Biomedical subjects

F Shiraga

Publications and source records attributed to F Shiraga.

At least 19 recordsLinked to original sources

PubMed2001

Prism adaptation response is useful for predicting surgical outcome in selected types of intermittent exotropia.

PURPOSE: To evaluate the prevalence of prism adaptation response in Japanese patients with intermittent exotropia (X [T]) using the prism adaptation test and to assess whether patients with selected types of X [T] benefit from surgical outcome to which prism adaptation response may contribute. METHODS: In a prospective study, 128 consecutive patients with X [T] between 1990 and 1995 were enrolled. The prism adaptation test was conducted by neutralizing the angle of deviation for 2 to 3 hours. Patients who showed an increase in exodeviation by 10triangle up or more with the prism adaptation test were defined as having a prism adaptation response. For classification of the pattern of X [T], we chose a value of 15triangle up as the difference between the distance and near measurements. RESULTS: The percentage of patients in whom the prism adaptation response was observed at near fixation was significantly larger than those at distance fixation [35 (27%) patients versus 10 (8%) patients, P <.05]. Of 35 patients shown to have a prism adaptation response at near fixation, 21 patients (83%) had the basic type of exotropia. Fourteen patients (17%) with the basic type were changed to convergence insufficiency type because of an increase in near deviation and were defined as pseudo basic type. Patients with pseudo basic type had a significantly better surgical outcome compared with that of true basic type, whereas in the convergence insufficiency type, no definite tendency was found between the two subtypes, true and pseudo types. CONCLUSION: Patients with the pseudo basic type of X [T] in whom a prism adaptation response was demonstrated had a more favorable surgical outcome.

Adaptation, Ocular↗

PubMed2001

Correction of cyclovertical strabismus induced by limited macular translocation in a case of age-related macular degeneration.

PURPOSE: To report a case of strabismus surgery performed to treat cyclovertical strabismus induced by limited macular translocation. METHODS: Case report. RESULTS: A 62-year-old man suffering with age-related macular degeneration and subfoveal choroidal neovascularization, RE, underwent limited macular translocation surgery. The fovea was rotated downward, and his visual acuity improved from 20/100 to 20/25 postoperatively. Cyclovertical diplopia persisted for 6 months after the operation. A Hess screen test revealed a pattern that simulated an underaction of the superior oblique muscle and inferior rectus muscle with an overaction of the ipsilateral inferior oblique muscle. To treat the diplopia, advancement of the superior oblique muscle tendon and resection of the ipsilateral inferior rectus muscle were performed. Binocular single vision with 140 seconds of arc for stereopsis was obtained. CONCLUSION: Cyclovertical strabismus after limited macular translocation is corrective with conventional surgery on the treated eye.

Choroidal Neovascularization↗

PubMed2001

Planned two-step vitrectomy for extremely large and thick subretinal hematoma.

PURPOSE: To describe a new surgical strategy, planned two-step vitrectomy, for a large and thick subretinal hematoma involving 3 or more quadrants of the fundus. SURGICAL METHODS: In a first-step vitrectomy, a retinotomy was made in the posterior pole, after any vitreous hemorrhage had been removed. Following fluid-gas exchange with no laser photocoagulation around the retinotomy, patients took a face-down position for a few days to a week to facilitate subretinal hemorrhage movement to the vitreous cavity and anterior chamber. In a second-step surgery, the hemorrhage in the vitreous cavity and anterior chamber was washed out. The remaining subretinal hemorrhage was aspirated, and the retina was reattached with fluid-gas exchange and laser photocoagulation around the retinotomy. RESULTS: The planned two-step vitrectomy was performed in 4 consecutive patients with large and thick subretinal hematomas involving 3 or more quadrants seen during a 3-year period. By a face-down position after the first-step vitrectomy, subretinal hemorrhage moved to the vitreous cavity and anterior chamber. The remaining subretinal hemorrhage in a smaller quantity could be easily removed, leading to retinal reattachment in the second-step surgery. CONCLUSIONS: The planned two-step vitrectomy is a safer and more effective procedure for removing a large quantity of subretinal hemorrhage in a shorter period of surgical time, compared with hemorrhage removal in a single vitrectomy.

