Definition of successful outcomes after surgery for each type of strabismus: a Delphi study

Comparison of horizontal muscle transposition and Inferior oblique weakening combined with horizontal surgery in V-pattern exotropia

Purpose

The objective of this study was to compare the effects of horizontal muscle transposition and inferior oblique weakening combined with horizontal surgery performed for V-pattern exotropia (XT) and to determine the most successful approach.

Methods

In our retrospective study, 52 patients who underwent horizontal surgery due to V-pattern XT and were followed up for at least 6 months were divided into two groups. Group 1 (n = 26) consisted of patients who underwent vertical transposition of the rectus muscles combined with horizontal surgery, and group 2 (n = 26) consisted of patients who underwent inferior oblique weakening combined with horizontal surgery. The two groups were compared before and after surgery in terms of visual acuity, refractive errors, deviation angles, pattern strabismus, fusion, stereopsis, over/under correction and surgical success.

Results

There was no difference between the two groups in terms of age, follow-up period, visual acuity, refractive errors, fusion or stereopsis. The amount of horizontal deviation was smaller in group 2 at the 1-6-month follow-ups. There was no difference between the two groups in terms of pattern collapse; however, the amount of pattern postoperatively was lower in group 2. The two groups were similar in terms of overcorrection; however, the undercorrection rate was higher in group 1. The surgical success rate was higher in group 2.

Conclusions

Inferior oblique weakening combined with horizontal surgery due to V-pattern XT was found to be superior to vertical transposition of the horizontal muscles in terms of surgical success and the amount of pattern postoperatively.

Surgical outcomes of medial Rectus advancement for consecutive exotropia

PURPOSE

To evaluate the surgical results of medial rectus muscle advancement for consecutive exotropia.

METHODS

The medical data of patients that underwent reoperation between the years 2000-2020 were collected and reviewed retrospectively. Patients who underwent medial rectus advancement for consecutive exotropia were included. The exclusion criteria were follow-up period shorter than 6 months, past reoperations and restrictive or paralytic strabismus. Success was defined as alignment within 10 PD of orthophoria at last follow-up. The success group of patients was compared with the failure group.

RESULTS

Twenty patients with mean postoperative follow-up from the second surgery of 34.7  ±  29.2 months were included. On last follow-up examination, 9 (45.0%) patients had a successful result. Nine patients had undercorrection and 2 had overcorrection. The two groups were similar in the preoperative amount of mean exotropia, 23.3  ±  9.9 PD in the success group and 29.8  ±  14.0 PD in the failure group. On last follow-up examination, the amount of mean deviation was 2.7  ±  2.6 PD exotropia in the success group and 13.4  ±  23.6 PD exotropia in the failure group.

CONCLUSION

Medial rectus advancement for the correction of consecutive exotropia was successful in almost half of the cases. Failure was usually due to undercorrection.

Extra Ocular Muscle Fenestration as a Weakening Maneuver for Surgical Management of Strabismus: A Randomized Pilot Clinical Trial

Purpose

This study aimed to evaluate the efficacy and safety of fenestration in comparison to the classic muscle recession as a weakening maneuver to horizontal and vertical extra ocular muscles in the surgical management of strabismus.

Patients and Methods

This is a pilot single blind parallel group randomized controlled trial with 1:1 allocation ratio. Male or female patients aged 1- to 60-years-old who were admitted to the Pediatric Ophthalmology and Strabismus Department for surgical correction of horizontal or vertical strabismus. Patients were randomly allocated by the envelop method to either group 1 (muscle fenestration, N=9) or group 2 (classic muscle recession, N=9). All participants were assessed at the first post operative day, at one week, and one month after the surgery for the outcomes.

Results

Postoperative ocular alignment evaluated at the first day, one week, and one month following the operation showed comparable results with no significant differences between both groups (p>0.05). The median postoperative pain score evaluated at the first day following the operation was significantly higher in fenestration group than recession group (the medians were 2.0 and 1.0, respectively, p=0.014). Alternatively, the medians of the pain score were equal in both groups at one week and one month postoperatively (p>0.999). One patient in the fenestration group developed progressive subconjunctival hemorrhage. In contrast, there was no postoperative complications in the recession group (p>0.999).

Conclusion

Efficacy and safety of muscle fenestration for correcting horizontal or vertical strabismus was comparable to the classic muscle recession.

Medial rectus disinsertion for management of chronic complete sixth nerve palsy

PURPOSE

To report the outcomes of the medial rectus (MR) disinsertion procedure for the management of refractory esotropia (ET) with or without Abnormal head posture (AHP) in chronic complete sixth nerve palsy.

METHODS

This is a retrospective case series of patients with sixth nerve palsy who suffered from residual ET and diplopia following the conventional strabismus surgeries and underwent MR disinsertion procedure between April 2017 and February 2020. This procedure was offered to the patients who declined to use prism and did not wish to perform surgery on the fellow eye. The demographic and clinical data, including sex, age, visual acuity, pre and postoperative angle of strabismus, duction limitations, results of forced duction and force generation tests, details of prior strabismus surgeries, orbital CT scan findings, and follow up duration were collected from the medical records.

