SEARCH · PubMed Health

Results for “Tenon Capsule”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

PubMed1994

Nonpeptidic analogues of the Arg-Gly-Asp (RGD) sequence specifically inhibit the adhesion of human tenon's capsule fibroblasts to fibronectin.

PURPOSE: Scar formation from the process of wound healing is mediated primarily by fibroblasts and is a major problem in ophthalmology in general and in glaucoma therapy in particular. Interactions between fibroblasts and glycoprotein components of the extracellular matrix (ECM) are among the major causes of scar formation. Recognition of ECM glycoproteins occurs via cell surface integrins that are specific for adhesion epitopes, such as the Arg-Gly-Asp (RGD-) containing amino acid sequence. The RGD sequence, which is present in several matrix and plasma proteins, including fibronectin (FN) and vitronectin, is involved in cell-ECM interactions that occur during inflammatory and homeostatic reactions. The present study was designed to examine the possibility of using RGD-mimetics as inhibitors of fibroblasts-FN interactions. METHODS: Two nonpeptidic mimetics of RGD were designed and constructed, and their inhibitory effect on the adhesion of human tenon's capsule fibroblasts to FN was examined. SF-6,5 consisting of the carboxylate group of Asp and the guanidinium group of Arg divided by a linear atom spacer and a newly designed mimetic, designated NS-11, were examined herein. RESULTS: The RGD mimetics, SF-6,5 and NS-11, but not an Arg-Gly-Glu (RGE) mimetic inhibited the adhesion of ocular fibroblasts to immobilized FN. SF-6,5 and NS-11 did not inhibit adhesion of the fibroblasts to laminin or spontaneous proliferation of fibroblasts. Trypsin pretreatment of the nonpeptidic RGD mimetics did not affect their ability to inhibit adhesion of the ocular fibroblasts to FN, whereas that of the RGD-containing peptide was abolished by the pretreatment. CONCLUSION: Nonpeptidic mimetics of RGD are attractive candidates for therapeutic agents to prevent the formation of scar tissue and related RGD-dependent pathologic events.

Antibodies, Monoclonal↗

PubMed1991

The effects of glaucoma medications on Tenon's capsule and conjunctiva in the rabbit.

Glaucoma filtering surgery fails most frequently due to fibrosis at the episcleral-conjunctival/Tenon's capsule interface. Sherwood et al have suggested that chronic topical antiglaucoma medications increase conjunctival inflammatory cells, which could increase the likelihood of fibrosis and subsequent bleb failure. In a pilot study in a rabbit model, we placed timolol, pilocarpine, and epinephrine, or a combination of all three, in one eye of 24 animals twice daily for 7 months. The fellow eye received distilled water. Microscopic examination revealed no statistically significant change in the number of acute or chronic inflammatory cells, fibroblasts, or goblet cells in the treated as compared with the control eyes. A longer duration of drug administration, or drug administration followed by surgical intervention, may be required to produce an effect on the conjunctiva and Tenon's capsule, if such an effect exists.

Administration, Topical↗

PubMed1987

Normal rabbit aqueous humour, fibronectin, and fibroblast conditioned medium are chemoattractant to Tenon's capsule fibroblasts.

Some of the chemotactic and chemokinetic properties of rabbit Tenon's fibroblasts were examined in a 48-well micro-chemotaxis chamber. Normal rabbit aqueous humour, fibronectin, and fibroblast conditioned medium were used in the assay, and all were shown to be chemoattractant. In addition, aqueous humour was shown to be powerfully chemotactic. Since the failure of human trabeculectomies is associated with migration of fibroblasts to the operation site, the study of the chemoattractant influences acting on these cells may allow manipulation of their behaviour in order to influence favourably the outcome of surgery.

Animals↗

PubMedDate not supplied

Triamcinolone acetonide with vitrectomy for treatment of macular edema associated with branch retinal vein occlusion.

PURPOSE: To review the efficacy of a combination of triamcinolone acetonide (TA) injection and pars plana vitrectomy (PPV) for the treatment of macular edema associated with branch retinal vein occlusion (BRVO). METHODS: Seventeen eyes with macular edema associated with BRVO underwent PPV with an intraoperative injection of TA (10 mg) into the vitreous cavity. Residual or recurrent macular edema was treated with postoperative sub-Tenon capsule injections of TA (20 mg). RESULTS: With PPV and an intraoperative injection of TA, 82% of eyes showed rapid reduction of macular edema; foveal thickness decreased from 507 +/- 115 microm preoperatively to 261 +/- 123 microm 2 months after surgery (P = 0.0041). However, 59% of eyes showed recurrence of macular edema during the follow-up period. Twelve eyes with residual or recurrent macular edema received sub-Tenon capsule injections of TA; of these eyes, 9 showed substantial reduction of macular edema. Foveal thickness decreased from 381 +/- 102 microm to 256 +/- 56 microm (P = 0.0076) 2 weeks after postoperative injections of TA. At the final visit, visual acuity (logMAR) improved from 0.74 +/- 0.40 preoperatively to 0.40 +/- 0.34 (P = 0.010). CONCLUSION: An intraoperative injection of TA in combination with PPV has the potential to facilitate the absorption of macular edema associated with BRVO. In addition, residual or recurrent macular edema can be treated with additional sub-Tenon capsule injections of TA.

