Effects of slanted bilateral lateral recession vs conventional bilateral lateral recession on convergence insufficiency intermittent exotropia:a prospective study

AIM:To observe the surgical effects of slanted bilateral lateral recession(S-BLR)versus conventional bilateral lateral recession(C-BLR)in convergence insufficiency intermittent exotropia(CI-IXT).METHODS:Using a randomized,double-blind,prospective design,22 patients with CI-IXT who were admitted to Renmin Hospital of Wuhan University from July 2019 to December 2020 were included.Patients were randomly divided into either S-BLR or C-BLR group for their subsequent strabismus surgery.All patients were followed up for 12mo.Near deviation,distant deviation,and neardistance difference(NDD)were measured in all patients.RESULTS:Twelve months after surgery,NDD improvement was 10(8,13)prismatic degrees(PD)in S-BLR group and 3(1,6)PD in C-BLR group(P=0.011).The near deviation of S-BLR group was 0(-2,2)PD,while that of C-BLR group was-4(-6,-3)PD(P=0.005).Before and after surgery,the difference in the distant deviation between the two groups was not statistically significant.There was no statistically significant difference in near stereopsis between the two groups(P=0.380)at 12mo.The success rate at 12mo after operation was 90.91%and 72.73%in the two groups(P=0.280).CONCLUSION:CI-IXT patients treated with S-BLR have better surgical outcomes than those treated with C-BLR,which indicates S-BLR is a safe and effective operation pattern.

Effectiveness of modified inferior oblique muscle belly transposition for V-pattern exotropia combined with mild to moderate inferior oblique muscle overaction

AIM:To investigate the effectiveness of a modified inferior oblique muscle belly transposition for treatment of V-pattern exotropia combined with mild to moderate inferior oblique muscle overaction.METHODS:Thirteen cases(23 affected eyes)of V-pattern exotropia with inferior oblique muscle overaction(+or++)who underwent the modified inferior oblique muscle belly transposition procedure were retrospectively reviewed.The amount of V-pattern,grade of inferior oblique overaction,degree of vertical strabismus,abnormal head posture,and the fovea-disc angle were evaluated before and after surgery.RESULTS:The V-pattern was corrected in all cases,and the amount of V-pattern reduced by 17.85±5.13 prism diopter(PD)on average(t=16.07,P<0.001).The surgical cure rate for mild to moderate inferior oblique muscle overaction was 87.0%(20/23).The degree of the foveadisc angle has a mean reduction of 5.45°±2.87°(t=3.95,P=0.003)after surgery.The mean vertical deviation in 5 cases with a small-angle hypertropia(5.23±3.06 PD)in the primary position reduced by 3.15±1.86 PD(t=6.10,P<0.001).No serious complications were observed.CONCLUSION:The modified inferior oblique muscle belly transposition procedure can effectively treat mild to moderate inferior oblique overaction and relieve the V-pattern,which is safe and easy to perform.

Comparison of bilateral/unilateral lateral rectus recession and unilateral recession-resection for intermittent exotropia:a Meta-analysis

AIM: To compare the effectiveness of unilateral recession-resection(R&R) and bilateral/unilateral recession(BLR/ULR) for treatment of basic type of intermittent exotropia [IX(T)].METHODS: A comprehensive literature search was performed using PubMed, EMBASE, and the Cochrane Library, to identify randomized controlled trials and comparative studies regarding the effectiveness of R&R and BLR/ULR for IX(T). Based on which, a Meta-analysis was then performed in terms of long-term success rate, overcorrection rate, and recurrence rate.RESULTS: Nine studies in total satisfy the specified eligibility criteria. BLR is at disadvantage to R&R at a short-term follow-up [<2 y, OR 0.56(0.33-0.94) for success rate; OR 2.11(1.17, 3.81) for undercorrection rate]. However, BLR achieved a higher success rate [OR 2.49(1.61, 3.86)] and a lower undercorrection rate [OR 0.40(0.23, 0.71)], compared to that of R&R at a long-term followup(>2 y). There is no significant difference was found in overcorrection rate, regardless of the length of follow-up time [OR 0.85(0.41, 1.75)]. In the treatment for small-angle IX(T), the final outcome was significantly different between the groups, demonstrating a more successful alignment [OR 0.37(0.18, 0.74)] and a lower undercorrection [OR 3.50(1.28, 7.26)] in the R&R group than in the ULR group. While for moderate-angle IX(T)(20 PD-25 PD), the effectiveness of R&R and ULR is quite equivalent with similar success rate [OR 1.08(0.65, 1.79)] and undercorrection rate [OR 0.89(0.54, 1.48)]. CONCLUSION: As regard to the effect of BLR and R&R, R&R shows an advantage over BLR at short term. But, BLR is more effective in the long term for the basic typeIX(T) in children. R&R surgery should be a better choice for the treatment of small-angle IX(T) of ≤20 PD than ULR. However, both of ULR and R&R are recommended for moderate-angle IX(T) from 20 PD to 25 PD.

