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At least 19 recordsLinked to original sources
PubMed1993

[Insertion of the Tenon capsule onto the rectus muscles].

The localisation and definition of the capsule of Tenon insertion on the rectus muscles is of prime importance to the strabismus surgeon. The depth of the superior sub-Tenon space was measured on 22 adult human eyes after fixation in formalin. Although the measurements revealed major differences between the eyes, the following results were found: inferior rectus muscle = 7.8 mm +/- 1.79 (5.2-13.0), medial rectus = 12.6 mm +/- 2.15 (8.4-17.2), superior rectus muscle = 16.7 mm +/- 2.39 (12.7-21.5), and lateral rectus muscle = 19.0 mm +/- 2.19 (14.5-22.0). Histological studies of 2 other human eyes confirmed the notion of a band of insertion on rectus muscles as the posterior limit of the sub-Tenon space. As far as this insertion, the capsule of Tenon is a dense connective tissue composed of many collagen and elastin fibers, but after the band insertion, it becomes virtual through its fusion with the perimysium of the rectus muscle.

Adult↗
PubMed2003

[The inhibition effect of photodynamic on human Tenon capsule fibroblast cells].

OBJECTIVE: To investigate the inhibition of photodynamic effect on human Tenon capsule fibroblast cells in vitro. METHODS: The human Tenon capsule fibroblast cells were divided into nine groups named as group A to I, each group had four wells. Group A to G, each group was added photosensitizer benzoporphyrin derivative monoacid ring A (BPD) with end concentration of 2.50 x 10(3) g/L, 1.25 x 10(3) g/L, 0.62 x 10(3) g/L, 0.31 x 10(3) g/L, 0.16 x 10(3) g/L, 0.08 x 10(3) g/L, 0.04 x 10(3) g/L respectively. Then the culture cells were irradiated by 689 nm diode laser with dosage of 2.4 J/cm(2) after BPD treatment for 15 minutes. Group H was treated with Mitomycin C (MMC) at concentration of 0.2 g/L. Group I was control without any treatment. All the cells were kept cultured for another 24 hours and then MTT colorimetric assay was applied to measure the relative inhibitory rate of photodynamic effect on the cells. RESULTS: There is statistical significance between group A to H and group I with the method of one way analysis of variance. When compared to group I, the relative inhibitory rates of group A to G are 93.3%, 91.0%, 90.3%, 87.1%, 66.0%, 41.6%, 12.5% respectively, and the inhibitory rate of group H (MMC) is 93.0%. CONCLUSION: Photodynamic effect can inhibit the proliferation of human Tenon capsule fibroblast cells in vitro. The inhibitory rate appears to be dependent on the concentration of the photo sensitizer.

Cell Division↗
PubMed2004

Altered transcripts expression of matrix metalloproteinases and their tissue inhibitors in tenon capsule of patients with glaucoma.

PURPOSE: To determine the transcripts expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in Tenon capsule of patients with primary glaucoma and non-glaucomatous patients who serve as the control. PATIENTS AND METHODS: Specimens of Tenon capsule were obtained intraoperatively and evaluated with the reverse transcriptase-polymerase chain reaction method. The transcripts levels of MMP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2 relative to that of glyceraldehyde phosphate dehydrogenase were determined. RESULTS: The transcripts levels of MMP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2 were not correlated with age in the control group. There were differences in the transcripts expression of MMP-2 (P < 0.001), MMP-9 (P = 0.017), TIMP-1 (P < 0.001), and TIMP-2 (P = 0.001) among the control, primary open angle glaucoma, and primary angle-closure glaucoma groups (Kruscal-Wallis H test). Comparing with the controls, open angle glaucoma had decreased transcripts levels of MMP-2 (P = 0.001) and TIMP-1 (P = 0.006) while angle-closure glaucoma had decreased transcripts levels of MMP-2 (P < 0.001), MMP-9 (P = 0.004), TIMP-1 (P < 0.001), and TIMP-2 (P < 0.001) (Mann-Whitney U tests). CONCLUSION: The transcripts expression of certain MMPs and TIMPs is altered in Tenon capsule of glaucoma patients, which might result from long-term application of topical glaucoma medications.

Adolescent↗
PubMed2002

Apoptosis gene expression and death receptor signaling in mitomycin-C-treated human tenon capsule fibroblasts.

