OBJECTIVETo observe the experimental results and histopathological changes of acellular xenogenic dermal matrix (X-ADM) and allogeneic sclera used as wrapping materials of hydroxy apatite (HA) ocular implants in New Zealand white rabbits.

METHODSTwenty-four rabbits received unilateral eye enucleating and the sockets were implanted with HA spherical implants wrapped with either acellular xenogenic dermal matrix or allogeneic sclera at random. The rabbits were examined for inflammation and implant exposure and sacrificed at 1, 2, 4, 6, 8 and 12 weeks after implantation. The sockets with the grafts were exenterated and the specimens were assessed histopathologically and ultrastructurally with light or transmission electron microscopy for the changes in inflammation reaction and vascularization.

RESULTSCompared to allogeneic sclera at the same stage of implantation, acellular xenogenic dermal matrix demonstrated more active and earlier growth of fibroblasts and new vessels with abundant collagen deposition. There were few inflammatory cells and no rejection was found.

CONCLUSIONThis experiment showed that the acellular xenogenic dermal matrix, with fast neovascularization and low immunity, can be an ideal material of ocular implant and a good substitute for allogeneic sclera.

Animals ; Dermis ; transplantation ; Eye, Artificial ; Female ; Hydroxyapatites ; Male ; Rabbits ; Sclera ; transplantation ; Swine ; Transplantation, Heterologous ; Transplantation, Homologous

OBJECTIVETo evaluate the histocompatibility of homologous acellular dermal matrix as a wrapping material for a hydroxyapatite orbital implant and compare the speed of fibrovascular ingrowth in hydroxyapatite orbital implant wrapped with homologous acellular dermal matrix and homologous sclera respectively.

METHODSTwenty four New Zealand rabbits were divided into two groups randomly. One group is implanted with hydroxyapatite orbital implant wrapped with homologous acellular dermal matrix behind the globe, the other group with homologous sclera. The observation included immunological reaction of the globe postoperation. Biopsies of implanted material were taken on weeks 1, 4, 8 and 12 postoperation for histopathological and electron microscope examination.

RESULTSHistological examination showed the homologous acellular dermal matrix has no immunological and inflammatory reaction after implanted in orbit. But the speed of fibrovascular ingrowth is a little slower than that of homologous sclera.

CONCLUSIONSThe homologous acellular dermal matrix has the better histocompatibility as an encapsulating biomaterial, it can be a new material instead of homologous sclera.

Animals ; Biocompatible Materials ; Dermis ; transplantation ; Female ; Male ; Orbital Implants ; Rabbits ; Sclera ; transplantation ; Transplantation, Homologous

PURPOSE: To emphasize the importance of conjunctival flap or amniotic membrane covering on the scleral allograft for scleral necrosis following pterygium excision. METHODS: Five eyes in four patients showed signs of impending perforation caused by scleral necrosis following pterygium excision, with strontium irradiation in four eyes and with instillation of mitomycin C in the other eye for preventing recurrence of pterygium. All cases were transplanted human sclera stored at -20 degrees C in Eye-Bank. Among them, the patient's own conjunctiva was used to cover the scleral allograft with interrupted sutures in four eyes, where in the other eye the scleral allograft was alternatively covered over by using human amniotic membrane stored at -70 degrees C. RESULTS: The results of all five cases were very successful without any complications during an average follow-up of 19 months (range 6~25 months). CONCLUSIONS: Based on the clinical experiences of these five cases, we concluded that the covering of the scleral allograft with conjunctiva or amniotic membrane is a very important procedure to ensure the successful viability of the scleral allograft, which is a natural structure of the conjunctiva and sclera.
Allografts* ; Amnion ; Conjunctiva ; Follow-Up Studies ; Humans ; Mitomycin ; Necrosis* ; Pterygium* ; Recurrence ; Sclera ; Strontium ; Sutures ; Transplantation, Homologous*

Following reports on successful ocular surface reconstruction using amniotic membrane, many trials of amniotic membrane transplantation are being doing to treat various ocular surface diseases. We treated pterygium with amniotic membrane transplantation and assessed the effectiveness of this method. Pterygia in 15 eyes of 15 patients were surgically excised during December 1996 to January 1997. Over the bare sclera, amniotic membrane was attached with sutures. After a mean follow-up of 72+/-20 days. 3 cases were recurred (rate 20%). The complications encountered were: persistent conjunctival injection in 10 cases (67%); pyogenic granuloma in one case (7%); loss of transplanted membrane (7%). No other serious complications were noted. Considering a short follow-up period, the recurrence rate is not low and there is also possibility of recurrence in 10 cases of persistent conjunctival injection. Therefore, this approach appears ineffective compared with other method.
Amnion* ; Follow-Up Studies ; Granuloma, Pyogenic ; Humans ; Membranes ; Pterygium* ; Recurrence ; Sclera ; Sutures ; Transplantation