Long-term postoperative outcomes of bilateral lateral rectus recession vs unilateral recession-resection for intermittent exotropia

AIM: To discuss the long-term postoperative results of bilateral lateral rectus recession(BLR) and unilateral lateral rectus recession-medial rectus resection(RR) in therapy of intermittent exotropia.METHODS: We retrospectively analyzed 213 cases of intermittent exotropia who underwent surgery between2008 and 2010. The patients were grouped into BLR group and RR group. Motor outcomes were divided into three groups on the basis of the angle of deviation after surgery: overcorrection(esotropia/phoria 】5△), orthophoria(esotropia/phoria ≤5△to exotropia/phoria ≤10△), and undercorrection/recurrence(exotropia/phoria 】10△).Titmus test was used to evaluate stereoacuity, the stereoacuity 【800s of arc meaned the patients had stereopsis. Surgical outcome including motor criteria and sensory status were compared at postoperative 6, 12,24 mo and at 36 mo examination between groups. RESULTS: At 12, 24 mo after surgery, the motor outcomes had no difference(P 】0.05) between groups.However, the motor outcomes at 6, 36 mo were signally different in each group, indicating the success rate in RR group at 6mo was higher than that in BLR group(83.02%vs 82.24%, P 【0.05) but the result was contrary at the 3y examination(60.75% vs 43.40%, P 【0.05). No statistical significance were found in the sensory outcomes between the groups at mean of 3.7y follow-up.CONCLUSION: The motor outcomes in RR group were better than in BLR group at 6mo after surgery, while the3 y outcomes were better in BLR group. This may be due to the recurrence rate of the BLR was lower than the RR group’s.

Survival analysis following early surgical success in intermittent exotropia surgery

AIM:To assess the consecutive recurrence following early success of intermittent exotropia surgery and to determine the clinical factors that affect the survival.METHODS:One hundred and thirty-five patients who underwent intermittent exotropia surgery and experienced early surgical success[≤5 prism diopters(PD)esophoria(E)to≤10 PD exophoria(X)on the postoperative sixth month]were enrolled in this study.Their consecutive survival on the postoperative first year,second year and third year and at the last visit of fourth year or more,and the factors that might affect their survival,were analyzed.The final surgical outcomes after the postoperative fourth year were also investigated by dividing the patients into the success group(≤5 PD E to≤10 PD X)and the failure group(】5 PD esodeviation or】10 PD exodeviation)RESULTS:The survival rates from the Kaplan-Meier analysis were 97.78%,92.89%,83.70%and 50.49%on the postoperative first,second and third years and fourth year or more,respectively.None of the clinical factors was determined to have affected the survival.The amount of the exodrift was largest(2.29 PD)between the first year and the second year,and smallest(1.47 PD)between the fourth year and the last visit.Sixty-three patients had their final visit after the postoperative fourth year,and 29 of them were in the failure group.Twentyfive patients in the failure group had an intermittent exotropia(IXT)of【20 PD with good to fair distant fusion;two had an IXT of【20 PD with poor distant fusion;one had an IXT of≥20 PD with fair distant fusion;and another had delayed-onset consecutive esotropia.The exodeviation on the postoperative sixth month was smaller in the success group than in the failure group(2.81 PD vs 5.86 PD,P=0.012).The reoperation rate for recurrent IXT was 3.7%.CONCLUSION:The survival rate steadily decreases with the exodrift,but the amount of the exodrift decreases with long-term follow-up.The final outcomes demonstrate favorable results via surgical success or small-angle IXT with good fusion in most of the patients.A smaller deviation on the postoperative sixth month is associated with long-term survival.

