Biomedical subjects

I Fukushima

Publications and source records attributed to I Fukushima.

At least 19 recordsLinked to original sources

PubMed1999

Idiopathic polypoidal choroidal vasculopathy in Japanese patients.

OBJECTIVE: To describe the vascular nature and clinical features of idiopathic polypoidal choroidal vasculopathy in Japanese patients. METHODS: Patients thought to have idiopathic polypoidal choroidal vasculopathy were examined with binocular ophthalmoscopy, slitlamp biomicroscopy with a contact lens, fluorescein angiography, and indocyanine green angiography. RESULTS: From January 1993 to December 1997, 35 eyes in 32 patients were diagnosed as having idiopathic polypoidal choroidal vasculopathy. Men were predominantly affected (22 patients [69%]). Most patients were unilaterally involved (29 patients [91%]) and elderly, with a mean age of 65.7 years (range, 44-82 years). Ocular manifestations were relatively mild, with serous or hemorrhagic detachments of the retinal pigment epithelium and neurosensory retina in the posterior pole. Most patients had a favorable course, although some experienced recurrence, and a few eyes developed disciform scarring. In all patients, indocyanine green angiograms demonstrated branching vascular networks with polypoidal dilations at terminals of the network beneath the retinal pigment epithelium. These lesions were mostly in the macula (33 eyes [94%]), with a few in the peripapillary area. CONCLUSIONS: Idiopathic polypoidal choroidal vasculopathy in Japanese patients differs from that in American patients. It seems that this disorder occurs in elderly Japanese patients and should be treated as a distinct clinical entity. It is probably a peculiar form of choroidal neovascularization beneath the retinal pigment epithelium. We propose the term "polypoidal choroidal neovascularization" for this disorder.

Adult↗

PubMed1999

Surgically induced degeneration and regeneration of the choriocapillaris in rabbit.

BACKGROUND: Retinal pigment epithelium (RPE) and choriocapillaris play an important role in maintaining the outer retina. Clinical and experimental studies have shown that there is a close relationship between them. To examine the relationship between RPE and choriocapillaris we developed an animal model in which degeneration and regeneration of the choriocapillaris can be created easily and reproducibly. METHODS: Using pigmented rabbits a retinal detachment (about 7 disk diameters) was created in the eye and the detached retina was surgically removed. A half area of the exposed RPE was mechanically debrided using a silicone brush. The other half area remained untouched. The eyes were morphologically examined at 3, 7, and 14 days and 4 and 8 weeks after the surgery using scanning or transmission electron microscopy. Changes in the choriocapillaris after the RPE debridement were also evaluated by corrosion vascular casts. RESULTS: The debrided area was resurfaced with elongated RPE in 7 days after surgery. The replaced RPE was dedifferentiated but it gradually recovered cell polarity by 4 weeks after surgery. The choriocapillaris beneath the debrided area underwent degeneration; however, it regenerated by 4 weeks after surgery, corresponding to the timing of the morphologic recovery of the replaced RPE. CONCLUSION: This animal model of surgically induced degeneration and regeneration of the choriocapillaris may be useful to clarify the relationship between RPE and choriocapillaris and to study potential treatments for choroidal vascular diseases.

Animals↗

PubMed1999

Indocyanine green angiography and pathophysiology of multifocal posterior pigment epitheliopathy.

PURPOSE: To clarify the pathophysiology of multifocal posterior pigment epitheliopathy (MPPE), or bullous retinal detachment (RD)-an unusual manifestation of central serous chorioretinopathy (CSC)-we evaluated indocyanine green (ICG) angiographic findings of patients with MPPE. METHODS: Indocyanine green angiography was performed on 45 eyes of 26 patients with MPPE in our clinic during a 4-year period and compared with clinical and fluorescein angiographic (FA) findings. RESULTS: Ophthalmoscopically, in the posterior pole there were multiple yellowish-white retinal exudations, associated with flat, serous RD and bullous RD in the lower periphery. Fluorescein angiography demonstrated multiple massive leakages from the choroid into the subretinal space. These leakage sites corresponded to the retinal exudations. Indocyanine green angiography showed hyperfluorescence in the posterior pole of the choroid. The hyperfluorescence was first seen in the middle phase and became prominent in the late phase. This finding seems to be due to extravasation from the choriocapillaris. After laser photocoagulation of the leakage sites seen on FA, the leakages stopped and the retinal exudations and RD were resolved. Indocyanine green angiography, however, revealed hyperfluorescence in the posterior pole that was seen in active stage. DISCUSSION AND CONCLUSION: These ICG angiographic findings for MPPE show that hyperpermeability of the choroidal vessels may be the primary causative lesion. This is followed by an intrastromal accumulation of the extravasated choroidal fluid, which may be subclinical. Involvement of the retinal pigment epithelium may be secondary, and then the disease becomes manifest with RD. In MPPE, a severe form of CSC, the retinal pigment epithelium is involved extensively and widely, and prognosis is unfavorable. We conclude that MPPE and CSC represent opposite ends of a common morbid spectrum.

