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S C G Tseng

Publications and source records attributed to S C G Tseng.

12 recordsLinked to original sources
PubMed2005

Characterisation of myofibroblasts in fibrovascular tissues of primary and recurrent pterygia.

AIMS: To determine the presence and origin of myofibroblasts in pterygia. METHODS: 86 specimens including head, body, and fibrovascular tissue from 52 primary and 34 recurrent pterygia and five exenterated eyes without pterygia were searched for the origin of myofibroblasts. All tissues were subjected to haematoxylin and eosin staining, immunohistochemistry using antibodies against alpha smooth muscle actin (alpha-SMA), desmin, vimentin, and caldesmon, and transmission electron microscopy (TEM). The phenotype of fibroblasts subcultured in a serum free medium from pterygium fibrovascular tissues was characterised by the above antibodies. Bundles of dense fibrous tissues were noted in 86% of the fibrovascular tissue specimens evaluated. Cells within these bundles were characterised as myofibroblasts based on positive staining to alpha-SMA, but negative to desmin and caldesmon, markers for smooth muscle cells. Interestingly, positive alpha-SMA staining was also found in the periorbital fibroadipose tissue posterior to Tenon's capsule near the nasal conjunctiva in all exenterated specimens. All first passage fibroblasts expressed vimentin, some were positive to alpha-SMA, but all were negative to desmin or caldesmon. Cells in pterygium fibrovascular tissues showed ultrastructural features of intracytoplasmic bundles of microfilaments, consistent with myofibroblastic differentiation. CONCLUSION: These studies collectively demonstrate the presence of contractile myofibroblasts bundle in pterygia and in the periorbital fibroadipose tissue posterior to Tenon's capsule of exenterated eyes without pterygium.

Actins↗
PubMed2005

In vitro and in vivo killing of ocular Demodex by tea tree oil.

AIMS: To compare the in vitro killing effect of different agents on Demodex and to report the in vivo killing effect of tea tree oil (TTO) on ocular Demodex. METHODS: Survival time of Demodex was measured under the microscope. Sampling and counting of Demodex was performed by a modified method. RESULTS: Demodex folliculorum survived for more than 150 minutes in 10% povidone-iodine, 75% alcohol, 50% baby shampoo, and 4% pilocarpine. However, the survival time was significantly shortened to within 15 minutes in 100% alcohol, 100% TTO, 100% caraway oil, or 100% dill weed oil. TTO's in vitro killing effect was dose dependent. Lid scrub with 50% TTO, but not with 50% baby shampoo, can further stimulate Demodex to move out to the skin. The Demodex count did not reach zero in any of the seven patients receiving daily lid scrub with baby shampoo for 40-350 days. In contrast, the Demodex count dropped to zero in seven of nine patients receiving TTO scrub in 4 weeks without recurrence. CONCLUSIONS: Demodex is resistant to a wide range of antiseptic solutions. Weekly lid scrub with 50% TTO and daily lid scrub with tea tree shampoo is effective in eradicating ocular Demodex.

Animals↗
PubMed2004

Rat enterocyte cultures on human amniotic membranes.

BACKGROUND: Rat enterocytes were cultured on human amniotic membranes. METHODS: Intestine of neonatal DA rats was digested using collagenase and dispase according to the technique developed by Evans. The harvested enterocytes were cultured on human amniotic membranes using standard cell culture techniques. RESULTS: After the second day of culture, some intestinal epithelial units started to gradually detach from the membrane, dispersing as single cells and disappearing within a few days. On the contrary, other units showed signs of cell proliferation. The cultured cells underwent morphologic changes, survived, and remained attached to the amniotic membrane for 3 weeks. Paraffin sections of the membrane showed cultured cytokeratin-positive cells attached to the membrane as a monolayer. CONCLUSIONS: Human amniotic cell membranes help to maintain rat enterocytes in culture for a long time period (3 weeks), possibly via secretion of trophic factors. This technique may provide a valuable tool to study the development and the properties of these epithelial cells in a culture environment.

Amnion↗
PubMed2004

Keratolimbal allograft in corneal reconstruction.