PURPOSE: To examine the effect of mitomycin-C on the expression of apoptosis genes in human Tenon capsule fibroblasts and to evaluate whether death receptor signaling modulates mitomycin-C cytotoxicity. METHODS: Bcl-2, Bax, Bcl-x, Fas (CD95) and tumor necrosis factor (TNF) receptor expression was determined by flow cytometry in control and mitomycin-C-treated Tenon fibroblasts. Fibroblast death was quantified using a lactate dehydrogenase release assay. The effect of Fas and TNF-receptor signaling was evaluated using Fas-specific antibodies and soluble TNF-alpha. RESULTS: Tenon fibroblasts constitutively express Bcl-2, Bax, and Bcl-x in culture. Mitomycin-C (0.4 mg/mL) induced a small but consistent increase in the expression of all three proteins. Tenon fibroblasts express low levels of Fas but are resistant to the effects of Fas-receptor ligation. Mitomycin-C (0.01-1.0 mg/mL) led to a significant increase in Fas expression at all concentrations tested (P < 0.01). Pretreatment with mitomycin-C (0.4 mg/mL) rendered fibroblasts susceptible to agonistic anti-Fas monoclonal IgM antibodies (50-500 ng/mL) and led to a further 50% reduction in viable fibroblasts at 48 hours, compared with mitomycin-C alone (P < 0.05). Antibodies that block the Fas receptor did not inhibit mitomycin-C-induced apoptosis. CONCLUSIONS: Mitomycin-C alters apoptosis gene expression and primes fibroblasts to the effects of Fas receptor ligation. Factors other than the level of Fas receptor expression modulate the response to Fas receptor signaling. Determining the signals that regulate fibroblast apoptosis may help to refine therapeutic strategies for switching off the subconjunctival healing response and maintaining intraocular pressure control.

Antibiotics, Antineoplastic↗
PubMed2006

[Anti-proliferative effect of herpes simplex virus thymidine kinase gene system on human Tenon capsule fibroblasts in vitro].

OBJECTIVE: To observe anti-proliferative effect of herpes simplex virus thymidine kinase gene system (HSV-tk) on human Tenon capsule fibroblasts (HTFs) and it's mechanism. METHODS: Retroviral vector was constructed containing HSV-tk gene and transfer to packaging cell line PT67. The positive clones was selected with G418 and the supernatant was collected which contains virus particles. The titer of the virus was also calculated. The virus particles were verified by transmission electron microscope (TEM). PCR was carried out to detect the integrity of tk gene into viral DNA genome. HTFs cells were infected with the virus and the positive clones were selected for propagation culture. RT-PCR and Western blot were used to detect tk gene expression. The anti-proliferative effect of tk gene on HTFs cells was determined by MTT. Apoptosis of cells was detected by Hoechst 33258 DNA staining and flow cytometry. The morphologic changes of the cell were observed by TEM. RESULTS: The retroviral vector pL (tk) SN was constructed successfully which was verified by enzyme cutting. The shape of virus particles derived from the package cells appeared to be oval or spherical under TEM with the diameter around 100 nm. The tk gene was detected in the viral DNA genome by PCR. The virus titer was 4 x 10(7) cfu/ml. The expression of tk gene was detected by RT-PCR and Western blot both in mRNA and protein level. The anti-proliferative effect of tk gene on HTFs cells was dose-dependent, all cells were died 5 days after 5 x 10(-3) g/L GCV being added, IC50 = 6 x 10(-4) g/L. Both necrosis and apoptosis were observed in this study and the apoptosis rate was increased with increasing dose of GCV. CONCLUSIONS: The proliferation of HTFs cells in vitro could be effectively inhibited by the killing effect of HSV-tk-GCV system through the pathway of necrosis and apoptosis.

Antiviral Agents↗
PubMed2005

Inhibitive effects of quercetin on rabbit tenon capsule fibroblasts proliferation.

PURPOSE: To study the inhibitive effects of quercetin (QU) on the fibroblasts proliferation of rabbit Tenon's capsule and its mechanism. METHODS: Cultured fibroblasts were exposed to different concentrations of QU solution and investigated by microculture tetrazolium (MTT) assay. The effect of QU was observed on cells cycle using the flow cytometer. RESULTS: QU can suppress the proliferation of rabbit Tenon's capsule fibroblasts in vitro and show a dose-time dependent tendency. Flow cytometer results showed 26.92% cell increase in G1 phase, 23.50% decrease in S phase and 3.42% decrease in G2 phase. CONCLUSIONS: QU can suppress the proliferation of rabbit Tenon's capsule fibroblasts in vitro and show a dose-time dependent tendency. QU may effect all phase of cell cycle and inhibit cell proliferation by inhibiting G1 phase transitting to S phase and G2 phase.

