The synthesis of silafluorene derivatives from aminobiphenyl compounds and dihydrosilanes via a double sila-Friedel-Crafts reaction using a borane catalyst has been achieved. This method is applicable to the synthesis of a variety of silafluorene derivatives, such as multisubstituted silafluorenes, spirosilabifluorenes, and silicon-bridged terphenyl compounds, which are not readily obtained using conventional synthetic methods. In addition, we have demonstrated the transformation of the amino groups in these silafluorene derivatives into other substituents.
PURPOSE: To report 2 cases of central retinal artery occlusion (CRAO) who underwent retinal endovascular surgery with injection of tissue plasminogen activator (tPA) into the retinal artery and showed a remarkable improvement in visual acuity and retinal circulation. METHODS: Standard 25-G vitrectomy was performed under local anesthesia. Simultaneously, tPA (80,000 units/mL) solution was injected into the retinal artery of the optic disc for 2-3 min using a microneedle. Changes in visual acuity, fundus photography, optical coherence tomography (OCT), fluorescein angiography, and laser speckle flowgraphy (LSFG) results were examined. RESULTS: Both cases could be treated within 12 h after the onset of CRAO. Case 1 was a 47-year-old woman. Her visual acuity improved from counting fingers before operation to 0.08 logMAR 1 month after the surgery. However, thinning of the retina at the macula was observed by OCT. Case 2 was a 70-year-old man. His visual acuity improved from counting fingers to 0.1 logMAR 2 months after the surgery. Both fluorescein angiography and LSFG showed improvement in retinal circulation after the surgery in case 2. CONCLUSIONS: Retinal endovascular surgery with injection of tPA into the retinal artery was feasible and may be a way to improve visual acuity and retinal circulation when performed in the acute phase of CRAO.
