Biomedical subjects

Shwu-Jiuan Sheu

Publications and source records attributed to Shwu-Jiuan Sheu.

At least 19 recordsLinked to original sources

PubMed2006

Axial myopia is an extremely significant risk factor for young-aged pseudophakic retinal detachment in taiwan.

PURPOSE: To investigate the possible risk factors of retinal detachment (RD) after cataract extraction and intraocular lens implantation in a geographic defined racially uniform population. METHODS: Submitted claim records and charts of 9398 insurance beneficiaries who underwent cataract extraction and intraocular lens implantation between August 1999 and December 2001 were consecutively collected from the Bureau of National Health Insurance (BNHI). At the end of 2003, any ophthalmologic diagnosis and related treatment based on procedure and diagnosis codes listed in physician bills were evaluated. RESULTS: The cumulative risk of RD in our study group was 0.76% at the end of follow-up. The mean follow-up time was 36.92 +/- 8.89 months. Sex distribution had no significant effect on the occurrence of RD after cataract extraction, whereas age distribution showed significant influence on the risk of RD after cataract surgery (P = 0.0307), as did the history of RD (P < 0.0001) and Nd-YAG laser posterior capsulotomy (P = 0.0001). Axial length also had a significant effect on the risk of RD after cataract extraction (P < 0.0001). The longer the axial length, the more impact on the risk of RD carried by young age. CONCLUSIONS: The results showed that axial myopia is an extremely significant risk factor for young-aged pseudophakic RD in Taiwan.

Adult↗

PubMed2005

Suppression of choroidal neovascularization by intramuscular polymer-based gene delivery of vasostatin.

The purpose of this study was to evaluate the efficacy of gene delivery of angiogenesis inhibitor, vasostatin (VS), in suppressing experimental model of choroidal neovascularization (CNV). A mammalian expression vector carrying VS, pCMV3-VS, was constructed and evaluated for its ability to produce VS in transfected cells using western blot analysis and a cell viability assay. CNV was induced in Brown Norway rats by fundus argon laser photocoagulation and evaluated by fundus fluorescein angiography (FAG). Ten days post-laser treatment, gene delivery was achieved by intramuscular (IM) injection of poly-(N-vinyl pyrrolidone) (PVP) polymer conjugated with pCMV3-VS (PVP-VS) or a control vector (PVP-vector). Systemic VS expression was analysed by western blot analysis and enzyme linked immunosorbent assay (ELISA), and the extent of CNV was monitored by FAG analysis at different time intervals post-PVP treatment. Transfection of pCMV3-VS into muscle cells resulted in increased production and release of exogenous VS, which specifically inhibited the proliferation of endothelial cells. Besides, IM injection of PVP-VS, but not PVP-vector, led to elevated VS level in plasma for 30 days. After laser photocoagulation, rats injected with PVP-VS exhibited significantly lower incidence of CNV comparing with animals of control groups (P < 0.01) for at least 42 days. Moreover, rats treated with PVP-VS also showed a significant reduction in the CNV lesions compared with control groups (P < 0.001) for at least 42 days. Above all, no overt adverse effects were observed in rats received PVP-VS. These results demonstrate the potential of IM VS gene delivery for CNV treatment.

Angiogenesis Inhibitors↗

PubMed2005

Conjunctival aspergilloma with multiple mulberry nodules: a case report.

A 30-year-old healthy female presented with a 1-year history of chronic mucous discharge, tearing, and irritation in the left eye. Slit-lamp examination revealed severe papillary and follicular reaction surrounding a movable subconjunctival mass on the left upper tarsal conjunctiva. Incision and curettage were performed to establish the diagnosis. Multiple peculiar black mulberry nodules were obtained. The clumps of septate hyphae seen with periodic acid-Schiff stain were characteristic of fungus ball (aspergilloma). The patient's symptoms improved significantly after surgery without any antifungal therapy. Although rarely reported, aspergillus is a common fungus in the conjunctiva that may seed into the subconjunctiva. We present this case to remind ophthalmologists of such a rare cause of recalcitrant conjunctival inflammation in immunocompetent patients.

Adult↗

PubMed2005

Treatment of macular holes with indocyanine green-assisted retinal internal limiting membrane peeling.

