This study was conducted to investigate the effect of ascorbic acid on oxidative injury of cultured porcine retinal pigment epithelial (RPE) cells induced by t-butylhydroperoxide. The porcine RPE cells were cultured in Dulbecco's modified Eagle's medium and the culture medium was replaced with one containing 0.01 mM to 5 mM ascorbic acid and/or 0.2 mM t-butylhydroperoxide. After 2 hours incubation, the test medium was replaced with the control medium. The number of cells was counted with a Coulter counter after a 2-day incubation period. The medium was pretreated with 900 U/ml and the previous procedure was repeated to eliminate the toxic effects of hydrogen peroxide induced by ascorbic acid. Not only t-butylhydroperoxide (p < 0.01) but also ascorbic acid (p < 0.01) were found to have dose-dependent cytotoxicity on RPE cells. The cytotoxicity was more significant when both agents were added to the culture media. In the presence of catalase, the cytotoxicity of ascorbic acid became insignificant (p > 0.05). The cytotoxicity of t-butylhydroperoxide decreased when 1 mM and 5 mM of ascorbic acid was added to the culture media with catalase pretreatment (p = 0.0277). These results indicate that ascorbic acid was toxic to RPE cells in our culture model but this cytotoxicity was not detected in the presence of catalase. With catalase pretreatment, ascorbic acid in relatively high concentration provided protection against oxidative injury of t-butylhydroperoxide.
Animals ; Ascorbic Acid/*pharmacology ; Cell Count ; Cell Survival/drug effects ; Cells, Cultured ; Culture Media ; Dose-Response Relationship, Drug ; Free Radicals ; Oxidative Stress/*drug effects ; Peroxides/antagonists & inhibitors/toxicity ; Pigment Epithelium of Eye/cytology/*drug effects ; Reactive Oxygen Species/toxicity ; Swine ; tert-Butylhydroperoxide

proliferative vitreoretinopathy (PVR) is the most common cause of failure in retinal reattachment surgery. Three different procedures were performed in 20 pigmented rabbits to devise a simple model to induce experimental PVR. Rabbits were assigned randomly to three groups (I, II, and III). Group I rabbits (5 rabbits, 10 eyes) rereived normal saline into the vitreous cavity, after an iatrogenic retinal tear was made. In group II rabits (8 rabbits, 8 eyes), a suspension of retinal pigment epithelium (RPE) and choroid from the left eye was transferred into the vitreous cavity of the right eye. In group III rabbits (7 rabbits, 7 eyes), a suspension of RPE and choroid from the left eye was transferred into the vitreous cavity of the right eye after an iatrogenic retinal tear was made. The fundus was observed for 2 months with an indirect ophthalmoscope. The incidence of retinal detachment in group I was zero (O/IO), that of group II was 37.5% (3/8), and that of group III was 85.7% (6/7). Electron microscopic findings of the vitreous strand of one eye of group II showed a central melanocytic core, peripheral fibroblasts, and intercellular collasen fibril. Electron microscopic findings in one eye of group III revealed a subretinal membrane composed of suspected RPE and glial cells.
Animals ; *Disease Models, Animal ; Pigment Epithelium of Eye/pathology ; Rabbits ; Retinal Diseases/*etiology ; Vitreous Body/pathology

Proliferative vitreoretinopathy(PVR) is the most common cause of failure in retinal reattachment surgery. We performed three different procedures in 20 pigmented rabbits to get a simple model to induce experimental PVR. Rabbits were assigned randomly to three groups(I, II and III). Group I rabbits(5 rabbits, 10 eyes) received normal saline into vitreous cavity, after iatrogenic retinal tear was made. In group n rabbits(8 rabbits, 8 eyes), suspension of retinal pigment epithelium(RPE) and choroid of left eye was transferred into vitreous cavity of right eye. In group III rabbits(7 rabbits, 7 eyes), suspension of RPE and choroid of left eye was transferred into vitreous cavity of right eye after iatrogenic retinal tear was made. We observed the fundus for 2 months with, indirect ophthalmoscope. Incidence of retinal detachment of group I was zero(0/10) , that of group II was 37.5%(3/8), and that of group III was 85.7%(6/7). Electron microscopic findings of vitreous strand of one eye of group n showed central melanocytic core, peripheral fibroblast, and intercellular collagen fibril. Electron microscopic finding of one eye of group III revealed subretinal membrane composed of suspected RPE and glial cell.
Choroid ; Collagen ; Fibroblasts ; Incidence ; Membranes ; Neuroglia ; Ophthalmoscopes ; Rabbits* ; Retinal Detachment ; Retinal Perforations ; Retinaldehyde ; Vitreoretinopathy, Proliferative*

