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Y Tano

Publications and source records attributed to Y Tano.

At least 145 records · Page 8Linked to original sources
PubMed1997

Using a reference point and videokeratography for intraoperative identification of astigmatism axis.

PURPOSE: To estimate the misalignment of the astigmatism axis caused by intraoperative identification of the axis without using reference points. SETTINGS: Osaka University Medical School, Suita, Japan. METHODS: This study included 38 eyes of 19 patients with no ocular pathology except refractive error and 32 eyes of 16 patients with cataract. A point was marked on the nasal conjunctiva, on the "intraoperative" horizontal axis as estimated by the examiner using a surgical microscope while the patient lay on the operating table in the supine position. Videokeratography was performed with the patient seated, and the degree of axial misalignment was determined by measuring the angle between the conjunctival mark and the horizontal axis identified on the video image. RESULTS: Mean axial misalignment for all patients was 4.4 degrees +/- 2.8 (SD), which could theoretically cause about a 15% loss of surgical effect. The maximal misalignment was 14 degrees, which would correspond to a 48% loss of astigmatic correction. CONCLUSION: The results of this study suggest that intraoperative identification of the astigmatism axis without using reference points may reduce the surgical effect because of axis misalignment. The use of a reference point and preoperative videokeratography may increase the accuracy of identification of the astigmatism axis.

Adult↗
PubMed1997

The effect of nitric oxide synthase inhibitor on form-deprivation myopia.

PURPOSE: Form-deprivation myopia (FDM) is believed to result principally from actions of substances that modulate information processing in the retina. We used a chick model to investigate what role nitric oxide (NO), a gaseous neuromodulator, might play in the development of FDM. METHODS: We injected different concentrations of the NO synthase inhibitor N omega-nitro-L-arginine methyl ester (L-NAME) (30 ml) into the left eyes and the same volume of saline into the right eyes of 6-day-old chicks. Both eyes of most chicks were occluded for 6 days with translucent goggles. After removal of the goggles, the refraction was measured by retinoscopy and the axial lengths with an A-mode ultrasound. In some chicks we measured the concentration of NOx (nitrite and nitrate) in the retina. A few chicks, not wearing occluders after injection of L-NAME and saline, ERG and refraction, were examined 6 days after the treatment. RESULTS: In chicks that wore occluders, refractive error and axial length were significantly less affected in eyes injected with L-NAME (180, 360, or 540 mM) compared to control (right) eyes. ERG changes were reversible, except in eyes injected with the highest concentration (540 mM) of L-NAME. The eyes of chicks, injected with L-NAME and reared without occlusion, had normal refractive values. After 6 days of form deprivation, the concentration of NOx in the retina of eyes injected with L-NAME (180 mM) was significantly less than the concentration in eyes injected with saline. CONCLUSIONS: The injection of L-NAME before occlusion of developing chick eyes leads to reversible modifications in retinal function and inhibits the development of form-deprivation myopia.

Animals↗
PubMed1997

Value of thyroid stimulating antibody in the diagnosis of thyroid associated ophthalmopathy of euthyroid patients.

AIMS/BACKGROUND: Thyroid associated ophthalmopathy (TAO) of euthyroid patients is difficult to diagnose because clinical findings overlap with other conditions, and no confirmatory diagnostic tests are available. Recently, it was reported that TSH binding inhibitor immunoglobulin (TBII) and thyroid stimulating antibody (TSAb) are sensitive markers of TAO. The sensitivity of these antibodies in the detection of TAO were therefore studied to determine if they could be a useful criterion in the diagnosis of TAO of euthyroid patients. METHODS: Serum values of TBII and TSAb of 35 patients with euthyroid TAO (group A) were compared with those of 27 patients with Graves' disease and TAO (group B). The relation between the serum value of TSAb and the eye symptoms of patients with euthyroid TAO were also examined by multiple linear regression analysis. RESULTS: In group A, TBII was positive in 10 cases (28.6%) and TSAb was positive in 29 cases (82.9%). In group B, both TBII and TSAb were positive in all cases (100%). The titre of serum TBII in group A (15.6% (SD 18.0%)) was significantly lower (p < 0.0001) than in group B (57.9% (21.5%)). The titre of serum TSAb in group A (1400.9% (2163.9%)) was significantly lower (p = 0.0026) than in group B (2243.9% (1472.8%)). Among the eye findings of patients with euthyroid TAO, keratopathy was significantly (p = 0.034) related to the value of TSAb. CONCLUSION: These results suggest that the activity of TSAb is a more sensitive marker of euthyroid TAO than is TBII, and could be a useful criterion in the diagnosis of TAO of euthyroid patients.