Removal of the internal limiting membrane (ILM) has been proposed as a useful surgical approach to enhance the closure of macular holes and the adjuvant indocyanine green (ICG) staining has been reported to facilitate ILM peeling. This study attempts to determine the efficacy and safety of ICG-assisted retinal ILM peeling in macular hole surgery. Seventeen eyes of 16 patients with stage 3 or 4 macular holes were included. All eyes underwent a pars plana vitrectomy, including the peeling of the posterior cortical hyaloid when necessary. ICG dye (0.5%) was instilled into the posterior vitreous cavity and left in place for 30 seconds. The retinal ILM was peeled after ICG removal. The procedure was completed with an intraocular tamponade (16% perfluoropropane), after which the patient remained in a face-down position for 1-2 weeks. ICG staining greatly facilitated the surgeon's ability to visualize and peel the ILM during surgery. Anatomic closure of the macular hole was achieved in 15 eyes (88.2%). However, the postoperative best-corrected visual acuity improved by two or more Snellen lines in only three eyes, remained the same in 13 eyes, and deteriorated in one eye. There was no statistically significant improvement in postoperative visual acuity. In conclusion, while ICG facilitates ILM peeling by providing a stark contrast between the stained ILM and the unstained retina, our results revealed that ICG might cause retinal damage and hinder visual acuity improvement.

Aged↗

PubMed2005

Risk factors for retinal detachment after cataract surgery in southern Taiwan.

BACKGROUND: This study was designed to investigate potential risk factors for retinal detachment (RD) after cataract surgery in southern Taiwan. METHODS: This was a prospective cohort study. Submitted charts and claimed records for insurance beneficiaries who underwent cataract extraction between August 1999 and December 2001 were collected from the Bureau of National Health Insurance. Data from these records were examined, including demographic characteristics, past history, refractive status, axial length, and type and complications of cataract extraction. At the end of 2002, any ophthalmologic diagnosis and related treatments, based on procedure and diagnosis codes listed in physician bills, were evaluated. RESULTS: A total of 9,398 patients were evaluated. The cumulative risk of RD in our study group was 0.4% at the end of follow-up. The mean follow-up time was 25.5 +/- 7.7 months. Age had a significant influence on the risk of RD after cataract surgery (p = 0.006), whereas gender did not. Axial length also had a significant effect on the risk of RD after cataract extraction (p < 0.001), whereas systemic disease or the type of operation did not correlate significantly with RD. Intraoperative complications had a significant influence on RD risk only in patients aged more than 60 years (p = 0.042). Neodymium:yttrium-aluminum-garnet (Nd:YAG) laser posterior capsulotomy significantly reduced the risk of RD only in patients aged 50 years or younger (p < 0.001). CONCLUSION: Our results show that young age and long axial length are both significantly associated with RD after cataract surgery. A more restrictive attitude towards early cataract extraction may therefore be appropriate, especially in highly myopic patients.

Adult↗

PubMed2005

Stretch-stimulated activity of large conductance calcium-activated potassium channels in human retinal pigment epithelial cells.

AIM: The aim of this study was to investigate the effect of membrane stretch on the activity of BK(Ca) channels and determine whether change in BK(Ca)-channel activity induced by membrane stretch can be altered in the presence of riluzole. METHODS: The effect and mechanisms of membrane stretch on the activity of large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels in human retinal pigment epithelial (RPE) cells were investigated using the patch-clamp technique. RESULTS: In cell-attached patches, an increase in BK(Ca)-channel activity was induced by membrane stretch, which is mainly mediated by the increase in the number of long-lived openings. With inside-out patches, application of pipette suction did not modify single-channel conductance of BK(Ca) channels; however, it did enhance the channel activity. Membrane stretch-induced channel activity was found to be independent of the level of intracellular Ca(2+). Membrane stretch also potentiated riluzole-stimulated BK(Ca)-channel activity. CONCLUSIONS: BK(Ca) channel can be stimulated by membrane stretch in human RPE cells. During an increase in tensile strength of RPE, the BK(Ca) channel might exert a protective action against deleterious tension by promoting a hyperpolarizing outflow that forces the cell to rest.