RESULTS

Six patients were enrolled in this study. Mean age was 35.0  ±  14.0 years, and mean follow-up was 15.3  ±  5.9 months. The ET at the Primary position (PP) was 35.0  ±  18.4 prism dioptre (PD) before MR disinsertion, which decreased to 14.2  ±  17.4 PD after MR disinsertion procedure. Four cases needed additional complementary surgeries to improve residual ET in PP. No case developed overcorrection. Abduction deficiency was -5.0  ±  1.3 before MR disinsertion, which improved to - 2.8  ±  0.5 units at last follow-up. The mean of induced adduction deficiency was - 2.9  ±  0.4 at last follow-up.

CONCLUSIONS

MR disinsertion can be considered in patients with chronic complete sixth nerve palsy and refractory diplopia when the conventional methods have failed.

Factors associated with the effectiveness of part-time patching for intermittent exotropia in children

PURPOSE

To evaluate the factors associated with the efficacy of low-dose part-time patching in children with intermittent exotropia (IXT).

METHODS

In this prospective observational study, we enrolled 186 patients diagnosed with IXT. Outcome measures included office based control scales, magnitude of exo-deviation, and stereoacuity at near and distance after daily patching for 2 h. We analyzed the clinical data and demographic factors association with improvement of IXT.

RESULTS

The study was completed by 152 subjects of total enrolled patients on a consecutive basis followed up for 1 year. Decrease in the magnitude of exo-deviation, improvement of control, and or gain of stereoacuity were observed in 31.6% patients of the recruited subjects after part-time patching. Multivariate analyses showed that prognostic factors determining improvement to part-time patching included convergence insufficiency (CI) type IXT (p = 0.016), poor distance stereopsis (p = 0.044), and large exotropic deviation at distance (p = 0.025).

CONCLUSIONS

CI-type exotropia, large distance magnitude of exo-deviation, or poor distance stereopsis appear to be associated with a better response to part-time patching. Therefore low dose part-time patching may be a useful non-surgical treatment alternative to delay surgery in these cases.

Surgical treatment of consecutive exotropia: Comparison of different surgical methods applied to one eye in one session

PURPOSE

To compare the different surgical methods performed on a single eye in a single session and the factors that affect the success of patients having consecutive exotropia (XT) developed after esotropia surgery.

METHODS

The medical data of the patients who underwent surgery for consecutive XT were reviewed retrospectively. Patients with followed of 6 months or more were divided into four groups; patients with medial rectus (MR) advancement (Group 1 = 10), MR advancement and MR resection (Group 2 = 12), MR advancement and lateral rectus (LR) recession (Group 3 = 13), MR advancement, MR resection, and LR recession (Group 4 = 14). Success results and possible risk factors were investigated.

RESULTS

Forty-nine patients with consecutive XT (21 female, 28 male) were enrolled in the study. The mean age of overall patients was 22.97 years at surgery for consecutive XT. The groups did not display significant differences in terms of surgery ages, gender, refraction values, visual acuity, amblyopia, inferior oblique overaction, limitation of adduction, surgical success rates, and follow-up time (p > 0.05). Patients of Group 4 had larger preoperative and postoperative deviation, while Group 1 had smaller (p < 0.05). The surgical success rates of Groups 1, 2, 3, 4 were 90%, 75%, 76.9%, and 50%, respectively (p = 0.192). Statistically, no factor was found to be effective in surgical success rates (p > 0.05).

CONCLUSION

Surgical treatment of consecutive XT is successful in most of the patients with numerous surgical options performed on a single eye in a single session. Patients, particularly with a high amount of deviation should be warned about the possibility of additional surgery.

A single inferior rectus muscle surgery for treatment of congenital superior oblique palsy with small deviation in primary position

PURPOSE

To evaluate outcomes of one muscle surgery for treatment of congenital superior oblique palsy (SOP) with Knapp Class V.

METHODS

Medical records were retrospectively reviewed for the patients with the congenital SOP type V who underwent surgical treatment through one muscle surgery between July 2015 and September 2020. The surgical procedure was resection-recession on the contralateral inferior rectus muscle of the hypertrophic or paretic eye. Vertical alignment at nine cardinal gaze positions, and resolution of the abnormal head posture were evaluated pre- and postoperatively. The follow-up was scheduled regularly at postoperative day 1, 1 week, 1 month, and followed by 2-month intervals until 18 months.

RESULTS

Twelve patients were included in this study, with a mean age of 6.4 years (range from 3 to 10 years). The mean follow-up period was 10.5 months after surgery (range from 6 to 18 months). The average vertical deviation at primary position was 6.33△ ± 2.93△ preoperatively and 0.75△ ± 1.14△ postoperatively (p < 0.05). The average vertical deviation at downgaze was 23.33△ ± 4.75△ preoperatively and 1.92△ ± 1.62△ postoperatively (p < 0.05). All patients had an abnormal head position preoperatively. Postoperative results indicated that the patients' abnormal head position had been improved significantly.

CONCLUSIONS

The surgical procedure of resection-recession on a single inferior rectus muscle is a successful intervention for the correction of superior oblique palsy (SOP) with Knapp Class V.