tanikawa atsuhiro

BACKGROUND AND OBJECTIVE: The authors developed a new technique for retrobulbar anesthesia and compared it with the conventional transcuta-neous method in 223 eyes undergoing vitrectomy. PATIENTS AND METHODS: In the new technique, a 24-mm-long 19-gauge curved cannula with a 27-gauge straight needle with an oval tip was inserted into the sub-Tenon's space, and then the oval-tipped needle was replaced with a 50-mm-long 25-gauge curved needle. Anesthetic was then injected into the muscle cone from the syringe. The authors compared 118 eyes undergoing vitrectomy with the new technique and 105 eyes undergoing the procedure with conventional anesthesia. RESULTS: The pain scores were 0.1 ± 0.32 for the new technique and 1.57 ± 0.73 for the conventional technique (P &lt .001). Additional anesthetic required was 0.1 ± 0.33 mL using the new technique and 0.3 ± 0.68 mL using the conventional method (P = .03). CONCLUSION: This novel approach to retrobulbar anesthesia using a guarded cannula is safe and effective, causing less pain than the conventional technique.

Stem/progenitor cells of the human corneal epithelium are present in the human corneal limbus, and several corneal epithelial stem/progenitor cell markers have been reported. Recently, the neurotrophin family receptors were reported to be useful markers of corneal epithelial stem/progenitor cells. Therefore, we examined an enzymatic separation method for obtaining corneal epithelial stem/progenitor cells and measuring the change in the expression of low-affinity neurotrophin receptor p75 (p75(NTR)), a receptor belonging to the neurotrophin family. As a result, it was found that our separation method preserved cell viability. Furthermore, p75(NTR) was mainly observed in epithelial basal cells as were the corneal epithelial stem/progenitor markers p63 and integrin beta 1. p75(NTR) was also observed in the cultured cells, but its frequency decreased with passage. In conclusion, we propose that our culture method will enable the culture of corneal stem cells and that it is a useful tool for elucidating the molecular basis of the niche that is necessary for the maintenance of epithelial stem cells in the corneal limbus. Furthermore, we conclude that p75(NTR) is a useful cell marker for evaluating the characteristics of stem/progenitor cells in culture.

We described the possibility of retinal regeneration using a novel and efficient technique for culturing and separating retinal stem/progenitor cells from iris tissue. Immunohistochemical staining of adult agouti mouse iris tissue revealed the presence of nestin/low-affinity neurotrophin receptor p75 (p75(NTR))-positive cells on the endothelium camerae anterioris side. Cultured mouse iris-derived cells contained little or no melanin and were found to be positive for nestin. Most nestin-positive cells were analyzed for the coexpression of p75(NTR) as a cell membrane protein. When the p75(NTR) was used as a marker to sort the cells, we obtained a dense population of nestin-positive cells. Furthermore, the nestin/p75(NTR)-positive cells were able to differentiate into neural retina cells. Thus, this culture and separation technique is useful for obtaining retinal stem/progenitor cells from adult mouse iris tissue and for the efficient production of neural retina cells.

The authors have developed a new technique for removing large and hard lens fragments or crystalline lenses with hard nuclei dislocated into the vitreous cavity using an optic fiber-free intravitreal Surgical system (OFFISS). The OFFISS visualizes the fundus Without a fiberoptic and facilitates the bimanual technique. The lens materials are stabilized with one hand and the fragmatome to emulsify the lens fragments is controlled with the other. The lens fragments or subluxated crystalline lenses can be removed through 20-gauge incisions. This technique was used in 14 cases and was found to be safe and nor invasive. [Ophthalmic Surg Lasers Imaging 2009;40:331-335.]

We examined the toxic effect of the staining solution such as indocyanine green (ICG) on cultured retinal pigment epithelium (RPE) cells. The ICG included sodium iodide (IP-ICG) decreased the cell activity as compared with the ICG without sodium iodide (IF-ICG). IP-ICG dissolved in 5% glucose solution, instead of balanced salt solution (BSS), hardly decreased the cell activity. Trypan blue dissolved in 5% glucose solution, as compared with one in BSS, did not improve the cell activity. These results suggest that IF-ICG in 5% glucose solution might reduce the toxic effect on RPE cells.

To report three cases of idiopathic Creutzfeldt-Jakob disease (CJD) with visual symptoms. Patient 1 initially visited our ophthalmology department complaining of blurred vision. Electro-retinography (ERG) showed a selective reduction of the b wave before she was diagnosed with CJD. Patient 2 had normal ERG results even with severely advanced CJD. However, a reduction of the b wave on ERG was observed 1 month before the patient died. Patient 3 had visual disturbances at the initial visit, but the ERG result was normal even after the CJD had advanced. Atrophy of the visual cortex was later observed. CJD can alter the vision in various ways. The selective reduction of the b wave on ERG indicates the retinal involvement. However, visual disturbances may occur without the retinal implications. Ophthalmologists should be aware that the visual impairment can be the first symptom of CJD.