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Biomedical subjects

Y Tano

Publications and source records attributed to Y Tano.

At least 163 records · Page 9Linked to original sources
PubMed1996

Surgical removal of submacular hemorrhage using tissue plasminogen activator and perfluorocarbon liquid.

PURPOSE: To assess the result of surgical removal of submacular hemorrhage by using tissue plasminogen activator and perfluorocarbon liquid. METHODS: In 22 consecutive patients (22 eyes), subretinal hemorrhage associated with age-related macular degeneration, which involved the fovea and completely obscured the choroidal vascular pattern, was treated by pars plana vitrectomy. The hemorrhages were liquefied with tissue plasminogen activator, squeezed into the vitreous cavity with perfluorocarbon liquid, and then evacuated. RESULTS: Efficacy of the procedure was judged by the best postoperative corrected visual acuity, which was 20/100 or better in 16 eyes (73%). Submacular hemorrhage recurred in four (18%) eyes, epiretinal membrane formed in three (14%) eyes, and retinal detachment occurred in three (14%) eyes. Best-corrected final visual acuity was improved postoperatively in 18 (82%) of the 22 eyes, unchanged in three (14%) eyes, and decreased in one (5%) eye, final visual acuity was 20/200 or better in 15 eyes (68%) and limited in other eyes by subretinal hemorrhage of greater than 30 days' duration or subfoveal neovascularizations. CONCLUSIONS: Use of tissue plasminogen activator and perfluorocarbon liquid in surgical removal of submacular hemorrhage may improve the outcome of surgery by reducing surgically induced retinal damage.

Aged↗
PubMed1996

Progressive outer retinal necrosis after bone marrow transplantation.

PURPOSE: To describe a case of progressive outer retinal necrosis in a human immunodeficiency virus-negative immunosuppressed patient undergoing treatment for graft-versus-host disease after bone marrow transplantation. METHOD: Onset, course, and outcome of the patient's eye disease were analyzed. RESULTS: Findings and course were typical for the recently described progressive outer retinal necrosis syndrome. CONCLUSION: Progressive outer retinal necrosis is not limited to the acquired immunodeficiency syndrome but may occur in patients immunocompromised because of other conditions.

Adolescent↗
PubMed1996

Retinotomy and foveal translocation for surgical management of subfoveal choroidal neovascular membranes.

PURPOSE: To report a surgical procedure for excising subfoveal neovascular membranes and translocating the fovea in an attempt to maintain the function of the sensory retina to preserve central vision, based on the technique of macular relocation. METHODS: Three patients with subfoveal neovascular membranes underwent surgery for the creation of a nearly 180-degree retinal flap, removal of neovascular tissue, and reattachment and rotation the retina with translocation of the fovea over functional pigment epithelium. RESULTS: In one patient with age-related macular degeneration, best-corrected visual acuity improved from 20/200 preoperatively to 20/20 postoperatively. A second patient, also with age-related macular degeneration, experienced a worsening of best-corrected visual acuity from 20/700 to 20/ 2,000. In the third patient, with myopic degeneration, best-corrected visual acuity improved from 20/700 to 20/70. Complications included the development of epimacular proliferation in two eyes and retinal detachment and neovascular glaucoma in one eye. CONCLUSION: The technique of foveal translocation has the potential for restoring central visual function in certain patients with subfoveal neovascular membranes.

Aged↗
PubMed1996

Indocyanine green angiographic findings in Vogt-Koyanagi-Harada disease.

PURPOSE: To report the indocyanine green angiographic findings associated with Vogt-Koyanagi-Harada disease and compare them with fluorescein angiographic findings and monochromatic scanning laser images. METHODS: In a prospective study, indocyanine green angiography, by scanning laser ophthalmoscopy or infrared fundus photography, was performed in ten consecutive patients (20 eyes) with Vogt-Koyanagi-Harada disease during the acute stage before and recovery stage after corticosteroid treatment. Findings were compared with fluorescein angiographic features and monochromatic scanning laser imaging. RESULTS: During the acute stage of the disease, indocyanine green angiography disclosed a dark background in the early phase and multiple, non-uniform hypofluorescent lesions in the midphases. Lesions were more numerous and extensive than areas either of serous retinal detachment on monochromatic scanning laser imaging or of punctate hyperfluorescence on fluorescein angiography. During the recovery stage, the abnormal dark background on indocyanine green angiography at initial examination resolved, with choroidal vessels visible in all cases, but nonuniform hypofluorescent lesions persisted in most eyes. Fluorescein angiography disclosed hypofluorescent patchy areas, and confocal infrared laser imaging showed some bright reflective lesions in three patients with especially severe clinical symptoms. On final examination after an average of 17.7 months, both angiographies still disclosed abnormal findings in these three patients. CONCLUSIONS: Indocyanine green angiographic findings suggest that choroidal inflammation may cause a transient choroidal circulatory disturbance during the acute stage of Vogt-Koyanagi-Harada disease. In more severe cases, this dysfunction may secondarily damage the retinal pigment epithelium.