Adolescent↗
PubMed1997

Differentiating full thickness macular holes from impending macular holes and macular pseudoholes.

AIMS: The reliability of scanning laser ophthalmoscope (SLO) microperimetry in differentiating full thickness macular holes from macular pseudoholes and impending macular holes was evaluated. METHODS: 106 eyes with the clinical diagnosis of full thickness macular holes, macular pseudoholes, and impending (stage 1) macular holes were examined for the presence of deep or relative scotoma using SLO microperimetry. The relation between these scotomas and the clinical diagnosis was studied. RESULTS: Deep and relative scotomas were detected in all 57 eyes with clinically defined full thickness macular holes. In contrast, among 49 eyes diagnosed with macular pseudoholes or impending macular holes, no deep and only one relative scotoma was observed. The sensitivity of the presence of a deep scotoma as an indicator of the clinical diagnosis of a full thickness macular hole was 100% (57 of 57), and the specificity was 100% (49 of 49). The sensitivity of the presence of a relative scotoma was 100% (57 of 57) and the specificity was 98.0% (48 of 49). CONCLUSION: With SLO microperimetry, full thickness macular holes can be precisely and objectively distinguished from other conditions that mimic macular holes.

Adult↗
PubMed1997

Correlation of anterior chamber-associated immune deviation with suppression of corneal epithelial rejection in mice.

PURPOSE: The authors investigated the effect of anterior chamber corneal (AC) inoculation of genetically graft-identical antigen on T-cell immunity and the suppression of alloepithelial rejection in mice. METHODS: Antigen-specific suppression of delayed-type hypersensitivity (DTH) and suppression transferability were tested in BALB/c mice injected with irradiated allogeneic B10.D2 splenocytes into AC. Other groups of BALB/c mice received irradiated B10.D2, BALB/c, or C3H/He splenocytes in the AC of the right eye. Seven days later, B10.D2 or C3H/He corneal lenticules were grafted at the limbus of the left eye (keratoepithelioplasty). Alloepithelial rejection of each grafted eye was evaluated according to clinical findings. The DTH response of the keratoepithelioplasty recipients against B10.D2 minor antigen was tested at the end of clinical observation (4 months after grafting). Also examined was spleen component transfer from BALB/c mice with AC inoculation of B10.D2 splenocytes to syngeneic acceptors and its effect on suppression of epithelial rejection against B10.D2 antigen. RESULTS: Inoculation of B10.D2 splenocytes into BALB/c AC induced antigen-specific DTH suppression, which suppression was transferable. During the 4-month observation period, AC inoculation of B10.D2 minor antigen significantly enhanced the survival of B10.D2-derived epithelium, but not of C3H/He-derived epithelium, in BALB/c mice. However, AC inoculation of BALB/c or C3H/ He splenocytes did not enhance B10.D2 epithelial survival in BALB/c mice. Incapability of antigen-specific DTH response generation was observed in the BALB/c mice with B10.D2 splenocytes in the right AC and B10.D2-derived epithelium in the left eye. Single transfer of spleen components from BALB/c mice with AC inoculation of B10.D2 splenocytes to syngeneic acceptors only delayed B10.D2 minor antigen-stimulated epithelial rejection, whereas supplementary transfers of the identical spleen components at different time intervals showed more significant effect in rejection delay. CONCLUSIONS: The results showed that AC inoculation of B10.D2 splenocytes in BALB/c mice induced antigen-specific suppression of DTH response, in a phenomenon termed anterior chamber-associated immune deviation (ACAID). It also was shown definitely that ACAID can suppress alloepithelial rejection in a murine keratoepithelioplasty model. Adoptive transfer of splenocytes from ACAID-induced mice merely affords short-term suppression of epithelial rejection, suggesting that an additional mechanism may be involved in ACAID maintenance.

Adoptive Transfer↗
PubMed1997

The antigen-bearing eye and the spleen are indispensable in maintaining anterior chamber-associated immune deviation.

PURPOSE: To investigate the role of the eye and the spleen in maintaining suppression of delayed-type hypersensitivity (DTH) after anterior chamber (AC) inoculation of allogeneic splenocytes. METHODS: Suppression of DTH response was tested in BALB/c mice after AC inoculation of allogeneic B10.D2 splenocytes. Seven days after AC injection, the antigen-inoculated eyes were enucleated or the spleens were removed. After enculeation or splenectomy at different time intervals, DTH responses in groups of the BALB/c mice were examined. Spleen components obtained from BALB/c mice that had been primed by B10.D2 splenocytes in the AC 7 days earlier were transferred intravenously to groups of naive syngeneic acceptors. At various intervals after adoptive transfer, variations of DTH responses were tested. RESULTS: Inoculation of B10.D2 splenocytes to the AC of BALB/c mice induced antigen-specific suppression of DTH. Either enucleation of the antigen-inoculated eyes or splenectomy weakened the DTH-suppressive effect within 5 weeks and abolished it within 9 weeks, whereas the mice retaining both antigen-inoculated eyes and spleens maintained longstanding DTH suppression. Adoptive transfer of spleen components to syngeneic acceptors demonstrated DTH suppression for only 3 weeks. CONCLUSIONS: The antigen-inoculated eye and spleen are required for long-standing suppression of DTH after AC inoculation of allogeneic splenocytes.

