Hydrogen Peroxide-Induced Cell Death in a Human Retinal Pigment Epithelial Cell Line, ARPE-19

The loss of retinal pigment epithelium (RPE) with aging is related to age-related macular degeneration (AMD). This study was conducted to investigate the mechanism of hydrogen peroxide (H2O2) induced cell death in a human retinal pigment epithelial cell line, ARPE-19. Hydrogen peroxide was added at different concentrations to ARPE-19 cells and cultured. The cytotoxicity was assayed by mitochondrial function using 3- (4, 5-dimethylthiazol-2-yl) -2, 5-diphenyl tetrazolium bromide (MTT) testing. The patterns of cell damage were assessed using an acridine orange-ethidium bromide differential staining method, in situ end labeling (ISEL) assay and transmission electron microscopy (TEM). Catalase, a major antioxidant, was used to prevent cell death. The cleavage of procaspase 3 and poly (ADP-ribose) polymerase (PARP) was determined by western blot analysis. Hydrogen peroxide significantly induced cell death in ARPE-19 cells, whereas pretreatment of the cells with catalase prevented cell death. Application of the ISEL assay and acridine orange/ethidium bromide staining demonstrated that the H2O2-induced cell death occurred by an apoptotic mechanism at lower concentrations of H2O2 (400, 500, 600 microM), whereas higher concentrations of H2O2 induced necrosis rather than apoptosis. Caspase 3 was associated with the apoptotic pathway in human RPE cell death. Western blot analysis confirmed caspase 3 activation and cleavage of substrate proteins in ARPE-19 cells treated with an H2O2 concentration of 600 microM. These results indicate that treatment with H2O2 induces apoptotic and necrotic cell death in ARPE-19, and that caspase 3 is associated with apoptotic cell death. Therefore, H2O2 may induce the destruction of RPE cells in AMD by the combined effects of apoptosis and necrosis.

Correlation of sFas Level with Uveitis Severity

PURPOSE: The aim of this study is to determine the soluble Fas (sFas) levels in both sera and aqueous humor in patients with uveitis and compare them to the uveitis severity. METHODS: We measured the sFas levels in both sera and aqueous humor (AH) of patients (n=40) with uveitis and non-uveitis controls (n=27). The patients with uveitis comprised 24 Behcet's disease, 6 panuveitis, 5 anterior uveitis, 2 lens induced uveitis, 1 Vogt-Koyanagi-Harada-disease, 1 sarcoidosis, and 1 retinal vasculitis. The severity of uveitis was determined by the Hogan's grading method (0~4 grade) at the time of sampling. RESULTS:The concentration of aqueous sFas in uveitis patients was significantly higher than that in nonuveitis controls, while there was no difference in the serum concentration of sFas between the two groups. In the paired samples of serum and AH, obtained simultaneously, the aqueous sFas levels were higher than serum Fas levels in patients with uveitis, whereas the non-uveitis controls displayed significantly lower sFas levels in AH than in the serum. The sFas levels in AH or serum were not different between Behcet's uveitis and non-Behcet's uveitis. However, in patients with Behcet's uveitis, circulating sFas strongly correlated with aqueous sFas, which was not so in those with non-Behcet's uveitis. Patients (n=29) with more active (grade> or =2) uveitis had significantly higher levels of aqueous sFas than those (n=11) with less active (grade<2) uveitis. After treatment with steroid and/or immunosuppressive agents, aqueous sFas levels were decreased in parallel with a reduction in the number of inflammatory cells in the anterior chamber. CONCLUSIONS: The levels of sFas were elevated in patients with uveitis and correlated well with uveitis severity.

