Controlled Delivery of Vancomycin from Collagen-tethered Peptide Vehicles for the Treatment of Wound Infections.

Despite the great promise of antibiotic therapy in wound infections, antibiotic resistance stemming from frequent dosing diminishes drug efficacy and contributes to recurrent infection. To identify improvements in antibiotic therapies, new antibiotic delivery systems that maximize pharmacological activity and minimize side effects are needed. In this study, we developed elastin-like peptide and collagen-like peptide nanovesicles (ECnVs) tethered to collagen-containing matrices to control vancomycin delivery and provide extended antibacterial effects against methicillin-resistant Staphylococcus aureus (MRSA). We observed that ECnVs showed enhanced entrapment efficacy of vancomycin by 3-fold as compared to liposome formulations. Additionally, ECnVs enabled the controlled release of vancomycin at a constant rate with zero-order kinetics, whereas liposomes exhibited first-order release kinetics. Moreover, ECnVs could be retained on both collagen-fibrin (co-gel) matrices and collagen-only matrices, with differential retention on the two biomaterials resulting in different local concentrations of released vancomycin. Overall, the biphasic release profiles of vancomycin from ECnVs/co-gel and ECnVs/collagen more effectively inhibited the growth of MRSA for 18 and 24 h, respectively, even after repeated bacterial inoculation, as compared to matrices containing free vancomycin, which just delayed the growth of MRSA. Thus, this newly developed antibiotic delivery system exhibited distinct advantages for controlled vancomycin delivery and prolonged antibacterial activity relevant to the treatment of wound infections.

Risk of Nonarteritic Anterior Ischemic Optic Neuropathy After Cataract Surgery.

PURPOSE: To determine whether the development of nonarteritic anterior ischemic optic neuropathy (NAION) is increased after receiving cataract surgery in a large general population. DESIGN: Nationwide, population-based, retrospective cohort study. METHODS: Setting: A 12-year nationwide, population-based, retrospective cohort study including 1,025,340 beneficiaries in the 2002-2013 Korean National Health Insurance Service database. PATIENTS: We identified 40,356 patients who had undergone cataract surgery and matched non-cataract surgery controls (1:2) using estimated propensity scores in reference to age, sex, demographics, comorbidities, and co-medications. OBSERVATIONS: Kaplan-Meier curves and Cox proportional hazard models were generated to determine the risk of developing NAION in the cataract surgery group compared to the non-cataract surgery group. MAIN OUTCOME MEASURES: Effect (hazard ratio [HR]) of cataract surgery on NAION development. RESULTS: The 10-year incidence probability of NAION was 0.70% (95% confidence interval [CI], 0.55%-0.86%) in the cataract surgery group and 0.27% (95% CI, 0.25%-0.29%) in the non-cataract surgery group (P < .0001, log-rank test). The cataract surgery group had an increased risk of developing NAION compared to the non-cataract surgery group (HR = 1.80; 95% CIs, 1.46-2.21) even after adjusting for demographics, comorbidities, Charlson comorbidity index, and co-medications. CONCLUSION: Our results suggest that patients undergoing cataract surgery have an increased risk of NAION.

Risk of Stroke After Nonarteritic Anterior Ischemic Optic Neuropathy.

PURPOSE: To determine whether nonarteritic ischemic optic neuropathy (NAION) raises the risk of subsequent stroke in the general population. DESIGN: Population-based, retrospective cohort study. METHODS: Setting: Nationwide, population-based, retrospective cohort study. PATIENTS: Of 1 025 340 beneficiaries in the National Health Insurance Service-National Sample Cohort database (2002-2013), we included 400 952 eligible individuals in the analysis. OBSERVATIONS: To determine the effect of incident NAION on the occurrence of subsequent stroke, we used time-varying covariate Cox regression models. Model 1 included only incident NAION as a time-varying covariate. Model 2 included Model 1 and defined demographics. Model 3 included Model 2, comorbidity, co-medication, and Charlson index score. MAIN OUTCOME MEASURES: Effect (hazard ratio [HR]) of NAION on stroke development. RESULTS: Of 400 952 eligible individuals, 1125 patients developed NAION and 16 998 patients suffered from stroke. NAION was not associated with an increased risk of subsequent stroke in Model 1, with HR of 1.31 (95% confidence interval [CI], 0.89-1.92). This was consistent, after adjusting for demographics and/or confounding factors, in Model 2 (HR = 1.19, 95% CI, 0.81-1.75) and Model 3 (HR = 1.10, 95% CI, 0.75-1.62). CONCLUSIONS: Our results suggest that NAION per se is not associated with a subsequent risk of stroke in the general population.

Diclofenac versus fluorometholone after strabismus surgery in children.