Adoptive Transfer↗
PubMed1997

Secondary vitrectomy for the treatment of macular holes occurring after vitrectomy.

Tangential foveal traction by the posterior vitreous cortex is regarded as the main cause of full-thickness macular holes. This report documents two cases of full-thickness macular holes that developed after vitrectomy for other diseases in the apparent absence of the cortical vitreous traction. Autologous serum with pars plana vitrectomy was used to treat these cases. Anatomic closure of the holes was achieved. Macular holes developing after vitrectomy may have an etiology other than tangential vitreous traction, and secondary vitrectomy is useful in treating such holes.

Adult↗
PubMed1997

[Emulsification experiments with dimethylsiloxane/phenylmethylsiloxane copolymer].

We compared the emulsification tendency of dimethylsiloxane/phenylmethylsiloxane copolymer (DPC; 5%-phenylated, specific gravity 0.984) with that of silicone oil (dimethylsiloxane; SO, specific gravity 0.966) and fluorosilicone oil (methyl-3,3,3-trifluoropropylsiloxane; FSO, specific gravity 1.256), which are clinically used as an intraocular tamponade. After SO, DPC and FSO were placed in a glass container with an equal amount of albumin solution (1 mg/ml) or gamma-globulin solution (1 mg/ml), and shaken SO and DPC, with their specific gravities being closer to water, showed less emulsification than FSO. Following vitrectomy, DPC was injected into the rabbit vitreous cavity, but did not seem to show any severe histological damage. Highly-phenylated DPC, which is slightly heavier than water, may be useful to treat inferior retinal detachment in place of FSO.

Animals↗
PubMed1997

An applicator-shaped scleral depressor for vitreoretinal surgery.

This article describes an instrument that combines a standard T-shaped scleral depressor at one end with a cotton applicator-shaped depressor at the other end. The applicator-shaped depressor has a matted surface to prevent slippage. This simple instrument has several advantages over depressors now available for intraoperative use.

Eye Diseases↗
PubMed1997

Subretinal fluid drainage with the erbium:YAG laser in rabbit eyes.

BACKGROUND AND OBJECTIVE: To evaluate the efficacy and safety of the erbium:yttrium-aluminum-garnet (Er:YAG) laser for choroidotomy as a means of performing external drainage of subretinal fluid with less risk of choroidal bleeding. MATERIALS AND METHODS: The authors tested this application in a rabbit model of retinal detachment by evaluating the effects of Er:YAG laser energy on the bare choroid at various energy settings (1, 2, 3, or 5 mJ/pulse) and repetition rates (2, 4, 10, or 30 Hz). RESULTS: Although the choroid was not perforated at low energy and frequency settings, choroidotomy was successfully achieved as energy and repetition rate were increased. Through higher energy levels per pulse and higher repetition rates, choroidotomy was achieved at lower total energy levels. No retinal damage was detected after laser choroidotomy. Choroidal bleeding was noted in 2 of 97 eyes; however, no subretinal hemorrhage occurred. CONCLUSION: These results indicate that the Er:YAG laser may be a clinically useful tool for retinal reattachment surgery.

Animals↗
PubMed1996

Retrospective survey of surgical outcomes on rhegmatogenous retinal detachments associated with atopic dermatitis.

OBJECTIVE: To determine the clinical features and surgical outcomes of retinal detachment associated with atopic dermatitis. METHODS: One hundred twenty-one eyes of 98 patients with atopic dermatitis and rhegmatogenous retinal detachment were surgically treated and followed up for 1 year or longer. Fundus examination data on retinal breaks and detachment, and follow-up data on anatomic reattachment were obtained and compared between phakic and aphakic eyes using the chi 2 test. RESULTS: Breaks were often multiple and located at the ora serrata (72%) and in the ciliary epithelium (15%). Irregularly shaped breaks (13.5%) and giant breaks (16%) also were seen. Most detachments (71%) were localized and shallow. No significant difference was identified with or without a history of cataract surgery. The prognosis after the initial surgery (reattachment rate, 72%) was unfavorable because of new break formation, but the results of reoperation (reattachment rate, 93%) were as successful. CONCLUSIONS: Patients with atopic dermatitis may have an abnormality in the anterior retina and ciliary epithelium that predisposes to retinal detachment. Findings suggest a possible traumatic trigger and the need to perform an encircling scleral buckle procedure with widespread retinopexy initially in these patients.