Evaluation of dynamic stereopsis in intermittent exotropia patients

AIM: To delineate the characteristics of the dynamic stereopsis test and analyze related parameters in intermittent exotropia [X(T)] patients. METHODS: Fifty-seven X(T) patients and 55 normal subjects were enrolled in this study. The normal and X(T) groups were used to test the reproducibility and reliability of the dynamic stereopsis test, and Bangerter filters with densities of 0.2 were then used to simulate suppression to test for traditional and dynamic stereopsis. In the X(T) group, the measurements included 1) dynamic stereopsis test comprising three parts: motion+disparity, motion only and disparity only; 2) ocular deviation angle; 3) Bagolini striated lens test; 4) disease course; and 5) Titmus stereopsis test. RESULTS: The test-retest reliability of the dynamic stereopsis method was 0.901 in the normal and X(T) groups, and none of the X(T) patients were able to pass the static and dynamic stereopsis tests after using the 0.2 Bangerter filter. The accuracy rate was greater than 80% in the normal group and 31.81%, 36.36%, and 45.45% for the motion+disparity, motion-only and disparityonly components of the traditional test for X(T) patients diagnosed with stereoblindness via traditional tests,respectively. Patients with a long disease course(>1 y) had worse dynamic stereopsis than those with a short disease course(<1 y; P<0.05, Chi-square test). The deviation angle was not correlated with the motion+disparity, disparityonly, or the motion-only test components(all P>0.05, Chisquare test). CONCLUSION: Dynamic stereopsis is preserved in certain X(T) patients diagnosed with stereoblindness via traditional tests. A long disease course was shown to be a negative factor for dynamic stereopsis in X(T) patients which might be associated with worse progression, and provide good references clinically.

Surgery at early versus late for intermittent exotropia:a Meta-analysis and systematic review

AIM:To compare the outcomes between early surgery and late surgery for intermittent exotropia(IXT)with a Metaanalysis.METHODS:Scientific databases including PubMed,Embase,Web of Science,Cochrane and China National Knowledge Infrastructure were searched prior to December 16,2019.From this broad database search,we performed some Meta-analysis including eleven independent studies,to further evaluate the outcome(s)when comparing early versus late surgery for IXT.The boundaries between early and late surgery and the surgery methods were not inconsistent,so subgroup analyses were conducted by different boundaries of age at surgery and different surgical approaches.The pooled odds ratios(ORs)and the 95%confidence interval(CI)were estimated according to the random-effects model for high heterogeneity between studies.RESULTS:Eleven retrospective studies were included in this Meta-analysis.No significant difference between early and late surgery was observed for IXT patients(OR_(First follow-up)=0.88,95%CI 0.53-1.44,P=0.61;OR_(Final follow-up)=1.48,95%CI 0.94-2.31,P=0.09).However,sensitivity analysis performed by sequentially omitting individual studies showed that the final follow-up result was not stable.Subgroup analyses revealed that an earlier surgical procedure could lead to a better outcome in the 4-year boundary subgroup as well as the bilateral lateral rectus recession(BLR)subgroup for the final follow-up(OR_(4y)=2.64,95%CI 1.57-4.44,P=0.00;OR_(BLR)=2.25,95%CI 1.36-3.74,P=0.00).CONCLUSION:Early surgery for IXT provides a better long term follow-up outcome when patients are younger than 4 years old or choose the BLR surgical method.

Clinical risk factors for the development of consecutive exotropia:a comparative clinical study

AIM： To compare a group of patients with consecutive exotropia with patients who had ≤ 10 prism diopters （PD） esotropia or no deviation postoperatively in terms of probable clinical risk factors for the development of consecutive exotropia. METHODS： The study recruited fourteen patients who developed consecutive exodeviation during follow-up period after the correction of esotropia who were categorized as group 1 and thirty-one patients who had still ≤10 PD esotropia or no deviation at the final visit that were considered as group 2. Clinical risk factors leading the development of consecutive deviation were analyzed as the main outcome measures. RESULTS： The mean age of patients was 4.57±3.11y in group 1 and 5.10±3.52y in group 2 （P=0.634）. There was no significant difference of preoperative near and distant deviations among two groups （P =0.835, 0.928 respectively）. The mean amount of medial rectus recession and lateral rectus resection was similar in both groups （P=0.412, 0.648 respectively）. Convergence insufficiency and neurological diseases were more frequent in group 1 （P-0.007, 0.045）. Accompanying neurological disease was found to be as a significant factor increasing the risk of the development of consecutive exotropia significantly [odds ratios （OR）： 5.75 （1.04-31.93）]. CONCLUSION： Accompanying neurological disease appears to be a significant clinical risk factor for the development of consecutive exodeviation during postoperative follow-up after the correction of esotropia. However, larger studies are needed in order to interpret the results to the clinical practice and to ascertain other concurrent risk factors.