Aged↗

PubMed2001

Endogenous amoebic endophthalmitis.

A 42-year-old man experienced abrupt reduction of vision in the left eye and had vitreous opacity and hypopyon on initial examination. He underwent an emergency vitrectomy and phacoemulsification with posterior capsulectomy, followed by a 2-week course of intravenous fluconazole and antibiotics. The final visual acuity was 20/20 OS. Amoebas, together with polymorphonuclear cells, were observed on examination of specimens of the aqueous humor and vitreous fluid obtained during the surgery. Staphylococcus epidermidis was also cultured from the vitreous fluid. The amoebas had a crescent-shaped periphery of the cytoplasm and ambiguous nuclei. Ultrastructurally, the cytoplasm was surrounded by a thick electron-dense coating. The early vitrectomy and combined use of antibiotics and antifungals might have led to the good visual outcome in this patient.

Adult↗

PubMed2000

Large Bielschowsky head-tilt phenomenon and inconspicuous vertical deviation in the diagnostic positions in congenital superior oblique palsy.

PURPOSE: To report a case of congenital superior oblique palsy with an unusually large Bielschowsky head-tilt phenomenon (BHP) and disproportional inconspicuous vertical deviation. METHODS: Case report. RESULTS: An 18-year-old woman presented with slight compensatory head tilting and a Bielschowsky head-tilt phenomenon of 50 Delta on left tilting. Magnetic resonance imaging revealed atrophy of the left superior oblique muscle. A Hess screen test showed a slight underaction of the left superior oblique muscle, but neither an obvious overaction of the ipsilateral inferior oblique muscle nor inhibitory palsy of the contralateral superior rectus muscle was found. With a 3-mm recession of the ipsilateral superior rectus muscle, Bielschowsky head-tilt phenomenon decreased to 25 Delta. CONCLUSION: A large Bielschowsky head-tilt phenomenon was possibly caused by an increased gain of the otolith-ocular reflex affecting the vertical rectus muscle.

Adolescent↗

PubMed2000

Identification of ingrowth site of idiopathic subfoveal choroidal neovascularization by indocyanine green angiography.

PURPOSE: This study aimed to determine whether indocyanine green (ICG) angiography is useful to identify the ingrowth site of idiopathic choroidal neovascularization (CNV), which can predict visual outcomes after surgical removal of idiopathic CNV. DESIGN: Consecutive, observational case series. PARTICIPANTS: Twenty-six patients with idiopathic subfoveal CNV, of whom six underwent submacular surgery. INTERVENTION: Indocyanine green videoangiography with a scanning laser ophthalmoscope. MAIN OUTCOME MEASURES: We studied ICG videoangiographic images of choroidal neovascular membranes from the early phase to the late phase with special attention to abnormal findings, which can indicate the ingrowth site of CNV. RESULTS: Early ICG angiography demonstrated distinct neovascular vessels in 24 of the 26 patients (92%). Hypofluorescent rims continuously or intermittently surrounded neovascular membranes on late ICG angiograms in 21 of the 26 patients (81%). In 22 of the 26 patients (85%), ICG angiography demonstrated hypofluorescent areas within the CNV. These hypofluorescent areas frequently became ring shaped in the middle to late phase of the ICG angiography. In 14 of 16 patients (88%) with CNV larger than half a disc area, the filling of neovascular vessels appeared from the inside of the hypofluorescent areas and branched out toward the surrounding hyperfluorescent membrane in the early phase. In all six patients who underwent surgical removal of CNV, ICG videoangiography showed these hypofluorescent areas from which neovascular vessels emanated. Three of the four surgical patients, in whom hypofluorescent areas or central fluorescent areas surrounded by ring-shaped hypofluorescence were extrafoveal or juxtafoveal, had a best postoperative visual acuity of 20/60 or better. In contrast, both surgical patients with subfoveal hypofluorescent areas had a best postoperative visual acuity of 20/70 or worse. CONCLUSIONS: Although further observations are needed, ICG angiography may be a useful adjunct in the identification of the ingrowth site of idiopathic CNV, which can predict visual outcomes after surgery.