Animals↗
PubMed1998

[Interferon-alpha 2b inhibits proliferation of human tenon capsule fibroblasts].

PURPOSE: To evaluate the potential effect of interferon-alpha 2b(IFN alpha-2b) as antifibrotic treatment after glaucoma filtering surgery. METHODS: The MTT method was used to study the inhibitory effect of IFN alpha-2b on human Tenon capsule fibroblasts in vitro. The antimetabolites including 5-fluorouracil (5-FU), homoharringtonine(H.H) and mitomycin C(MMC) were also assessed. RESULTS: The IC50 values of IFN alpha-2b, 5-FU, H.H and MMC on fibroblasts at 48 hours were 60.578 mg/L, 5.447 mg/L, 0.531 mg/L, 1.329 mg/L respectively. CONCLUSION: The effect of IFN alpha-2b to inhibit proliferation of fibroblast was less than that of antimetabolites. Further investigation of other aspects of suppress(suppress) wound healing as a possible antifibrotic agent should be deserved.

Antimetabolites↗
PubMed2002

[The function of Tenon's capsule revisited].

Tenon's capsule is at the forefront of today's strabismus news. Its function as a muscle pulley was recognized by Tenon himself in 1806. Neiger, then Koornneef, and more recently Demer gave a more modern description of Tenon's capsule. The anterior or muscular part is made up of collagen, elastic, and smooth muscle fibers. It forms a sleeve around extraocular muscles from the Tenon foramen to their scleral insertion. Directly in front of the foramen, it includes a zone of strong capsular-muscular adherence, which is also solidly suspended by ocular suspension system to the periosteum of the orbit; the intermuscular membrane consolidates the adherence zones of the rectus muscles. The posterior part is simply a condensation of collagenous fibers. The function of Tenon's capsule is essential. At the place where it adheres to the muscles, the sleeve that it forms around the muscles plays the role of a pulley diverting the muscle's path, with the pulley representing the proximal functional insertion of the muscle. The position of a rectus muscle's pulley is stable during ocular movements perpendicular to the axis of this muscle because of the transversal and radial fastening of the capsular-muscular adherence zone. During movements along the muscle axis, the pulley moves with the ocular globe. In fact, it is positioned actively to accompany the ocular globe's movements. The anomalies of these pulleys can contribute to or be responsible for an extraocular muscle imbalance: a position anomaly, an instability, a displacement, or a pathological adherence of one pulley can be the cause. Surgery of Tenon's pulley has always been an integral part of extraocular muscle surgery. Any intervention on the muscular level involves, to a lesser or greater extent, the operated muscle's pulley. Different examples demonstrate this.

Eponyms↗
PubMed1992

Five-minute treatments with fluorouracil, floxuridine, and mitomycin have long-term effects on human Tenon's capsule fibroblasts.

Proliferating human Tenon's capsule fibroblasts were exposed for 5 minutes to a wide range of concentrations of fluorouracil, floxuridine, and mitomycin. High concentrations of all three agents had prolonged effects on cell proliferation and morphologic characteristics compared with untreated control cells up to 36 days. The highest concentrations of both floxuridine (15,000 micrograms/mL) and mitomycin (1000 micrograms/mL) had an apparent cidal effect, reducing cell numbers below initial cell density. In contrast, although the highest concentration of fluorouracil (25,000 micrograms/mL) inhibited cell proliferation by more than 50% relative to the untreated control cells at 36 days, the cell numbers still increased fourfold compared with the initial cell density. These results demonstrate that 5-minute treatments with high concentrations of these drugs have prolonged effects on the proliferation of human Tenon's capsule fibroblasts in vitro. Single-dose regimens using high concentrations of these drugs at the time of operation may achieve results similar to those of protocols that involve repeated applications.

Cell Division↗
PubMed2006

[Fibroblasts from primary and recurrent pterygia and Tenon's capsule in cell culture].

