BACKGROUND: It has been reported that nitroglycerin relaxes not only vascular smooth muscle but also uterine smooth muscle. The aim of the present study was to investigate the effect of nitroglycerin on rat uterine contractile activity in vitro. The effects of nitroglycerin on myometrial spontaneous activity and oxytocin-induced contractions were also observed. METHODS: Uterine smooth muscle tissues were obtained from non-pregnant female rats (n = 21). The uterine segments were mounted in tissue baths. After spontaneous or oxytocin-induced activity had been accomplished, nitroglycerin in various concentrations was added to the bath and the effects were continuously registered. RESULTS: Nitroglycerin induced a dose-dependent inhibition of spontaneous as well as oxytocin-induced myometrial contractile activity. Complete muscular relaxation on spontaneous contractility was obtained at a concentration of 50 microgram/ml. Complete muscular relaxation on oxytocin-induced contractility was obtained at a concentration of 75 microgram/ml. CONCLUSIONS: Nitroglycerin inhibited the uterine contractile response to exogenous oxytocin as well as spontaneous in the estrous rat.
Animals ; Baths ; Female ; Humans ; Muscle, Smooth* ; Muscle, Smooth, Vascular ; Nitroglycerin* ; Oxytocin ; Rats* ; Relaxation

Purpose: To compare refractive error measured by hand-held wavefront aberrometers with postcycloplegic autorefraction (AR) and cycloplegic refraction (CR). Methods: The medical records of patients who received refractive measurements using the wavefront aberrometer, postcycloplegic AR, and CR between January 2014 and January 2016 were retrospectively analyzed. The mean differences, 95% confidence intervals, and limits of agreement (LOA) were calculated for the refractive vector components (M, J0, and J45). Results: Fifty-one patients (9.0 ± 5.5 years, male 41.2%) were enrolled in this study, and only the right eye of each was included. Refractive errors ranged from -9.25 to +7.25 diopters (D) for spherical equivalent (median, 0.75 D). The M component was not significantly different among the three methods (p = 0.080). However, the J0 vector component was significantly different (p < 0.001). After post hoc analysis, the wavefront aberrometer obtained more positive values for J0 compared to the other methods. The J45 component was not significantly different among the three methods (p = 0.143). The mean difference between the wavefront aberrometer and postcycloplegic AR was -0.115 D (LOA, -1.578 to 1.348 D) for M, 0.239 D (LOA, -0.371 to 0.850 D) for J0, and -0.015 D (LOA, -0.768 to 0.738 D) for J45. The mean difference between the wavefront aberrometer and CR was -0.220 D (LOA, -1.790 to 1.350 D) for M, 0.300 D (LOA, -0.526 to 1.127 D) for J0, and -0.079 D (-0.662 to 0.504 D) for J45. Conclusions The wavefront aberrometer showed good agreement with postcycloplegic AR and CR in spherical equivalents, but tended to produce slightly myopic results. The wavefront aberrometer also overestimated with-the-rule astigmatism. Therefore, we recommend that the device be used for estimations of refractive error, which may be useful for patients who have postural difficulties, live in undeveloped countries, or are bedridden.

PURPOSE: We prospectively examined the effects on refractive power after strabismus surgery using suturing materials of different thickness. METHODS: Postoperative sutures were done using 6-0 vicryl on the right eye and 7-0 vicryl on the left eye in 16 patients (32 eyes) who received bilateral horizontal rectus muscle recessions. Cycloplegic refraction was performed preoperatively and at 1 week, 1 month, 3 months, and 6 months after surgery. RESULTS: We found a significant decrease in the refractive power at 180 degrees meridian resulting in with-therule astigmatism during the first month after surgery in the 6-0 vicryl group and during the first week in the 7-0 vicryl group. The changes in refractive power gradually returned to preoperative states in each group. There was no statistical significance between the two groups. However, the decrease in refractive power at the 180( meridian resulting in with the rule astigmatism was less in the 7-0 vicryl group. CONCLUSION: With-the-rule astigmatism after horizontal muscle recession surgery is a temporary phenomenon and this tendency is decreased with the use of thinner suture materials.
Astigmatism ; Humans ; Polyglactin 910 ; Prospective Studies ; Strabismus* ; Sutures

PURPOSE: Currently, when injecting botulinum a toxin into the extraocular muscle, EMG (Electromyography) is used for accurate location. In this study, we examined the effects of subtenon botulinum toxin injection without EMG guidance by quantifying the morphological changes of the extraocular muscle fibers in rabbits. METHODS: Using 10 New Zealand white rabbits, 10 units of botulinum a toxin in 0.1 ml of normal saline was injected into the subtenon space of the superior rectus muscles, 5 mm from the muscle insertion in right eyes. As a control, 0.1 ml of normal saline was injected into the subtenon space of the superior rectus muscles in left eyes. At 3 weeks after injections, the bilateral superior rectus muscles of each rabbit were carefully dissected from the globe. Cross-sections of 5 micrometer thickness were obtained at the site, 5 mm from the insertion of each superior rectus muscle. Sections were stained with Masson's trichrome and observed by light microscopy. Using Image-Pro Plus software, the diameter of the orbital layer myofibers was measured and statistical analysis was done using the Kruskal-Wallis test. RESULTS: The average diameter of the orbital layer fiber cells after botulinum toxin injection was 11.5+/-2.26 micrometer at 3 weeks, whereas that of the control was 14.4+/-3.77 micrometer. The difference was statistically significant (p<0.01). CONCLUSIONS: The diameter of myofibers in the orbital layer was reduced after subtenon botulinum a toxin injection. Further studies on the duration of botulium toxin in subtenon space and the change in the size of myofibers depending on the dosage of botulinum toxin will be necessary.
Botulinum Toxins ; Botulinum Toxins, Type A* ; Microscopy ; Muscles ; Nerve Block* ; Orbit ; Rabbits