Adult↗

PubMed2000

Choroidopathy in patients with sarcoidosis observed by simultaneous indocyanine green and fluorescein angiography.

PURPOSE: To examine choroidopathy in patients with sarcoidosis. METHODS: In a prospective clinical study, 10 consecutive patients (20 eyes) with sarcoidosis underwent simultaneous indocyanine green (ICG) and fluorescein angiography (FA) with a double detector of scanning laser ophthalmoscopy. Angiographic findings recorded on videotapes were evaluated, and the relation of ICG angiographic findings with systemic activity and the extent of retinal inflammation was analyzed. RESULTS: Indocyanine green angiographic findings, not evident with fluorescein, were multiple lobular hypofluorescent spots in the posterior pole in 10 eyes of 5 patients, isolated hypofluorescent plaques in 2 eyes of 1 patient, hyperfluorescent spots in 3 eyes of 2 patients, and segmental choroidal vascular wall staining in 6 eyes of 4 patients. The multiple lobular hypofluorescent spots with ICG were observed at a significantly higher rate in eyes with extensive retinal vascular leakage of fluorescein than in eyes with minimal leakage (chi-square test, P = 0.0007). CONCLUSIONS: The patients with sarcoidosis showed choroidal abnormalities that could be revealed by ICG angiography, but not by funduscopy or FA. Simultaneous ICG and FA angiography may be useful for examining choroidal lesions in sarcoidosis.

Adult↗

PubMed2000

Evaluation of leukocyte dynamics in choroidal circulation with indocyanine green-stained leukocytes.

PURPOSE: To develop a new method with which to visualize leukocytes moving through the choroidal vessels of pigmented animals and enable the evaluation of leukocyte dynamics in the choroidal microcirculation. METHODS: Pigmented rabbits and monkeys were used in this study. Leukocytes, collected by centrifugal separation of autologous blood, were stained with indocyanine green (ICG) dye. The ICG-stained leukocyte fluid was injected into the vein, and the fundus image was obtained with a scanning laser ophthalmoscope. The image was recorded on videotapes and analyzed with a personal computer-based image analysis system. RESULTS: In pigmented rabbits, fluorescent leukocytes moving in the choroidal circulation were clearly visible for more than 1 hour. In monkeys, distinct fluorescent dots were seen moving approximately 50 to 200 microm in the foveal avascular zone for more than 30 minutes after the injection of the ICG-stained leukocyte fluid. Dim fluorescent dots were seen moving in the fundus. Although the movement of these dim dots was difficult to trace, they seemed to be moving in the choroidal vessels. In the rabbits, the mean flow velocity of leukocytes moving without plugging was 0.48 +/- 0.14 mm/sec in the peripheral choriocapillaris. In the monkeys, the mean flow velocity of distinct fluorescent leukocytes without plugging was 2.45 +/- 0. 48 mm/sec in the posterior choroid. CONCLUSIONS: In pigmented rabbits and monkeys, this method allows visualization of leukocytes passing through the choroidal vessels and provides a new way to investigate, noninvasively and in vivo, leukocyte dynamics in the choroidal microcirculation.

Animals↗

PubMed1999

Surgical treatment of submacular hemorrhage associated with idiopathic polypoidal choroidal vasculopathy.

PURPOSE: To report the visual outcome of surgical treatment of submacular hemorrhage associated with idiopathic polypoidal choroidal vasculopathy. METHODS: Eight eyes of eight consecutive patients with thick submacular hemorrhages associated with idiopathic polypoidal choroidal vasculopathy were treated with pars plana vitrectomy and tissue plasminogen activator-assisted removal of subretinal blood (December 1995 to September 1997) or intravitreal 100% sulfur hexafluoride gas injection without tissue plasminogen activator (October 1997 to March 1998). RESULTS: Postoperatively, laser treatment was performed for active polypoidal lesions outside the foveal avascular zone in four eyes. A retinal pigment epithelial tear was seen outside the foveal avascular zone in three eyes, and one eye developed a retinal detachment. The best-corrected visual acuity improved (by 3 or more lines) or stabilized in seven of the eight eyes. Four eyes had a final best-corrected visual acuity of 20/40 or better, and three eyes had a final best-corrected visual acuity of 20/50 to 20/200. In one eye, the visual acuity decreased from 20/100 to 20/500 because of the development of a subfoveal neovascular membrane. The membrane was excised, and histologic examination showed fibrovascular tissue between the retina and retinal pigment epithelium (type 2 pattern). CONCLUSIONS: Surgical intervention may be of benefit in eyes with submacular hemorrhage associated with idiopathic polypoidal choroidal vasculopathy.

