Adjustable suture strabismus surgery in pediatric patients using pull-string technique

Long-term outcomes of adjustable strabismus surgery at a Pakistani university hospital

PURPOSE

Strabismus, whether congenital or acquired, is a common visual and cosmetic problem, especially for the young. Adjustable suture strabismus surgery is not in vogue in our country. This technique gives the surgeon a second attempt to provide a better outcome for the patients. Our objective was to assess the long-term success of adjustable strabismus surgery in terms of postoperative alignment.

METHODS

We carried out a prospective study utilizing the fornix approach for adjustable strabismus surgery, in mainly horizontal, but also vertical strabismus in adults and cooperative children, to enhance the postoperative outcomes. The patient characteristics, preoperative deviation, type and pattern of strabismus, were evaluated and analyzed. The postoperative alignment was evaluated at 1 year and beyond, to assess the success of this adjustable surgery.

RESULTS

This study recruited 50 adults and children with a female predominance of 39 (78%); and with the mean age being 18.34 ± 9.88 years. Exotropia was the primary diagnosis in the majority with 21 (42%) cases; with purely horizontal strabismus in 23 (46%) cases. The mean preoperative horizontal deviation was 48.76 ± 20.35 prism diopters (PD) and the mean postoperative horizontal deviation was 2.73 ± 3.63 PD. The mean preoperative vertical deviation was 4.8 ± 8.54 PD whereas the mean postoperative vertical deviation was 0.86 ± 1.73 PD. The Wilcoxon Signed Ranks test analyzed the difference between the two which was statistically significant (p = 0.000). Surgical success, defined as postoperative horizontal alignment within ≤ 10 PD of orthotropia at the end of one year or more of follow-up after surgery, was achieved in 49 (98%) cases. The average follow-up was 21.47 ± 8.7 months.

CONCLUSION

Adjustable strabismus surgery has very good long-term outcomes in terms of postoperative alignment and patient satisfaction.

A Novel Method Ensuring an Immediate Target Angle After Horizontal Strabismus Surgery in Children

Purpose

Pediatric strabismus surgery has low success rates and high reoperation rates because of difficult alignment measurements and the nature of different strabismus types. Furthermore, adjustable sutures are not easily employed in children on an OPD basis.

Methods

This was a retrospective comparative case study of children less than 12 years old who underwent strabismus surgery and were followed up at least 6 months postoperatively. We proposed a novel method that combines adjustable sutures and corneal light reflexes in regular strabismus surgery to improve surgical results. Efficacy and safety were evaluated and compared with those in a regular fixed-suture group.

Results

In total, 128 children (88: exotropia and 41: esotropia) in the novel method group (Group 1) and 109 (71: exotropia and 38: esotropia) in the regular fixed-suture group (Group 2) were enrolled. The primary outcome was the immediate target angle (for esotropia within 4 PD of orthotropia and exotropia within 8 PD of esotropia within the first week postoperatively); the secondary outcome was success at the 6-month visit (angle of deviation < 10 PD). Consequently, there was a significantly higher proportion of achieving the immediate target range and success rate in both exotropic and esotropic patients in Group 1 than in Group 2. A significantly lower reoperation rate was also demonstrated in Group 1. No complications were noted in either group.

Conclusions: The novel method enabled a higher proportion of subjects to achieve an immediate target range and success rate and a lower chance of reoperation among both esotropic and exotropic patients.

