We investigated the long-term scleral toxicity after single intraoperative exposure to mitomycin-C(MMC) at 2 different exposure length of time and with or without profuse irrigation after the MMC applications during glaucoma filtering surgery(GFS) in rabbit eyes. Albino rabbits undergoing GFS received a single exposure to MMC 0.5 mg/ml for 1 or 5 minutes with placing MMC-soaked sponges between the conjunctival flap and the scleral bed. A subsequent irrigation of the exposed tissue with 250 ml of balanced salt solution(BSS) was done in one group but not in the other groups. Six months after GFS, the eyes were enucleated and fixed in glutaraldehyde for transmission electron microscopy(TEM). TEM revealed degenerative changes of the fibroblasts at the middle portion of sclera in all MMC treated groups. There were some differences between the groups with 1 minute and 5 minutes exposure to MMC. No discernible differences existed in the ultrastructural findings of the scleral fibroblasts between the groups with or without BSS irrgation after 5-minutes exposure to MMC. Our observation suggest that an exposure to MMC 0.5 mg/ml can cause longterm scleral fibroblast toxicity. There was no discernible differences in scleral fibroblast toxicity between the groups with and without profuse BSS irrigation.
Fibroblasts* ; Filtering Surgery* ; Glaucoma* ; Glutaral ; Mitomycin* ; Porifera ; Rabbits ; Sclera

No abstract available.
Aphakia/*surgery ; Female ; Humans ; Lens Implantation, Intraocular/*methods ; *Lenses, Intraocular ; Male ; Sclera/*surgery ; *Vitrectomy

Mitomycin C(MMC) is one of the alkylating agents, which is commonly used adjunctively to inhibit the over-growth of the fibroblasts in high-risk filtering surgery. However, it increases the incidence of the complications including persistent postoperative hypotony. The hypotony may be caused by the toxic effect of MMC on the ciliary epithelium. The morphological changes of the ciliary epithelium were evaluated using transmission electron microscope four and twelve weeks after the application of balanced salt solution(BSS) and MMC on the exposed sclera against the ciliary body in the rabbit eyes. There was no specific change in the ciliary epithelium four and twelve weeks after the application of BSS. Four weeks after the application of 0.2mg/ml of MMC, the mitochondria in the nonpigmented epithelium of the applied region were swollen mildly. The mitochondria of both pigmented and nonpigmented epithelia were swollen moderately in the region applied with 0.5mg/ml of MMC. Twelve weeks after the application of either 0.2 or 0.5mg/ml of MMC, the mitochondria were swollen markedly, the nuclear membranes in the pigmented and nonpigmented epithelia were wrinkled, and the heterochromatins of the nuclei faded in both applied and contralateral ciliary epithelia. These findings indicate that mitomycin C causes degenerative changes in the ciliary epithelium decrease aqueous production.
Alkylating Agents ; Ciliary Body ; Epithelium* ; Fibroblasts ; Filtering Surgery ; Heterochromatin ; Incidence ; Mitochondria ; Mitomycin* ; Nuclear Envelope ; Sclera

PURPOSE: To evaluate the change of axial length (AL), intraocular pressure (IOP), and corneal astigmatism after scleral shortening with scleral invagination in the rabbit eye. METHODS: The authors performed scleral shortening (3 mm) with scleral invagination in two groups of 6 eyes each: 180 degrees (group 1) and 360 degrees (group 2). RESULTS: Average AL shortening was more prominent in group 2 (0.5 +/- 0.17 mm) than in group 1 (0.37 +/- 0.29 mm), but the difference was not statistically significant. IOP increased immediately after the procedure and was maintained at a high level through 2 months postoperatively. Induced corneal astigmatism was more prominent in group 1 than in group 2. The difference was statistically significant in group 1 (p< 0.05) but not in group 2. CONCLUSIONS: In the scleral shortening with scleral invagination procedure, a large amount of scleral invagination resulted in more shortening of axial length, but there was more corneal astigmatism in 180-degree invagination of the sclera than in 360-degree. Further research is required to determine the effect of the extent of scleral invagination on the change of these values.
Animals ; Astigmatism/*etiology ; Corneal Diseases/*etiology ; Eye/*pathology ; *Intraocular Pressure ; Postoperative Period ; Rabbits ; Sclera/*surgery

The authors investigated the toxicity of two antimetabolites. 5-fluorouracil(5-FU) and mitomycin-C(MMC) on the rabbit cornea and sclera following glaucoma filtration surgery(GFS). Forty rabbits were divided into four groups; the first control group(I) was the balanced salt solution soaked group(BSS) during GFS, the second(II) was the 5-FU subconjunctival injected group(5-FU SC) after GFS, the third(III) was the 5-FU soaked group(5-FU) during GFS, and the fourth(IV) was the MMC soaked group(MMC) during GFS. At the fifth day after GFS, scanning electron microscopic findings showed that corneal epithelial cells were most seriously damaged in 5-FU SC group, slightly damaged in 5-FU group, and no change in MMC and BSS group. At six months after GFS, transmission electron microscopic observation on sclera revealed the most profound degenerative changes in 5-FU group, and followed by an order of MMC, 5-FU SC, and BSS group. These results suggest that the dosage and application method of antimetabolites should be selected with great caution to prevent ocular toxicity.
Antimetabolites ; Cornea* ; Epithelial Cells ; Filtering Surgery* ; Filtration* ; Fluorouracil* ; Glaucoma* ; Mitomycin* ; Rabbits ; Sclera*