The Relation of Microalbuminuria with Diabetic Retinopathy in Diabetic Patients without Proteinuria

It has been well known that diabetic retinopathy is related to proteinuria in diabetes. However there still remains a controversy regarding the association between microalbuminuria and diabetic retinopathy. To know the effect of microalbuminuria on the development of diabetic retinopathy, we studied the presence of microalbuminuria in 80 diabetic patients who had no proteinuria or a history of renal disease were included in this study. We examined 24 hour microalbuminuria by radioimmunoassay and examined the presence and severity of diabetic retinopathy. Among the total of 80 patients with diabetes, microalbuminuria[20microgram/min] was found in 40%[32 patients] and diabetic retinopathy was in 46.3%[37 patients]. The prevalence of microalbuminuria was higher in diabetic retinopathy group[73.0%, 27 of 37 patients] than in normal control group[11.6%, 5 of 43 patients][p<0.001]. The amount of microalbuminuria showed significant correlation with the severity of diabetic retinopathy[r=0.461, p<0.001]. Duration of diabetes was significantly longer in diabetic retinopathy group than in normal group[10.8+/-5.3 years vs 4.8+/-4.1 years, p<0.001]. There was no statistical significance in blood pressure, fasting blood sugar, HbA1 C, serum cholesterol or lipid between the two groups. With these above results, we suggest that microalbuminuria may be associated with the development of diabetic retinopathy in diabetes and thus, microalbuminuria may be a useful marker for the early detection of diabetic retinopathy.

Role of the Vt i reous in Branch Retinal Vein Occlusion in Association with Macular Edema and Neovascularization

The main cause of decreased visual acuity in branch retinal vein occlusion (BRVO) are macular edema and vitreous hemorrhage due to retinal neovascularization.We retrospec- tively studied the association of macular edema, neovas- cularization and vitreous hemorrhage according to the vitreoretinal relationship in 51 eyes of 51 BRVO patients. The eyes were classified as having vitreomacular attachment (VMA) or vitromacular separation (VMS) and posterior vitreous detachment (PVD) state and studied macular edema and retinal neovascularization development according to the vitreoretinal realtionship. The prevalence of VMA was 37 (72.5%) of the eyes and VMS was 14 (27.5%) eyes. VMA group had macular edema in 75.7% (28 of 37 eyes)and no macular edema was present in VMS group.Those 42 eyes who had partial or no PVD, 35.7% (15 of 42 eyes)developed retinal neovascularization and 9 eyes of complete PVD did not occur neovascularization. Although no significant relationship was found, vitreous hemorrhage developed in 21.4% (9 of 42 eyes) of only partial or no PVD group. VMA and PVD state may influence the presence of macular edema and retinal neovascularization in association with BRVO.

The Effect of Tissue Plasminogen Activator on Premacular Hemorrhage

Early vitrectomy is recommended for eyes with premacular hemorrhage, which facilitates fibrovascular proliferation and macular traction. To assess the effect of tissue plasminogen activator(tPA)on the absorption of premacular hemorrhage, we injected tPA(25 microgram)into the vitreous cavity of 13 eyes with premacular hemorrhage and followed for 30 days. We classified the type of hemorrhage according to the site of hemorrhage and the presence of posterior vitreous detachment(PVD). Four eyes had complete PVD following vitrectomy, 4 eyes had a hemorrhage in the subhyaloid space and 5 eyes had a hemorrhage in the subinternal limiting membrane. The mean absorption time of hemorrhage after tPA injection was 5. 5 days in 4 eyes of complete PVD and 12. 7 days in the remaining types. Visual acuity improved in 9 eyes, remained stable in 3 eyes and worsened in 1 eyes following tPA injection. Five eyes required pars plana vitrectomy due to recurrent vitreous hemorrhage and macular traction. TPA seemed to be considered another method of treatment in the eyes of premacular hemorrhage, especially in the vitrectomized eyes or eyes with complete PVD.

A Case of Bacterial Endophthalmitis Following Penetrating Keratoplasty

Endophthalmitis is an intraocular inflammation caused by bacteria or fungus. Although endophthalmitis may result from an endogenous source elsewhere in the body, it most commonly occurs following intraocular surgery or penetrating ocular injury. But endophthalmitis following penetrating keratoplasty reveals the significantly lower incidence than by other causes. We have experienced one case of bacterial endophthalmitis following penetrating keratoplasty which was proved to be Pseudomonas aeruginosa by bacterial culture. In spite of two intravitreal injection of proper antibiotics, his clinical symptoms and signs did not improve and his visual acuity decreased to hand movement. So, we performed pars plana vitrectomy and third intravitreal injection of antibiotic and achieved a successful results with final visual acuity of 6/20. We report a case of endophthalmitis following penetrating keratoplasty and with the review of literature.