An animal experiment was done to evaluate the efficacy of tissue coating with sodium hyaluronic acid and subconjunctival injection of triamcinolone acetate in reducing the severity of postoperative adhesions following strabismus surgery. Experimental animals underwent a mild traumatic surgical procedure in one superior rectus muscle and a severe traumatic surgical procedure in the other superior rectus muscle. Each group was divided into control group, sodium hyaluronate coating group and triamcinolone acetonide injection group. Grading the severity of adhesions through surgical exploration of operative sites and histological comparison after 4 weeks revealed a significant reduction of postoperative adhesions in sodium hyaluronate group compared with control group under conditions of severe surgical trauma. But triamcinolone groups have no significant differences compared with control groups by statistical analysis. Tissue protection afforded by sodium hyaluronate may lead to an effective method which minimizes the surgical trauma to the tissues and reduces the postsurgical adhesions following strabismus surgery.
Animals ; Eye Diseases/etiology/*prevention & control ; Hyaluronic Acid/administration & dosage/*therapeutic use ; Injections ; Oculomotor Muscles/pathology ; Postoperative Complications/prevention & control ; Rabbits ; Strabismus/*surgery ; Tissue Adhesions/prevention & control ; Triamcinolone Acetonide/administration & dosage/therapeutic use ; Wound Healing

We reviewed 71 cases of recurred retinal detachment after trans pars plana vitrectomy managed with fluid gas exchange with sulfur hexafluoride gas between January 1984 and April 1986 in order to identify the anatomic and functional success rate. The causes of vitrectomy were as follows: retinal detachment with peripheral retinal breaks(29 eyes) or giant dialysis(10 eyes) complicated by proliferative vitreoretinopathy, retinal detachment with no breaks(16 eyes), traction retinal detachments(6 eyes), and others(3 eyes). The anatomic and functional success rate was affected by the grade of proliferative vitreoretinopathy. In 71 cases performed fluid gas exchange with sulfur hexafluoride gas, anatomic success rate was 38%(27/71) and functional sucess rate was 22.5%(16/71).
Retinal Detachment* ; Retinaldehyde* ; Sulfur Hexafluoride ; Traction ; Vitrectomy ; Vitreoretinopathy, Proliferative

ERG was checked by an instrument set up by authors in eyes with vitreous opacity with and without retinal disorders. It is composed of a preamplifier(frequency response of 0.3Hz~240Hz, gain of 80 decibel), Tektronix 5103N oscilloscope(with 5A18N dual trace amplifier and 5B12N dual time base). Retina was stimulated by Grass P22 photostimulator at settings of 1, 4, 8, and 16 light in tensities. Following findings were obtained; 1. Voltage of a-wave was much increased with little change of b-wave, when intensities of photostimulation was increased. 2. Definite ERG waves were recorded with high intensities of light stimulation, when low intensities failed to produce them. 3. Even in high intensities of light stimulation, oscillatory potentials were not recorded. 4. In case of diffuse retinal damage and vitreous opacities, peak time of a and b wave were markedly delayed as well as decrease of voltages.
Electroretinography* ; Poaceae ; Retina ; Retinaldehyde

