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.

Effects of Ocular Parameters on Medial Rectus Faden Operation with Recession for Esotropia

Background: In the treatment of infantile and accommodative esotopia medial rectus (MR) recession combined posterior fixation suture (Faden operation) can be used. But, there is very limited literature on effect of ocular parameters (axial length, medial rectus width and the distance of medial rectus insertion to limbus) to this operation. Objective: To evaluate effects of ocular parameters on medial rectus Faden operations with recession for esotropia. Material and Methods: In this retrospective study, 38 patients (57 eyes) who underwent Faden operation with unilateral or bilateral recession (4 - 4.5 mm) on medial rectus were divided into three groups according to axial length, medial rectus width and the distance of medial rectus insertion to limbus. Preoperative and postoperative deviations compared. Results: 11 cases were infantile esotropia, 46 cases were acquired esotropia. Female/male rate was 19/19. The mean preoperative amount of esotropia at near was 49.95 ± 17.36 prism diopters (PD) and postoperative 1 week 11.77 ± 11.14 PD, 1 month 12.02 ± 11.52 PD and 6 months 9.46 ± 10.19 PD. The mean preoperative amount of esotropia at distance was 38.84 ± 19.03 PD and postoperative 1 week 7.25 ± 11.29 PD, 1 month 6.54 ± 10.52 PD and 6 months 4.40 ± 9.08 PD. Due to axial length, in shorter eyes, the decrease in mean post-operative deviation was statistically significant. Due to medial rectus width and the distance of medial rectus insertion, there was no statistically significant difference. Conclusions: Axial length has an effect on medial rectus Faden operations with recession but medial rectus width and medial rectus insertion distance from limbus do not.

Congenital dysplasia involving both medial and inferior recti: clinical features and surgical outcomes

AIM: To investigate the clinical features and surgical outcomes of congenital dysplasia involving both inferior recti(IR) and medial recti(MR) muscles.METHODS: A retrospective review was conducted including cases of simultaneous congenital dysplasia of IR and MR that were diagnosed and surgically treated at the Zhongshan Ophthalmic Center, Sun Yat-sen University, China, from July 2009 to November 2019. Ocular motility, ocular alignment at distance(6 m) and near(33 cm) by prism alternating cover test and stereoacuity were assessed in all patients before and after surgery. RESULTS: A total of five patients(four males and one female;three with right eye and two with left eye congenital dysplasia) were included in this review. The patients ranged in age from 10 to 42 y(21±13.4 y). The main clinical findings were hypertropia and exotropia of the affected eye, along with motility limitations in adduction and depression. Lateral rectus(LR) recession/transposition combined with IR resection was performed in one case. Two scheduled surgeries were performed in four cases, with one involving superior rectus recession and IR resection and the others LR recession and MR resection. Mean±SD pre-surgical exotropia of 51.0±31.11 prism diopter(PD) and hypertropia of 29.20±7.12 PD in the primary position were decreased to 3.6±12.90 and 3.2±10.09 PD, respectively, at two years after surgery, with a success rate of 60% and an undercorrection rate of 40%. CONCLUSION: The main clinical features associated with simultaneous MR/IR congenital dysplasia are hypertropia and exotropia of the affected eye along with motility limitations in adduction and depression. Scheduled two-stage surgeries achieved a success rate of 60%.

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.

Relation between preoperative hyperopia and surgical outcome in infantile esotropia

AIM: To evaluate the relation between preoperative hyperopia and surgical outcomes of infantile esotropia in patients younger than 24 months of age.METHODS: Medical records of patients who underwent bilateral medial rectus muscle recession for infantile esotropia between November 1, 2002 and December 1, 2011 were retrospectively reviewed. Patients were divided into two groups according to the degree of preoperative hyperopia. Group I had less than +3.0 diopter(D) of hyperopia and group II had between +3.0 and +5.0 D of hyperopia. Postoperative alignments were evaluated 1 wk, 3, 6 mo, and 1 y after surgery. Following the 1-year postoperative visit, patients were monitored yearly. Relationships between preoperative factors including hyperopia and postoperative outcomes were evaluated. RESULTS: Forty-six patients were included, with 33 patients in group I and 13 patients in group II. The preoperative mean refractive error was +0.88 D in group I and +3.45 D in group II. Surgical outcomes were not significantly different between groups at any postoperative time point examined. Cumulative probability of surgical success, prevalence of inferior oblique overaction, dissociated vertical deviation, and re-operation rate were not significantly different between groups.CONCLUSION: Preoperative moderate hyperopia(less than +5.0 D) did not affect the surgical outcome of infantile esotropia. Therefore, the surgical correction of esotropia should be considered when the angle of esodeviation is unchanged following hyperopia correction, even in children with moderate hyperopia.

Consecutive Exotropia after Convergent Strabismus Surgery—Surgical Treatment

Purpose: In this study the results of consecutive exotropia surgical treatment by using different surgical technics are presented. Methods: This study included 34 patients, aged 21 to 47 years (mean 27.9), who underwent medial rectus muscle advancement alone or in combination with medial rectus resection and/or lateral rectus recession. The mean interval between original surgery and surgery for consecutive exotropia was 8.5 years (range: 5.5 years to 14 years). Most of patients had 2 and more prior surgeries (73.5%) sold by an adduction deficit (47.06%). Results: The overall mean preoperative exodeviation was 35.12 ± 10.13 PD. Satisfactory alignment (within 10 PD of orthophoria) was achieved in 20 patients (58.8%) at 10 days after surgery and 24 patients (70.5%) at final 6-month follow-up. The most common surgical procedures were unilateral MR advancement and LR recession—47%. Conclusion: Medial rectus advancement is an effective method of surgical treatment, especially in cases with adduction limitation, but the risk of the eyelid fissure narrowing in cases of MRM advancement more than 5 mm associated with resection is present. In our opinion for reducing this risk in cases of XT with big angle of deviation, performing a smaller amount of advancement associated with recession of LRM can prevent the development of a such complication.