PURPOSE: To examine the effects, complications, and safeties of sclera allograft and amniotic membrane transplantation with fibrin glue as surgical treatment methods for scleromalacia. METHODS: The study included 14 eyes of 14 scleromalacia patients who needed surgical treatment. Among them, seven eyes of seven patients whose scleral defect was small (<6 mm) were operated on using only fibrin glue and no suturing, while seven eyes of seven patients whose defect was large (>6 mm) were operated on using fibrin glue and minimum suturing. Amniotic membrane transplantation was performed at the site of the conjunctival defect. RESULTS: In all of the cases, the results of grafting were successful throughout the follow-up period, which was 14.6+/-4.4 months, on average (ranging from 12 to 27 months). No particular complication was observed during the follow-up period after using fibrin glue. CONCLUSIONS: For scleromalacia patients, sclera allograft and amniotic membrane transplantation were performed using fibrin glue. The grafted sclera survived successfully, allowing this treatment modality to be considered an effective and safe option without complications.
Amnion ; Eye ; Fibrin ; Fibrin Tissue Adhesive ; Follow-Up Studies ; Humans ; Safety ; Sclera ; Transplantation, Homologous ; Transplants

OBJECTIVEUse xenologous sclera (pig sclera) as wrapping materials for hydroxyapatite (HA) ocular implants in enucleated New Zealand white rabbits.

METHODSTen rabbits were unilaterally enucleated and the sockets implanted with 10 mm HA spherical implants. All implants were wrapped with pig sclera. The rabbits were killed 4 weeks later and the sockets were examined clinically for inflammation and implant exposure. Exenterated specimens were assessed histopathologically for inflammation and vascularization.

RESULTSNo clinical evidence of implant exposure or extrusion was detected in rabbits receiving pig sclera wrapped implants. Histopathologically the xenologous (pig) sclera displayed moderate inflammation, as well as maintain its lamellar arrangement without disruption. Fibrovascular ingrowth was complete in all implants.

CONCLUSIONXenologous (pig) sclera behaves similar clinically to homologous sclera as a wrapping material for spherical HA ocular implants in a rabbit model, and may represent a reasonable alternative to sclera in such procedures in humans.

Animals ; Durapatite ; Neovascularization, Pathologic ; Orbital Implants ; Prosthesis Implantation ; methods ; Rabbits ; Sclera ; blood supply ; pathology ; transplantation ; Swine ; Transplantation, Heterologous

PURPOSE: To investigate the results when using the acellular dermal allograft (SureDerm(R), Hans Biomed Co., Korea) as a new wrapping material for porous orbital implants. METHODS: The charts of 11 patients who underwent either primary or secondary insertion of Medpor(R) orbital implants after enucleation or a new insertion after removal of previous orbital implants were reviewed. Medpor(R) orbital implants either 18 or 20 mm were wrapped with SureDerm(R) in 4x4 cm sections that were 1-mm-thick. Four rectus muscles were fixed to the SureDerm(R) wrapped implant, and a conjunctival suture was made with 6-0 Vicryl. All patients had follow-up periods longer than 10 months and were evaluated to determine the success of wrapping and to identify any complications. RESULTS: The average age of the patients was 48.3 years. The patients wore artificial eyes for 9 weeks after the operation, and the follow-up periods were 22.4 months on average. There was no case of implant or SureDerm(R) exposure, inflammation, and other significant complications except in one case that required fornix reconstruction to allow the subject to wear an artificial eye. CONCLUSIONS: Acellular dermal allograft appears to be a good substitute material if preserved sclera is not available when inserting orbital implants with wrapping.
Eye, Artificial ; Follow-Up Studies ; Humans ; Inflammation ; Muscles ; Orbit ; Orbital Implants ; Polyglactin 910 ; Sclera ; Sutures ; Transplantation, Homologous