PURPOSE: To evaluate fibroblast proliferation activity of the Tenon capsule from primary and recurrent pterygia. METHODS: A randomized prospective study was performed with 43 surgical samples from 30 primary and 13 recurrent pterygia, and samples of normal Tenon capsule from the same pterygium patients. Proliferation, migration, and confluence rate, and patient age, lesion location and type (fleshy or involutive; primary or recurrent) were evaluated. Data were submitted to statistical analysis. RESULTS: Of the 30 cultivated primary pterygia, 21 migrated and proliferated, and 18 (60%) went to confluence. Migration, proliferation and confluence started much later in fibroblasts from normal Tenon than from pterygia lesion. The recurrent pterygia showed migration, proliferation, and confluence starting much earlier than the primary ones. There was no statistically significant difference in the start of migration, proliferation and confluence between fleshy and involuted pterygia, or between pterygias of Grades I-II and III-IV. CONCLUSION: Pterygium fibroblasts are more viable than normal Tenon in cell culture. Migration, proliferation, and confluence differ in primary and recurrent pterygia. Fleshy and involutive pterygia are similar in culture; there is also no difference between pterygia according to lesion size in cell culture.

Adult↗
PubMed1989

Risk factors for the development of Tenon's capsule cysts after trabeculectomy.

Tenon's capsule cysts (TCCs) are a complication of glaucoma filtering surgery. They are frequently associated with substantial elevations in intraocular pressure (IOP) beginning 2 to 8 weeks postoperatively. To determine the incidence and possible risk factors for the development of TCCs, case records of all patients who received trabeculectomy over a 4-year period at the Wills Eye Hospital were reviewed. The incidence of TCCs was 28% in those who underwent trabeculectomy. Characteristics of patients after trabeculectomy in whom TCCs developed were compared with patients after trabeculectomy in whom TCCs did not develop. Both univariate and multivariate techniques were used to assess the association of characteristics associated with the development of TCCs. Factors associated with increased risk (P less than 0.05) were: history of prior TCCs, argon laser trabeculoplasty, male gender, and the use of preoperative sympathomimetics. The use of a compression shell was associated with decreased risk (P less than 0.05).

Adult↗
PubMed1982

Cysts of Tenon's capsule following filtration surgery.

Hypertrophy of Tenon's capsule resembling a cyst and recurrence of increased intraocular pressures occurred shortly after glaucoma filtration surgery in eight patients on whom a variety of surgical techniques had been used. Preoperatively, the patients generally had secondary glaucomas with intraocular pressures exceeding 40 mm Hg. The cysts of Tenon's capsule were uniformly localized to the filtration site and were dome-shaped and hard. They were associated with intraocular pressures near the preoperative levels. Three patients were successfully treated with corticosteroids and massage. The others required surgical intervention to restore adequate filtration. Prompt recognition of a Tenon's capsule cyst and appropriate management can restore function to an otherwise failing filtration bleb.

Adult↗
PubMed1989

Long-term morphologic effects of antiglaucoma drugs on the conjunctiva and Tenon's capsule in glaucomatous patients.

Conjunctival and Tenon's capsule biopsies from two patient groups were quantitatively analyzed by light microscopy. Group A consisted of 20 patients with a primary glaucoma for whom surgery was a planned primary treatment modality. Group B was comprised of 20 patients with a primary glaucoma who had received at least two types of antiglaucoma topical medication, for a minimum of 1 year (mean, 7.7 years) before surgery. All slides were examined by two masked observers. A significant increase in the number of macrophages, lymphocytes, mast cells, and fibroblasts in the conjunctiva and Tenon's capsule and a significant decrease in the number of epithelial goblet cells were seen in the group that received long-term drop therapy. These results suggest that exhaustive medical therapy, before surgery is offered, increases the number of tissue inflammatory cells. It is possible this may enhance the risk of external bleb scarring and filtration surgery failure.

Combined Modality Therapy↗
PubMed1982

Importance of Tenon's capsule in squint surgery.

A procedure for dealing with Tenon's capsule in squint surgery on the horizontal muscles, which preserves intact the relations of the various expansions of Tenon's capsule, distorts and damages them as little as possible and replaces Tenon's capsule as an intact layer over the muscle at the end of surgery is outlined. It depends on adequate fixation and the avoidance of damage to and distortion of Tenon's capsule by the use of muscle hooks to 'fish' for the muscle. It is claimed that this method produces less fibrosis around the muscle post-operatively and allows a better final result.