Modified Target Angle as a Predictor of Success in Strabismus Management after Orbital Fracture

Surgery for strabismus secondary to orbital fracture reconstruction surgery has had low success rates and high reoperation rates due to its incomitant nature and complex underlying mechanisms. There has been no consensus as to which of the various methods for improving the surgical results are best. We proposed a modified target angle criteria that combined the regular target angle and a favorable Hess area ratio percentage (HAR%) threshold to evaluate surgical results within the first postoperative week and conducted a retrospective chart review. According to the criteria of the modified target angle at the first postoperative week, a total of 63 patients were divided into two groups: Group 1, patients who fulfilled the criteria (49 patients); and Group 2, those who did not (14 patients). Sex, type of fracture, and the use of porous polyethylene sheets and titanium mesh during reconstruction surgery were significantly different between the groups. Group 1 showed a significantly higher percentage of patients who met the criteria of HAR% > 65% at the first week and >85% (i.e., a successful outcome) at the 6-month visit (p < 0.01). Additionally, Group 1 had a higher HAR% at the first postoperative week (p < 0.01). In conclusion, the patients meeting the criteria of the modified target angle at the first postoperative week had a favorable outcome at the 6-month visit in both ocular alignment and ocular movement.

Adjustable Sutures in the Treatment of Strabismus: A Report by the American Academy of Ophthalmology

PURPOSE

To review the scientific literature that evaluates the effectiveness of adjustable sutures in the management of strabismus for adult and pediatric patients.

METHODS

Literature searches were performed in the PubMed database through April 2021 with no date limitations and were restricted to publications in English. The searches identified 551 relevant citations, of which 55 were reviewed in full text. Of these, 17 articles met the inclusion criteria and were assigned a level of evidence rating by the panel methodologist. The search included all randomized controlled studies regardless of study size and cohort studies of 100 or more patients comparing the adjustable versus nonadjustable suture technique, with a focus on motor alignment outcomes or reoperation rates.

RESULTS

The literature search yielded no level I studies. Of the 17 articles that met the inclusion criteria, 11 were rated level II and 6 were rated level III. Among the 12 studies that focused on motor alignment outcomes, 4 small randomized clinical trials (RCTs) did not find a statistically significant difference between groups, although they were powered to detect only very large differences. Seven of 8 nonrandomized studies found a statistically significant difference in motor alignment success in favor of the adjustable suture technique, both overall and in certain subgroups of patients. Successful motor alignment was seen in both exotropia (in 3 studies that were not limited to children) and esotropia (in 1 study of adults and 2 of children). The majority of included studies that reported on reoperation rates found the rates to be lower in patients who underwent strabismus surgery with adjustable sutures, but this finding was not uniformly demonstrated.

CONCLUSIONS

Although there are no level I studies evaluating the effectiveness of adjustable sutures for strabismus surgery, the majority of nonrandomized studies that met the inclusion criteria for this assessment reported an advantage of the adjustable suture technique over the nonadjustable technique with respect to motor alignment outcomes. This finding was not uniformly demonstrated among all studies reviewed and warrants further investigation in the development and analysis of adjustable suture techniques.

Laser-Assisted Adjustable Suture Technique in Strabismus Surgery

Purpose

The aim of this study was to assess the efficacy and safety of a new technique (argon laser-assisted lysis of the adjustable suture) in strabismus surgery.

Patients and Methods

Recession of lateral rectus muscle was done and was secured to the sclera at the predetermined recession position after suspending it 1.5–2.5 mm farther. A 10-0 nylon suture was placed at the original insertion site, passed under the previously tied muscle suture knot, and tied, advancing the muscle to the new scleral insertion. Postoperatively in the same day of surgery, if the targeted slight overcorrection was not achieved, a topical anesthetic was given, and argon laser was used to cut the nylon suture providing additional muscle recession.

Results

Forty-two patients with exotropia were included: 11 children and 31 adults. Eleven (26.2%) patients became orthophoric immediately following muscle recession. Thirty-one (73.8%) patients were undercorrected with a mean residual angle of 8.2±3.3 pd. After laser-assisted release of the suture, 12 (28.6%) patients were orthophoric, with 4 (9.5%) patients still undercorrected and 26 (61.9%) patients overcorrected. By the end of 6 months postoperatively, the overall success rate of the procedure was 88.1%, with only 5 (11.9%) patients with exotropia.

Conclusion

The laser-assisted adjustable suture technique had an overall success rate of 88.1% with only 11.9% of the patients showing exotropia. The technique can help achieve successful alignment.