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Hung-Chiao Chen

Publications and source records attributed to Hung-Chiao Chen.

7 recordsLinked to original sources
PubMed2004

Reduction of indocyanine green-associated photosensitizing toxicity in retinal pigment epithelium by sodium elimination.

OBJECTIVE: To determine if eliminating sodium affects indocyanine green (ICG) photosensitizing toxicity and uptake in cultured human retinal pigment epithelial (RPE) cells. METHODS: Cultured human RPE cells were exposed to ICG (2.5 mg/mL) in balanced salt solution and sodium-free balanced salt solution for 2 minutes. Afterwards, ICG was removed, and the cells were irradiated with a light beam (4 x 10(4) lux) for 40 minutes. Toxicity was monitored using light microscopy, calcein AM-ethidium homodimer 1 staining, trypan blue exclusion test, and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium viability assay. Indocyanine green uptake was measured by optical absorption at 790 nm. RESULTS: Photoreactive changes occurred in RPE cells exposed to ICG and light. These changes included cell shrinkage, cell death, pyknotic nuclei, reduced viability, and reduced mitochondrial dehydrogenase activity. These changes were less severe when ICG was dissolved in sodium-free balanced salt solution. In addition, ICG uptake was reduced when the solvent was sodium-free balanced salt solution. CONCLUSION: Indocyanine green and intense light exposure in RPE cells caused photosensitizing toxicity that was reduced when sodium in the solvent was eliminated and replaced with other cations. CLINICAL RELEVANCE: Eliminating sodium from the solvent reduced ICG uptake into RPE and its associated photosensitizing toxicity. This reconstitution method of ICG may be helpful for safer intravitreal ICG use in macular hole surgery.

Acetates↗
PubMed2004

Adjunctive treatment with interferon alpha-2b may decrease the risk of papilloma-associated conjunctival intraepithelial neoplasm recurrence.

PURPOSE: To report a case of bilateral papilloma virus-positive conjunctival intraepithelial neoplasm and the treatment results of using adjunctive interferon alpha-2b. METHODS: Case report and literature review. RESULTS: A 73-year-old man underwent subtotal excisional biopsy of the 270-degree gelatinous limbal lesion of the right eye to avoid creating a limbal deficiency and cicatricial change. Total excisional biopsy of the temporal elevated leukoplakic limbal lesion was performed on his left eye. Histology examination showed bilateral intraepithelial neoplasia, and human papilloma virus-16 and -18 were detected by polymerase chain reaction in both lesions. Two supplemental perilesional injections of interferon alpha-2b in the right eye were given, and the residual mass decreased in size gradually and completed clinical resolution 7 weeks following initial surgery. Although no recurrence was noticed in the right eye, recurrence of the conjunctival intraepithelial neoplasm lesion was noticed in the left eye. CONCLUSION: Adjunctive therapy might lower CIN recurrence rate, especially in extensive lesions, when surgical excision cannot ensure a tumor-free margin. Our bilateral case provided a good control example for the recurrence with or without adjunctive therapy.

Aged↗
PubMed2004

Central corneal thickness of normal-tension glaucoma and non-glaucoma populations in ethnic Chinese.

BACKGROUND: The variations in central corneal thickness can influence intraocular pressure measurement. The aim of our study was to determine whether there is a difference in the central corneal thickness between normal-tension glaucoma (NTG) and non-glaucoma populations. METHODS: This prospective study included 33 consecutive patients with NTG and 33 age- and gender-matched healthy subjects as control subjects. The NTG patients were grouped according to the refractive error into group 1 (spherical equivalent +2.5 D approximately -6.0 D) and group 2 (spherical equivalent more than -6.0 D). Central corneal thickness was measured using a ultrasonic pachymeter. The mean central corneal thickness of the NTG and healthy subjects were compared using the student t-test and Nilcoxon Rank Sum test. RESULTS: The mean (+/- SD) central corneal thickness in the healthy subjects and NTG patients was 554.1 (+/- 36.3) and 547.2 (+/- 31.4) microns, respectively. There were no statistical significant differences between these two groups (p=0.411). The median central corneal thickness in the NTG group 1 and group 2 eyes was 545, and 547.5 microns, respectively. The difference was not statistically significant, either (p=0.799). Ten patients (30%) of NTG had high myopia (group 2), and their median age was 38.5 years old, which was significantly younger than that of the group 1 patients (50 years old, p = 0.0003). CONCLUSION: This study indicated that there were no significant differences of central corneal thickness between NTG patients and healthy subjects in our clinic.

