The mechanical characteristics and performance evaluation of a newly developed silicone airway stent (GINA stent).

Central airway obstruction (CAO) can be attributed to several benign or malignant conditions. Although surgery is the preferred therapeutic option for the management of CAO, bronchoscopic treatment can be performed in scenarios where the surgical procedure is not possible. Recent years have witnessed several improvements in the field of bronchoscopic treatment, especially with regard to airway stents. Current research involves new attempts to overcome the existing shortcomings pertaining to the stents (migration, mucostasis, and granulation tissue formation). The authors have recently developed a new silicone airway stent (GINA stent) with an anti-migration design, dynamic structure that enables the reduction of stent cross-sectional area, and radio-opacity. The present study aimed to evaluate the mechanical characteristics and performance of the novel GINA stent using a porcine tracheal stenosis model. In the current study, all the tests involved the comparison of the GINA stent [outer diameter (OD, mm): 14; length (L, mm): 55] with the Dumon stent (OD: 14; L: 50). The mechanical tests were performed using a digital force gauge, in order to determine the anti-migration force, expansion force, and flexibility. The present study evaluated the short-term (3 weeks) performance of the two stents after implantation [GINA (n = 4) vs. Dumon (n = 3)] in the porcine tracheal stenosis model. The results pertaining to the comparison of the mechanical properties of the GINA and Dumon stents are stated as follows: anti-migration force (18.4 vs. 12.8 N, P = 0.008); expansion force (11.9 vs. 14.5 N, P = 0.008); and flexibility (3.1 vs. 4.5 N, P = 0.008). The results pertaining to the comparison of the short-term performance of the GINA and Dumon stents are stated as follows: mucus retention (0/4 vs. 0/3); granulation tissue formation (0/4 vs. 0/3); and migration (1/4 vs. 2/3). The GINA stent displayed better mechanical properties and comparable short-term performance, compared to the Dumon stent.

A case of central retinal artery occlusion after chiropractic manipulation of the neck.

Here we report a case of central retinal artery occlusion after chiropractic manipulation on the neck. A 49-year old man presented at the hospital because of sudden visual loss in his right eye after chiropractic neck manipulation. He had received chiropractic manipulation of the neck by a chiropractor eight days prior. When he first visited us, his best corrected visual acuity in his right eye was hand motion. A full ophthalmic examination was performed. There was cherry-red spot in the macula in his right eye. We performed a fluorescein angiogram and cervical color Doppler. The arterio-venous transit time in the fluorescein angiogram was delayed, and we detected stenosis of the right internal carotid artery with diffuse atherosclerotic plaques in the right common carotid artery. We prescribed ginko biloba extract (Tanamin). Three years after his first visit, the best corrected visual acuity of his right eye was 20 / 200.

A case of bilateral endogenous Pantoea agglomerans endophthalmitis with interstitial lung disease.

We here in report a case of bilateral endogenous endophthalmitis caused by Pantoea agglomerans (P. agglomerans) in a patient who had interstitial lung disease and was treated with oral corticosteroids. A 72-year-old man presented with decreased visual acuity in both eyes nine days after he received oral corticosteroids. He had marked uveitis, cataracts, and vitreous opacities. Cultures were taken of blood, aqueous humor, and vitreous. We initially suspected a fungal etiology and treated him with antifungal drugs; however, the intraocular disease progressed without improvement. Vitreous culture was positive for P. agglomerans. The patient underwent pars plana vitrectomy with cataract surgery bilaterally, followed by a 2-week course of antibiotics. The final visual acuity was 20/25 in the right eye and 20/200 in the left eye. This is the first report of bilateral endogenous endophthalmitis caused by P. agglomerans in Korea; it is also the first case reported outside of the United States.

Relationship between topographic patterns and corneal astigmatism in Korean adults.

The anterior corneal surface is one of the most important elements determining the optical performance of the eye. Corneal topography provides quantitative data about the anterior corneal surface. We studied the corneal topography of 200 normal corneas in 110 adult subjects. All of the eyes were examined using the Corneal Analysis System (EyeSys 2000, Houston, Texas). The topographic maps were grouped into the following patterns: round, oval, symmetric bow tie, asymmetric bow tie, and irregular. The symmetric and asymmetric bow tie patterns were the most common topographic pattern (33.0%, and 32.5%, respectively) in our study population, followed by oval (14.5%), irregular (12.5%), and round (7.5%) patterns. The mean corneal astigmatism calculated from videokeratographic data was 0.32 D for round, 0.63 D for oval, 1.16 D for symmetric bow tie, 1.21 D for asymmetric bow tie, and 0.43 D for irregular patterns. There were significant differences among the corneal astigmatic values in the topographic patterns (p < 0.01, Gabriel post hoc test). The distributions of symmetric and asymmetric bow tie patterns were skewed toward greater amounts of corneal astigmatism. In conclusion, the results of this study demonstrate the relationship between topographic patterns and corneal astigmatism and should provide one possible normal standard for corneal topography in Korean adults.