Altered intrinsic functional connectivity of the primary visual cortex in youth patients with comitant exotropia: a resting state fMRI study

AIM： To evaluate the differences in the functional connectivity（FC） of the primary visual cortex（V1） between the youth comitant exotropia（CE） patients and health subjects using resting functional magnetic resonance imaging（f MRI） data.METHODS： Totally, 32 CEs（25 males and 7 females） and 32 healthy control subjects（HCs）（25 males and 7 females） were enrolled in the study and underwent the MRI scanning. Two-sample t-test was used to examine differences in FC maps between the CE patients and HCs. RESULTS： The CE patients showed significantly less FC between the left brodmann area（BA17） and left lingual gyrus/cerebellum posterior lobe, right middle occipital gyrus, left precentral gyrus/postcentral gyrus and right inferior parietal lobule/postcentral gyrus. Meanwhile, CE patients showed significantly less FC between right BA17 and right middle occipital gyrus（BA19, 37）.CONCLUSION： Our findings show that CE involves abnormal FC in primary visual cortex in many regions, which may underlie the pathologic mechanism of impaired fusion and stereoscopic vision in CEs.

Post-operative strabismus control and motor alignment for basic intermittent exotropia

AIM：To assess strabismus control and motor ocular alignment for basic exotropia surgery at 5y follow-up.METHODS：The medical records of 80 consecutive patients aged less than 17 years of age,who underwent surgery for basic exotropia by a single surgeon between years 2000 to 2009 and completed a minimum of 5y follow-up post-operatively were reviewed.Pre- and post-operative characteristics were documented at 1wk,6mo,1,3 and 5y follow-up.Subjects at 5-year follow-up were assigned to the success group if they had a postoperative angle of deviation within 10 prism diopters of exotropia or within 5 prism diopters of esotropia for distance on prism cover test,and had moderate to good strabismus control.The remaining subjects were assigned to the failure group.RESULTS：Post-operative surgical success at one week was 75%,which decreased to 41% at 5y follow-up.The success group was noted to have more patching pre-operatively（P=0.003）.The duration of patching a day（P=0.020） and total duration of patching preoperatively（P=0.030） was higher in the success group.Surgical success at 1y（P=0.004） and 3y（P=0.002） were associated with higher surgical success at 5y follow-up.CONCLUSION：Post-operative motor alignment and strabismus control for basic exotropia surgery at 1y and beyond is associated with higher exotropia surgery success at 5-year follow-up.There is an association between pre-operative patching and 5-year surgical success of basic intermittent exotropia surgery.

Factors affecting residual exotropia after two muscle surgery for intermittent exotropia

AIM： To study the factors affecting residual exotropia（〉10 PD） at 4-6wk postoperative visit following two rectus muscle surgery for intermittent exotropia [bilateral lateral rectus（LR） recession or unilateral recess resect procedure].METHODS： A retrospective chart review of patients with intermittent exotropia ≤50 PD who underwent two rectus muscle surgery in between Jan. 2011 to Dec. 2013 was performed. Possible factors were compared between patients with residual exotropia（〉10 PD） and successful outcome（within 10 PD of orthotropia） at the 4-6wk postoperative visit. Effect/dose ratio was calculated by dividing the effect of surgery by the total amount（mm） of muscle surgery done.RESULTS： One hundred and fifty-seven patients with mean age of 14y（range 3-53y） were included. Twentyseven patients（17.2%） had residual exotropia at 4-6wk postoperative follow up. Age at surgery（P=0.009） and preoperative deviation for distance（P≤0.001） and near（P=0.001） were identified as important predictors of unsuccessful outcome. The occurrence of residual exotropia was not affected by amblyopia, anisometropia, lateral incomitance, pattern deviation, vertical deviation, type of exotropia or type of surgery done（recess-resect or bilateral LR recession）. The effect/dose ratio was more in deviations 〉40 PD in the both recess-resect and bilateral LR recession type of surgery. The effect/dose ratio was less in patients with residual exotropia as compared to the successful outcome group（1.36 PD/mm vs 2.05 PD/mm in the bilateral LR recession surgery and 1.93 PD/mm vs 2.63 PD/mm in the unilateral recess-resect surgery）.CONCLUSION： Residual exotropia is seen in 17% of patients after two muscle surgery for intermittent exotropia. Patients with older age and larger preoperative deviation have greater chances of developing failure of two muscle strabismus surgery for intermittent exotropia.