Adult↗
PubMed2003

Cytotoxicity of indocyanine green on retinal pigment epithelium: implications for macular hole surgery.

OBJECTIVE: To evaluate the potential cytotoxic effects of indocyanine green (ICG) on cultured human retinal pigment epithelium (RPE) and the resultant implications for macular hole surgery. METHODS: Human RPE cells were exposed to ICG in concentrations from 0.001 to 5 mg/mL. The exposure duration ranged from 5 minutes to 3 hours. Light microscopy, MTS viability assay, and calcein AM-ethidium homodimer 1 staining were used to evaluate the cytotoxic effects of ICG. RESULTS: The RPE cells incubated with up to 5 mg/mL of ICG for 5 minutes or less exhibited no morphologic change and no significant decrease in dehydrogenase activity. When RPE cells were exposed to 5 mg/mL of ICG for 10 minutes, 1 mg/mL of ICG for 20 minutes, or 0.01 mg/mL of ICG for 3 hours, cell morphologic features were altered, mitochondrial dehydrogenase activity decreased, and some cells were necrotic. CONCLUSIONS: Indocyanine green caused cytotoxicity in cultured human RPE in a dose- and time-dependent manner. Cell death occurred by necrosis. CLINICAL RELEVANCE: Exposure of RPE cells to ICG concentrations up to 5 mg/mL for 5 minutes or less was not injurious; prolonged exposure to a low ICG concentration was toxic. Since ICG may be retained in the vitreous cavity for a lengthy period, thorough washout of ICG during macular hole surgery is required.

Cell Death↗
PubMed2003

Early postoperative capsular block syndrome.

BACKGROUND: Postoperative capsular block syndrome (CBS) is a unique and rare complication of continuous curvilinear capsulorhexis (CCC). The purpose of this study was to analyze the clinical characteristics and results of early postoperative CBS. METHODS: Patients who developed early postoperative CBS after cataract surgery from October 1998 through September 2002 were retrospectively identified. All eyes underwent smooth phacoemulsification after anterior CCC. An intraocular lens (IOL) was implanted into the capsular bag. Neodymuim:YAG (Nd:YAG) laser peripheral anterior capsulotomy or posterior capsulotomy was performed when resolution did not occur or the intracoular pressure was elevated. RESULTS: Eight eyes of eight patients were included in the study. These patients presented with a shallow anterior chamber, anteriorly displaced IOL, distended capsular bag, and myopic shift within the first week after the surgery. One eye was associated with secondary angle-closure glaucoma. No CBS resolved without intervention during the follow-up period. The Nd:YAG laser peripheral anterior capsulotomy (4 eyes) and posterior capsulotomy (4 eyes) were successful in resolving the CBS in all eyes, and normalized the intraocular pressure in the eye with secondary angle-closure glaucoma. CONCLUSION: Postoperative CBS did not resolve spontaneously in most cases. Only a small percentage of early postoperative CBS was associated with secondary glaucoma. The Nd:YAG laser peripheral anterior capsulotomy and posterior capsulotomy were successful in treating postoperative CBS.

Adult↗
PubMed2003

Perfluorocarbon liquid-assisted external drainage in the management of central serous chorioretinopathy with bullous serous retinal detachment.

The differential diagnosis of serous retinal detachment (RD) includes Vogt-Koyanagi-Harada syndrome, severe hypertensive choroidopathy, posterior scleritis, multifocal choroiditis, metastatic tumor, and uveal effusion. Some cases of serous retinal detachment occur as a result of central serous chorioretinopathy (CSCR). Typical CSCR generally affects healthy middle-aged males and is characterized by localized serous RD of the neurosensory retina and retinal pigment epithelium in the macula that often spontaneously improve within 2 to 3 months. On rare occasions, variant CSCR with bullous RD occurs which is frequently misdiagnosed. We report on a case of variant CSCR with severe bullous serous retinal detachment in the left eye that was initially treated at another hospital under the misdiagnosis of rhegmatogenous retinal detachment. Because the retinal detachment developed so fast that a laser could not be applied to all leaking spots, we performed a pars plana vitrectomy, pertluorocarbon liquid-assisted external drainage, and final treatment with an endolaser. The retina was well attached after this management.

Adult↗