Aged↗

PubMed2001

Intraoperative mitomycin-C without conjunctival and Tenon's capsule touch in primary trabeculectomy.

OBJECTIVE: To verify whether intraoperative mitomycin C (MMC) without conjunctival and Tenon's touch is effective in inhibiting the development of thin, avascular blebs in eyes undergoing primary trabeculectomy. DESIGN: Noncomparative, interventional study. PARTICIPANTS: Fifteen eyes of 15 consecutive patients undergoing primary trabeculectomy. INTERVENTION: All eyes underwent trabeculectomy with intraoperative MMC (0.25 mg/ml for 3 minutes) without either conjunctival or Tenon's touch. Patients were examined 1 month, 3 months, 6 months, and 12 months after surgery. Intraocular pressure (IOP) and number of medications were evaluated at each examination. The appearance of the bleb was classified at the last examination into one of three groups: flat and vascularized; elevated but not avascular; or elevated, thin, and avascular. MAIN OUTCOME MEASURES: Intraocular pressure, number of antiglaucoma medications, and appearance of the bleb. RESULTS: Preoperative mean IOP was 30.57 +/- 10.92 mmHG: Statistically significant IOP reductions were observed 1 month, 3 months, 6 months, and 1 year after surgery (P < 0.01). Twelve months after surgery, the mean IOP was 14.92 +/- 6.53 mmHG: Five eyes (33.3%) showed an IOP less than 15 mmHg without antiglaucoma medication at the 12-month examination. The bleb was considered elevated, thin, and avascular in 12 of 15 eyes (80%) at the end of follow-up. CONCLUSIONS: Intraoperative MMC at 0.25 mg/ml for 3 minutes without either conjunctival or Tenon's touch was not effective in eliminating the development of thin, avascular blebs in eyes undergoing primary trabeculectomy.

Conjunctiva↗

PubMed2005

Ptosis and orbital fat prolapse after posterior sub-Tenon's capsule triamcinolone injection.

PURPOSE: To describe the occurrence of orbital fat prolapse and blepharoptosis after posterior sub-Tenon (PST) triamcinolone injection. DESIGN: Retrospective review of consecutive case series. PARTICIPANTS: Patients with ptosis and orbital fat herniation after PST triamcinolone injection. METHODS: Charts of all patients with ptosis and orbital fat herniation presenting after PST triamcinolone injection to the oculoplastics service of the Cole Eye Institute between 1999 and 2003 were reviewed. Charts were reviewed for patient age, indication, dates of injections, time to patient complaint or time to referral for ptosis, and marginal reflex distance (MRD1). MAIN OUTCOME MEASURES: Ptosis and orbital fat herniation after PST triamcinolone injection. RESULTS: Eleven patients with a history of ipsilateral PST triamcinolone injections were seen with ptosis and orbital fat prolapse. Ten charts were available for review. Mean patient age was 64 years (range, 45-78 years). Patients underwent 1 to 9 ipsilateral injections, and 2 patients underwent bilateral injections. Patients were seen for ptosis evaluation on average 22.5 months (range, 3-56 months) after the initial injection, and 6.6 months (range, 0-20 months) after the most recent injection. All patients demonstrated significant orbital fat prolapse in conjunction with statistically significant ptosis (P = 0.016). Tissue was obtained in 3 cases. Histologic findings in 1 case showed orbital fat infiltrated by histiocytes that seemed to contain phagocytosed material. CONCLUSIONS: Posterior sub-Tenon triamcinolone injection may cause ptosis associated with orbital fat prolapse. This finding may be a relatively common complication of PST triamcinolone injection. We recommend counseling patients about this risk before PST triamcinolone injection.

Adipose Tissue↗

PubMed1998

Use of autologous Tenon's capsule and scleral patch grafts for repair of excessively draining fistulas with leaking filtering blebs.

PURPOSE: To report the use of autologous Tenon's and partial-thickness scleral tissues for patch graft revisions of excessively draining fistulas associated with leaking filtering blebs. METHODS: Appropriate sized pieces of autologous Tenon's tissue and partial-thickness scleral tissue were dissected near the surgical sites and used as patch grafts to effectively repair excessively draining fistulas with leaking filtering blebs. RESULTS: Both Tenon's and partial-thickness scleral patch grafts were useful in adequately closing the excessively draining fistulas. CONCLUSION: Autologous Tenon's and scleral tissue patch grafts appear to be safe and effective for the repair of excessively draining fistulas, and are useful when patch grafts are unexpectedly needed.