Cell Line↗

PubMed2005

Intravitreal tissue plasminogen activator and pneumatic displacement of submacular hemorrhage secondary to retinal artery macroaneurysm.

PURPOSE: To assess the efficacy of treating submacular hemorrhages secondary to retinal arterial macroaneurysm with intravitreous tissue plasminogen activator (tPA) and gas. PATIENTS AND METHODS: Six consecutive patients (6 eyes) with submacular hemorrhage secondary to retinal arterial macroaneurysm were included in this study. Tissue plasminogen activator, at a dose of 50 microg/0.1 mL, was injected through the pars plana into the vitreous cavity. Gas (0.3-0.5 mL of perfluoropropane) instillation followed tPA injection, either immediately after injection or sometime during the next day. RESULTS: Best postoperative visual acuity improved in 5 of 6 eyes (83%) and was unchanged in 1 of 6 (17%) eyes. In 5 of 6 (83%) eyes, the procedure resulted in complete or partial displacement of submacular hemorrhage out of the foveal area. CONCLUSIONS: Intravitreous injection of tPA and gas, followed by prone positioning of the patient, is an effective and simple treatment of submacular hemorrhage secondary to retinal arterial macroaneurysm. No complication occurred in this series.

Aged↗

PubMed2005

Update on uveomeningoencephalitides.

PURPOSE OF REVIEW: Uveomeningoencephalitides, commonly known as Vogt-Koyanagi-Harada (VKH) disease, are characterized by chronic bilateral granulomatous panuveitis involving the central nervous, auditory and integumentary systems. Visual prognosis is generally favourable, but outcomes in patients with VKH disease may vary. Also, the treatment of choice differs in different parts of the world. This review addresses the literature on the possible pathogenesis, diagnosis and treatment of this disorder. RECENT FINDINGS: Atypical presentations of VKH disease, as well as those associated with interferon-alpha therapy, have been reported. Most reports suggest an association with autoimmunity. The diagnostic criteria were revised by the International Workshop on VKH in 1999, allowing for the presence of different ocular findings in the early and late stages of the disease. New techniques have also been developed to aid in the rapid diagnosis of VKH disease and evaluation of treatment. Different routes of administration of corticosteroid and adjuvant therapy were tried, with positive results. SUMMARY: Although the pathogenesis of VKH disease is uncertain and antigen-specific treatment strategies have not yet been developed, reports increasingly suggest an autoimmune nature for uveomeningoencephalitides. Currently, systemic corticosteroid therapy remains the standard initial treatment. Different routes of administration are used to reduce the frequency of side effects of systemic corticosteroids, and there are various adjuvant therapies. With the aid of modern equipment, early diagnosis and prompt and appropriate treatment, resulting in better visual outcomes, can be anticipated. A large-scale, multinational, prospective study is warranted to determine the optimal initial therapy.

Humans↗

PubMed2004

Significant prognostic factors for Vogt-Koyanagi-Harada disease in the early stage.

This study identified possible prognostic signs in the acute stage of Vogt-Koyanagi-Harada (VKH) disease in a retrospective chart review of all patients diagnosed with VKH disease between 1991 and 2001. Those who were diagnosed more than 1 month after the onset of ocular symptoms were excluded. Data recorded included age, sex, clinical features, systemic manifestations, recurrence, treatment, complications, and final visual acuity. Exudative retinal detachment was ranked into 3 grades (grade 1: within peripapillary 3 disc diameters and arcade; grade 2: larger than grade 1 but no inferior retinal detachment; grade 3: inferior or total retinal detachment). Of the 31 patients, 19 were males and 12 were females. Mean age at presentation was 38.55 +/- 10.63 years. The mean follow-up period was 33.09 months. Extraocular manifestations were present in 17 cases. Four patients had at least one complication, including cataract in seven eyes and glaucoma in one eye. Forty-nine eyes (79%) had a final visual acuity of 6/12 or better. Final visual acuity was significantly better in younger patients (p = 0.023) and those who had less extensive retinal detachment (p = 0.006), no pigmentary change (p = 0.008) and no complications (p = 0.030). The visual prognosis of VKH disease is variable, though generally favorable. In the acute stage, the extent of retinal detachment may be an important risk factor for visual outcome. Further study of this factor as an indicator for treatment is necessary.

