A comparison of sutures for adjustable strabismus surgery

Electrospun Polymeric Core-sheath Yarns as Drug Eluting Surgical Sutures

Drug-coated sutures are widely used as delivery depots for antibiotics and anti-inflammatory drugs at surgical wound sites. Although drug-laden coating provides good localized drug concentration, variable loading efficiency and release kinetics limits its use. Alternatively, drug incorporation within suture matrices is hampered by the harsh fabrication conditions required for suture-strength enhancement. To circumvent these limitations, we fabricated mechanically robust electrospun core-sheath yarns as sutures, with a central poly-l-lactic acid core, and a drug-eluting poly-lactic-co-glycolic acid sheath. The electrospun sheath was incorporated with aceclofenac or insulin to demonstrate versatility of the suture in loading both chemical and biological class of drugs. Aceclofenac and insulin incorporated sutures exhibited 15% and 4% loading, and release for 10 and 7 days, respectively. Aceclofenac sutures demonstrated reduced epidermal hyperplasia and cellularity in skin-inflammation animal model, while insulin loaded sutures showed enhanced cellular migration in wound healing assay. In conclusion, we demonstrate an innovative strategy of producing mechanically strong, prolonged drug-release sutures loaded with different classes of drugs.

A survey of outcome of adjustable suture as first operation in patients with strabismus

Background:

Adjustable suture used for years to improve the outcome of strabismus surgery. We surveyed outcome of our patients with strabismus who underwent adjustable suture.

Materials and Methods:

This retrospective study was performed at Ophthalmology Centre of Feiz Hospital in Isfahan on 95 participants that candidate for adjustable suture strabismus surgery. Patients were divided into three age groups: Under 10 years, 10-19 years, and 20 years and over. Outcome of adjustable suture surgery consequence of residual postoperative deviation was divided into four groups: Excellent, good, acceptable, and unacceptable.

Results:

Out of 95 patients studied, 51 (53.7%) were males and 44 (46.3%) were females. The mean of deviation angles were 53.8 ± 17.9 PD (Prism dioptres) in alt XT, 44.5 ± 12 PD in alt ET and 52 ± 13.5 PD in const ET, 47.1 ± 13.1PD in cons XT, respectively. There was no significant difference between the groups (P = 0.051). Results of surgery were in 38 patients (40%) excellent, in 31 patients (32.6%) good, in 19 patients (20%) acceptable, and in 7 patients (7.4%) unacceptable. Seven (7.4%) patients required reoperation.

Conclusions:

In the present study, the frequency of re-operation was much lower than other similar studies (7.4% vs. 30-50%). This suggests that the adjustable technique that used in our study can be associated with lower reoperation than other adjustable techniques used in the other similar studies.

Releasable adjustable suture technique for children

PURPOSE

Residual esotropia is a problem for children with esotropia that can follow bilateral medial rectus recession, and the use of adjustable sutures is nearly impossible. The aim of this work is to describe a new suture technique to overcome this problem.

METHODS

Medial rectus muscle was recessed and secured to the sclera at the predetermined recession position after suspending it 1.50-2.00 mm farther. A second, releasable suture was placed at the original insertion site, passed under the previously tied muscle suture knot, and tied in a strengthened loop knot, advancing the muscle to the new scleral insertion. The looped end was left long enough to be kept in the inferior fornix. The next day, if the child was undercorrected, intranasal midazolam was given and the releasable suture was drawn out, providing additional muscle recession. Patients aged 10 to 94 months (mean 34 months) with angle of deviation 20 to 60 prism diopters (PD; mean 33 PD) and with follow-up 1 to 12 weeks (mean 4.5 weeks) were studied. Success was defined as alignment within 10 PD.

RESULTS

Of 50 children with esotropia, 32 (64%) were successfully aligned, and 18 (36%) were undercorrected with residual angle 14 to 25 PD (mean, 18 PD). After release of the suture, 15 children (83%) were successfully aligned, and 3 children were still undercorrected. The overall success rate was 94%.

CONCLUSION

Releasable adjustable suture is a new technique that can help strabismologists attempt bilateral medial rectus recession in children, with a second chance for correction during early postoperative period.

Underlying processes in the implicit association test: dissociating salience from associations

The authors investigated whether effects of the Implicit Association Test (IAT) are influenced by salience asymmetries, independent of associations. Two series of experiments analyzed unique effects of salience by using nonassociated, neutral categories that differed in salience. In a 3rd series, salience asymmetries were manipulated experimentally while holding associations between categories constant. In a 4th series, valent associations of the target categories were manipulated experimentally while holding salience asymmetries constant. Throughout, IAT effects were found to depend on salience asymmetries. Additionally, salience asymmetries between categories were assessed directly with a visual search task to provide an independent criterion of salience asymmetries. Salience asymmetries corresponded to IAT effects and also accounted for common variance in IAT effects and explicit measures of attitudes or the self-concept.

Negative Priming Effects in Children Engaged in Nonspatial Tasks: Evidence for Early Development of an Intact Inhibitory Mechanism

Three experiments are reported that examined conceptual negative priming effects in children 5 to 12 years of age. Experiment 1 used a negative priming variant of a flanker task requiring the naming of a central color blob flanked by irrelevant distractors. Experiment 2 used a negative priming variant of the Stroop color-word task. Experiment 3 used a same-different matching task with novel 3-D shapes. Results revealed significant and equivalent magnitudes of negative priming across the tested age groups for all 3 tasks. It is concluded that the inhibitory mechanism underlying conceptual (i.e., identity or semantic) negative priming in visual selective attention tasks is intact in young children. Because the findings and conclusions diverge from the developmental literature on negative priming, the authors attempt to reconcile the contradictions by pinning down the reasons for the discrepancies.

Eye muscle surgery

In the past year experimental studies have analyzed the ease with which specific sutures can be adjusted, have investigated ways to prevent adhesions in animal models, and have studied variations of the inferior oblique at the surgical capture site. Our knowledge of rectus extraocular muscle pulleys continues to improve, and the value of botulinum toxin type A in the treatment of several conditions has been further documented. New surgical techniques include slanted recessions of the lateral rectus muscles, combined monocular resection and bilateral anterior transposition of the inferior oblique, and intraoperative use of acetylcholine during inferior oblique myectomy. Favorable results have been reported after clinically important modifications to the superior oblique muscle silicone expander and anterior transposition of the inferior oblique procedures, as well as after bilateral inferior rectus muscle recession in dysthyroid ophthalmopathy. Conjunctival inclusion cysts, anterior segment ischemia despite microvascular dissection, and corneal topographic changes are reported as complications occurring after strabismus surgery. Recent publications discussing these issues are reviewed here.