AIMS: To compare the effects of topical diclofenac sodium with those of fluorometholone on intraocular pressure (IOP) and conjunctival inflammation after strabismus surgery. METHODS: We retrospectively analysed 60 Korean children who underwent strabismus surgery for intermittent exotropia in an institutional referral centre. Patients received topical diclofenac 0.1% or fluorometholone 0.1% after surgery for up to 4 weeks. IOP, patient discomfort, conjunctival inflammation and conjunctival injection were evaluated at 1, 2, 3 and 4 weeks after surgery. RESULTS: In the fluorometholone group, 23% showed an increase of ≥10 mm Hg compared to the baseline IOP within 4 weeks of surgery. The fluorometholone group showed a significant change in IOP compared to baseline (p<0.001) at all follow-up time points, whereas the diclofenac group showed no significant increase in IOP. An increased risk of IOP elevation of ≥10 mm Hg was observed after fluorometholone use in patients under 7 years of age. There was no significant difference in patient discomfort, conjunctival inflammation or conjunctival injection between the two groups. Conjunctival injection was more pronounced with muscle resection than with recession at 1 month after surgery. CONCLUSIONS: Postoperative topical diclofenac is an excellent substitute for steroids, particularly in young children under 7 years of age.

Efficacy and safety of limbal-conjunctival autografting with limbal fixation sutures after pterygium excision.

PURPOSE: To evaluate the efficacy and safety of limbal-conjunctival autografting with limbal fixation sutures after pterygium excision. METHODS: We retrospectively reviewed the records of 90 patients (103 eyes) who received limbal-conjunctival autografts with limbal fixation sutures after excision of the primary pterygium (82 eyes) and recurrent pterygium (21 eyes). RESULTS: The study subjects comprised 41 male patients (47 eyes) and 49 female patients (56 eyes) with a mean age of 51.1 ± 10.5 years (range 32-77). The mean follow-up period was 18.9 ± 9.2 months (range 12-50). Among the 103 eyes, recurrence occurred in 2 eyes (1.9%) after 2 and 4 months, respectively. As complications, 1 case of conjunctival cyst and 2 cases of pseudopterygium at the donor site were reported. CONCLUSIONS: Limbal-conjunctival autografting with limbal fixation sutures appears to be an effective and safe method of reducing the recurrence rate after pterygium excision.

Adjustment in patients with asystole during strabismus surgery.

PURPOSE: To investigate whether patients who developed asystole during strabismus surgery under general anesthesia also develop asystole during adjustment, and whether adjustment can safely be performed under topical anesthesia in these patients. DESIGN: Retrospective, noncomparative interventional case series. METHODS: Adjustment was performed with topical anesthesia in four patients aged 28, 32, 50, and 53 years who exhibited asystole during strabismus surgery under general anesthesia. Blood pressure and electrocardiogram were monitored during the adjustment. RESULTS: Adjustment was successfully completed in all patients without asystole. Two patients showed oculocardiac reflex (OCR), with a reduction in heart rate (HR) >20% of the baseline value. One of these patients exhibited severe OCR that developed when the patient's posture was changed from the supine to the sitting position for measurement of the angle of strabismus after adjustment, and again during conjunctival manipulation after conjunctival closure. No patient required atropine. CONCLUSIONS: Adjustment can safely be performed under topical anesthesia in patients who developed asystole during strabismus surgery under general anesthesia.

Imaging of the superior rectus in superior rectus overaction after retrobulbar anesthesia.

OBJECTIVE: Vertical diplopia after cataract surgery caused by an overaction of an extraocular muscle is more common when the superior rectus muscle is involved, whereas contracture is more common when the inferior rectus muscle is involved. However, no documented imaging has been presented. The aim of this report was to study the superior rectus in such a patient with magnetic resonance imaging (MRI). DESIGN: Observational case report. METHODS: Ophthalmologic examination and thin-sectioned MRI across the superior rectus muscle were performed in a patient with superior rectus overaction after cataract surgery. MAIN OUTCOME MEASURES: Ocular alignment, ocular movement, and the superior rectus muscle on MRI. RESULTS: Magnetic resonance imaging disclosed focal thickening of the superior rectus muscle near the orbital apex in a patient who showed superior rectus overaction after retrobulbar anesthesia for cataract extraction. CONCLUSIONS: The focal thickening of the superior rectus muscle in this patient is consistent with the theory that segmental contracture leads to overactive muscles after retrobulbar anesthesia.

Persistent diplopia after retrobulbar anesthesia.

PURPOSE: To determine the causative factors of persistent diplopia after retrobulbar anesthesia. SETTING: Strabismus Section, Department of Ophthalmology, Seoul National University, Seoul, South Korea. METHODS: Prism and alternate cover tests in the diagnostic positions of gaze and ductions/versions were performed in 28 patients with persistent diplopia 6 months after retrobulbar anesthesia. The Lancaster test, Bielshowsky head tilt test, double Maddox rod test, fundoscopic examination for torsion, forced duction test, force generation test, tensilon test, thyroid function test, and/or orbit computed tomography were performed when necessary. RESULTS: Most of the patients (26 patients, 93%) did not have diplopia before retrobulbar anesthesia. Of the 14 patients with extraocular muscles imbalance, 12 patients showed vertical rectus overaction (11 superior recti, 1 inferior rectus) and 2 patients, mild vertical rectus underaction. Nine patients were presumed to have a sensory strabismus related to the preoperative poor vision, but this went unnoticed preoperatively. Three patients showed a small vertical deviation without any specific causative factors. CONCLUSIONS: Fifty percent of the cases of diplopia were associated with either direct trauma or anesthetic myotoxicity to the extraocular muscles, in which overactions were more common than underactions. Thirty-two percent of the patients were presumed to have sensory strabismus, which suggested the importance of preoperative examination for strabismus as well as providing an explanation about the risk of postoperative diplopia before surgery.