Microphthalmos with cyst which results from a defect of ventral fissure is a rare malformation, with no previously reported case in Korea. The defect permits neuroectodermal tissue to proliferate into the orbit, forming a cystic structure that remains connected to the inferior aspect of the diminutive globe. We have observed such a malformation in a 8-year-old girl and surgically excised the diminutive eye and communicating cyst en-bloc.
Child ; Female ; Humans ; Korea ; Microphthalmos* ; Neural Plate ; Orbit

PURPOSE: Temporary deafferentation (TD) by local anesthesia in small parts of the body induces an immediate and reVersible reorganization of the receptive field (RF). It is thought that an adaptation for deafferentation would occur in the visual system. Therefore, in this study, simultaneous multi-single unit recording (SMSUR) from visual cortex (VI cortex) of rats have been carried out to characterize; 1) the TD-induced changes in the populational activities of single neurons, 2) the alteration of the neural network among neurons in each area during TD and 3) the synaptic mechanism underlying the neuronal plasticity of the visual system. METHODS: Using four channels of a multi-electrode made from tungsten microwire, the neuronal activities (evoked responses and spontaneous activities) and networks in the VI cortex of anesthetized rats have been investigated. In this study, TD was induced by a retrobulbar injection of lidocaine (2%, 0.1 ml). RESULTS: After the induction of TD, the cortical neurons showed reversed changes in their evoked reoponses. The induction of TD suppressed the activities of the target cells in the VI cortex. However, TD also caused facilitation of the activities of the neighboring neurons. The spontaneous activities of the neighboring neurons were also gradually facilitated after the induction of TD and then gradually recovered to their initial control period values. CONCLUSIONS: The results from the present study suggest that; 1) TD-induced plasticity of the central visual system involving the VI cortex may be due to disinhibition of the lateral inhibition and 2) the spontaneous activities of the VI cortical neurons, as well as evoking responses, may be involved in the TD-induced visual plasticity of anesthetized rats.
Anesthesia, Local ; Animals ; Electrophysiology ; Lidocaine ; Neuronal Plasticity ; Neurons ; Plastics ; Rats* ; Tungsten ; Visual Cortex*

The purpose of this study was to evaluate the susceptibility of various intraocular lenses(IOLs) of different optic material to Nd:YAG laser in vitro. Four models of IOLs manufactured by different companies were selected and ten IOLs for each model were used for this study. Two models had lathe-cut polymethylmethacrylate(PMMA) optic, one silicone compound optic, and one acrylate/methacrylate copolymer optic. Q-switched Nd: YAG laser(7901 Nd-YAG laser, Coherent, Palo Alto, CA, USA) was used. The He-Ne aiming beam was focused on the posterior surface of optic, 2mm apart from the center of optic, and sixteen shots were applied to each optic with energy levels ranging from 0.3 to 2.0mJ with increment of 0.1 or 0.2mJ in a circular pattern. The spots were examined under phase contrast microscope and scanning electron microscope. The averages(+/-SD) of energy threshold at which damage was detected were 0.49+/-0.12mJ in silicone compound optic, 0.67+/-0.19mJ in acrylate/methacrylate copolyer optic, and 0.72+/-0.11mJ and 0.89+/-0.09mJ in lathe-cut PMMA optics. All interclass differences were statistically significant except the difference between lathe-cut PMMA optic with lower damage threshold and acrylate/methacrylate copolymer optic(Mann-Whitney test, p<.05). In conclusion, silicone compound and acrylate/methacrylate copolymer optics are more susceptible to Nd:YAG laser than PMMA optic in vitro and this suggests that in patients with high risk of developing severe posterior capsular opacification after cataract surgery, implantation of IOLs with PMMA optic is preferable and early Nd:YAG laser posterior capsulotomy with low energy is recommended in cases of implantation of foldable IOLs.
Cataract ; Humans ; Lasers, Solid-State* ; Lenses, Intraocular* ; Polymethyl Methacrylate ; Posterior Capsulotomy ; Silicones