Adult↗

PubMed1999

[Histological proof of indocyanine green angiography--healthy eyes].

PURPOSE: To determine the histological localization of indocyanine green (ICG) in the healthy rat eye and to correlate this with ICG angiographic findings. METHODS: After intravenous ICG dye injection, the rat eyes were enucleated and processed by freeze-substitution fixation with acetone. The tissue sections were stimulated with an 805-nm diode laser and observed with an infrared microscope with an intensified charge coupled device camera. The histological examinations of ICG localization were correlated with the ICG angiographic images. RESULTS: ICG dye did not leak from the retinal and iris vessels. However, in the choroid, extravasation of ICG from the choriocapillaris was observed. The extravascular ICG from the choriocapillaris slowly diffused to the choroidal stroma but did not diffuse to the neurosensory retina through the retinal pigment epithelium. CONCLUSIONS: Change in the localization of ICG in ocular tissue was demonstrated in the ICG angiographic findings. These results help to interpret clinical ICG angiographic findings.

Animals↗

PubMed1997

Intrachoroidal microvascular abnormality: a previously unrecognized form of choroidal neovascularization.

PURPOSE: To evaluate the histopathologic and histochemical characteristics of intrachoroidal microvascular abnormality. METHODS: Forty eyes obtained at autopsy from human donors ranging in age from 20 to 91 years (25 diabetics, 15 nondiabetics) were analyzed. Choroids were processed for alkaline phosphatase flat-embedding. Vascular patterns were examined and analyzed before embedding and serial sectioning. RESULTS: Intrachoroidal microvascular abnormality had the most prominent alkaline phosphatase reaction product of choroidal vessels. These formations appeared as ameboid or cobweb-like vascular networks (area, 0.05 to 4.6 mm2) in the choroidal stroma external to the choriocapillaris. They appeared as both single or groups of formations in the posterior pole and equatorial regions in all subjects. Intrachoroidal microvascular abnormality was found in five subjects with diabetes: four with type I diabetes mellitus, and one with type II diabetes mellitus. One subject had proliferative diabetic retinopathy, three had background retinopathy, and one had no retinopathy. Intrachoroidal microvascular abnormality was connected with all levels of choroidal vasculature. Microaneurysms were observed within intrachoroidal microvascular abnormality formations in most subjects but not in other choroidal vessels. CONCLUSIONS: Intrachoroidal microvascular abnormality is a form of intrachoroidal neovascularization. This neovascularization has features similar to intraretinal microvascular abnormalities found in diabetic subjects but seems to form independently of the status of retinopathy. The presence of microaneurysms in intrachoroidal microvascular abnormalities and not other choroidal vessels supports the view that aneurysms may be aborted attempts at neovascularization.

Adult↗

PubMed1997

[Indocyanine green infrared fluorescence angiography and histopathological correlation in experimental choroidal circulatory disturbance. Report 1].

We performed an experimental study on choroidal circulatory disturbance to clarify basic problems about interpretation of retino-choroidal lesions in indocyanine green fluorescence angiography (ICG angiography). We severed all of the posterior temporal ciliary arteries, to produce choroidal circulatory disturbance. Fluorescein angiography and ICG angiography were performed using scanning laser ophthalmoscope immediately, and 2 days after occlusion. These findings were compared with histopathological findings from the same specimen. Immediately after occlusion, choroidal vessels were filled with the red blood cells in the lesion that showed hypofluorescence in both types of angiography. Two days after occlusion, the fundus had a grayish white edematous appearance which was similar to choroidal infarction. The retinal pigment epithelial cells. (RPEs) in infarcted lesion progressed to liquefied necrosis. Fluorescein angiography showed hyperfluorescence in the lesion, and ICG angiography showed hypofluorescence in the early phase, but hyperfluorescence at the margin of the lesion in the late phase. This result showed that damaged RPEs were stained by ICG dye. In reading ICG angiography, we have to consider that the ICG angiogram is greatly modified by the condition of the RPEs.