Acute Disease↗
PubMed1996

Macular coloboma-like lesions and pigment abnormalities as complications of cryotherapy for retinopathy of prematurity in very low birth-weight infants.

PURPOSE: Cryotherapy for retinopathy of prematurity (ROP) is effective in reducing the incidence of blindness in premature infants. However, macular complications associated with successful treatment have not yet been well studied. METHODS: Eighteen very low birth-weight (< 1,251 g) infants (32 eyes) who received cryotherapy for ROP were examined serially for regression of disease and for development of macular abnormalities. Patient characteristics and treatment factors were evaluated to identify risk factors associated with the development of macular abnormalities after successful cryotherapy. RESULTS: Eleven of 32 eyes (34.4%) that had undergone cryotherapy developed significant macular abnormalities, including macular coloboma-like change (six eyes), macular hyperpigmentation (two eyes), irregularly mottled macular hyperpigmentation and hypopigmentation (two eyes), and macular hyperpigmentation and hypopigmentation with subretinal proliferation (one eye). Corrected visual acuity in affected eyes ranged from 0.15 to 0.03 (20/133 to 20/666) compared with 1.0 to 0.2 (20/20 to 20/100) in treated eyes without macular abnormality (P = .0002). No difference in gestational age was noted between infants who did or did not develop macular coloboma-like lesions or pigment abnormalities. Eyes with macular abnormality had more posterior disease (P = .037) and received significantly more cryotherapy than did eyes without macular abnormality (P = .0005). CONCLUSIONS: In very low birth-weight infants receiving cryotherapy for ROP, development of macular coloboma-like lesions and macular pigment abnormalities were related to greater severity of ROP and a greater amount of cryotherapy. Macular abnormalities were associated with markedly worse visual outcomes than were treated eyes without macular abnormality.

Birth Weight↗
PubMed1996

A clinical evaluation of stereopsis required to see 3-D images.

Some children with esotropia who have been diagnosed as 'stereoblind' on the basis of conventional stereotests (which principally use static images with small disparity) may nevertheless enjoy stereopsis for three-dimensional (3-D) animations that use dynamic images with large disparity. The purpose of this study was to develop a new stereotest equipped with dynamic random-dot stereogram (DRDS) which has larger disparity with movement and use it with esotropic children to see if they can attain stereopsis for such images. Subjects were 17 esotropic children between 5 and 10 years old (mean age 6.8 years) who had failed to demonstrate stereopsis with the Titmus fly test. Seven children had infantile esotropia and 10 had partially accommodative esotropia. The test images were DRDS that were presented on a fluorescent screen (12 x 9 cm) viewed through a lenticular lens. The dots were displayed in circle and triangle patterns that have counterphase front-rear movement with maximum disparity of 800 s. Patients were placed with eyes at a distance of 60 cm from the screen and were instructed to point out the pattern (circle or triangle) that was produced. The average angle of strabismus was 7.7 delta by alternating prism cover test (5 m). Seven patients passed and 10 failed the DRDS test. There was no significant difference in the mean angle of strabismus or the age of examination between the two groups; however, the age at onset of strabismus was significantly higher in those who passed the DRDS test. These results suggest that the DRDS test is useful in evaluating the potential stereopsis in children with esotropia who do not pass conventional stereotests.

Accommodation, Ocular↗
PubMed1996

Detecting herpesvirus DNA in uveitis using the polymerase chain reaction.