Adult↗

PubMed2004

Macular hole in Behcet's disease.

Behcet's disease is an inflammatory disorder of unknown cause, characterized by recurrent oral aphthous ulcers, genital ulcers, uveitis, and skin lesions. Ocular involvement occurs in 60-80% of patients with Behcet's disease and presents as panuveitis in most cases. Posterior segment involvement may lead to irreversible alterations and significant vision loss. The development of a partial or full-thickness macular hole, though rarely reported, may cause serious vision loss. In this report, we present two cases of macular hole in the worse eye of bilateral cases of Behcet's disease, and discuss the possible mechanisms and management in such cases.

Adrenal Cortex Hormones↗

PubMed2004

The influence of hypotonicity on large-conductance calcium-activated potassium channels in human retinal pigment epithelial cells.

The aim of this study was to characterize the effects of hypotonicity on the activity of large-conductance Ca(2+)-activated K+ (BK(Ca)) channels in human retinal pigment epithelial (RPE R-50) cells. Effects of hypotonicity on ion currents were investigated with the aid of the patch-clamp technique. A regulatory volume decrease in response to a hypotonic solution (200 mOsm/L) was observed that could be blunted by paxilline. In whole-cell current recordings, a hypotonic solution (200 mOsm/L) reversibly increased the amplitude of K+ outward currents (I(K)). The increase of I(K) could be reversed by iberiotoxin (200 nM), paxilline (1 microM), or tetrandrine (5 microM), but not by glibenclamide (10 microM), disulphonic acid (DIDS) (100 microM), or dequalinium dichloride (10 microM). In RPE R-50 cells pretreated with thapsigargin, aristolochic acid, or pertussis toxin, the increased amplitude of I(K) in response to hypotonicity was unaltered. In cell-attached patches, an increase in BK(Ca)-channel activity was observed during hypotonicity-induced cell swelling. The enhanced channel activity elicited under this condition was mainly mediated by an increase in the number of long-lived openings. These findings support the evidence for the coupling of volume swelling to the functional activity of BK(Ca) channels.

Alkaloids↗

PubMed2003

Optic neuritis: clinical analysis of 27 cases.

We retrospectively reviewed 27 cases diagnosed as idiopathic optic neuritis between 1992 and 2001 at Kaohsiung Veterans General Hospital to assess the clinical features, visual prognosis, neuroimaging, laboratory studies, and development of multiple sclerosis in Chinese patients with optic neuritis. Patient age ranged from 13 to 54 years (mean, 35.8 +/- 11.3 years). Five cases presented as bilateral optic neuritis and 22 as unilateral. Visual function improved gradually from 2 weeks after treatment. Twelve (44.4%) cases showed disc swelling and ocular pain was also noted in 44.4% of patients. All cases that underwent visual field and visual evoked potential tests showed abnormality in lesion eyes. Of the 23 cases that underwent neuroimaging studies, including computerized tomography (17 patients) and magnetic resonance imaging (6 patients), 10 revealed optic nerve thickening. Four cases (14.8%) developed multiple sclerosis during follow-up (mean, 4.3 years). The incidence of disc swelling was higher than that reported by the Optic Neuritis Treatment Trial, but the incidence of initial ocular pain, the presence of periventricular plaques, and the development of multiple sclerosis were lower in our study. The unilateral group had significantly better visual outcome than the bilateral group.

Adolescent↗

PubMed2003

Mechanism of inhibitory actions of oxidizing agents on calcium-activated potassium current in cultured pigment epithelial cells of the human retina.