Animals↗

PubMed1997

[Indocyanine green infrared fluorescence angiography and histopathological correlation in experimental choroidal circulatory disturbance. Report 2].

We performed an experimental study on choroidal circulatory disturbance to clarify basic problems about interpretation of retino-choroidal lesions in indocyanine green fluorescence angiography (ICG angiography). We severed the posterior ciliary arteries to produce choroidal circulatory disturbance. Fluorescein angiography and ICG angiography were performed at one week, and one month after occlusion. These findings were compared with histopathological findings. One week after occlusion, the area of choroidal infarct showed occlusion of choriocapillaris and proliferation of the retinal pigment epithelial (RPE) cells, this area showed hypofluorescence in the early phase ICG angiography. The hypofluorescence area increased in the late phase. One month after occlusion, the lesion showed loss of choriocapillaris at the center and proliferation of fibroblast-like cells at the edge of the lesion. The subretinal strand showed hyperfluorescence in late phase ICG angiography. Proliferated RPE cells masked ICG fluorescence in the late phase. Fibroblast-like cells showed tissue staining. When reading ICG angiography, we have to take into account that the ICG angiogram is greatly modified by condition of the RPE.

Animals↗

PubMed1996

[Pulmonary typical carcinoid with metastases to pulmonary hilar, and mediastinal lymph nodes].

A 50-year-old woman was admitted to our hospital complaining of recurrent bloody sputum and hemoptysis. Chest X-ray films showed an infiltrative shadow in the left lower lung field. Chest computed tomograms showed a nodular tumor shadow near the left B8 and this tumor shadow was found between A8 and A9 by pulmonary arteriography. Bronchoscopic examination revealed a red coagulum in the left B8 and cytologic examination of broncho alveolar lavage fluid revealed atypical squamous cells. With a clinical diagnosis of squamous cell carcinoma of the lung, a left lower lobectomy with hilar and mediastinal lymph node dissection was done. A milk-white tumor was found in the lower lobe of the resected lung. The pathological diagnosis of the resected tissue specimen was carcinoid, accompanied by pulmonary, hilar, and mediastinal lymph node metastases. Reduced immunofluorescence by Chromogranin A and serotonin staining were further evidence that the tumor was atypical. This case is very interesting in that the tumor metastasized to the lung and lymph nodes, even-though it was pathologically typical.

Carcinoid Tumor↗

PubMed1996

[Indocyanine green infrared fluorescence angiography and vascular cast--preparation in experimental choroidal circulatory disturbance].

We performed experiments in 20 monkey eyes in order to clarify basic problems about interpretation of indocyanine green fluorescence angiography (ICG angiography). We severed the temporal group of posterior ciliary arteries to produce choroidal circulatory disturbance. ICG angiography was performed immediately, and 2 days, 4 days, and 2 weeks later. Following each ICG angiography, the eye was studied by plastic vascular cast technique with scanning electron microscopy. Immediately after occlusion, ICG angiography showed filling defect in the temporal choroidal hemisphere during the early phase. In the later phase, this area was gradually filled by the dye from choroidal arteries in the nasal hemisphere and the anterior ciliary arteries. Vascular cast preparations showed filling defect in the temporal choroidal hemisphere, corresponding with the early ICG angiogaphic findings. Both filling delay in ICG angiography and filling defect in vascular casts improved daily after occlusion. Two weeks after occlusion, The area of choroidal infarct temporal to the macula turned into chorioretinal atrophy. This area showed hypofluorescence in the early-phase ICG angiography and filling defect of the choriocapillaris in plastic casts. The early-phase ICG angiographic findings thus corresponded well with observations of vascular casts. We conclude that ICG angiography correctly reflects the actual circulatory disturbances in the choroid.

Animals↗

PubMed1996

[Indocyanine green angiography of choroidal neovascularization in age-related macular degeneration].