This study sought to characterize the biomechanical properties of rabbit sclera after posterior sclera reinforcement operation (PSR), which may provide valuable information for PSR in clinical setting. Uniaxial tension and ball-pressing methods were used. Different areas of the sclera samples from PSR were examined in pretest, relaxation and creep experiments respectively by using Instron5544 mechanical machine. The experimental results showed: When the implanted area of sclera samples was compared with that of other groups, the unit width stiffness coefficient increased remarkably at the linear stage, and the anti-deformation capacity was higher at the relaxation stage. However, the creep rate showed a significant decrease at the creep stage. That is to say, PSR could enhance the anti-deformation capacity of the weakened and thinned sections, reduce the sclera creep rate in the posterior sclera, and thus prevent the development of progressive myopia.
Animals ; Biomechanical Phenomena ; Female ; Implants, Experimental ; Male ; Myopia ; physiopathology ; surgery ; Rabbits ; Sclera ; physiology ; surgery ; Scleroplasty ; methods ; Stress, Mechanical

An 0.1 mm thin polyethylene sheet was used as an iris protector in posterior chamber intraocular lens implantation. An experiment using rabbits was done to determie the applicability of a polyethylene sheet as a glaucoma seton. The polyethylene sheet had 0.1 mm thickness and was cut into 5 mm X 8 mm. In the subconjunctival space, one end of the implant was at the corneoscleral limbus or introduced into the anterior chamber through a sclerectomy opening, and the other end was allowed to extend to the posterior surface of the sclera. The eyes with an implant showed a more prominent and larger filtering bleb than the control eyes without an implant. Postoperative foreign body inflammatory change was minimal on both grossly and light microscopically. Fibroconnective capsule lining the polyethylene sheet was 0.2 mm - 0.3 mm thick, and had a small amount of collagen, and fibroblasts, and a few lymphocytes. Number and configuration of histiocytes on the inner surface of the fibroconnective tissue lining the implants were different, according to the sclerectomy or bleb size. The major complications were extrusion of the implant and dislocation into the anterior chamber. Above results suggested that the polyethylene sheet was suitable as a glaucoma seton, but more flexible products were expected.
Anterior Chamber ; Blister ; Collagen ; Dislocations ; Fibroblasts ; Filtering Surgery* ; Foreign Bodies ; Glaucoma* ; Histiocytes ; Iris ; Lens Implantation, Intraocular ; Lymphocytes ; Polyethylene ; Rabbits ; Sclera

Preoperative aqueous humor, known to inhibit the growth of fibroblasts in tissue culture assay, was used as an adjunct to filtering surgery in rabbits to determine its effect in vivo on the outcome of filtering surgery. Fifteen rabbits underwent a posterior-lip sclerectomy in both eyes. In experimental eyes 1.4 ml preoperative aqueous humor and in fellow eyes 1.4 ml balanced salt solution were injected intracamerally. Gross and histopathological differences of bleb were observed. In this animal experiment, although there was no statistical significance or late postoperative effect, the rabbit eyes refilled with preoperative aqueous humor intracamerally just after filtering surgery, had a larger bleb and less fibroconnective tissue on the bleb than the control eyes in the early postoperative period.
Animals ; Anterior Chamber/*pathology ; Aqueous Humor/*physiology ; Connective Tissue/pathology ; Fibroblasts/pathology ; Isotonic Solutions ; Rabbits ; Sclera/surgery

BACKGROUND: The reconstruction of eyelid defects is extremely complex because both functional and aesthetic aspects should be considered. Numerous techniques for reconstruction are available for repairing eyelid defects, depending on the size, location, and extent of the defect. OBJECTIVE: This study was aimed at assessing the effectiveness and cosmetic consequences of various reconstruction techniques for eyelid defects after Mohs micrographic surgery. METHODS: Twenty patients who received a diagnosis of skin cancer of the eyelids from November 2005 to August 2009 were analyzed. Among them, 15 patients were treated with a local flap to reconstruct the defective eyelids, and the remaining patients were treated with primary closure. The medical records and photographs were reviewed by two independent physicians, and postoperative results were evaluated. RESULTS: Eyelid defects were reconstructed with various surgical techniques, such as primary closure, transposition flap, subcutaneous island pedicle flap, advancement flap, rotation flap, Tenzel flap, and hard palate mucous membrane graft. The cosmetic results were satisfactory, and 16 of 20 (80%) patients showed good to excellent results. However, one patient developed a sclera show and another patient showed tumor recurrence. CONCLUSION: Many reconstruction techniques can be used for eyelid defects. An optimal choice would be one that is based on the extent, depth, and location of the defect; skin condition and wishes of the patient; and the surgeon's experience. Furthermore, it is important to have an understanding of the anatomy of the eyelid, the basic principles of the reconstruction techniques, and the merits and drawbacks of each technique.
Diagnosis ; Eyelids* ; Humans ; Medical Records ; Mohs Surgery* ; Mucous Membrane ; Palate, Hard ; Recurrence ; Sclera ; Skin ; Skin Neoplasms* ; Transplants

Objective To observe the role of ultrasound biomicroscopy(UBM)in two-year post-operative follow-up for primary open-angle glaucoma patients with modified CO
Carbon Dioxide ; Follow-Up Studies ; Glaucoma, Open-Angle/surgery* ; Humans ; Microscopy, Acoustic ; Sclera/diagnostic imaging* ; Treatment Outcome