Aged↗

PubMed1999

Choroidal abnormalities in Behçet disease observed by simultaneous indocyanine green and fluorescein angiography with scanning laser ophthalmoscopy.

OBJECTIVE: To examine choroidopathy in patients with Behçet disease. DESIGN: Prospective clinical study. PARTICIPANTS: Thirty-three patients (63 eyes) with Behçet disease. INTERVENTION: Patients underwent simultaneous indocyanine green (ICG) and fluorescein angiography with a double detector of scanning laser ophthalmoscopy. MAIN OUTCOME MEASURES: Angiographic findings recorded on videotapes were evaluated. The relation of angiographic findings with systemic activity and aqueous inflammation was also analyzed. RESULTS: Fluorescein angiography showed leakage in varying degrees from retinal vessels in 30 patients (53 eyes, 84%). The ICG angiographic findings were choroidal vascular wall staining in 16 eyes (25%), hyperfluorescent spots in 42 eyes (66%) and hypofluorescent plaques in 22 eyes (35%), both of which were not evident with fluorescein, leakage from choroidal vessels in 3 eyes (5%), and irregular filling of choriocapillaris in 11 eyes (17%). These findings did not have a statistically significant correlation with the presence or absence of aqueous inflammation or oral aphthous ulcerations. CONCLUSIONS: The patients with Behçet disease showed choroidal abnormalities, which could be revealed only by ICG angiography, but not with funduscopy or fluorescein angiography. Simultaneous ICG and fluorescein angiography would be useful for examining choroidal lesions in Behçet disease.

Adult↗

PubMed1999

Prognostic factors for successful surgical outcome with preoperative prism adaptation test in patients with superior oblique palsy.

PURPOSE: This study evaluated the surgical outcome of patients managed with preoperative prism adaptation test (PAT) and investigated prognostic factors for successful motor alignment in adult patients with superior oblique palsy. METHODS: Prospective study of preoperative PAT was performed. Fifty-seven patients with superior oblique palsy, aged 16 to 81 years, participated in this study. Patients were assigned to surgery with the target angle based on either the original angle or the prism compensated angle. When the amount of neutralizing prism exceeded 4delta or more compared to the original angle of deviation, the patient was defined as having prism compensation, and the target angle for surgery was based on the amount of neutralizing prism. The motor success rate was compared between the 2 groups at the 3-month postoperative follow-up. RESULTS: The prism responders group showed a superior outcome compared to that of the prism non-responders group (77% successful outcome compared with 46%, p = 0.0397). The presence of prism compensation and the amount of vertical deviation were significant prognostic factors for successful motor alignment. CONCLUSION: Preoperative PAT is a useful prognostic indicator of successful surgical outcome in patients with superior oblique palsy.

Adaptation, Ocular↗

PubMed1998

Feeder vessel photocoagulation of subfoveal choroidal neovascularization secondary to age-related macular degeneration.

