PURPOSE: To evaluate the histopathologic changes after insertion of polymer made of poly- glycolic acid(PGA) and poly(lactic acid-co-glycolic acid)(PLGA)/5-FU following filtering surgery in the rabbit. METHOD: A polymer with 0.3 mm thickness made of PGA and PLGA/5-Fluorouracil(5-FU, 10% by weight) composite were made in a size of 3 x 7 mm. After full-thickness filtration surgery performed, PGA was inserted under the conjunctiva in group I, PLGA/5-FU was inserted in group II and none in control group. Twelve rabbit eyes were enrolled in each group. RESULT: Postoperatively, no serious complication was found in anterior segment. In the control eyes inflammatory cell reaction was minimal at 2 weeks after surgery and decreased thereafter. While severe fibrovascular tissue reaction with loss of conjunctival filtration space was noted at 2 and 4 weeks after surgery in group I, the filtration space was well maintained without fibrovascular tissue reaction until 4 weeks after surgery in group II. At 8 weeks after surgery, fibrous tissue reaction was observed in group I, but not in group II and contol. The polymer was not found and the filtration space was obliterated at 8 weeks after surgery in group I and II. CONCLUSION: PLGA/5-FU may be used as an effective adjunct to improve the success rate of the filtration surgery, without inducing serious fibrous tissue reaction. PGA was not suitable.
Conjunctiva ; Filtering Surgery* ; Filtration ; Polymers*

Objective: To assess the safety and incidence of subconjunctival fibrosis in rabbits eyes with and without intraoperative application of Seprafilm Bioresorbable Membrane (Genzyme Corp., Cambridge, MA) Methodology: A fornix based conjunctival peritomy was made on 20 eyes of10 rabbits. Ten eyes were randomly assigned to receive Seprafilm on the subconjunctival area while the opposite eye had no intraoperative application of the membrane. Two orbits (one rabbit) were exenterated each week for ten weeks and gross and histologic evaluation for signs of morbidity and scarring were performed Results: Seprafilm did not show any adverse effect on the rabbits eyes. All eyes with Seprafilm (100 percent) were a vascular while 5 eyes (50 percent) without Seprafilm showed the presence of conjunctival vascularity. Conjunctival mobility was normal in eyes with Seprafilm (100 percent) while the conjunctiva was immobile in 6 eyes (60 percent) without Seprafilm. Histologic sections on eyes without Seprafilm showed presence of fibrosis and inflammatory infiltrates in 7 eyes (70 percent) while only 2 (20 percent) and 3 eyes (30 percent) with Seprafilm showed the presence of fibrosis and inflammatory infiltrates, respectively. Failed "blebs" were evident in 6 eyes (60 percent) while only 4 eyes (40 percent) without Seprafilm were considered as functioning "blebs". All eyes with Seprafilm (100 percent) were considered as functioning "blebs" (p.005) and is statistically significant Conclusion: Pre-clinical evaluation has shown that Seprafilm is safe and effective in preventing postoperative subconjunctival fibrosis.
Animal ; FILTERING SURGERY ; MOLTENO IMPLANTS ; GLAUCOMA SURGERY ; SURGERY, FILTRATION ; SURGERY, FILTERING

The study was carried out to investigate the efficacy of subconjunctivally injected mitomycin-C (MMC) on glaucoma filtration surgery(GFS) in rabbit eyes. Each of 0.05mg, 0.1mg and 0.2mg MMC were injected subconjunctivally into the rabbit eye according to groups I, II, III respectively following GFS. The IOP were returned to preoperative level at postoperative 2 weeks in control group, and at postoperative 12 weeks in group I and II. Histologically the fibrotic reaction appears less intensively in the order of group III, II, I and control group at 2 weeks after GFS. At postoperative 12th week, fibroblasts are more frequently oberved in group I and II than control group. But the proliferation of collagenous and reticulin fibers are less in group I and II than control group. The least amount of fibroblasts, collagenous and reticulin fibers are found in group III. It is suggested that subconjunctival injection of lower concentration of MMC would be effective approval as an adjunctive method to improve more success rate of GFS from this study.
Collagen ; Fibroblasts ; Filtering Surgery* ; Filtration* ; Glaucoma* ; Mitomycin* ; Rabbits* ; Reticulin

