Long-Term Efficacy Of Surgical Treatment Of Infantile Nystagmus Syndrome

Background and purpose:Infantile Nystagmus Syndrome(INS)is a pathological eye tremor.The disease is characterized by reciprocity,rhythm and involuntary eyeball conjugate swing phenomenon and the incidence rate of INS is 1/350-1/20000.INS often accompanied by some eye diseases and a series of complications,such as amblyopia,strabismus,side view,torticollis.There are several treatments for INS,such as drug therapy,biological therapy and surgical treatment.Drug therapy and biological therapy has a certain degree of clinical application and has been proven to be safe and effective for short term results,but studies also found that the efficacy of maintenance time is relatively short and patients often can not get a thorough treatment because of its short efficacy.So its application is also subject to certain restrictions and failed to be widely used in clinical practice.Surgical treatment of INS can be rapid onset and has significant effect,so it has been more and more widely used in clinical.There were more reports on the treatment of INS,but only the short-term efficacy was observed in these researches.However,in recent years,INS patients generally began to pay attention to the long-term effect after surgery.In this study,a follow-up study was conducted on INS patients after 12 months of surgery,which was designed to study the long-term safety of INS by surgical treatment and to provide guidance for clinical surgical treatment of INS.Methods:This study was a retrospective case study.After screening,30 patients with INS(who were admitted to our hospital between January 2013 and December 2015)were included in the study,including 18 cases of male patients,12 cases of female patients.All patients were underwent INS surgery and no complications was occurred during the operation,and all patients were followed up for more than 12 months.There were 20 patients with head-to-peer compensatory mechanism and 17 patients with strabismus,among them,5 cases were exotropia,12 cases were concomitant esotropia,and the average strabismus was 22.3±6.8PD;The age range is between 6-10 years old with an average age of 7.5 years old.Preoperative examination was performed for every patients and the examination was included eye disease history and other disease history,external and intraocular examination,fundus examination,compensatory head check,eye check,monocular and binocular best corrected visual acuity,refractive status examination,oblique angle measurement,head position twist angle measurement,eye tremor frequency examination,nystagmus intensity examination.According to the INS patients were different surgical methods with nine kinds of operation Hertle summarized,according to whether patients with strabismus,compensatory head position,choose the following operation mode set block:for patients with inverted compensatory mechanism,correction of AHP was the main treatment method;combined strabismus surgery was also used for patients with coexisting strabusus;for patients with occlusion compensatory mechanism,the main treatment method was artificial eye astigmatism(ADS);for patients with non-compensatory mechanism,the main treatment were four straight muscle tendon retraction surgery.The patients were followed up on 1 months,2 months,4 months,6 months,9 months and 12 months.Patients were treated with complete surgical data,.Efficacy evaluation criteria are as follows:Visual acuity criteria:postoperative visual acuity increased by 2 lines considered effective;The criterion of head position:the disappearance of AHP is regarded as cured,after-surgery AHP less than or equal to 15° is regarded as improved and standard compensated head position with more than 15° is regarded as ineffective treatment;The first eye position is within the range of 10PD and is considered to be the ocular position;And the nystagmus after operation(nystagmus frequency,nystagmus amplitude)compared with the preoperative.Results:(1)In all 30 patients with INS,the number of patients with increase of two lines in the best corrected visual acuity was 23(76.7%).During the 12-month follow-up,the patient’s vision was steady.The long-term efficacy of surgical treatment is significant and stable;(2)Of the 17 patients with strabismus,the average strabismus was 3.4±2,7PD in 1 months,and 17 cases were positive(100%).During the 12-month follow-up,the patient’s strabismus was in a steady state with no recurrence;(3)In the 20 patients with head-end compensatory mechanism,there were 14(70.0%)patients with completely cured headache compensation(compensation head position was disappeared)and there were 6(30.0%)patients who achieved significant improvement after surgery(compensated head was less than or equal to 15°).Patients with head position compensation were in a stable state after surgery and long-term efficacy was significant and stable;(4)All patients’ postoperative nystagmus(frequency of nystagmus,amplitude of nystagmus,)were significantly reduced and the efficacy during the 12-month follow-up was significant and stable,No severe complications occurred.Conclusions:Surgical treatment of INS not only can significantly improve the patient’s vision,significantly improved patients with strabismus and AHP,significantly reduced the frequency of patients with nystagmus and nystagmus amplitude,but also has a significant long-term efficacy.Surgical treatment of INS has a good therapeutic effect and safety,and it should be further promoted in clinical practice.