BACKGROUND: Herpesviruses are involved in the pathogenesis of many ocular diseases including keratitis, iridocyclitis, and acute retinal necrosis syndrome. The rapid and accurate diagnosis of herpetic infections has become increasingly important with the rising incidence of immunosuppressive diseases. The purpose of this study was to evaluate the use of the polymerase chain reaction (PCR) to detect herpesvirus DNA in uveitis patients. METHODS: Aqueous samples were aspirated from 11 patients with active uveitis of suspected viral origin. Using PCR, masked samples were assayed for herpes simplex virus (HSV), varicella zoster virus (VZV), and cytomegalovirus (CMV) to assist in supporting the clinical diagnosis of viral aetiology. Masked controls included 10 aqueous humour specimens from normal patients undergoing cataract surgery and specimens from seven patients diagnosed with active non-viral uveitis--Behçet's disease, sarcoidosis, Fuchs' heterochromic iridocyclitis, or Harada's disease. RESULTS: Ten of 11 cases clinically diagnosed as being of possible viral aetiology yielded aqueous PCR positive for a herpesvirus. Eight patients were PCR positive for amplified HSV DNA, of whom two had acute retinal necrosis, one had corneal endotheliitis, and five had recurrent iridocyclitis. VZV DNA was detected in one case of iridocyclitis, and CMV DNA in one case of chorioretinitis. Successful therapy was based on the PCR results. Ten normal aqueous specimens and the seven uveitis samples from cases not suspected of a viral aetiology were PCR negative for HSV, VZV, and CMV. CONCLUSION: These results demonstrate that detecting herpesvirus DNA in the aqueous humour is useful to support a clinical diagnosis of viral uveitis.

Adolescent↗
PubMed1996

Cytokine effects on phagocytosis of rod outer segments by retinal pigment epithelial cells of normal and dystrophic rats.

PURPOSE: Phagocytosis of rod outer segments (ROS) is an important function of retinal pigment epithelial (RPE) cells. Since the details of the process are not fully known, we studied effects of cytokines produced by RPE and photoreceptor cells on phagocytosis of ROS by rat RPE cells. METHODS: RPE cells were isolated and cultivated from two strains of rats: Sprague-Dawley (SD) rats with normal phagocytosis and Royal College of Surgeons (RCS) rats, which have genetic deficiencies in ROS phagocytosis. A double immunofluorescence staining technique was used to study the effects in vitro of several cytokines on phagocytosis of ROS. RESULTS: We found that transforming growth factor beta-1 (TGF-beta 1) had dose-dependent effects on RPE cells of both strains of rat: at a concentration of 10 ng/ml, TGF-beta 1 significantly (p < 0.01) reduced total ROS (to 74% of control in SD rats and to 51% of control in RCS rats), reduced bound ROS (to 56% of control in SD rats and to 48% in RCS rats), and increased the ratio of ingested ROS to total ROS (to 140% in SD rats but not significantly in RCS rats). Treatment of medium with anti-TGF-beta 1 antibody before incubation of RPE cells of SD rats with TGF-beta 1 decreased the magnitude of these effects. The cytokine acidic fibroblast growth factor (aFGF, 10 ng/ml) affected RPE cells of SD rats only, decreasing ROS ingested to 56% of control and the ratio of ingested ROS to total ROS to 64% of control. We also examined effects of basic fibroblast growth factor and insulin-like growth factor. None of the cytokines tested increased ingestion of ROS by RPE cells of RCS rats. CONCLUSIONS: Our results suggest that TGF-beta 1 and aFGF have roles in regulating ROS phagocytosis by normal and dystrophic RPE cells in the rat.

Animals↗
PubMed1996

A new wound healing model of retinal pigment epithelial cells in sheet culture.

PURPOSE: To evaluate some RPE cell functions, such as wound healing, in a preparation more similar to in situ conditions, we developed a method to obtain and culture retinal pigment epithelial (RPE) cells as a sheet. And we assessed the effects of fetal bovine serum (FBS) on the rate of RPE wound healing. METHODS: We prepared RPE sheet cultures by incubating rat eyes in 0.1% proteinase K for 13 min, peeling away the neural retina-RPE complex, and then incubating the tissue for 1 h to promote spontaneous separation of the RPE sheet from the retina. After several days of incubation, the cultured sheets of RPE cells were examined by phase-contrast microscopy, scanning and transmission electron microscopy and immunocytochemistry. We made round defects 1 mm in diameter in cultured RPE sheets and estimated the rate of wound closure in media with different concentrations of FBS (0 to 10%). RESULTS: The RPE cells cultured in sheets retained their in situ features, including microvilli, tight junctions and gap junctions, and the distribution of actin and cytokeratin filaments. A wound was noted to close with restoration of a polygonal configuration. The rate of wound closure depended on serum concentration in the culture medium; when supplemented with 10% fetal bovine serum, wound closure was complete in approximately 40 h. CONCLUSIONS: The RPE sheet-culture technique we developed thus provides a suitable model for studying such RPE cell functions as wound healing or phagocytosis.