PURPOSE: To investigate the effects of varying the time of Mitomycin-C (MMC) subconjunctival injection before, during and after operation. METHOD: We divided rabbits into 3 groups according to injection time. Subconjunctival injections of 0.01% MMC 0.05 ml were given to the preoperative group at 6, 12 and 24 hours before operation, and to the postoperative group at 6, 12 and 24 hours after operation. The control group was given the injections during operation. Bleb formation and histologic analyses were studied for 4 weeks after operation. RESULTS For gross findings, the blebs of the preoperative and control groups were seen on the fourth day and completely formed at one week after operation, and were larger than those of the postoperative group. On the other hand, the blebs of the postoperative group were seen to have poor formation, displaying hypervascularity on the fourth day and disappearing one week after operation. For histologic findings, the proliferation of collagen fibers and the undifferentiation of fibroblasts observed in the preoperative and control groups were almost identical. But, the proliferation of collagen fibers and well-differentiated fibroblasts were seen to increase in the postoperative group, so aqueous flow was obstructed at week 3. CONCLUSIONS: Subconjunctival injections within 24 hours before or during glaucoma filtration surgery were better for bleb formation and preservation than those administerd after surgery.
Blister ; Collagen ; Fibroblasts ; Filtering Surgery* ; Filtration* ; Glaucoma* ; Hand ; Mitomycin* ; Rabbits*

PURPOSE: To investigate the effects of varying the time of Mitomycin-C (MMC) subconjunctival injection before, during and after operation. METHOD: We divided rabbits into 3 groups according to injection time. Subconjunctival injections of 0.01% MMC 0.05 ml were given to the preoperative group at 6, 12 and 24 hours before operation, and to the postoperative group at 6, 12 and 24 hours after operation. The control group was given the injections during operation. Bleb formation and histologic analyses were studied for 4 weeks after operation. RESULTS For gross findings, the blebs of the preoperative and control groups were seen on the fourth day and completely formed at one week after operation, and were larger than those of the postoperative group. On the other hand, the blebs of the postoperative group were seen to have poor formation, displaying hypervascularity on the fourth day and disappearing one week after operation. For histologic findings, the proliferation of collagen fibers and the undifferentiation of fibroblasts observed in the preoperative and control groups were almost identical. But, the proliferation of collagen fibers and well-differentiated fibroblasts were seen to increase in the postoperative group, so aqueous flow was obstructed at week 3. CONCLUSIONS: Subconjunctival injections within 24 hours before or during glaucoma filtration surgery were better for bleb formation and preservation than those administerd after surgery.
Blister ; Collagen ; Fibroblasts ; Filtering Surgery* ; Filtration* ; Glaucoma* ; Hand ; Mitomycin* ; Rabbits*

Sclerostomy is preferable full-thickness filtration surgery, if very low pressure are desired or if guard filtration surgery had failed. Laser sclerostomy can be performed in a less invasive manner than standard procedure, so it reduces scar formation and minimizes postoperative complications. The objective of this investigation was to determine the feasibility and parameters of laser sclerostomy using a diode laser. The diode laser with a fiberoptic delivery system is lightweight, portable and utilizes a 100 Volt outlet. Eighteen eyes of pigmented rabbits underwent a diode laser ab externo sclerostomy with energy 2 W, duration 1-2 seconds by applying endolaser probe, 0.5 mm from the limbus. Gross and histopathologic examination were done at 1 hour and 7 days after treatment. A patent fistula with formation of filtering bleb was achieved in all cases. There was a flattening of the filtration bleb at 3.3 postoperative days.
Blister ; Cicatrix ; Filtering Surgery ; Filtration ; Fistula ; Lasers, Semiconductor* ; Postoperative Complications ; Rabbits* ; Sclerostomy*

