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Biomedical subjects

Y Tano

Publications and source records attributed to Y Tano.

245 records · Page 14Linked to original sources
PubMedDate not supplied

Magnifying prismatic lenses for vitrectomy.

PURPOSE: Viewing the fundus at higher magnification during vitrectomy makes surgical procedures much safer; however, the scope of magnification of the peripheral fundus has been limited. For better visualization of the periphery of the fundus, we have developed two new contact lenses called magnifying prismatic lenses. METHODS: The magnifying 15 degrees and 30 degrees prismatic lenses are made of a glass with a high index of refraction (n = 1.883). The lenses have a convex upper surface to provide a magnified view of the peripheral fundus. RESULTS: These magnifying 15 degrees and 30 degrees prismatic lenses provide an approximately 2x magnified view of the peripheral fundus. They also provide a more extensive view of the peripheral fundus than a regular (plano-concave) prismatic lens when the eye is tilted. CONCLUSION: The magnifying prismatic lenses are useful for viewing into the peripheral fundus with higher magnification.

Fundus Oculi↗
PubMedDate not supplied

Ligneous conjunctivitis: a case report.

BACKGROUND: Ligneous conjunctivitis is a rare condition characterized by chronic, recurrent conjunctivitis associated with pseudomembrane, and it may involve other mucous membranes in the mouth, nasopharynx, trachea, and vagina. We examined and treated a case of presumed ligneous conjunctivitis. CASE: The patient was a 10-year-old boy. His chief complaints were visual impairment, discomfort, and discharge, but no itching in his eyes. His upper eyelids appeared thick without swelling. He had a past history of surgery for lid entropion. His two siblings had similar follicular conjunctivitis. OBSERVATIONS: This case exhibited several characteristics of ligneous conjunctivitis, such as large follicles, recurrent pseudomembrane and normal level IgE in the serum. Indispensable characteristics of vernal keratoconjunctivitis, strong itching, and extensive papillary formation, were not found. In spite of the lack of woody hardness of the conjunctiva, other clinical findings led to the diagnosis of ligneous conjunctivitis. Definite histological diagnosis was not obtained, because of the lack of common histological characteristics among previously reported cases with ligneous conjunctivitis. The boy had developed corticosteroid glaucoma after instillation of dexamethasone 0.1% for 7 months at a previous time. We successfully treated this case with combined instillation of fluorometholon and cyclosporin after trabeculotomy. CONCLUSIONS: Ligneous conjunctivitis must be considered as one type of differential diagnosis of vernal keratoconjunctivitis. Cyclosporin is an effective alternative for the treatment of ligneous conjunctivitis, especially in a case with a possible history of corticosteroid glaucoma.

Child↗
PubMedDate not supplied

Core vitrectomy preceding triple corneal procedure in patients at high risk for increased posterior chamber pressure.

We evaluated the effectiveness of performing a core vitrectomy to prevent intraoperative posterior chamber pressure evaluation in eyes at high risk for development of this complication, prior to penetrating keratoplasty, extracapsular cataract extraction and posterior chamber lens (IOL) implantation. Results in 10 cases with core vitrectomy were compared with 10 cases without (controls); in all eyes with vitrectomy, a posterior chamber IOL was easily implanted but four eyes of the control group developed vitreous complications. Our results indicate that core vitrectomy does facilitate IOL implantation during a triple corneal procedure in eyes at increased risk of elevated posterior chamber pressure.

Aged↗
PubMedDate not supplied

Human hepatocyte growth factor (HGF) in the aqueous humor.

Using an enzyme-linked immunosorbent assay, we measured the concentration of hepatocyte growth factor (HGF) in human aqueous humor and serum from 36 eyes of 33 patients and analyzed the relationship between HGF and several parameters of corneal endothelial cells. Aqueous HGF concentrations ranged from 0.020-0.194 ng/mL (average: 0.101 +/- 0.044 ng/mL) and was correlated positively with corneal endothelial cell density (r = 0.343, P = 0.04). The aqueous HGF level did not correlate with other corneal endothelial cell parameters or the serum HGF level. The HGF receptor, c-Met, was found in the corneal endothelial cell membranes. This study suggests that the aqueous humor HGF is a factor which maintains an integrity of corneal endothelial cells.

Aged↗
PubMedDate not supplied

Detection of HSV mRNA using reverse transcription-polymerase chain reaction for diagnosis in murine herpetic keratitis model.

Reverse transcription polymerase chain reaction (RT-PCR) was applied in the detection of herpes simplex virus-1 (HSV-1) mRNA from tear film and corneal epithelium in a murine herpetic keratitis model. The diagnostic value of this new technique for acute herpetic keratitis was evaluated in comparison with direct PCR for genomic DNA and viral culture. On day 2 postinfection (PI) of HSV, all mice showed dendritic keratitis, and PCR, RT-PCR, and viral culture were positive in all samples. On day 8 PI, no dendritic keratitis was observed in any mouse, PCR was positive in all samples, while RT-PCR was positive in only 5 of 12 samples and viral culture in only 2 of 12. The sensitivity of RT-PCR was lower than that of PCR, and approximately the same as viral culture; however, the findings of RT-PCR more closely concurred with clinical observations than the findings of PCR. These results show the potential of RT-PCR for rapid, specific diagnosis of acute herpetic keratitis.

