Biomedical subjects

San-Ni Chen

Publications and source records attributed to San-Ni Chen.

16 recordsLinked to original sources

PubMed2006

Treatment of rhegmatogenous retinal detachment in teenagers by pneumatic retinopexy technique.

PURPOSE: To evaluate the effectiveness of pneumatic retinopexy as an alternative technique for rhegmatogenous retinal detachment (RD) repair in teenagers. DESIGN: Retrospective, noncomparative, interventional case series. METHODS: We conducted a review of 19 patients (19 eyes) younger than 20 years of age who had undergone pneumatic retinopexy as the initial procedure for rhegmatogenous RD between 1995 and 2002. RESULTS: Fourteen boys and five girls (mean age of 17.1 years) were included in this study. Two eyes had a history of trauma. Seventeen eyes (89.5%) had myopia of > -3 diopters. The averaged refraction of the operated eyes was -6.11 diopters (range, -1.25 to -9.5 diopters). Macular detachment was found in 13 eyes (68.4%). Subretinal fibrosis was present in six eyes (31.6%). Pneumatic retinopexy resulted in reattachment in 16 eyes (84.2%) with one injection of gas. One patient required a second injection of gas. Two patients needed additional scleral buckling to attach the retina. Displaced subretinal fluid and delayed resorption of subretinal fluid were noted in four eyes. Mean follow-up period was 42.7 months (range, six to 75 months). CONCLUSIONS: Rhegmatogenous RD in teenagers can be treated with pneumatic retinopexy with an overall successful rate as in adults. More attention is required regarding the postoperative stage and follow-up period to ensure surgical success.

Adolescent↗

PubMed2006

Pediatric rhegmatogenous retinal detachment in taiwan.

PURPOSE: To describe the clinical features and surgical outcomes in a series of pediatric patients with rhegmatogenous retinal detachments in Taiwan. METHODS: Retrospective study of pediatric patients (age 1 to 15 years) with rhegmatogenous retinal detachment dated between January 1995 and December 2004. Patients with perforating ocular trauma were excluded. Patients were divided into four groups according to the predisposing factors: Group 1, those with congenital or developmental anomalies; Group 2, those with trauma history; Group 3, those with myopia greater than -3 D but excluding patients in Groups 1 and 2; and Group 4, the others with miscellaneous etiologies. Patients' age, sex, medical history, ocular history, type of detachment, macular status, refractive status, previous visual acuity, number and type of surgeries performed, postoperative retinal status, and current visual acuity were recorded. RESULTS: Thirty-five eyes of 32 patients were included in this study. The median age was 13 years, and 75% of patients were boys. There were 17 eyes (49%) in Group 1, 8 in Group 2 (23%), 8 in Group 3 (23%), and 2 in Group 4 (6%). Bilateral retinal detachment was present in 7 patients (22%). In Group 1, familial exudative vitreoretinopathy was present in 7 eyes; retinopathy of prematurity was noted in 5 eyes; Marfan's syndrome was present in 3 eyes; mental and growth retardation was present in 2 eyes. Macula sparing retinal detachment was found in 3 eyes. Retinal attachment was achieved in 28/35 eyes. Visual recovery was modest. CONCLUSION: Congenital or developmental anomalies, myopia, and trauma were the most common risk factors for pediatric rhegmatogenous retinal detachment in Taiwan. Regular follow-up for children at risk of developing rhegmatogenous retinal detachment is necessary for early detection.

Adolescent↗

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

Embolic cilioretinal artery occlusion due to carotid artery dissection.

PURPOSE: To report a case of embolic cilioretinal artery occlusion caused by carotid artery dissection. DESIGN: Interventional case report. METHODS: A 38-year-old woman presented with acute visual loss in her right eye. Funduscopy showed a cilioretinal artery occlusion, which was confirmed by a fluorescein angiography. An embolus was found in the distal segment of the vessel. RESULTS: Color Doppler images of right internal carotid artery (ICA) disclosed a pseudolumen, suggesting a diagnosis of carotid dissection. Retrobulbar color Doppler image showed relative low flow velocity in the ophthalmic artery without flow reversal. Magnetic resonance angiography and cerebral angiogram showed total occlusion of the right ICA. Follow-up visual field examination revealed an inferior central defect fed by the cilioretinal artery. CONCLUSION: The pathogenesis of retinal artery occlusion caused by carotid dissection may be embolic or hemodynamic. In our case, a permanent visual defect was related to embolic occlusion of the cilioretinal artery.

Adult↗

PubMed2004

Polypoidal choroidal vasculopathy in Taiwan.