Relation between early postoperative deviation and long-term outcome after unilateral lateral rectus recession and medial rectus resection for adult exotropia

AIM： To evaluate the relationship between early postoperative deviation and long-term outcome after unilateral recession and resection surgery for adult exotropia, and to evaluate exotropic shift after surgery.METHODS： This was a retroprospective study involving adult patients with exotropia who underwent unilateral recession and resection surgery and were followed up for at least 2 y. The results were evaluated at 2 y and the final visit. Factors influencing a successful outcome were analyzed. Early postoperative deviation at 1 wk was used to evaluate relationship with long-term outcome. The longterm outcome was classified into 3 groups： successful, acceptable, and poor. Successful outcome was defined as a distance deviation between esodeviation 8 prism diopters（PD） and exodeviation 10 PD.RESULTS： Forty-two patients were enrolled. The mean age at surgery was 26 y（range, 15-49 y）. The median follow-up period was 30 mo（range, 24-108 mo）. Successful outcome was found in 81% of patients at 2 y and in 71% at the final visit. Overcorrection at 1 wk postoperatively was associated with a successful outcome at 2 y. Initial postoperative alignment between orthotropia and esodeviation of 8 PD had the highest chance of a successful outcome（RR=2.2）. The mean postoperative exotropic drift was 4.7 PD at the first month and 9.3 PD at 2 y.CONCLUSION： Initial postoperative deviation can predict long-term outcome after unilateral recession and resection surgery for adult exotropia. The most desirable outcome at 1 wk post-operatively was orthotropia to small esodeviation. Most patients have exotropic drift at a subsequent follow-up, especially in the first month after surgery.

Quality of life in adult intermittent exotropia and the risk factors

AIM: To study the quality of life of adult patients with intermittent exotropia(IXT) in China and analyze the factors affecting the quality of life in IXT patients.METHODS: Total y 109 cases of normal eye(control group), 77 cases of IXT(IXT group) and 115 cases of strabismus control group(except IXT) were collected. The quality of life of the patients was assessed by Chinese version of adult strabismus patient’s quality of life scale(CAS-20). The differences of general characteristics, visual function and quality of life were analyzed, and the effects of individual factors and visual function on quality of life of patients with IXT were analyzed.RESULTS: The IXT group had a high proportion of patients with family history, low proportion of patients with amblyopia compared with strabismus control group. The proportion with normal near and far stereopsis of IXT group were lower than that of normal control group. The best corrected visual acuity of IXT group was higher than that of strabismus control group, but lower than the control group. In addition, the median strabismus degree in IXT group was higher than that in other strabismus control group. The median psychosocial scores and median visual function scores of the IXT group was lower than that of the normal control group, but not different from strabismus control group. Occupation status, course of disease, far stereopsis and near stereopsis significantly affected the quality of life in IXT patients.CONCLUSION: Adult IXT patients in China have a certain proportion of family history and lower quality of life, The main factors affecting the quality of life of IXT patients is stereopsis, course of disease and occupation status.

Comparison of contrast sensitivity based on the surgical results for intermittent exotropia

AIM: To compare contrast sensitivity(CS) based on the surgical results for intermittent exotropia(IXT) and to examine the relationship between CS and photophobia.METHODS: Medical records of the patients who underwent bilateral lateral rectus muscle recession for IXT between 4 and 12 years old were reviewed retrospectively. They were categorized based on the surgical results;successful correction group(n=36) and overcorrection group(esotropia ≥10 PD at 3 mo postoperatively, n=18). Using CGT-2000 test for CS was performed binocularly, and subjective reports of photophobia was investigated preoperatively and at 3 mo postoperatively. Objective photophobia was defined as a significant decrease in CS in the presence of glare.RESULTS: Preoperatively, there was no difference in CS between the groups. Postoperatively, under mesopic conditions, significant improvement of CS was observed at 6.3°, 4°, and 2.5° in the successful correction group and at 6.3° and 4° in the overcorrection group, regardless of glare. Under photopic conditions, at all visual angles except 0.64°, improvement in CS was noted in both groups while CS worsened significantly at 0.64° in the overcorrection group postoperatively. At all visual angles under photopic conditions postoperatively, regardless of glare, CS in the overcorrected group was significantly worse than that in the successful correction group, and CS was significantly decreased by addition of glare in both groups. All patients except one(96.4%) in the successful correction group and 8 patients(61.5%) in overcorrection group showed improvement of photophobia postoperatively, which correlated with CS under photopic conditions(P=0.001, 0.03).CONCLUSION: After surgery for IXT, CS under photopic conditions improve at all visual angles except 0.64°, while CS is significantly worse in the overcorrection group postoperatively at 0.64°. Subjective photophobia havesignificant correlation with CS under photopic conditions, and may be used as an objective indicator of photophobia.