The replenishment of corneal epithelial SC is a crucial step for reconstructing the ocular surface in patients suffering from devastating ocular surface diseases manifesting with total LSCD. KLAL is one of such procedures and has a long track record and a long follow-up for patients with bilateral total LSCD. This review summarizes the literature experiences and outline new strategies that are important to enhance the success of this procedure. Further research is needed to fully understand the biological processes involved in allogeneic tissue transplantation for preserving epithelial SC adhesion, migration, and survival.

Adult↗
PubMed2004

Clinical characteristics of conjunctivochalasis with or without aqueous tear deficiency.

AIM: To show characteristic ocular surface findings caused by conjunctivochalasis (CCh) in dry eye patients with or without aqueous tear deficiency (ATD). DESIGN: Comparative non-interventional cases. PATIENTS AND METHODS: Clinical data of five ATD patients without CCh (group A), eight CCh patients with ATD (group B), and eight CCh patients without ATD (group C) were retrospectively reviewed. Presence or absence of CCh was determined by fluorescein staining to outline tear meniscus and conjunctival folds with an enhancing filter. Dry eye symptoms, history of subconjunctival haemorrhage, meibum expression, tear break up time, fluorescein and rose bengal staining, and fluorescein clearance test, and other abnormal ocular surface findings were measured. RESULTS: CCh patients were significantly older (p = 0.001). In pure ATD, the principal symptom of dryness became worse as the day progressed. In contrast, blurry vision, burning sensation, and dryness became worse during reading in all CCh patients (p = 0.0008) or worse in the morning upon awakening in the majority patients with CCh only (p = 0.02). Besides the interpalpebral exposure, which was noted in ATD, positive fluorescein or rose bengal staining was noted in the redundant conjunctival folds and the non-exposure zone in CCh (p = 0.0008). Redundant conjunctival folds were present in both lower and upper bulbar conjunctiva, obliterating both lower and upper tear meniscuses, and spatially correlated with anterior migration of the mucocutaneous junction in CCh. Delayed tear clearance was significantly more prevalent in CCh than ATD (p = 0.0008). Vigorous blinking worsened in CCh but not in ATD (p = 0.0008). Lacrimal puncta were swollen in groups B and C, but not in group A (p = 0.04). CONCLUSIONS: CCh is not restricted to the lower bulbar conjunctiva, and contributes to pathogenesis of dry eye by obliterating both lower and upper tear meniscus, causing unstable tear film and by creating delayed tear clearance. Dry eye symptoms were worsened by downgaze during reading and by vigorous blinking. Other characteristic signs including subconjunctival haemorrhage, swollen puncta, anterior migration of the mucocutaneous junction, and patterns of dye staining also help distinguish dry eye associated with CCh from that caused by ATD alone.

Adult↗
PubMed2004

Correlation of long term phenotypic and clinical outcomes following limbal epithelial transplantation cultivated on amniotic membrane in rabbits.

AIM: To determine the epithelial phenotype in rabbits with total limbal stem cell deficiency (LSCD) after reconstruction with autologous limbal epithelial stem cells ex vivo expanded on rabbit amniotic membrane (AM). METHODS: Left eyes of 52 rabbits were rendered total LSCD, verified by impression cytology. The fibrovascular pannus of each cornea was removed. Group I (n = 10) received rabbit AM transplantation alone, while groups II-IV (n = 42) underwent transplantation of LSC cultured on rabbit AM (LSC-AM) from a small limbal biopsy taken from the right eye. Clinical outcome was graded as "success," "partial success," or "failure" depending on the corneal smoothness and avascularity. Epithelial phenotype was determined by immunostaining and graded as "corneal (K)," "conjunctival (J)," or "mixed (M)" depending on expression of K3 and Muc5AC. RESULTS: After 1 year follow up, group I showed 100% failure and groups II-IV showed 26% success (p<0.001). Clinical failure correlated with J phenotype p = 0.001), while clinical success correlated with K phenotype p = 0.01). When the phenotypic outcome was used for comparison, J phenotype was significantly high in group I (p = 0.003), while K phenotype was significantly high in groups II-IV (p<0.05). CONCLUSION: There is a strong correlation between clinical success and resultant corneal epithelial phenotype. Ex vivo expanded LSC can successfully reconstruct corneal surfaces with unilateral total LSCD.