PURPOSE: This study aimed to assess the feasibility of laser photocoagulation of feeder vessels of subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration. PATIENTS AND METHODS: Of 170 consecutive patients with subfoveal CNV secondary to age-related macular degeneration, feeder vessels were detected in 37 patients by means of indocyanine green videoangiography using a scanning laser ophthalmoscope. Dye laser photocoagulation was applied to extrafoveal feeder vessels, with the fovea spared. RESULTS: Twenty-six (70%) of those 37 patients had complete resolution of exudative manifestations. Persistent or worsened manifestations were seen in 11 patients (30%) because of recurrent CNV or persistent CNV. The visual acuity improved or stabilized in 25 patients (68%). Ten patients (27%) had a final visual acuity of 20/40 or better and six patients (16%) had a final visual acuity of 20/50 to 20/100. Significant factors prognostic of the visual outcome of 20/100 or better were small CNV (2 disc areas or smaller, Fisher's exact probability test, P = 0.041), the absence of white, fibrous tissue in neovascular membranes (Fisher's exact probability test, P = 0.003), and the closest distance of laser burns to the center of the foveal avascular zone (Fisher's exact probability test, P = 0.049). Preoperative visual acuity had a significant positive correlation with final visual acuity (Spearman's rank correlation test, P = 0.0076). CONCLUSION: Feeder vessel photocoagulation should be considered as a treatment option for subfoveal CNV secondary to age-related macular degeneration, because no other treatment method has a better visual outcome.

Aged↗

PubMed1998

Schwartz-Matsuo syndrome in retinal detachment with tears of the nonpigmented epithelium of the ciliary body.

PURPOSE: To elucidate clinical features of Schwartz-Matsuo syndrome (photoreceptor outer segment glaucoma) occurring in retinal detachment with tears of the nonpigmented epithelium of the pars plana or plicata of the ciliary body. METHODS: We reviewed retrospectively medical records of 17 consecutive patients (18 eyes) with retinal detachment caused by tears of the nonpigmented epithelium of pars plana (10 eyes) and pars plicata (8 eyes) of the ciliary body. RESULTS: Aqueous cells, ranging from 1+ to 3+, were found in 15 eyes, in contrast with no cells in the other 3 eyes. Eleven of the 15 eyes with aqueous cells showed circadian fluctuation of the intraocular pressure with a range, 4 mmHg or wider compared with the range in the fellow eye, but only 4 of these 11 eyes had a maximum pressure of 21 mmHg or higher. Photoreceptor outer segments were detected in the aqueous humor of 8 eyes out of 14 eyes with aqueous cells in which aqueous tap was done. The remaining 6 eyes had too small a number of aqueous cells for electron microscopy. CONCLUSION: Marked fluctuation of the intraocular pressure compared with the fellow eye, which was not necessarily associated with its rise, was found in retinal detachment with tears of the nonpigmented epithelium of the ciliary body, and should be included as one of key features for diagnosis of Schwartz-Matsuo syndrome.

Adolescent↗

PubMed1998

Two types of initial ocular manifestations in intraocular-central nervous system lymphoma.

PURPOSE: To study initial ocular manifestations of ocular-central nervous system (CNS) lymphoma. METHODS: The authors reviewed medical records of 10 consecutive patients with intraocular-CNS lymphoma seen at Okayama University Hospital during 16 years from 1981 to 1996. RESULTS: Three patients showed only vitreous opacity as an initial sign, whereas five other patients had typical yellowish-white infiltrates at the sub-retinal pigment epithelial (sub-RPE) level without vitreous opacity. Both manifestations were found in two patients. In seven patients, ocular symptoms developed first, followed by brain lesions. In contrast, in three patients the initial presentation was brain tumor, for which they received chemotherapy; subsequently, vitreous opacity without sub-RPE infiltrates developed. The diagnosis was made by vitrectomy in four patients, three of whom had also undergone brain biopsy; by aqueous tap in one; and by brain biopsy in one. The other four patients were diagnosed clinically, and one of them was confirmed later to have lymphoma by autopsy. CONCLUSIONS: The initial ocular manifestations of intraocular-CNS lymphoma were of two types, sub-RPE infiltrates and vitreous opacity. Keeping these two manifestations in mind will help physicians consider a diagnosis of intraocular-CNS lymphoma earlier.

Adult↗

PubMed1998

Transplanted and repopulated retinal pigment epithelial cells on damaged Bruch's membrane in rabbits.