Conjunctiva↗
PubMed1987

Cysts of Tenon's capsule following filtration surgery. Medical management.

Cysts of Tenon's capsule (encapsulated blebs) developed postoperatively in 77 (13%) of 607 eyes that underwent filtration surgery between 1980 and mid-1985. The annual incidence was not uniform, increasing markedly throughout the period. Seventy-four eyes were treated with medical therapy only. At a mean follow-up of 19 months, the success rate for these eyes, defined as an intraocular pressure (IOP) of 21 mm Hg or less, was 92%. The three eyes that underwent surgical revision subsequently failed clinically by the study criteria. Those patients in whom cysts of Tenon's capsule developed were compared with an age-matched control group to assess for possible differences in long-term outcome. There was a significantly higher IOP in the Tenon's cyst group at one and three months after surgery, and an increased proportion of IOPs above 30 and 40 mm Hg. At a six-month and later follow-up, there was no significant difference in the mean IOP or in progression of visual field loss. Causative factors were sought for the development of these cysts of Tenon's capsule. Prior conjunctival surgery, or previous cyst formation in the other eye, were the significant risk factors noted.

Adolescent↗
PubMed1984

Water flow in Tenon's capsule and subconjunctival tissue of rabbit.

The mode of water flow in the Tenon's capsule and the subconjunctival tissue was studied in the rabbit. Carbon-black ink injected under the Tenon's capsule was found to move along the plane of the capsule posteriorly toward the optic nerve sheath and also along the direction of the corneal limbus, but a very little amount moved through the layers of the capsule. The flow rates of physiological saline through the capsule were determined under various hydrostatic pressures, and the water flow conductivity through the capsule averaged 8.8 +/- 5.5 X 10(-12) cm4 dyne-1 sec-1 in 7 eyes. The Tenon's capsule offered a considerable resistance to water flow through its layers. The upper conjunctiva was dissected to the limbus and the wound was closed 1) after subconjunctival injection of saline and 2) after injection of concentrated sodium hyaluronate. One month later, a needle connected to a saline reservoir was inserted into the subconjunctival tissue of the treated area and the rate of water flow into the tissue was determined under various hydrostatic pressures. The results were compared with those in the normal eye. The water flow rate was significantly less in the treated eye than in the normal eye. The eyes treated with sodium hyaluronate tended to show a higher flow rate than those treated with saline. Histological examinations revealed that an intensive scar formation took place in the dissected area, indicating that scar formation greatly reduces water flow in the Tenon's capsule and subconjunctival tissue.

Animals↗
PubMed2003

Effects of thick Tenon's capsule on primary trabeculectomy with mitomycin-C.

PURPOSE: To investigate the effects of thick Tenon's capsule on primary trabeculectomy with adjunctive mitomycin-C. METHODS: In this prospective interventional case series of 45 consecutive uncomplicated glaucoma patients, 45 eyes with thick Tenon's capsule underwent primary trabeculectomy with intraoperative mitomycin-C (0.4 mg/ml for 3 min). Success was defined as intraocular pressure (IOP) <or= 21 mmHg with (qualified) or without (complete) medications. RESULTS: The mean follow-up period was 22.55 months. The mean preoperative IOP and number of medications were 28.91 +/- 7.06 mmHg and 1.68 +/- 0.73, respectively. The postoperative IOPs and the number of medications at all intervals were significantly lower than preoperative levels (p < 0.01 for each interval). The mean IOP was 11.03 +/- 3.93 mmHg (12.17 +/- 4.98 mmHg) at 24 months (12 months). Kaplan-Meier survival analysis revealed a qualified success rate of 93.1% (95.6%) after 24 months (12 months). During follow-up of the 45 eyes, 38 (84.4%) developed avascular thin-walled bleb, seven eyes (15.6%) had hypotony (IOP < 6 mmHg), 14 eyes (31.1%) had a shallow anterior chamber, and one eye (2.2%) had endophthalmitis. CONCLUSIONS: The use of mitomycin-C is associated with high success rates and good IOP control even in the presence of thick Tenon's capsule. However, thick Tenon's capsule does not seem to eliminate the development of complications in eyes undergoing primary trabeculectomy with mitomycin-C.

Adult↗