To understand the pathogenesis of proliferative vitreoretinal membrane formation which occurs in proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR), etc., accurate identification of the cellular components of the membrane is needed. This study was performed to identify cellular components of the membranes by means of immunohistochemical technique. 11 proliferative vitreoretinal membranes which were surgically obtained from 7 eyes with PVR and 4 eyes with PDR were stained with monoclonal antibodies against cytokeratin, glial fibrillary acidic protein (GFAP), or vimentin using immunoperoxidase technique (ABC method). In the PVR membranes, mean cell positivities for cytokeratin, GFAP and vimentin were 48%, 1% and 92%, respectively and in the PDR membranes, 0%, 5% and 93%, respectively. The above results suggest that retinal pigment epithelial cells and fibroblasts are major cellular components of PVR membranes, and that mesenchymal cells are major cellular components and glial cells are minor cellular components of PDR membranes.
Adolescent ; Adult ; Antibodies, Monoclonal ; Cell Membrane/metabolism/pathology ; Diabetic Retinopathy/metabolism/pathology ; Eye Diseases/metabolism/pathology ; Female ; Humans ; Immunoenzyme Techniques ; Intermediate Filament Proteins/*analysis ; Male ; Middle Aged ; Retinal Diseases/metabolism/*pathology ; Vitreous Body/metabolism/*pathology

Sympathetic ophthalmia is rare, bilateral, diffuse, and granulomatous inflammation of the uvea, which occurs days, months, or years after penetrating ocular injury or intraocular surgery. The cause of the disease is still unknown but seems to be an autoimmune disease by reaction of delayed hypersensitivity mediated by T-Iymphocyte. There have been 4 cases reports on sympathetic ophthalmia domestically untill now, which occurred after ocular penetrating injury. The authors experienced two cases of sympathetic ophthalmia; one occurred after implantation of intraocular lens and the other occurred after cyclocryotherapy. A brief review of the related literatures is presented.
Autoimmune Diseases ; Hypersensitivity, Delayed ; Inflammation ; Lenses, Intraocular ; Ophthalmia, Sympathetic* ; Uvea

Sympathetic ophthalmia is rare, bilateral, diffuse, and granulomatous inflammation of the uvea, which occurs days, months, or years after penetrating ocular injury or intraocular surgery. The cause of the disease is still unknown but seems to be an autoimmune disease by reaction of delayed hypersensitivity mediated by T-Iymphocyte. There have been 4 cases reports on sympathetic ophthalmia domestically untill now, which occurred after ocular penetrating injury. The authors experienced two cases of sympathetic ophthalmia; one occurred after implantation of intraocular lens and the other occurred after cyclocryotherapy. A brief review of the related literatures is presented.
Autoimmune Diseases ; Hypersensitivity, Delayed ; Inflammation ; Lenses, Intraocular ; Ophthalmia, Sympathetic* ; Uvea

In the process of closing a scleral wound caused by various conditions, incarceration af the conjunctiva, Tenon's capsule or vitreous in the wound can occur unexpectedly. We created such conditions experimentally to determine their intraocular complications. The experimental, materials were 12 albino rabhits(24 eyes) and the rabbits were divided into two groups(I and II). Group I rabbits(12 eyes) received no vinectormy and group II rabbits(12 eyes) received a vitrectormy. After the conjunctiva and Tenon's capsule flap was made, the tissue flap was inserted into the vitreous cavity through the sclerotomy site- Fundus examination with an indirect ophthalmoscope and enucleation for histology were performed at 3 days, 1 week, 3 weeks, 6 weeks, 3 months and 6 months after the experiment. The results were as follows: 1, Intraocular fibrovascular proliferation developed in all experimental rabbit eyes. 2. The more vitreous hemorrhage developed, the greater was the fibrovascular proliferation and the degree of fibrovascular proliferation was more marked in group II than group I. 3. The fibrovascular proliferation developed to a band in 3 weeks, then regressed gradually. 4. The fibrovascular band was composed of fibroblasts, stromal matrix and few vessels.
Conjunctiva ; Fibroblasts ; Ophthalmoscopes ; Rabbits ; Tenon Capsule ; Vitreous Hemorrhage ; Wounds and Injuries*