1.The Effect of Daunorubicin on Experimental Proliferative Vitreoretinopathy.
Jae Hyun LEE ; Hyung Woo KWAK ; Woo Jeong CHOI
Journal of the Korean Ophthalmological Society 1996;37(10):1656-1662
Proliferative vitreoretinopathy (PVR) is a main cause of failure in retinal reattachment surgery. There have been many studies about the inhibition of proliferative vitreoretinophthy with several drugs. Authors investigated the inhibitory effect of proliferative vitreoretinopathy and retinal toxicity with various concentration of daunorubicin after intravitreal injection into the eyes of the pigmented rabbit. 7 pigment rabbit (11eyes) were used as subjects. After lensectomy and vitrectomy, control group was injected dermal fibroblast and F-BSS, and treatment group was injected dermal fibroblast and 5, 10, 15, 30 nmol Daunorubicin. At two weeks after intravitreal injection, both group were enucleated and examined with gross finding, light--microscopy, and electronmicroscopy. In all control group, proliferative vitreoretinopathy was found, but only preretinal membrane formation was found in 5, 10 nmol Daunorubicin injected group. In 15 nmol Daunorubicin injected group, the retina structure was preserved normally. In 30 nmol Daunorubicin injected group, the retinal outer segment was degenerated in microscopic finding. These results show that Daunorubicin has a potent effect on proliferative vitreoretinopathy, especially in 15 nmol, but retinal toxicity is suspected in marethan 30 nmol.
Daunorubicin*
;
Fibroblasts
;
Intravitreal Injections
;
Membranes
;
Retina
;
Retinal Photoreceptor Cell Outer Segment
;
Retinaldehyde
;
Vitrectomy
;
Vitreoretinopathy, Proliferative*
3.Evaluation of Retinal Visual Acuity Using SLO in Young Healthy Volunteers.
Seung Young YU ; Hyung Woo KWAK ; Jae Myung KIM
Journal of the Korean Ophthalmological Society 1999;40(6):1599-1605
We have attempted to measure parafoveal retinal acuity directly on the exact retinal locus, while observing the retinal image in real time using the scanning laser ophthalmoscope(SLO 101, Rodenstock, Munish, Germany). By the SLO Visumetry software(Rodenstock v. 3.0), thirty eyes of healthy volunteers were examined in 20degrees image field. Using Snellen E as stimulus, the examination was performed from the fovea by the radial pattern. The maximal retinal distance point, which responded to stimulus, was recorded by the pixel, and the distance(mm) from the fovea was calculated by the Bennett formula. The maximum distance from the fovea at the given stimulus size was achieved as follows: 0.32+/-0.01mmat the 15 x15 arc of minute(0.333), 0.63+/-0.01mm at the 17 x17 arc of minute(0.294), 1.05+/-0.03 mmat 20 x 20 arc of minute(0.25), and 1.44+/-0.0 5 mmat the 23 x23 arc of minute(0.217). It was also revealed that the horizontal maximal distance from fovea at given stimulus size was statistically superior to the vertical maximal distance(p<0.05). In conclusion we were able to establish the normal range of parafoveal retinal acuity in healthy volunteers. It may serve as the baseline for subsequent study of retinal pathology and functional evaluation as well as its treatment.
Healthy Volunteers*
;
Pathology
;
Reference Values
;
Retinaldehyde*
;
Visual Acuity*
4.Studies of the Timolol Effect on Intraocular Pressure and Concentration in Aqueous Humor in the White Rabbit.
Young Don OH ; Hyung Woo KWAK ; Jae Myung KIM
Journal of the Korean Ophthalmological Society 1987;28(3):589-593
The effect of 0.25% and 0.5% Timolol on intraocular pressure and concentration in aqueous humor was studied after topical instillation in the white rabbit. The intraocular pressure was measured with pneuma tonometer and the Timolol concentration in aqueous humor was measured with High Preformance Liquid Chromatograph after fine needle aspiration of aqueous humor at various time intervals. The results were as follows; 1. The percentage reduction of intraocular pressure increased with time and reached a peak after 3 hours. 2. The concentration of Timolol in aqueous humor increased with time and reached a peak after 3 hours. 3. There was close correlation between intraocular pressure and Timolol concentration in aqueous humor.
Aqueous Humor*
;
Biopsy, Fine-Needle
;
Intraocular Pressure*
;
Timolol*
5.Histologic Study in Transplantation of Cultured Rabbit Retinal Pigment Epithelium.