Acute Disease↗
PubMedDate not supplied

Use of dynamic and colored stereogram to measure stereopsis in strabismic patients.

The effectiveness of movement or color has not been well studied in assessing stereopsis in patients with strabismus. We developed a new stereotest equipped with both a monochromatic dynamic random dot stereogram (DRDS) and a static-colored stereogram (SCS) and examined the stereopsis of patients with strabismus. Three-dimensional (3D) images were displayed on a liquid crystal display equipped with a parallax barrier system, allowing 3D images to be seen independently by each eye without glasses. A DRDS with maximum disparity of 3200 seconds of arc was displayed having front-rear movement. An SCS displaying cartoon characters with disparities of 400 seconds of arc was also tested and compared with the Titmus stereotest. A total of 52 strabismic patients were tested. The DRDS showed a significantly higher (P = 0.02) detection rate of stereopsis (39/52, 75%) as compared with the Titmus fly test (28/52, 54%). The SCS did not show any difference in the stereopsis detection rate (24/521, 46%) when compared with the Titmus animal test (20/52, 38%). Thus, the DRDS was useful in detecting stereopsis in patients without stereopsis on the conventional Titmus fly test, while the SCS did not show any difference when compared with the Titmus animal test. The DRDS may examine a different aspect of stereopsis from the static stereopsis measured by the Titmus stereotest or SCS.

Adolescent↗
PubMedDate not supplied

Corneal changes in spondyloepiphyseal dysplasia tarda.

BACKGROUND: A new type of corneal opacity with prominent corneal nerve fibers as an ocular complication of spondyloepiphyseal dysplasia tarda (SEDT). CASE: A 58-year-old woman, diagnosed with SEDT at 5 years of age, underwent a complete ophthalmological examination. OBSERVATIONS: The patient had no complaints and no history of eye disease. No relatives were reported to have suffered from SEDT. Slit-lamp examination disclosed a diffuse opacity in the central cornea in both eyes, which was localized in the middle to deep stroma. Dot opacities in the central and paracentral cornea were located in the middle of the stroma in both eyes. Optically clear regions were observed in the peripheral cornea of both eyes. More interestingly, corneal nerve fibers were visible passing from the limbus to the central cornea in both eyes. RESULTS: The etiology of the corneal opacities of this patient with SEDT is unknown. However, collagen and proteoglycan abnormalities in the skin of patients with SEDT have been reported. Therefore, such abnormalities may also be present in the cornea and these alterations may lead to corneal complications.

Blinking↗
PubMedDate not supplied

Detection and classification of mild irregular astigmatism in patients with good visual acuity.

Videokeratography has been available for a decade, and this test is essential for determining the presence and type of irregular corneal astigmatism. Three eyes diagnosed with myopic astigmatism and considered good candidates for refractive surgery with conventional examination were studied. Color-coded maps with videokeratography showed regular astigmatism in one eye and the existence of irregular astigmatism in two eyes. Videokeratography showed that one of these eyes had a keratoconus suspect pattern and the second showed a pattern consistent with pellucid marginal degeneration. Videokeratography can detect and classify irregular astigmatism in cases where routine examination shows no abnormal findings.

Adolescent↗
PubMedDate not supplied

Effect of a nitric oxide synthase inhibitor on lens-induced myopia.

PURPOSE: It has still not been determined whether the retinal mechanism causing form-deprivation myopia (FDM) is different from that causing lens-induced myopia (LIM). We previously reported that FDM was blocked by an intravitreal injection of the nitric oxide (NO) synthase inhibitor, N-nitro-L-arginine methyl ester (L-NAME). In this study, we investigated the effect of L-NAME on LIM in chicks. METHOD: The left eyes of 6-day-old chicks were injected with 30 microl of nontoxic concentrations of L-NAME (< or = 360 mM) or saline. The right eyes were injected with 30 microl of saline. A -16 dpt lens was placed in front of the left eye for 6 days. Another group of 6 chicks were injected with 180 mM L-NAME (left eye) and with saline (right eye) before placing -16 dpt lenses in front of both eyes. After removing the lens, the refraction and the axial length were measured. The effect of L-NAME (180 mM) on the retina of a separate group of chicks was examined by electroretinography 60 min after an intravitreal injection in non-LIM-treated eyes. RESULTS: The eyes of chicks that were injected with 180 or 360 mM L-NAME were less myopic and had significantly shorter axial lengths than control eyes. A significant decrease of the On response and an increase of the Off response were observed. CONCLUSION: The injection of L-NAME into developing chick eyes that were then covered with a -16 dpt lens resulted in a modifications of retinal function and an inhibition of the development of myopia. These results, combined with the earlier findings, suggest that NO modulates a common retinal pathway that leads to both LIM and FDM.

Animals↗