Abnormal medial rectus insertion presenting exotropia:a case report and review of the literature

I am Dr. Heeyoung Choi, from the Department of Ophthalmology of Pusan National University Hospital,Busan, Korea. I write to present a case report of abnormal medial rectus insertion presenting exotropia.

Botulinum toxin augmented bilateral lateral rectus recession versus three muscles surgery in large-angle intermittent exotropia

AIM: To report the surgical outcomes of correcting large angle intermittent exotropia in adult patients by bilateral lateral rectus muscle recession with intraoperative use of botulinum toxin and to compare the results with those of bilateral lateral rectus muscle recession and unilateral medial rectus resection. METHODS: The medical records of patients who underwent surgical correction of large angle intermittent exotropia [exotropia >50 prism dioptre(PD)] were retrospectively reviewed. Two groups of patients were identified;Group Ⅰ(21 patients) had bilateral lateral recti recession augmented with intraoperative botulinum toxin A(BTA) injection into the recessed muscles and group Ⅱ(30 patients) were treated by bilateral lateral recti recession with unilateral medial rectus muscle resection. Preoperative data were extracted for age, gender, refraction, type of exotropia, angle of stereopsis and angle of deviation. The main outcome measures were the postoperative angle of deviation and stereoacuity angle by Titmus test measured at the end of one year of postoperative follow up. RESULTS: By the end of the first postoperative year, 10 patients in group Ⅰ(47.6%) and 20 patients in group Ⅱ(66.7%) achieved esotropia/esophoria <5 PD or exotropia/exophoria <10 PD. The difference in surgical success rate was not statistically significant(P=0.1) but there was a statistically significant higher rate of undercorrection in group Ⅰ(P=0.03). On the other hand, 3 patients in group Ⅰ(14.3%) and 5 patients in group Ⅱ(16.7%) had improved stereopsis;this difference in the sensory outcome was not statistically significant(P=0.8). In the BTA augmented surgery group, good stereoacuity and smaller preoperative angle of deviation were associated with significantly higher surgical success rate(P=0.004, 0.01 respectively). CONCLUSION: BTA augmented bilateral lateral recti recession is associated with higher rate of undercorrection as compared to bilateral lateral recti recession with unilateral medial rectus resection in the correction of large angle intermittent exotropia. The surgical success rate in BTA augmented surgery group is observed to be higher in patients with preoperative smaller angle of deviation and in patients with good stereoacuity.

Multiple cranial nerve palsies with small angle exotropia following COVID-19 mRNA vaccination in an adolescent:A case report

BACKGROUND Several vaccines against the severe acute respiratory syndrome coronavirus 2 have been approved and widely distributed,raising public concerns regarding the side effects of immunization,as the incidence of ease.Although many adverse events following the coronavirus disease 2019(COVID-19)vaccine have been reported,neurological complications are relatively uncommon.Herein,we report a rare case of multiple cranial palsies following COVID-19 vaccination in an adolescent patient.CASE SUMMARY A previously healthy,14-year-old Asian girl with facial palsy presented to the emergency department with inability to close the right eye or wrinkle right side of the forehead,and pain in the right cheek.She had received second dose of the COVID-19 mRNA vaccine(Pfizer-BioNTech)18 days before onset of symptoms.She was diagnosed with Bell’s palsy and prescribed a steroid(1 mg/kg/day methylprednisolone)based on symptoms and magnetic resonance imaging findings.However,the next day,all sense of taste was lost with inability to swallow solid food;the gag reflex was absent.Horizontal diplopia was also present.Due to worsening of her condition,she was given high-dose steroids(1g/day methylprednisolone)for 3 days and then discharged with oral steroids.Improvement in the symptoms was noted 4 days post steroid treatment completion.At the most recent follow-up,her general condition was good with no symptoms except diplopia;ocular motility disturbances were noted.Hence,prism glasses were prescribed for diplopia relief.CONCLUSION Small-angle exotropia was observed in the facial,trigeminal,and glossopharyngeal nerve palsies,in our patient.The etiology of this adverse effect following vaccination was thought to be immunological.