Animals↗
PubMed1996

[Chronic necrotizing pulmonary aspergillosis complicated by pneumothorax].

A 66-year-old man was admitted to the hospital due to a rapidly progressing interstitial shadow in both lower fields on a chest roentgenogram taken on November 30 1993. The diagnosis was idiopathic interstitial pneumonia. A corticosteroid and a neutrophil elastase inhibitor were administered and the interstitial shadow resolved. A new infiltration shadow appeared in the right upper lung field one and a half months after the start of steroid therapy. This shadow gradually grew and Aspergillus fumigatus was detected in sputum cultures. In spite of treatment with FCZ+5-FC and 5-FC+AMPH, the abnormal shadow increased in size and mixed with the cavity, and the patient died of respiratory failure, with a pneumothorax caused by ruptures of the cavity formed by CNPA. The clinical and radiological course were considered to the indicative of chronic necrotizing pulmonary aspergillosis, which was described by Binder et al. in 1982.

Aged↗
PubMed1996

[Pneumonia and mortality in patients requiring prolonged mechanical ventilation].

We examined patients who required prolonged (>60 days) mechanical ventilation. A total of 31 patients were studied, 23 with pulmonary disease, 4 with neurologic disease and 4 with other conditions. Many of these patients were elderly. The survival rates one year and two years after the start of mechanical ventilation were 40% and 33%, respectively. Respiratory tract infection was the most common and most serious complication, and ventilator-associated pneumonia was the main cause of death. It is difficult but quite important to prevent these complications, especially ventilator-associated pneumonia.

Adult↗
PubMed1996

[Visual functional changes in idiopathic macular holes treated by vitrectomy].

We evaluated visual functional measurements, visual acuity, central retinal sensitivity in a Humphrey field analyzer, and binocular function in Stereotest, Amsler grid testing, of 51 idiopathic macular holes before and after vitrectomy. In 36 of 51 eyes (71%) where the macular hole was closed after vitrectomy, there were improvements in all visual functional measurements postoperatively. The eyes in which the macular hole was closed had significantly better visual acuity before vitrectomy than those in which the hole was not closed. In 16 of 51 eyes that had visual acuity of less than 20/200 preoperatively, central retinal sensitivity before vitrectomy was higher in the eyes where the macular hole was closed than in those in which it was not closed. These measurements are useful for evaluation of visual functional improvements after vitrectomy and can help to choose candidates for macular hole surgery.

Adult↗
PubMed1996

A technique for contact lens fixation during vitreous surgery.

The authors describe a technique for contact lens fixation during vitreous surgery. A contact lens support ring was designed that requires only a single suture for fixation and provides improved stability and centering of a sutured fundus contact lens. These features save time and allow concentration on the surgical goals rather than on the contact lens.

Contact Lenses↗
PubMed1995

Membrane delaminating wedge.

Iatrogenic retinal tears may complicate procedures to treat proliferative vitreoretinal diseases. To decrease the risk of this complication, we developed a new instrument, the membrane delamination wedge, that allows the surgeon to separate the proliferative membranes from the retina effectively and safely.

Diabetic Retinopathy↗
PubMed1995

Double-mirror peripheral vitrectomy lens.

Many surgeons use prism lenses to see the periphery of the fundus during vitrectomy; however, chromatic aberrations in higher-power prismatic lenses cause blurring of the peripheral image. For better visualization of the periphery of the fundus, we developed a new contact lens, the double-mirror peripheral vitrectomy lens. The new lens is a quartz cylinder with two mirrors, and it provides a crisp, clear, upright image of much more of the peripheral fundus than is visible through conventional prism lenses. The new lens also provides a wider area of view than conventional prism lenses.

Eye Diseases↗