PURPOSE: To compare the surgical outcomes of the two different methods used for Ahmed Glaucoma Valve (AGV) implantation between the donor scleral graft method and the partial-thickness scleral flap method. METHODS: We retrospectively reviewed medical records of 28 eyes of 26 patients diagnosed as neovascular glaucoma followed by AGV implantation. Based on the surgical method, the included eyes were divided into two groups. In the graft group (n = 18), the drainage tube was inserted into the anterior chamber, and then covered with preserved donor sclera. In the flap group (n = 10), the drainage tube was inserted under the partial-thickness scleral flap, and then covered with the flap. We compared the postoperative intraocular pressure (IOP), surgical success rates, and postoperative complications between the two groups. RESULTS: Postoperative IOP was not significantly different between the two groups (p = 0.967, 0.495 at 12 months, 24 months, respectively, by the Mann-Whitney U-test). The mean success periods were 53.1 +/- 10.1 months in the graft group versus 50.9 +/- 9.4 months in the flap group (p = 0.882 by log rank test), and cumulative success rates were 77.8% and 80.0% at one year, respectively. However, tube migration occurred more frequently in the flap group than in the graft group (p = 0.037 by Fisher's exact test). CONCLUSIONS: In AGV surgery for neovascular glaucoma, the scleral graft method may be associated with relatively less complication about tube migration than the scleral flap method. The surgical results, however, were not statistically different.
Adult ; Aged ; Aged, 80 and over ; Filtering Surgery/*methods ; Follow-Up Studies ; *Glaucoma Drainage Implants ; Glaucoma, Neovascular/physiopathology/*surgery ; Humans ; Intraocular Pressure ; Middle Aged ; Retrospective Studies ; Sclera/*transplantation ; *Surgical Flaps ; Treatment Outcome ; Young Adult

PURPOSE: To compare the surgical outcomes of the two different methods used for Ahmed Glaucoma Valve (AGV) implantation between the donor scleral graft method and the partial-thickness scleral flap method. METHODS: We retrospectively reviewed medical records of 28 eyes of 26 patients diagnosed as neovascular glaucoma followed by AGV implantation. Based on the surgical method, the included eyes were divided into two groups. In the graft group (n = 18), the drainage tube was inserted into the anterior chamber, and then covered with preserved donor sclera. In the flap group (n = 10), the drainage tube was inserted under the partial-thickness scleral flap, and then covered with the flap. We compared the postoperative intraocular pressure (IOP), surgical success rates, and postoperative complications between the two groups. RESULTS: Postoperative IOP was not significantly different between the two groups (p = 0.967, 0.495 at 12 months, 24 months, respectively, by the Mann-Whitney U-test). The mean success periods were 53.1 +/- 10.1 months in the graft group versus 50.9 +/- 9.4 months in the flap group (p = 0.882 by log rank test), and cumulative success rates were 77.8% and 80.0% at one year, respectively. However, tube migration occurred more frequently in the flap group than in the graft group (p = 0.037 by Fisher's exact test). CONCLUSIONS: In AGV surgery for neovascular glaucoma, the scleral graft method may be associated with relatively less complication about tube migration than the scleral flap method. The surgical results, however, were not statistically different.
Adult ; Aged ; Aged, 80 and over ; Filtering Surgery/*methods ; Follow-Up Studies ; *Glaucoma Drainage Implants ; Glaucoma, Neovascular/physiopathology/*surgery ; Humans ; Intraocular Pressure ; Middle Aged ; Retrospective Studies ; Sclera/*transplantation ; *Surgical Flaps ; Treatment Outcome ; Young Adult

Scleral necrosis and infection are serious late complications of pterygium treatment and are difficult to manage. We describe a 70-year-old Chinese male who presented with scleral necrosis and Pseudomonas aeruginosa infection 15 years after the excision of a pterygium. The infection was treated early and aggressively with intensive topical and intravenous antibiotics and the thin necrotic sclera was reinforced with a donor scleral patch graft when the scleral infection was clinically controlled. The integrity of the globe was maintained by a thin layer of sclera anterior to the graft after the graft gradually shrunk in size and retracted posteriorly. The eye was saved from possible scleral perforation and endophthalmitis. This case is reported to highlight the importance of early aggressive treatment of infection and the value of prophylactic repair of scleral necrosis in the management of these late complications of pterygium treatment.
Administration, Topical ; Aged ; Anti-Bacterial Agents ; Drug Therapy, Combination ; administration & dosage ; therapeutic use ; Humans ; Injections, Intravenous ; Male ; Necrosis ; Pseudomonas Infections ; drug therapy ; Pseudomonas aeruginosa ; Pterygium ; surgery ; Sclera ; pathology ; transplantation ; Scleral Diseases ; drug therapy ; microbiology ; Surgical Wound Infection ; drug therapy ; etiology