Study for analysis of the multifocal visual evoked potential.

PURPOSE: To introduce the clinical utility of the absolute value of the reconstructed waveform method in the analysis of multifocal visual evoked potential (mfVEP). METHODS: The mfVEP with 4-channel recording was performed using RETIscan® on 10 eyes of 10 normal subjects. Amplitudes were obtained from ring-shaped 6 areas and 4 sectors. The best visual evoked potential (VEP) response method and the absolute value of the reconstructed waveform method were compared in terms of analysis of the amplitudes. In order to assess the false positive rate of the examination, stimuli were administered with one-half of the cathode ray tube (CRT) monitor completely covered and the results were compared using 2 methods. RESULTS: The amplitudes in 6 areas and 4 sectors analyzed with the best VEP response method and the absolute value of the reconstructed waveform method showed no statistical difference (p > 0.05). The amplitude in the stimuli-blocked area of the absolute value of the reconstructed waveform method was smaller than that of the best VEP response method (p < 0.05) and the amplitude of the stimuli area showed no substantial difference between two methods (p > 0.05). CONCLUSIONS: The absolute value of the reconstructed waveform method has similar reproducibility and lower level of false positives relative to the best VEP response method. Therefore, it can be considered as a useful method in the analysis of the mfVEP.

A new norlupane triterpene from the leaves of Acanthopanax koreanum increases the differentiation of osteoblastic MC3T3-e1 cells.

A new norlupane-triterpene, 3alpha,11alpha-dihydroxy-20,23-dioxo-30-norlupane-28-oic acid (1), and four known compounds; 3alpha,11alpha-dihydroxy-23-oxo-lup-20(29)-en-28-oic acid (2), 3alpha,11alpha-dihydroxylup-20(29)-en-28-oic acid (3), ent-kaur-16-en-19-oic acid (4), and betulabuside B (5) were isolated from the methanolic extract of the leaves of Acanthopanax koreanum. Their chemical structures were elucidated by mass, 1D- and 2D-NMR spectroscopy. To investigate the bioactivities of these compounds, their effects on the differentiation of osteoblastic MC3T3-E1 cells were tested. Compounds 3 and 4 significantly increased osteoblastic cell growth and differentiation as assessed by the MTT assay and collagen content, respectively (p < 0.05). Compounds 1 and 5 significantly increased the growth of MC3T3-E1 cells and caused a significant elevation of osteoblastic cell differentiation as assessed by the alkaline phosphatase activity. These results suggest that the compounds isolated from A. koreanum leaves have a direct stimulatory effect on bone formation in vitro and may contribute to the prevention for osteoporosis.

Sudden unilateral visual loss after autologous fat injection into the nasolabial fold.

A 27-year-old female presented with sudden visual loss of her right eye after receiving an autologous fat injection into the right nasolabial fold. Fundus examination of the right eye showed multiple whitish patchy lesions with macular edema. Fluorescein angiogram showed deterioration of choroidal circulation with patchy choroidal filling and arm-to-retina circulation time and retinal arteriovenous passage time were delayed to 30 seconds and 20 seconds, respectively. There was no response in flash visual evoked potential (VEP). High dose steroid therapy (methylprednisolone 1 g/day/i.v.) was done and about 2 weeks later, the disc edema subsided and retinal arteriovenous passage time of fluorescein angiogram was normalized but there was no improvement in visual acuity. Absence of a cherry red spot, deterioration of choroidal circulation with patchy choroidal fillings seen in fluorescein angiogram, and no response in flash VEP suggests multiple choroidal infarction due to perfusion defect of the short posterior ciliary artery. The autologous fat injected is thought to have entered the dorsal nasal artery and the retrograde migration of the emboli to the ophthalmic artery might have caused the multiple occlusions of the short posterior ciliary artery.

The results of B-scan ultrasonography in different positions after vitrectomy and gas tamponade.

PURPOSE: To determine the proper time frame in which to assess retinal attachment status and to evaluate the superior retinal attachment status by performing B-scan ultrasonography in different positions on patients who have undergone pars plana vitrectomy and gas tamoponade. METHODS: In this prospective study, 23 patients (23 eyes) who had undergone pars plana vitrectomy and gas tamponade were investigated between June 2005 and February 2006. SF(6) (18%) was injected into the vitreous cavity of 15 eyes, and C(3)F(8) (14%) was injected into the vitreous cavity of 8 eyes. At postoperative day 1, day 3, week 1, week 2, and week 4, B-scan ultrasonography was performed in the supine, sitting, prone, right decubitus, and left decubitus positions. RESULTS: The proper time to evaluate the retinal attachment status was three days post-operatively in 10 eyes (66.7%) with SF(6) (18%) injections and two weeks post-operatively in six eyes (75%) that had C(3)F(8) (14%) injections. The superior retinal attachment status can be evaluated from the summation of B-scan ultrasonography results performed in the right decubitus and left ducubitus positions. CONCLUSIONS: The proper time to evaluate the retinal attachment status was related to the degree of the gas absorption when performing B-scan ultrasonography after pars plana vitrectomy and gas tamponade. To evaluate the entire retina, it is useful to perform B-scan ultrasonograhy in the prone, right decubitus and left decubitus positions.