Amnion↗
PubMed2003

Temporary amniotic membrane patching for acute chemical burns.

PURPOSE: To describe the surgical technique, and its usefulness, of temporary amniotic membrane patching (AMP) in the acute phase of ocular chemical injury. METHODS: Temporary AMP with modification in suture placement was performed on five eyes of five consecutive patients inflicted with acute chemical injury having a greater than grade II injury by the Roper-Hall classification. RESULTS: All patients reported herein presented with a large epithelial defect on the cornea and conjunctiva. Case 3 was classified as grade III while the other four cases were classified as grade II. The causative chemical agents were anhydrous acetic acid in Case 1, calcium oxide in Case 2, sodium hydroxide in Case 3, sodium silicate in Case 4, and sulphuric acid in Case 5. All cases experienced rapid relief of pain after AMP. Epithelialization of the cornea with improvement of visual acuity was observed in all cases when the amniotic membrane was removed within 2 weeks after surgery. During the mean follow-up of 19.6 months, the ocular surface remained stable and no cicatricial complications were noted. CONCLUSIONS: These results suggest that immediate AMP is quite useful for managing moderately severe acute ocular chemical injury by facilitating rapid epithelialization and pain relief, and securing ocular surface integrity.

Acute Disease↗
PubMed2003

Corneal stromal changes following reconstruction by ex vivo expanded limbal epithelial cells in rabbits with total limbal stem cell deficiency.

AIM: To study corneal stromal changes and the presence of myofibroblasts after transplantation of ex vivo expanded limbal epithelium. METHODS: A state of limbal deficiency was induced in 16 rabbits. After transplantation with autologous ex vivo expanded limbal epithelium on amniotic membrane (AM), their clinical outcomes were classified as success, partial success or failure according to surface smoothness, stromal clarity, and vascularisation. Clinical outcomes were correlated with phenotypic outcomes of corneal, conjunctival, or mixed epithelium, defined by expression of K3 keratin or MUC5AC. Immunostaining was performed with antibodies against collagen IV, fibronectin, and alpha-smooth muscle actin (alpha-SMA) to assess stromal wound remodelling. RESULTS: Rabbits were sacrificed after a mean follow up of 10 (SD 3.3) months. Collagen IV, expressed in the basement membrane of all three groups, was found in the stroma of the partial success, but not in that of the success or the failure. Fibronectin was absent in the success and the failure, but expressed in the stroma of the partial success. Alpha-SMA was expressed in superficial stroma of the partial success, but suppressed in areas with AM remnants. CONCLUSION: Restoration of a clear and transparent cornea is associated with a normal corneal epithelium and complete wound remodelling. In contrast, wound healing remains active and incomplete in conjunctivalised corneas, which remain opaque with myofibroblasts.

Actins↗
PubMed2003

Therapeutic penetrating keratoplasty in severe fungal keratitis using cryopreserved donor corneas.

AIMS: To investigate whether cryopreserved donor cornea could be used for therapeutic penetrating keratoplasty (PKP) to eradicate the infection, obviate complications, and preserve anatomical integrity in severe fungal keratitis. METHODS: In this retrospective, consecutive case series, 45 eyes of 45 patients with severe fungal keratitis, which exhibited anterior chamber collapse, corneal perforation, and/or large suppurative corneal infiltrate, received therapeutic PKP after removal of the infected corneal tissue, irrigation of the anterior chamber by 0.2% fluconazole solution, iris dissection of fibrinoid membrane, and iridectomy and therapeutic PKP using corneas cryopreserved at -20 degrees C. RESULTS: Among 45 eyes, 39 eyes (86.7%) were successfully eradicated the fungal infection without recurrence and maintained their anatomical integrity without any complication. Four of 45 eyes (8.9%) showed postoperative rise of intraocular pressure, of which three were controlled with subsequent antiglaucoma surgeries, whereas one eye needed additional antiglaucoma medications. Two of 45 eyes (4.4%) were enucleated because of uncontrollable fungal infection and secondary retinal detachment, respectively. 23 eyes received subsequent optical PKP and, among them, 21 maintained clear corneal grafts and two suffered from graft failure due to allograft rejections. CONCLUSION: Cryopreserved donor corneas are effective substitutes in therapeutic PKP to control severe fungal corneal infection and preserve the global integrity, and may offer additional advantages over conventional PKP in reducing allograft rejection, eradicating fungal infection during the postoperative period, and improving the success of optical PKP for visual rehabilitation.