BACKGROUND: Polypoidal choroidal vasculopathy (PCV) has been described since the 1980s with great variations in patient data in different countries. We report the first case series in the Taiwanese population. METHODS: We reviewed the medical records of all patients diagnosed with PCV between January 2000 and October 2001 at the retina clinics of Chang Gung Memorial Hospital. RESULTS: Eight patients (9 eyes) were enrolled. Six were men. The average age was 60.9 (range, 48-72). One patient had bilateral disease. All of the 9 eyes had polypoidal lesions in the macular area; 2 eyes had peripapillary lesions. The average follow-up time was 16.5 months. One eye (1/9) improved more than 2 lines in the Snellen chart, 4 eyes (4/9) changed within 1 line, and 4 eyes (4/9) deteriorated more than 2 lines. Seven eyes (7/9) had final visual acuities worse than 20/200 and 5 eyes (5/9) developed disciform scarring. CONCLUSIONS: The prognosis of PCV among Taiwanese patients seems worse than in other ethnic groups. A high incidence of disciform scar formation and predominantly centrally located polypoid lesions seem to play an important role in the poor prognosis.

Aged↗

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

Retinal toxicity of intravitreal tissue plasminogen activator: case report and literature review.

OBJECTIVE: To present the clinical picture of retinal toxicity of commercial tissue plasminogen activator (tPA). DESIGN: Case report and literature review. METHODS: Two successive intravitreal injections of tPA (50 micro g) 3 days apart with gas tamponade were given to treat a 49-year-old man with submacular hemorrhage. The adverse consequences of this treatment were monitored. A literature review of retinal toxicity of commercial tPA in animals was also done. MAIN OUTCOME MEASURES: Retinal findings, electroretinograph (ERG) and visual acuity testing. RESULTS: Diffuse pigmentary alterations sparing the posterior pole, poor visual acuity after the absorption of submacular hemorrhage, reduced scotopic and photopic ERG A- and B-waves were noted. CONCLUSIONS: This is the first reported case of retinal toxicity of commercial tPA in humans that resembles the descriptions of tPA-mediated retinal toxicity in animal models. The dosage of intravitreal tPA (between 50 and 100 micro g) may be toxic to the human retina.

Electroretinography↗

PubMed2003

Nuclear sclerotic cataract in young patients in Taiwan.

PURPOSE: To document the clinical features of discrete nuclear sclerosis in young patients. SETTING: Chang-Gung Memorial Hospital, Taoyuan, Taiwan, Republic of China. METHODS: The medical records of all patients younger than 45 years with nuclear sclerosis who had cataract surgery at 1 hospital were retrospectively reviewed. Patients with congenital cataract, ocular trauma, ocular disease in addition to myopia, and systemic disease associated with cataract were excluded. The patients' age, sex, bilateral lens status, axial length, original and preoperative refractive status, and preoperative and postoperative best corrected visual acuities (BCVAs) were recorded. RESULTS: Fifty-five eyes of 35 patients aged 32 to 45 years met the study criteria. Nuclear sclerotic cataract was bilateral in 20 patients. The mean age at surgery was 40.64 years +/- 3.63 (SD). The mean refraction before the development of cataract was -7.80 +/- 3.57 diopters (D) and the mean preoperative refraction, -17.40 +/- 6.05 D. The mean axial length was 28.09 +/- 2.31 mm. The postoperative BCVA was 20/22 or better in 53 eyes (96.4%). CONCLUSIONS; In patients younger than 45 years with cataract in Taiwan, nuclear sclerosis was not a rare cause of visual loss and axial myopia was strongly associated with the formation of nuclear sclerosis. Bilateral sclerosis was observed in most cases. Patients with an axial length greater than 27.0 mm had the greatest risk. Surgical treatment was therapeutic.

Adult↗

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↗

PubMed2003

Surgical treatment of retinal detachment following acute retinal necrosis syndrome: surgical results in four patients.

BACKGROUND: Acute retinal necrosis (ARN) syndrome is an uncommon but severe ocular disease that typically affects otherwise healthy individuals. It is frequently complicated with retinal detachment and the visual prognosis in such patients is usually poor. METHODS: We operated on four eyes in four patients from 1999 through 2001. Three ophthalmologists in our hospital did these operations, respectively. The surgical methods included pars plana vitrectomy, lensectomy, encircling scleral buckling combined with membrane dissection, air-fluid exchange, endolaser photocoagulation, and retinal tamponade with silicone oil or perfluoropropane gas. RESULTS: Three patients received one operation and the other one needed a second operation to release the retinal traction. One patient needed a lensectomy at the time of vitrectomy. Macular attachment was achieved in all four eyes (100%). Vision improved in two patients but none achieved visual acuity better than 20/200. The complications were cataract in three patients, macular pucker in three, and silicone keratopathy in one. CONCLUSION: Our results suggest that modern vitrectomy techniques provide a very high retinal attachment rate in patients with retinal detachment following ARN syndrome.

Adult↗

PubMed2002

High-density vitreous substitute in the management of advanced Coats' disease.