AIMS: The authors studied how artificially damaged Bruch's membrane influenced growth and differentiation of transplanted embryonic retinal pigment epithelial (RPE) cells and of host RPE cells in rabbits. METHODS: Embryonic RPE cells obtained from pigmented rabbits were transplanted into the subretinal space of adult albino rabbits. The host RPE was removed with a silicone cannula, and Bruch's membrane was damaged by scratching with a microhooked 27 gauge needle under the detached retina in closed vitrectomy. The transplantation sites were examined 3, 7, and 14 days after surgery by light and electron microscopy. RESULTS: Varying degrees of damage in Bruch's membrane were observed. Pigmented and hypopigmented RPE cells showed a normal polarity and tight junctions were seen at the sites of mild to moderate damage 3-7 days after the surgery. In contrast, fibroblast-like cells with no such features of RPE cells formed multiple layers at the sites of severe damage involving the full thickness of Bruch's membrane and the choriocapillaris even 14 days after the surgery. Without transplantation, host RPE cells repopulated the damaged areas in the same way as transplanted RPE cells. CONCLUSIONS: Transplanted embryonic RPE cells as well as host RPE cells grew and differentiated on the moderately damaged Bruch's membrane, while the severely damaged Bruch's membrane did not allow differentiation of RPE cells although these cells could grow and cover the damaged areas.

Animals↗

PubMed1998

Treatment options In subfoveal choroidal neovascularization secondary to age-related macular degeneration.

Laser photocoagulation of the entire area of the neovascular lesion is the only proven treatment for subfoveal choroidal neovascularization secondary to age-related macular degeneration with a poor natural history. However, there are some limiting factors such as patient eligibility, a significant decline in visual acuity after treatment, and a very low possibility of a final vision of 20/100 or better. Although no large benefit of other treatment modalities, such as indocyanine green videoangiography-guided laser photocoagulation, surgical removal of neovascular membranes, and radiation therapy, has yet been proven, carefully selected patients may be suitable candidates for such treatments. This article reviews the status of treatment modalities for subfoveal choroidal neovascularization secondary to age-related macular degeneration, including laser photocoagulation of the entire area of the neovascular lesion, and discusses factors prognostic of visual outcome in these treatment options.

Choroid↗

PubMed1995

Intraoperative observation of the vitreous base in patients with atopic dermatitis and retinal detachment.

PURPOSE: Patients with atopic dermatitis often develop tears around the vitreous base. An attempt was made to determine whether these patients had any abnormalities of the vitreous base that would lead to formation of such tears. METHODS: The medical records and intraoperative videotape recordings of 12 patients with atopic dermatitis and retinal detachment who underwent vitrectomy were reviewed. RESULTS: Tears were located at the ora serrata or in the nonpigmented epithelium of the pars plana or plicata of the ciliary body. The vitreous gel at its base was condensed like fluffy cotton in all of the patients, whereas the retina and the continuing nonpigmented epithelium around the ora serrata were wrinkled by contraction of the overlying abnormal gel. CONCLUSION: Frequent occurrence of oral dialyses and tears of the nonpigmented epithelium of the ciliary body in patients with atopic dermatitis could be attributed to the abnormal vitreous gel at its base.

Adolescent↗

PubMed1994

Expression patterns of two fibroblast growth factor receptor genes during early chick eye development.

The expression patterns of two distinct types of fibroblast growth factor receptor (FGFR) genes, FGFR1 and FGFR2, were compared during early chick eye development. In situ hybridization was performed with riboprobes synthesized from cDNA fragments of FGFRs cloned by the polymerase chain reaction method. FGFR1 was expressed in the prospective lens, neural retina, pigment epithelium and mandibular mesenchyme. In contrast, FGFR2 was expressed predominantly in the periocular mesenchyme of a 2.5 day-old embryo. In the 5.5-day-old embryo, transcripts of FGFR2 were detected in the prospective corneal epithelium. The results suggest that expression patterns of FGFR1 and FGFR2 are complementary and ligands of each FGFR might be involved differentially in early chick eye development. It is concluded that the action of FGFs on pigment epithelium and lens cells reported so far, probably occurs through FGFR1, and both types of FGFR are involved in head mesenchymal development.

Animals↗