Administration, Oral↗
PubMed2002

Ex vivo preservation and expansion of human limbal epithelial stem cells on amniotic membrane cultures.

BACKGROUND/AIM: Amniotic membrane (AM) transplantation effectively expands the remaining limbal epithelial stem cells in patients with partial limbal stem cell deficiency. The authors investigated whether this action could be produced ex vivo. METHODS: The outgrowth rate on AM was compared among explants derived from human limbus, peripheral cornea, and central cornea. For outgrowth of human limbal epithelial cells (HLEC), cell cycle kinetics were measured by BrdU labelling for 1 or 7 days, of which the latter was also chased in primary cultures, secondary 3T3 fibroblast cultures, and in athymic Balb/c mice following a brief treatment with a phorbol ester. Epithelial morphology was studied by histology and transmission electron microscopy, and phenotype was defined by immunostaining with monoclonal antibodies to keratins and mucins. RESULTS: Outgrowth rate was 0/22 (0%) and 2/24 (8.3%) for central and peripheral corneal explants, respectively, but was 77/80 (96.2%) for limbal explants (p <0.0001). 24 hour BrdU labelling showed a uniformly low (that is, less than 5%) labelling index in 65% of the limbal explants, but a mixed pattern with areas showing a high (that is, more than 40%) labelling index in 35% of limbal explants, and in all (100%) peripheral corneal explants. Continuous BrdU labelling for 7 days detected a high labelling index in 61.5% of the limbal explants with the remainder still retaining a low labelling index. A number of label retaining cells were noted after 7 day labelling followed by 14 days of chase in primary culture or by 21 days of chase after transplantation to 3T3 fibroblast feeder layers. After exposure to phorbol 12-myristate 13-acetate for 24 hours and 7 day labelling, HLEC transplanted in athymic mice still showed a number of label retaining basal cells after 9 days of chase. HLEC cultured on AM were strongly positive for K14 keratin and MUC4 and slightly positive in suprabasal cells for K3 keratin but negative for K12 keratin, AMEM2, and MUC5AC. After subcutaneous implantation in athymic mice, the resultant epithelium was markedly stratified and the basal epithelial cells were strongly positive for K14 keratin, while the suprabasal epithelial cells were strongly positive for K3 keratin and MUC4, and the entire epithelium was negative for K12 keratin and MUC5A/C. CONCLUSIONS: These data support the notion that AM cultures preferentially preserve and expand limbal epithelial stem cells that retain their in vivo properties of slow cycling, label retaining, and undifferentiation. This finding supports the feasibility of ex vivo expansion of limbal epithelial stem cells for treating patients with total limbal stem cell deficiency using a small amount of donor limbal tissue.

Adult↗
PubMed2002

Amniotic membrane transplantation for reconstruction after excision of large ocular surface neoplasias.

AIM: To evaluate the clinical outcome of patients in whom ocular surface reconstruction was performed using amniotic membrane transplantation (AMT) after the excision of large (>20 mm square) ocular surface neoplasias (OSN). METHODS: A non-comparative interventional case series. In 16 eyes of 16 patients, excision of large OSN including conjunctival intraepithelial neoplasia (CIN), primary acquired melanosis, and malignant melanoma was followed by adjunctive cryotherapy and suturing of a single layer of amniotic membrane (AM) with the basement membrane side facing up to the healthy bordering tissue. Epithelial healing, complications, and tumour recurrences were analysed. RESULTS: During a mean follow up of 23.7 (SD 11, range 11-43) months, ocular surface healing was rapid and complete in all cases. One complication of pyogenic granuloma was noted. Tumour recurrence occurred in one out of 10 CIN cases (10%), no recurrences were observed in the patients with melanotic lesions. CONCLUSIONS: AMT in lieu of conjunctival or mucosal autograft is an effective substrate for reconstructing the ocular surface following excision of large OSN. AMT is effective in managing large OSN by avoiding the complications that may be associated with conventional removal, specifically in cases where the limbal architecture is destroyed by surgical resection or adjuvant therapies.

Adult↗