Central Retinal Artery Occlusion in Association with Thyroid Ophthalmopathy

Thyroid ophthalmolopathy causes bilateral proptosis, restricted ocular movements and optic neuropathy due to inflammatory cell infiltration into the soft tissue. We report a case of central retinal artery occlusion after thyroid ophthalmopathy by swelling of retrobulbar soft tussue and compression of optic nerve and brief review of related literature was presented.

Treatment of Total Hyphema Following Trauma and Surgery with Tissue Plasminogen Activator

Delayed clearing from the total hyphema resulting from ocular trauma and surgery causes intractable glaucoma and corneal staining by blood-pigments such as hemoglobin and small amounts of hemosiderin. The management of hyphema includes supportive medical care such as bed rest and surgical procedures such as paracentesis and removal of blood clot to enhance the secretory function of trabecular meshwork. However, surgical intervention has many complications and should be used only when it is absolutely necessary. We used the recombinant intraocular tissue plasminogen activator as a method for minimizing complications and sequeles in three patients with total hyphema. Hyphema resolved in all patients who had been treated with 10ug of recombinant tissue plasminogen activator following 5 days medical treatment. In study, we experienced a case of vitreous hemorrhage. In conclusion, we recommend that eyes with complicated large or total hyphema may be considered for intracameral tissue plasminogen activator as a first procedure comparing to surgical intervention, but further invesigation is needed for timing and dosage of drug usage.

The Effect of Cyclosporin Therapy on Endogenous Uveitis

Endogenous uveitis is characterized by frequent remissions and exacerbations which lead to visual loss, and treated with immunosuppresive agents. We evaluated the therapeutic effect and complicantions of 15 patients (25 eyes) with endogenous uveitis who were treated with cyclosporin (Implanta). The inflammatory activities of anterior chamber and vitreous were reduced significantly after 1, 3, and 8 month follow-up of cyclosporin therapy, and the visual acuity was improved or sustaind in 52% of all patients. If cyclosporin therapy is intolerable, combining the cyclosporin with low dose of a steroid should be considered.

Complications of Perfluorocarbon Liquids as an Intraoperative Tool

Perfluorocarbon liquids(PFCLs) have recently been used to facilitate surgery in a variety of condition, including proliferative vitreoretinopathy, giant retinal tears, diabetic tractions, retinal detachment with a rhegmatous component, dislocated crystalline lenses. Although the ocular toxicity of PFCLs has been evaluated in a number of animal studies, few reports have focused on ocular complications associated with their clinical use. We evaluated complications of PFCLs as an intraoperative tool in a series of 55 patients. We had used two kinds of PFCLs, Vitreon(perfluorophenanthrene) and DK-line(perfluorodecaline) intraoperatively. 10 eyes had intraoperative complications. Subretinal PFCLs(6 eyes), subretinal hemorrhage(3 eyes), subretinal hemorrhage with subretinal PFCLs(1 eye) were observed. Postoperative complications of PFCLs as an only intraoperative tool were preretinal small dreplets(4 eyes), subretinal small droplets(4 eyes) and small dreplets in anterior chamber(2 eyes). In case of posterior retinal break, careful injection should be considered. Postoperative small residual droplet of perfluorocarbon in sub- and preretinal space did not cause any toxic effects in these patients. But remained droplet in anterior chamber should be removed to avoid significant corneal toxity.