PURPOSE: To identify the mechanisms by which oxidative stress with oxidizing agents alters the activity of ion channels in human retinal pigment epithelial (RPE) cells. METHODS: The effects of oxidizing agents on ion currents were investigated in human RPE R-50 cells with the aid of the whole-cell, cell-attached, and inside-out configurations of the patch-clamp technique. RESULTS: In the whole-cell configuration, t-butyl hydroperoxide (t-BHP; 1 mM), thimerosal (30 microM), and 4,4'-dithiodipyridine (DTDP; 30 microM) suppressed voltage-dependent K(+) current (I(K)) that was sensitive to inhibition by iberiotoxin or paxillin, yet not by apamin or 5-hydroxydecanoate sodium. Meclofenamic acid or Evans blue, but not diazoxide, reversed the decrease in I(K) caused by t-BHP. In cells dialyzed with ceramide (30 microM), neither t-BHP (1 mM) nor thimerosal (30 microM) had any effect on I(K), whereas DTDP (30 microM) slightly suppressed it. In cell-attached recordings, t-BHP (1 mM), thimerosal (30 microM), and DTDP (30 microM) suppressed the activity of large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels. Dithiothreitol (10 microM) reversed DTDP-induced decrease in channel activity. Under current-clamp conditions, cell exposure to oxidizing reagents caused membrane depolarization. In cells dialyzed with ceramide (30 microM), membrane potential remained unaltered in the presence of t-BHP. CONCLUSIONS: The results demonstrate that hydrophilic oxidants (e.g., t-BHP and thimerosal) suppress I(K) and suggest that the underlying mechanism of this inhibitory action may involve the generation of intracellular ceramide. However, the inhibition of BK(Ca) channels by DTDP, a membrane-permeable oxidant, in human RPE cells may result from the direct inhibition of BK(Ca) channels and indirectly from an increase in the intracellular production of ceramide.

Cells, Cultured↗

PubMed2003

Endogenous uveitis: experiences in Kaohsiung Veterans General Hospital.

BACKGROUND: The distribution of uveitis varies in different parts of the world, which is attributed to geographic, alimentary or genetic factors. Epidemiological studies in uveitis may be extremely important in an effort to better understand the etiology of the disease and the classification of its subtypes. The purpose of this study was to determine the profile and characteristics of endogenous uveitis in southern Taiwan. METHODS: Retrospective chart review ofthe patients diagnosed and treated as endogenous uveitis in Kaohsiung Veterans General Hospital from January 1991 to December 2000 was performed. Demographic data, past history, ophthalmic examination and other laboratory tests were recorded and analyzed. RESULTS: One-hundred and sixty patients were collected, including 93 (58.1%) males and 67 (41.9%) female, with average age of 41.1 +/- 17.1 years (range 16-77), and mean follow-up period of 13.7 months. The diagnoses included 46 (28.8%) cases of acute anterior nongranulomatous uveitis (AAU), 26 (16.3%) cases of Vogt-Koyanagi-Harada (VKH) disease, 18 (11.3%) cases of intermediate uveitis, 14 (8.8%) cases of Behcet's disease, 26 (16.3%) cases of infectious origin, 7 (4.4%) cases of other diagnoses, and 23 (14.4%) undefined cases. Final visual acuity equal to or better than 0.5 was obtained in 78.2% of eyes of AAU, 65.4% of eyes of VKH disease, 48.1% of eyes of Behcet's disease, and 66.7% of eyes of intermediate uveitis. CONCLUSIONS: Acute anterior nongranulomatous uveitis was the most common endogenous uveitis, while VKH was the most common panuveitis in this series. As infectious origin contributes a significant proportion of endogenous uveitis, infectious etiology should be considered in any type of uveitis that responds poorly to conventional treatment.

Adolescent↗

PubMed2003

Prognostic factors for Vogt-Koyanagi-Harada disease.