PURPOSE: By recording the electrically evoked potential (EEP) we tried to verify that focal electrical stimulation of retina sends a signal to the cortex that is similar to that elicited by light and also to investigate optimal stimulus parameters. METHODS: Five New Zealand white rabbits were placed under anesthesia. A tungsten bipolar stimulating electrode (diameter: 250 um) was placed on the vitreal surface of the retina. Cutaneous Ag/AgCl patch electrodes of VEP were used to record EEP. EEP was recorded at each stimulation. Focal visual evoked potentials (VEPs) were also recorded and compared to the focal EEP to ascertain cortical origin of the EEP, and similarities of the EEP to the VEP were determined. RESULTS: EEP recordings were elicited in 8 eyes. Current amplitudes which produced detectable responses ranged from 100 to 5000 micro A. In our best series, EEP amplitudes increased by 8 to 119 micro V in response to the current increasing from 100 to 1000 micro A. In comparing latencies of the EEP and focal VEP, the EEP latencies were 12~16 ms faster, which supports our EEP recording was done properly. CONCLUSIONS: EEPs obtained using VEP setting with adequate parameters of current duration and threshold level for the retinal implant showed that use of the EEP response is a good way to monitor the proper functioning of the retinal implant.
Anesthesia ; Electric Stimulation ; Electricity* ; Electrodes ; Electrophysiology ; Evoked Potentials ; Evoked Potentials, Visual ; Rabbits ; Retina* ; Retinaldehyde ; Tungsten ; Visual Prosthesis

OBJECTIVES: This randomized, multicenter, open-label, parallel clinical trial was carried to compare the therapeutic efficacy and the proportion of successful switch between 'direct switching method' and 'start-tapering switching method' when switching an antipsychotic to olanzapine. METHODS: This study included both inpatients and outpatients who fulfilled the criteria for schizophrenia as defined in the ICD-10 from 13 hospitals, and were in need to be appropriate for switching antipsychotics. Subjects were randomly assigned to one of the two switching methods. For 'direct switching method' group, previous antipsychotics were abruptly discontinued and 10mg of olanzapine was administered, whereas for 'start-tapering switching method' group, initially 10mg of olanzapine was administered and previous antipsychotics was gradually tapered for 2 weeks. Olanzapine was used for 6 weeks and the dose was adjusted within the range of 5-20mg. The therapeutic efficacy was measured with PANSS, BPRS, and CGI-Severity. A successful switching was defined as the completion of the 6 week trial without either worsening of the symptom(i.e. CGI-S score becomes worse twice consecutively) or the exacerbation of extrapyramidal symptoms(i.e. Simpson-Angus Scale scores becomes worse). RESULTS: 103 schizophrenic patients were participated in this study. There were no differences in baseline characteristics such as the demographic variables, the severity of symptoms, the history of previous antipsychotics treatments, the dosage of olanzapine used and the compliance between two groups. The proportion of successful switch was 71.1% for "direct switching method" and 82.2% for "start-tapering switching method", and there was no significant difference between the two switching methods. Also response rates to olanzapine based on total PANSS total scores were not different between the two groups(26.9% vs. 31.1%). At the time of completion of the trial, the scores of PANSS total, PANSS subscales, CGI-S and BPRS have significantly decreased after switching to olanzapine. But the changes of all scales measuring therapeutic efficacy in both endpoint and weekly analyses were not significantly different between the two switching methods. CONCLUSION: Although this study trial has many limitations and problems as an open clinical trial, the results may suggest that there were no significant differences between the two switching methods in the therapeutic efficacy. It was also found that the additional therapeutic benefits could be obtained by switching their antipsychotics to olanzapine.
Antipsychotic Agents ; Compliance ; Humans ; Inpatients ; International Classification of Diseases ; Outpatients ; Schizophrenia ; Weights and Measures