The effects of growth factors on Tenon's capsule fibroblasts in serum-free culture

Trabeculectomies in fellow eyes have an increased risk of tenon's capsule cysts

OBJECTIVE

To assess outcomes and complications of primary trabeculectomies in fellow eyes in a large group of patients. The assumption was that first and fellow eyes undergoing fistulizing surgical procedures behave similarly in the postoperative period.

DESIGN

Retrospective nonrandomized comparative trial (paired eye study).

PARTICIPANTS

Over a 4-year period, 566 consecutive patients underwent primary trabeculectomy, all without antifibrotic agents. One hundred thirty-eight of these patients underwent bilateral surgery.

INTERVENTION

A primary trabeculectomy was performed.

MAIN OUTCOME MEASURES

Preoperative data, postoperative intraocular pressure, and visual acuity were monitored. In addition, complications and the need for consecutive surgical procedures were noted.

RESULTS

The mean follow-up period of these trabeculectomies was 27.4 months (range, 7-62 months). Of the 124 bilateral adult cases, no statistical difference was found in intraocular pressures, number of antiglaucomatous medications, and success or failure rates between the two eyes. The need for enhancement procedures, such as needling or surgical excision of Tenon's capsule cysts, was significantly higher in fellow eyes than in first eyes (16 vs. 6 cases; P = 0.03; Mann-Whitney U test). Hypotony as a complication occurred more frequently in fellow eyes.

CONCLUSIONS

Primary trabeculectomies performed in both eyes of patients have a remarkably similar clinical course. Failures of first eyes may be a reason to use antimetabolites in primary trabeculectomy of the fellow eye. The present data suggest that fellow eyes have a greater risk of Tenon's capsule cyst formation. This may be important for patient counseling before surgery. These results may additionally be important for clinical studies. Given that first and fellow eyes do not behave in an absolutely similar manner, study designs making intraindividual comparisons may not be feasible.

The role of the immune system in conjunctival wound healing after glaucoma surgery

The immune system has a fundamental role in the development and regulation of ocular healing, which plays an important role in the pathogenesis of most blinding diseases. This review discusses the mechanisms of normal wound healing, describing the animal and fetal wound healing models used to provide further insight into normal wound repair. In particular, conjunctival wound repair after glaucoma filtration surgery will be used to illustrate the contributions that the different components of the immune system make to the healing process. The potential role of macrophages, the possible regulatory effect of lymphocytes, and the important role of growth factors and cytokines in the wound healing reaction are discussed. The significance of the immune system in the pathogenesis of aggressive conjunctival scarring is addressed, particularly assessing the predisposing factors, including drugs, age, and ethnicity. The rationale behind the pharmacological agents currently used to modulate the wound healing response and the effects these drugs have on the function of the immune system are described. Finally, potential new therapeutic approaches to regulating the wound healing response are reported.

Increased expression of transforming growth factor-beta1, acidic fibroblast growth factor, and basic fibroblast growth factor in fetal versus adult fibroblast cell lines

OBJECTIVES

Fetal wound healing occurs without scar tissue formation. Differences in growth factor expression between fetal and adult fibroblasts have been explored. Recently we used RNA expression studies to demonstrate that transforming growth factor (TGF)-beta1, acidic fibroblast growth factor (alpha-FGF), and basic fibroblast growth factor (beta-FGF) could be detected in both fetal and adult fibroblast cell lines. In addition, adult fibroblasts showed greater relative expression of these growth factors than fetal fibroblasts. The aim of this study was to identify the level of protein expression in fetal and adult fibroblasts.

STUDY DESIGN/METHODS

Fetal and adult fibroblasts were grown in culture using standard and serum-free media. After protein extraction, Western blot studies were performed to detect the presence and amount of TGFbeta-1, alpha-FGF, and beta-FGF growth factor proteins. beta-Tubulin was used as a control.

RESULTS

TGFbeta-1, alpha-FGF, and beta-FGF proteins were detected in fetal and adult fibroblasts grown in standard and serum-free media. The fetal fibroblasts showed higher levels of all three growth factor proteins compared with the adult fibroblasts.

CONCLUSIONS

Western blot studies suggest higher levels of TGFbeta-1, alpha-FGF, and beta-FGF expression in fetal fibroblasts. It is clear that significant differences exist in the expression/production of these growth factors and it seems likely that further study of these differences will help elucidate the unique healing capabilities of fetal fibroblasts.

Basic science and clinical aspects of wound healing in glaucoma filtering surgery

Success of glaucoma filtration surgery is influenced by the wound healing response. Attention has been focused on pharmacological agents to control a process that leads to excessive scarring and eventual failure of glaucoma filtration surgery. Several agents, including 5-fluorouracil and mitomycin C, as well as other antiproliferative drugs will be discussed. Newer antifibrotic agents and novel drug delivery systems are under development in tissue culture and animal models in an effort to improve efficacy and safety. This article summarizes current treatment modalities and future prospects to prevent excessive wound healing and improve the success of glaucoma filtration surgery.