One hundred forty eyes with choroidal neovascularization (ChNV) in age-related macular degeneration were examined with fluorescein and indocyanine green (ICG) angiography. ChNVs covered with subretinal hemorrhage, and ChNVs with retinal pigment epithelial (RPE) detachment were demonstrated at a higher rate and more clearly with ICG angiography than with fluorescein angiography. On the other hand, ChNVs in serous retinal detachment, and in disciform lesions were demonstrated more clearly with fluorescein angiography than with ICG angiography. These results show that ICG angiography is valuable for delineating "occult ChNVs" with subretinal hemorrhage or RPE detachment in age-related macular degeneration.

Aged↗

PubMed1995

[Choroidal neovascularization with indocyanine green infrared fluorescence angiography and vascular cast preparation].

Indocyanine green infrared fluorescence angiography (ICG angiography) was compared with the fluorescein angiography (FAG) to evaluate its benefit. Experimentally induced choroidal neovascularization (ChNV), by laser photocoagulation of monkey eyes was studied by means of cast preparation correlating with findings of ICG angiography. FAG could detect ChNV more clearly than ICG angiography. However, some (2/35 sites) ChNVs with subretinal hemorrhage could be detected only with ICG angiography. In the early phase, the densely distributed part or thick vessels of ChNV could be detected with ICG angiography. On the other hand, the loose part could not be detected. Cast preparation did not show morphologic difference between leaky and non-leaky lesions with ICG angiography. These results showed that ICG angiography could not produce clearer results than FAG. However, ChNVs covered with subretinal hemorrhage could be detected only with ICG angiography. ICG angiography has complementary value in conjunction with FAG in order to detect ChNVs.

Animals↗

PubMed1995

[Dye leakage from choroidal neovascularization with indocyanine green angiography].

The ultrastructure of experimentally induced choroidal neovascularization was studied in correlation with dye leakage in indocyanine green (ICG) infrared fluorescence angiography. Newly formed vessels which demonstrated leakage of ICG extended into the subretinal space without enclosure of retinal pigment epithelium (RPE), and the endothelial cells were immature. Choroidal neovascularization which did not demonstrate leakage of ICG was enclosed by RPE without retinal detachment, and the endothelial cells were mature. The newly formed vessels with immature endothelium in the subretinal space that were covered with multiple layers of RPE demonstrated no leakage. These results show that ICG leaks form choroidal neovascularization which has immature vessels that are not enclosed by RPE and that extend into the subretinal space.

Animals↗

PubMed1995

[Dark rim around choroidal neovascularization in indocyanine green angiography].

Experimentally produced choroidal neovascularization (ChNV) surrounded by a dark rim in indocyanine green (ICG) angiography was studied histopathologically. Dark rims were seen in 28% of ChNVs which were detected with ICG angiography 2 weeks after photocoagulation. During the developing stage of ChNV, the dark rim around it was seen in the early phase of ICG angiography, but in the late phase, the dark rim became unclear because of extravascular dye leakage. During the regressive stage, the dark rim was seen in all phases of angiography. It was especially clear in the late phase. Histopathologically, at the site of the dark rim the retinal pigment epithelial cells proliferated to surround the ChNV in the subretinal space during both stages. These results show that proliferated retinal pigment epithelium surrounding ChNV blocks the fluorescence of the choroid, and causes the dark rim. The dark rim is helpful for diagnosis of ChNV.

Animals↗

PubMed1994

Survey of complications of indocyanine green angiography in Japan.

PURPOSE: We evaluated the safety of indocyanine green for use in fundus angiography. METHODS: We sent a questionnaire concerning complications of indocyanine green to 32 institutions in Japan, which were selected on the basis of the client list from the Topcon Company, which manufactures the indocyanine green fundus camera. RESULTS: Ophthalmologists at 15 institutions responded, reporting a total of 3,774 indocyanine green angiograms performed on 2,820 patients between June 1984 and September 1992. Before angiography, intradermal or intravenous indocyanine green testing, or both was performed at 13 of 15 institutions. For three patients, the decision was made not to proceed with angiography after positive preangiographic testing. The dosage of indocyanine green used for angiography varied from 25 to 75 mg, depending upon the institution. There were 13 cases of adverse reactions (0.34%), ten of which were mild reactions such as nausea, exanthema, urtication, itchiness, and urgency to defecate, and did not require treatment. Also recorded were one case of pain of the vein, which required treatment, and two cases of hypotension. The two hypotensive patients required treatment for shock. CONCLUSIONS: A comparison of frequency of adverse reactions to indocyanine green with the previously reported frequency of such reactions to fluorescein sodium indicated that indocyanine green is a safe as fluorescein for use in angiography.