Adolescent↗
PubMed1996

Immunohistochemical distribution of basic fibroblast growth factor in experimental retinal ischaemia and reperfusion in the rat.

It has been proposed that basic fibroblast growth factor (basic FGF) mediates the neovascular response in a variety of conditions, including diabetic retinopathy and branch retinal vein occlusion. To test the hypothesis that basic FGF was released from retinal stores as a result of retinal ischaemia, transient retinal ischaemia was induced, followed by 48 h of reperfusion, in the rat by combined central retinal vasculature and optic nerve ligation. The immunolocalization of basic FGF was studied in the retina. We found that basic FGF in the normal retina is present around the deeper retinal vessels and in the neuronal tissue of the outer plexiform layer. In the eyes that had ischaemia followed by reperfusion, there was moderate cellular oedema with retinal swelling, and mitoses in the inner nuclear and plexiform layers. There were no changes evident at the immunohistochemical level either in the intensity or distribution of stores of basic FGF. We conclude from these data that stores of basic FGF are not altered dramatically under the conditions of transient experimental ischaemia and reperfusion in the rat, despite the presence of cellular proliferation.

Animals↗
PubMed1996

Intraocular oxygen tension in eyes with proliferative diabetic retinopathy with and without vitreous.

BACKGROUND: Intraocular oxygen tension was measured in the eyes of patients with proliferative diabetic retinopathy with or without vitreous in order to determine local differences in tissue oxygenation in the vitreous cavity before and after vitrectomy. METHODS: We measured oxygen tension, using polarographic oxygen electrodes, at various intraocular locations in 30 eyes of 29 patients with diabetic traction retinal detachment who were candidates for vitrectomy (pre-vitrectomy group) and 13 eyes of 13 diabetic patients who had previously undergone vitrectomy (post-vitrectomy group). RESULTS: In the pre-vitrectomy group, oxygen tensions proximal to the neovascularization of the disc and the neovascularization elsewhere were significantly higher than the values obtained at other locations in the vitreous cavity. In the post-vitrectomy group, however, the oxygen tensions at those locations were significantly lower than those in the pre-vitrectomy group. There were no significant differences between the values obtained at any of the measurement locations in the post-vitrectomy eyes. CONCLUSION: Neovascular tissues in the eyes of diabetic patients demonstrated higher oxygen tensions than non-neovascular tissues. This finding suggests that neovascular issue may compensate for intraocular hypoxia by releasing oxygen from the front. Successful diabetic vitrectomy reduces the activity of the neovascular tissue and equalizes levels of oxygenation in the tissue of the vitreous cavity.

Diabetic Retinopathy↗
PubMed1996

Expression of Na+/myo-inositol cotransporter mRNA in normal and hypertonic stress rat eyes.

We studied the localization of Na+/myo-inositol cotransporter (SMIT) mRNA in normal and hypertonic stress rat eyes by in situ hybridization histochemistry using cRNA probes. SMIT mRNA signals were observed in the iris-ciliary body, the lens epithelial cells, and the ganglion cell layer and the inner nuclear layer of the retina. There was a rapid increase on SMIT mRNA in the retina of hypertonic stress rats compared with control rats. These findings suggest that Na+/myo-inositol cotransporter gene expression is osmotically regulated in vivo to protect retinal neuronal function against hypertonic stress.

Animals↗
PubMed1996

Differential distribution of mRNA encoding cAMP-specific phosphodiesterase isoforms in the rat brain.

We studied the distributions of four different cyclic AMP-specific phosphodiesterase isoform mRNAs (APDE1-4) and compared them with that of 63 kDa calmodulin-stimulated phosphodiesterase (CPDE) in the rat brain by in situ hybridization histochemistry using specific radiolabeled oligonucleotides. The distribution patterns were unique for all the APDE isoforms examined here. Although no significant signals for APDE1 could be detected anywhere in the rat brain, all other isoforms were expressed ubiquitously but unevenly and showed overlapping distribution patterns. Among all the APDE isoforms studied here, APDE3 showed the strongest and the most extensive expression. Its distribution pattern implies that it may modulate different cellular processes associated with learning and memory. Compared to APDE3, the levels of expression of APDE2 and APDE4 were weaker, the latter showing the weakest expression. Our study suggests that different isoforms of APDE are expressed together in the same class of neurons implying complex interactions among different signaling pathways, thereby mediating distinct and specific functions.

3',5'-Cyclic-AMP Phosphodiesterases↗