness＞hcmianopsia＞annular scotoma＞arch scotoma and coccntral scotoma＞arch scotoma＞coccntral scotoma＞gcncral reduction of sensitivity is in seriousness order.6.There is no tcndcncy that visual field dcfcct appears more in one quadrant.7.Bilateral visual field defect of the patients with optic nerve contusion is consistent:superior temporal quadrant-superior nasal quadrant,infranasal quadrant-infratcmporal quadrant,superior nasal quadrant-superior temporal quadrant, infratcmporal quadrant-infranasal quadrant.Dcfcctcd area of eyes on injured side is bigger than that of contralatcral eyes.8.The points with the highest defected value appear more on injured side,and more in under half visual field of eyes on injured side,more in above half visual field of contralateral eyes.9.The more the points with the highest dcfcctcd value is near to center,the more visual activity reduce.10.The more the absolute value of MD is big,the more visual activity reduce.11.Visual field defect is not very consistent with full VEP.AP100 and A/LT of VEP are better indicators.