BACKGROUND: Vogt-Koyanagi-Harada disease is a chronic bilateral granulomatous panuveitis with involvement of the central nervous system, auditory and integumentary systems. The prognosis depends mostly on the development of complications or not. The purpose of this study was to identify the prognostic factors of Vogt-Koyanagi-Harada (VKH) disease. METHODS: Retrospective chart review of all the patients diagnosed with VKH disease between 1991 and 2000 was performed. Data recorded included age, sex, clinical features, systemic manifestations, recurrence, HLA typing, treatment, complications, and final visual acuity. Statistical analysis was performed using Statistical Products and Services Solutions. RESULTS: There were thirty-nine patients, the mean age at presentation was 39.82 +/- 12.38 years. The majority (46.2%) of patients were probable VKH disease, followed by incomplete type (43.5%), with only 10.3% complete type. Ten patients had at least one complication, including cataract in 19 eyes, glaucoma in 4 eyes and choroidal neovascularization in 3 eyes. Fifty eyes (64.1%) had final visual acuity of 6/12 or better. The interval between ocular symptom and treatment had significant effect on the development of complicaion (p = 0.022) and recurrence (p = 0.003), which were also significantly associated with the final visual acuity (p = 0.007). For patients who were diagnosed and treated within two weeks, the extent of exudative retinal detachment correlated significantly with final visual acuity (p = 0.001). CONCLUSIONS: The visual prognosis of VKH disease is generally favorable. The development of complications or recurrence was significantly associated with the visual outcome. Interval between development of ocular symptom and treatment seemed to be an important predictor in the early stage of VKH. It is important to start the treatment early even when the typical features of VKH disease have not completely appeared.

Adolescent↗

PubMed2003

A suprasellar meningioma simulating atypical retrobulbar optic neuritis.

A 39-year-old female came with the chief complaint of acute decrease of left eye vision for the past 2 weeks. No history of systemic diseases or headache was complained. The visual acuity of the left eye was "hand motion", and rapidly responded to methylprednisolone therapy in 3 days. On tapering oral prednisolone, the visual acuity decreased again from 20/20 to light perception in the left eye. The magnetic resonance image (MRI) study showed a large suprasellar mass. The patient underwent craniotomy and removal of the tumor successfully, and the pathological report turned out to be a meningioma. The visual acuity of the left eye remained poor after the surgery. In conclusion, neuroimaging study is necessary in every case of presumed retrobulbar optic neuritis which shows atypical course. Early detection of a brain tumor may save the vision of the patient.

Adult↗

PubMed2002

Frequency doubling technology perimetry in age-related macular degeneration.

BACKGROUND: The role of frequency doubling technology perimetry (FDT) in glaucoma has been promising in terms of speed and simplicity as well as in its high sensitivity and specificity compared to conventional automatic perimetry. In this study, we investigated the possible role of FDT in exudative type age-related macular degeneration (ARMD). METHODS: FDT using full-threshold C-20 mode was performed in patients with ARMD. The macula was classified into 3 zones by the distance from the fovea center (zone I: central 1 degrees, zone II: central 3 degrees except zone I, zone III: central 5 degrees except zones I & II). The lesion was scored into 3 ranks by the area ratio of involvement in each zone. The retinal scores, visual acuity and disease duration were compared with the FDT scores of the central target, which was graded into 5 ranks according to the probability level of abnormal points on total deviation plots using Spearsman's rank correlation method. RESULTS: Measurements from 32 eyes (30 patients) with exudative ARMD were collected. The FDT scores of the central target correlated significantly with the lesion scores in zone III (p = 0.033), but not with the lesion scores in central 3 degrees (zone I: p = 0.383, zone II: p = 0.077). Visual acuity was weakly correlated with the FDT scores of the central target (p = 0.022), and the lesion scores in zone III (p = 0.038), but strongly correlated with the lesion scores in zone I and zone II (p < 0.001). The FDT scores of the central target were within normal limit in 20 eyes. CONCLUSIONS: Our results suggest that FDT using full-threshold C-20 mode is not sensitive enough for the detection of small macular lesions in ARMD. Therefore, it might not be a useful functional evaluation in ARMD. Further modification of the central target of FDT is necessary to detect small macular lesions in ARMD.

Aged↗

PubMed2002

Choroidal osteoma masquerading as central serous chorioretinopathy.

We report a rare case of choroidal osteoma masquerading as central serous chorioretinopathy. A 39-year-old man complained of intermittent episodes of blurred vision in the left eye for 2 months. Fundus examination of the left eye showed a dome-shaped elevation at the macular center. Fluorescein angiography showed a patch of pinpoint leakage resulting in a well-defined pool of dye at the macular center. Initial diagnosis was recurrent central serous chorioretinopathy with sequelae in the left eye. Five months later, serous detachment recurred. Computerized tomography and ultrasonography showed a bony plaque at the choroid level, and choroidal osteoma was diagnosed.

Adult↗