Effect of Bilateral Lateral Rectus Recession in Intermittent Exotropia according to the Limbus Insertion Distance

Purpose: The aim of this work was the evaluation of the effect of the limbus insertion distance (LID) of the lateral rectus on the surgical results of bilateral lateral rectus recession in intermittent exotropia (IXT) in children and adults. Patients and Methods: This retrospective study included 76 patients. The patients were divided into two groups: group I (age 5 - 13 y), group II (>13 y). All the patients had basic type of intermittent exotropia (IXT) and all of them underwent bilateral lateral recessions according to the preoperative angle of deviation. Intraoperatively, the distance of limbus insertion was measured by surgical calipers. The dose response effect was calculated as the difference between the preoperative angle and postoperative angle divided by total amount of recession and cases were followed at 1 month, 3 months, 6 months and 12 months postoperative. Results: The mean LID in group I was (6.2 ± 0.61 mm) and (6.1 ± 0.55 mm) in group II. The mean dose response (MDR) at 1 year postoperative was (2.32 ± 0.25 mm) in group I and (2.26 ± 0.23) in group II. In patients with LID 6.25 mm who had larger mean dose response (2.52 ± 0.15). There was a significant positive correlation between the LR muscle LID and the dose-response effect. Conclusion: There is positive correlation between the LID of the LR muscle and the recession effect in bilateral lateral rectus recession in treatment of IXT.

Silicone Band in the Surgical Treatment of Manifest Exotropia

Purpose: A silicone band was sutured anteriorly to the edge of the lateral rectus muscle neotendon during recession surgery in order to reduce and delay the reoccurrence after exotropia surgery. Methods: Collected data of 12 patients (8 males and 4 females), aged 7 - 54 years with diagnosis of constant manifest exotropia and mean angle deviation in primary position of 15,04o(sd 1,18) for near and of 13,23o (sd 0,71) for distance. All patients underwent surgical treatment consisting of lateral rectus recession and silicone band apposition in correspondence to the anterior edge of the lateral rectus muscle neotendon. Results: A substantial reduction of the mean angle deviation was observed in all patients after surgery. No adverse bandrelated effects were detected. Conclusion: The silicone band in the surgical treatment of manifest exotropia could be a valuable aid in delaying the relapse thanks to its physical and structural features and to its biocompatibility.

Medial Rectus Muscle Advancement in Consecutive Exotropia

Purpose: Consecutive exotropia is a frequent consequence of surgery for convergent strabismus that may develop at differing rates postoperatively. Several surgical options on horizontal recti have been proposed, but none report a clearly standardized amount of surgery. The present study provides further results of the medial rectus muscle advancement. Methods: Twenty-eight patients, age range 6 - 55 years, who had undergone unilateral or bilateral medial rectus advancement to the physiological insertion, with or without contemporary unilateral lateral rectus muscle recession, were included in the study. Factors leading to the onset of consecutive exotropia were analyzed. Results: After 2 - 3 years, the overall mean angle reduction was 21.3 prismatic diopters (PD) for distance and 22.8 PD for near, with an effectiveness on near vision lower than expected. Only in the 7 cases with a preoperatively larger exotropia at near (of at least 10 PD), the reduction was 17.0 PD for distance and 24.6 PD for near. In unilateral medial rectus muscle advancement, the mean reduction was 14.3 PD for distance and 16.3 PD for near;in bilateral advancement it was 25.8 PD and 25.2 PD respectively. Conclusion: Medial rectus advancement is preferable to other options, especially in cases with convergence deficit, if no excess of divergence or limitation of bulb rotation is present, for which a lateral rectus muscle recession is indicated. Unilateral and bilateral surgeries are useful for exotropia of about 15 PD and 25 PD respectively. The effectiveness depends weakly or not at all by the amount of the previously executed recession.