A Clinical Study of Penetrating Ocular Injuries

To evaluate the epidemiological features of penetrating ocular injuries and to indentify factors influencing visual outcome we analyzed retrospectively 410 eyes of 402 patients who were treated at St. Mary's hospital from January 1, 1984 to December 31, 1994. Three hundred thirty four (83.1%) of the patients were male and the peak age was the third decade in both sexes. Little seasonal variation was noted. The accidents occurred more frequently at 4-5 p.m. and 10-12 p.m. and the peak time varied according to the type of accidents. Home accidents(27.4%) were the most common and traffic accidents(24.9%), industrial accidents(22.4%) came next. Two hundred fourteen (53.2%) were inflicted by sharp objects such as spectacles or glass. The cornea(63.1%) was the most common site of perforation and the laceration tended to occur at corneal conter, 6-10mm in length (37.5%). Conjunctival laceration(21.7%), lid laceration(33.2%) and the lens damage(31.5%)were accompanied. The most common surgical procedures was primary closure(83.2%), followedby lid repair and lens aspiration. Evisceration was performed in 54 eyes(13.2%), and the traffic accidents and blunt trauma were the main cause of the procedure. Final visual acuity was better in eyes with only corneal laceration than in eyes with scleral involvement.

Clinical Survey of Interferon Retinopathy

We studied the retinal complication of systemic alpha-interferon in 52 patients who had chronic myelogenous leukemia of chronic phase. 32 patients of them were systemically injected with alpha-interferon for 6 months or more, and 20 patients who were not injected were used as a control. In the injected group, 10 of the 32 patients(31%) showed retinopathies such as yellowish white subretinal deposits, multiple blot shaped hemorrhages, and cotton wool spots. However in the control group, there was only one patient who showed blot shaped hemorrhage. The injected group had significantly much higher chance to have retinopathy than the control group(p0.05). The sex and hematologic factor did not affect the development of retinopathy(p<0.05). Since the patients under long term treatment of systemic alpha-interferon are at higher risk of retinopathy, their fundus should be examined periodically.

Decentration and Tilt of Posterior Chamber Lens According to Anterior Capsulotomy

To evaluate the abnormal positions of intraocular lens after cataract extraction and intraocular lens implantation, the study used the image analysis technique. Tilting and decent ration of posterior chamber intraocular lens(PCL) were studied according to the anterior capsulotomy. 103 patients(120 eyes) were randomized into 6 groups(20 eyes each) according to posterior chamber lens style and anterior capsulotomy type, and measured the degrees of tilting and decent ration of PCL by Scheimpflug camera. Three piece PCL implantation group showed significant less tilting than one piece PCL implantation group at postoperative 1 week. In one radial tear of anterior capsulotomy group, three piece PCL showed less tilting than one piece PCL. At postoperative 2 months, continuous curvilinear capsulorhexis without radial tear group showed significant less decent ration and tilting than one radial tear group. At postoperative 1 week and 2 months tilting of the continuous curvilinear capsulorhexis group was less than two or more radial tears group. As time passes from 1 week to 2 months tilting decreased significantly, but decentration did not showed significant decrease.

Clinical Analysis of Uveitis by the Diagnostic Studies

In order to investigate the efficiency of various laboratory studies of uveitis, we performed a series of studies including complete boold count, immunologic tests and radiolgic examination for 70 patients with uveitis and same number of controls who had visited at St. Mary's Hospital, Catholic University Medical College from October 1992 to May 1993. The series of uveitis consists of 24 patients(34.3%) of anterior uveitis, 20 patients(28.6%) of posterior uneitis and 17 patients(24.3%) of intermediate uveitis. Only 7 cases presented positive results for the specific laboratory studies. Two patients of uveitis were positive for cytomegalovirus IgM, one for toxoplasma IgG and one for VDRL. One patient showed evidence of sacroilitis on sacroiliac joint X-ray. Skin test for Clonorchis sinensis was positive in one patient of uveitis. One case in the control group was positive for toxoplasma IgG. From the above results, we suggest that the selective laboratory studies should be carried out on the basis of the patient's histories and ocular findings for the more specific and etiological diagnosis of uveitis.

Hyphema, angle recession and macular hemorrhage induced by air bag

Air bag has gained increasing acceptance as a device that reduce serious head and chest injury in vehicle accident. Although air bag reduces incidence and severity of facial and periorbital trauma, the possibility of ocular trauma by air bag inflation itself cannot be trivialized. We experienced a patient who developed hyphema, angle recession and macular hemorrhage after air bag inflation, and reviewed the available literatures regarding this type of injury.