Aged↗

PubMed2006

[Changes of Smad2 and type I collagen expressions on cultured human Tenon's capsule fibroblasts transfected with Smad7 vector].

The purposes of this research is to investigate Smad2, phosphorylated Smad2 (p-Smad2) and type I collagen expressions in the cultured human Tenon's capsular fibroblasts (HTFs) transfected with Smad7 vector and to elucidate the mechanism of Smad7 in blocking tissue fibrosis after filtration surgery. Nucleofector was used to transfect Smad7 vector into HTFs. Reverse transcription real-time quantitive polymerase chain reaction (real-time RT-PCR) was then used to detect Smad7 mRNA expression levels. The expressions of HA-probe fusion protein, Smad2, p-Smad2, alpha2-type I procollagen (COL1A2) mRNA and carboxyterminal propeptide of type I procollagen (PICP) were determined by real-time RT-PCR, Western blot, cellular immunofluorescence assay and radioimmunoassay. The items mentioned above were also detected after HTFs being stimulated by TGF-beta2 (10 ng/ml). HTFs and vector-HTFs were used as control groups. Clones with Smad7 overexpression were successfully established. Results of real-time RT-PCR proved that there was no difference of Smad2 mRNA between Smad7 overexpression clone and the control groups whether stimulated by TGF-beta2 or not. The increase of p-Smad2 expression stimulated by TGF-beta2 was inhibited in Smad7 overexpression clone by Western blot assay. It only took 56.01% and 53.48% of control groups. In cellular immunofluorescence assay, the p-Smad2 positive cells in Smad7 overexpression clone only took 31.02% and 29.41% of control groups. Smad7 -HTFs could also abolish the increase of COL1A2 mRNA expression and PICP concentration stimulated by TGF-beta2. It is possible that Smad7 can block the signal transduction of TGF-beta by downregulating the expression of p-Smad2 in HTFs. However, it doesn't affect the expression of Smad2.

Collagen Type I↗

PubMed2006

Elasticity, viscosity, and deformation of orbital fat.

PURPOSE: For development of a finite element analysis model of orbital mechanics, it was necessary to determine the material properties of orbital fat and its degree of deformation in eye rotation. METHODS: Elasticity and viscosity of orbital fat of eight orbits of four calves and two orbits of one rhesus monkey were measured with a parallel-plate rheometer. The degree of deformation of orbital fat was studied in two human subjects by magnetic resonance imaging (MRI) through the optic nerve in seven (first subject) or fourteen positions of gaze from left to right. Bifurcations of veins in the fat were used as markers for displacement of the fat. RESULTS: The elastic shear modulus (G') of calf orbital fat was between 250 Pa and 500 Pa, and of monkey orbital fat it was between 500 Pa and 900 Pa. The viscous shear modulus (G'') of calf orbital fat was between 80 Pa and 150 Pa, and for monkey orbital fat it was between 300 Pa and 500 Pa. In the MRI scans, it was found that markers in the fat, 1 to 5 mm posterior to the sclera, rotated with the eye for 36% to 53% of eye rotation; the remainder was accounted for by sliding of the eye within the Tenon capsule and within the orbital fat. CONCLUSIONS: Elastic and viscous shear moduli of orbital fat are low. Little energy is dissipated in the fat. The required deformation of the fat during eye rotation is limited because the eye slides, to some extent, within the Tenon capsule.

Adipose Tissue↗

PubMed1999

Suture loop to aid in ganciclovir implant removal.

BACKGROUND: The ganciclovir implant (Vitrasert; Bausch & Lomb Inc, Claremont, Calif) has been a useful device in the management of cytomegalovirus retinitis. Seven months after placement, implant exchange is often considered. However, removal may be difficult and may result in vitreous hemorrhage or intraocular dislocation. OBJECTIVE: To describe a suture loop attached to the implant strut and left in the sub-Tenon space to aid in implant removal. METHODS: Twenty-five eyes of 17 patients received a ganciclovir implant with an 8-0 nylon suture loop left beneath the Tenon capsule and underwent at least 6 months of follow-up. Two of these eyes subsequently had a similarly modified ganciclovir implant placed at a separate site (inferonasally) with at least 6 additional months of follow-up. Six eyes of 3 patients had the implant removed as part of an exchange and underwent at least 4 months of follow-up. RESULTS: In the 25 eyes, there were no cases of endophthalmitis, wound leak, suture exposure, or other complications. At implant removal in the 6 eyes previously mentioned, the loop was used for traction on the implant and aided in localization of the implant strut. In these 6 eyes, there were no cases of retinal or choroidal detachment, visually significant vitreous hemorrhage, implant dislocation, or other complications. CONCLUSION: A sub-Tenon capsule suture loop is well tolerated and can assist in ganciclovir implant removal.

Adult↗

PubMed1966