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*

During filtration surgery for glaucoma, the conjunctival incision site is sutured watertightly with a suture material like 10-0 nylon. However, this suture material may cause the infiltration of inflammatory cells, and the proliferation and migration of fibroblasts and collagen fibers at the junction of the conjunctiva and episclera. Subsequently, the arrangement of collagen fiber in episclera would be disrupted and the outflow of aqueous humor could be occluded. In the search for a more suitable suture material, the fibrin glue(Tisseel(R)) was introduced recently. It is claimed to be simple to use and safe, causes less damage and less inflammatory reaction than nylon. The authors used 10-0 nylon(control group) on the right eye and fibrin glue(Tisseel(R))(experimental group) on the left eye of a white rabbit's conjunctival suture. We compared and evaluated the clinical and histological effects of the suture material on the suture site as well as on the intraocular region. The results were as follows; 1. In the experimental group, conjunctival injection and chemosis were mild and disappeared rapidly. 2. The filtering bleb was macroscopically well formed and maintained from the third postoperative day in both groups, but, thereafter, it decreased in size in two cases of the control group. 3. There was no difference in the inflammatory reaction in anterior chamber in both groups postoperatively. 4. In the experimental group, there was loosening of the fibroblasts proliferation and lesser infiltration of inflammatory cells at the postoperative second and fourth week. And the arrangement of collagen fibers in episclera was intact. The above findings strongly suggest fibrin glue(Tisseel(R)) as a suture material in the filtration surgery of glaucoma is clinically promising.
Anterior Chamber ; Aqueous Humor ; Blister ; Collagen ; Conjunctiva ; Fibrin* ; Fibroblasts ; Filtering Surgery* ; Filtration* ; Glaucoma ; Nylons ; Rabbits* ; Sutures

Antimetabolites, 5-fluorouracil(5-FU) and mitomycin-C(MMC), are used to promote the success rate of the glaucoma filtration surgery(GFS). The authors observed and compared the duration of bleb formation and complications by slit-lamp biomicroscopy, and the inhibition of fibroblast proliferation and of fibrosis by light microscopy following GFS in 4 group rabbits. One hundred and twenty rabbits comprised in this study 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. For the maintenance of bleb formation, MMC, 5-FU SC, 5-FU and BSS group showed 0%, 26.7%, 16.7%, 100% at the 1 month after GFS, and 0%, 0%, 0%, 73.3% at the 2 months after GFS, respectively, which suggested that MMC group lasted longest. The inhibition of fibrosis and fibroblast proliferation became higher in the order of MMC, 5-FU, 5-FU SC, BSS group at 2 weeks after the surgery. At 3 months after GFS, there was no conspicuous statistic difference(P>0.05) between 5-FU SC and 5-FU group, but some differences(P<0.001) in the rest groups. From these results, we concluded that antimetabolites such as 5-FU and MMC could be used effectively in cases of poor prognosis of GFS. However, the dosage and application method of antimetabolites should be considered very carefully and further research will be necessary to find out the optimal dosage with minimum toxicity.
Antimetabolites ; Blister ; Fibroblasts ; Fibrosis ; Filtering Surgery* ; Filtration* ; Fluorouracil* ; Glaucoma* ; Microscopy ; Mitomycin* ; Prognosis ; Rabbits*

A histologic study was performed if fibroblast proliferation could be inhibited in rab bits by deli very of bleomycin(1.35mg), an antineoplastic antibiotics, in a collagen sponge implant. Results showed that fibroblast proliferation was markedly inhibited and bleb longevity was prolonged when compared to controls. And inflammatory cell infiltration was noted around filtration wound.
Antibiotics, Antineoplastic ; Bleomycin* ; Blister ; Collagen* ; Fibroblasts ; Filtering Surgery* ; Filtration ; Glaucoma* ; Longevity ; Porifera* ; Wounds and Injuries