Consecutive Endophthalmitis after Intraocular Surgery

Postoperative endophthalmitis has been greatly improved over the past decade by the use of improved medical therapy and the use of vitrectomy. However, the appropriate use of the different treatment modalities and the appropriate time of vitrectomy in the treatment of postoperative endophthalmitis remains controversial. We have experienced consecutive endophthalmitis following 2 cases of cataract surgery, 1 case of glaucoma filtering surgery with cataract operation and 1 case of secondary posterior chamber intraocular lens(PCL) implantation. We report the presumed cause of endophthalmitis and its therapeutic results. 1. Four of five patients who underwent cataract and combined glaucoma surgery were detected Pseudomonas aeruginosa and its infective cause presumed to be the I and A Kit of phacoemulsifier(Cavltron Kelman 8000). 2. More severe 3 of 4 patients who developed postoperative endohthalmitis were treated with vitrectomy and mild 1 patient was treated medically. 3. At the time of follow-up(mean, 11 months), the final corrected average visual acuity of 20/30 was achieved.

Consecutive Endophthalmitis after Intraocular Surgery

Postoperative endophthalmitis has been greatly improved over the past decade by the use of improved medical therapy and the use of vitrectomy. However, the appropriate use of the different treatment modalities and the appropriate time of vitrectomy in the treatment of postoperative endophthalmitis remains controversial. We have experienced consecutive endophthalmitis following 2 cases of cataract surgery, 1 case of glaucoma filtering surgery with cataract operation and 1 case of secondary posterior chamber intraocular lens (PCL) implantation. We report the presumed cause of endophthalmitis and its therapeutic results. 1. Four of five patients who underwent cataract and combined glaucoma surgery were detected Pseudomonas aeruginosa and its infective cause presumed to be the I and A Kit of phacoemulsifier (Cavltron Kelman 8000). 2. More severe 3 of 4 patients who developed postoperative endohthalmitis were treated with vitrectomy and mild 1 patient was treated medically. 3. At the time of follow-up (mean, 11 months), the final corrected average visual acuity of 20/30 was achieved.

Chemical Analysis of Subretinal Fluid in Rhegmatogenous Retinal Detachment

A chemical analysis of subretinal fluid was made in 15 patients (16 eyes) who had undergone retinal detachment surgery from March 1, 1991 to July 31, 1991 at St. Mary's Hospital, Catholic University Medical College. The protein concentration of subretinal fluid ranged from 1.0gm/dl to 7.1gm/dl, and the average protein concentration of subretinal fluid of retinal detachment for 90 days or more showed 5.13 +/- 1.71gm/dl and that of subretinal fluid of retinal detachment for less than 90 days was 2.06 +/- 1.29gm/dl. This revealed increasing tendency of protein concentration in proportion to the duration of detachment (p<.05), and the protein concentration of subretinal fluid did not show any differences according to the size of retinal detachment. Sugar ranged from 32mg/dl to 96mg/dl, and chloride was from 92mEq/L to 126mEq/L. From this study, we found that the protein concentration of subretinal fluid increased in proportion to the duration of retinal detachment. On the contrary, sugar and chloride concentration was not related to the duration of retinal detachment.

The Effects of Tissue Plasminogen Activator in Experimental Hyphema of White Rabbits

The purpose of this study is to observe the resorption effect of the anterior chamber blood by introducing tissue plasminogen activator (tPA). The results were as follows: 1. Hyphema of the tPA injection group was cleared completely within six days under the slit lamp examination, while no injection group and saline injection group showed no complete erythrocyte resorption even up to 21 days (p<0.01). 2. In the tPA injection group, intraocular pressure (lOP) returned to normal level in short period of time. However, in the other two groups lOPs were maintained higher than in the tPA injection group (p

The 13q14 Deletion in Retinoblastoma

Retinoblastoma is the most common intraocular malignant tumor in children. Retinoblastoma is divided two groups, hereditary and non-hereditary. Hereditary retinoblastoma is relakd to chormosomal abnormalities. By banding technique of somatic chromosome in retinoblastoma, deletion of chromosome 13q14 is found, but it has not been reported domestically. We experienced two cases of retinoblastoma with chromosome 13q14 deletion.