Aged↗

PubMed1994

[Indocyanine green fluorescence angiography in Harada disease].

Indocyanine green fluorescence angiography (ICG angiography) can reveal choroidal circulation, and so it is used to observe uveitis. We examined 29 eyes of 15 patients with Harada disease using ICG angiography. In the early phase, filling delay of choroidal circulation was the most remarkable finding in cases with flat retinal detachment in the posterior pole. In the early to late phase choroidal vessels were indistinct, and speckled hypofluorescence on the diffuse background fluorescence was seen. Leakage from the choroid into the subretinal space was seen in ICG angiography at the same leak points seen in fluorescein angiography. In 3 patients, the area of retinal detachment showed hypofluoresence in the late phase. Areas of Dalen-Fuchs spots showed hypofluorescence. ICG angiography clearly revealed severe disturbance of choroidal circulation in Harada disease, and filling delay of the choroidal circulation and indistinct choroidal vessels correlated with the severity of this disease. ICG angiography helps to evaluate the pathology of Harada disease clinically.

Adolescent↗

PubMed1994

[An experimental study of diode laser photocoagulation and indocyanine green dye-enhanced diode laser photocoagulation in the primate retina].

A diode laser, emitting light in the near-infrared range (803 nm), was used for photocoagulation at mild, moderate, and strong intensities with or without intravenous administration of indocyanine green (ICG) in 7 eyes of 4 rhesus monkeys. The retinochoroidal lesions were studied histopathologically from 24 hours to 3 months after treatment, and choroidal vascular casts were studied by electron microscopy. Mild diode laser burns caused occlusion of the choriocapillaris and slight outer retinal damage. Moderate and severe burns caused more marked occlusion of the choriocapillaris, deep choroidal vessels, and choroidal nerves. There was little difference between ICG-enhanced and non-enhanced mild burns, but ICG-enhanced moderate and severe burns showed larger retinochoroidal lesions and more complete obstruction of the choriocapillaris than did burns without ICG enhancement. It seems that at moderate and strong levels, ICG-enhanced diode laser burns have more apparent effect on the retina and choroid, particularly on the choroidal vessels.

Animals↗

PubMed1993

[Fibronectin in the chorioretinal wound after laser photocoagulation].

Fibronectin (Fn) is a glycoprotein which mediates adhesion, extension, migration, and chemotaxis of the cells. We did a histochemical study of the time course of appearance and distribution of Fn in the chorioretinal wound after laser photocoagulation. In the normal chorioretinal tissue, Fn was detected in the internal limiting membrane, Bruch's membrane, and the endothelium of chorioretinal vessels. Shortly after laser photocoagulation, Fn appeared on Bruch's membrane and in the endothelium of choroidal vessels and choroidal stroma, and was prominent by one week after laser photocoagulation. Although Fn disappeared when wound healing was accomplished, it was still detected on Bruch's membrane one month after laser photocoagulation. These findings suggest that Fn is related to chorioretinal wound healing after laser photocoagulation.

Animals↗

PubMed1993

[The effect of corticosteroid on the repair of the retinal pigment epithelium].

The effect of corticosteroid on the repairing process of the retinal pigment epithelial cells (RPE) after laser photocoagulation was investigated. Mild-intensity krypton red laser photocoagulations were performed on the monkey retina. After laser photocoagulations, betamethasone (0.5 mg/kg) were administered intramuscularly every day for 1-14 days. Moreover, the same doses of betamethasone were also administered intramuscularly for one week from the 1st to 7th day after laser photocoagulation on other monkeys. The photocoagulated lesions were observed with light and transmission electron microscopy. In monkeys that received corticosteroids, the migration and the proliferation of RPE were markedly inhibited, and the metaplasia to fibroblast-like cells of RPE was not observed. These results showed that large doses of corticosteroid inhibited the repair process of the injured RPE.

Animals↗