Advanced Coats' disease is a threat to vision. Management of advanced Coats' disease has long been a challenge to ophthalmologists. Some people have attempted to use pars plana vitrectomy and intraocular diathermy on diseased vessels followed by intraocular gas or silicone oil injection. However, internal drainage is technically difficult. We present a case of advanced Coats' disease for which, after an encircling buckle and pars plana vitrectomy, intravitreal injection of perfluorodecaline was used to displace the subretinal fluid to the peripheral subretinal space, and transscleral external drainage was achieved. Finally panretinal laser photocoagulation, cryotherapy and endodiathermy were performed on diseased vessels. Visual improvement and reattachment of the posterior pole were achieved. So we think a high-density vitreous substitute can be a useful adjunct in the management of advanced Coats' disease. It minimizes the disadvantages of the internal or external approaches, while maintaining most of the advantages of both.

Adolescent↗

PubMed2002

Excessive myopia and anisometropia associated with familial exudative vitreoretinopathy.

BACKGROUND: To describe associations between familial exudative vitreoretinopathy (FEVR) and refractive status. METHODS: We conducted retrospective studies of patients with clinical diagnoses of familial exudative vitreoretinopathy from June 1986 through September 2000. All patients had cycloplegic refraction, visual acuity with correction, and underwent fundus examination. Ocular history since early childhood was described. RESULTS: Nine patients were recruited. All had excessive myopia, which was noted since early childhood. Amblyopia was noted in seven of the nine patients. Asymmetric FEVR was found in four of the nine patients. In all four patients with asymmetric FEVR, anisometropia equal to or greater than 2.5D was noted. Myopia was higher and amblyopia was more severe in the eye more severely affected with FEVR. CONCLUSION: Excessive myopia, anisometropia and amblyopia were more likely to occur in eyes with familial exudative vitreoretinopathy. Patients with asymmetric disease tended to have higher myopia in the eye with more severe degree of FEVR as compared with the paired eye and thus correlated with anisometropia.

Adolescent↗

PubMed2002

Eyewall resection for a uveal malignant melanoma under local anesthesia.

A 44-year-old man was referred to our hospital for ciliary body tumor management. A uveal melanoma in the left eye without systemic metastasis was our impression after a series of examinations. We treated this patient with eyewall resection under local anesthesia. Eyewall resection was previously regarded as a complicated procedure that should be performed under general anesthesia. Our surgery was successful, and there were no complications related to the local anesthesia. We followed up this patient for 3 years, and no recurrence was found. Eyewall resection is a good alternative to enucleation for treating a ciliary body melanoma. Under a premise of survival, eyewall resection can maintain part of the visual function and cosmetics. General anesthesia is not indispensable when a patient's health does not allow its use.

Adult↗

PubMedDate not supplied

Presumed choroidal atypical tuberculosis superinfected with cytomegalovirus retinitis in an acquired immunodeficiency syndrome patient: a case report.

BACKGROUND: To report an unusual case of multifocal choroidopathy with uveitis and cytomegalovirus (CMV) retinitis in a patient with acquired immunodeficiency syndrome (AIDS) after initially presenting with pulmonary tuberculosis (Mycobacterium kansasii). CASE: Slit-lamp biomicroscopy and indirect ophthalmoscopic examination were done. Vitreous biopsy, pars plana vitrectomy, and retinal biopsy were performed. Computer tomography scan, magnetic resonance imaging and biopsy of the brain were also carried out. OBSERVATIONS: Multiple yellowish-white, round, slightly elevated subretinal pigment epithelium lesions were noted in areas devoid of the atrophic retina of previous CMV infection. Anterior uveitis and vitritis were also noted. Vitreous, retina, and brain biopsy did not offer any clue for diagnosis. The visual acuity improved later, along with recovered immunity under the anti-tuberculosis medications and the cocktail therapy for AIDS. CONCLUSIONS: Combined CMV retinitis and atypical tuberculosis chorioretinitis, although rare, can develop in the patients with AIDS. Systemic dissemination of atypical tuberculosis infection should be responsible for the choroidopathy in this patient.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

Retinal neovascularization and an angioma-like lesion after demarcation photocoagulation for rhegmatogenous retinal detachment.

Laser photocoagulation might aggravate the ischemia of an area of retinal detachment and predispose the retina to formation of neovascularization and an angioma-like lesion. We present a case of retinal neovascularization (RNV) and an angioma-like lesion occurring after demarcation photocoagulation for rhegmatogenous retinal detachment (RRD). A 20-year-old woman suffered from a retinal atrophic hole with localized shallow retinal detachment in the right eye. Laser photocoagulation was performed to wall off the area of detachment. Fifteen months later, RNV and an angioma-like lesion had developed in the previously detached retina. Treatment with demarcation photocoagulation for RRD may run a risk of formation of RNV and angioma-like lesion if the retina is not reattached.

Adult↗