Journal of the Korean Ophthalmological Society 1997;38(3):391-397
The authors investigated the possibility of transplantion of cultured retinal pigment epithelial cell to normal pigmented rabbit retina. Focal retinal detachment was made in the pigment rabbit retina, and the cultured RPE cells were injected into subretinal space. The neural retina spontaneously rettached withim 6 days. At 4 weeks after tranplantation, eyes were enucleated and examined with light-microscopy and electron-microscopy. The transplanted RPE cells were proliferated with multilayer in electronmicroscopic finding, and the tight-junction was found between proliferative RPE cells. The outer segment and nucleus of photoreceptor cell were well preserved in microscopic finding. As a result, the cultured RPE cells can be sucessfully transplanted to normal pigmented rabbit retina, and photoreceptor cell was not changed after transplantation.
Epithelial Cells
;
Photoreceptor Cells
;
Retina
;
Retinal Detachment
;
Retinal Pigment Epithelium*
;
Retinaldehyde*
6.Analysis of Operative Treatment and the Outcome of the Lumbar Disc Surgery in Lumbar Disc Herniation
Yak Woo ROH ; Byoung Kee KIM ; Myung Hun KWAK ; Kwoang Jae LEE
The Journal of the Korean Orthopaedic Association 1983;18(1):50-56
A herniated lumbar intervertebral disc has been the most common cause of low back pain and sciatica since Mixter and Barr reported it in 1934. Our methods of treatment were the conservative treatment and the excision of the herniated disc for a limited number of carefully selected cases. The results of disc surgery relate to a number of factors, unquestionably the most important being patient selectivity. We emplopyed Finneson's lumbar disc surgery predictive score card to determine the relationship between patient selection and the outcome of lumbar disc surgery in operative cases. This report is to give a clinical review of 46 cases of the herniated disc upon which surgical removal were performed at Eul-Ji General Hospital from March 1981 to July 1982. The results were obtained as follows: 1. The most common age group were 21 to 40 year old. 2. In 46 surgically treated cases, 34 cases were male (74%) and 12 cases were female (26%). 3. The bulging of disc was found in 25 cases and the ruptured disc was found in 14 cases. The most common site of the lesion was L4-5 intervertebral disc with 30 cases (65%) and the next L5-Sl intervertebral disc with 10 cases (22%). 4. The outcomes of lumbar disc surgery were evaluated at follow-up as good in 77 per cent, fair in 11 per cent, marginal in 7 per cent and poor in 5 per cent of the patients. 5. The predictive scores of each result category were averaged and were as follows; Good: 77.1, Fair: 67.3, Marginal: 58.0, Poor: 40.0 6. The average predictive scores of each result category fell within the anticipated parameters of the score card. 7. The score card may be utilized as reliable system for presurgical patient selection.
Female
;
Follow-Up Studies
;
Hospitals, General
;
Humans
;
Intervertebral Disc
;
Intervertebral Disc Displacement
;
Low Back Pain
;
Male
;
Patient Selection
;
Sciatica
7.Improved Culture Method of Retinal Pigment Epithelial Cells and Functional-morphological Characteristics In Vitro.
Hyung Woo KWAK ; Jae Kyung PARK ; Jung Hyoo MOON ; Jae Myung KIM
Journal of the Korean Ophthalmological Society 1995;36(4):614-625
To study the isolation and purification and proliferation of the cell in cell culture system, and to develop an improved culture method by a modified cell isolation technique and modified culture medium. The RPE cells were cultured in 3 different mediums: type I(MEM medium with 20% FCS) type II(F-10 medium with 20% FCS) and type III(DMEM medium with 10% FCS, EGF, hydrocortisone, insulin, ethanolamine, phosphoethanolamine, chorea toxin, triiodotyronine, adenine, transferrin and BPE). We compared population doubling(P.D.), population doubling time(P.D.T), morphologic changes and phagocytic activity during a 7week period. Rapid proliferation and high purity of retinal pigment epithelial cells(RPE cells) showed in type III culture medium. Type III culture medium presented the best results in P.D., P.D.T. and cell purification. In type III culture medium, single RPE cells produced about 6 X 10(7) RPE cells in the 7week period and morphology and phagocytic activity were well maintained, when UV-B irradiation at RPE was used to produce melanin, it had no effect, but the RPE cell was inhibited by UV-B irradiation. This improved culture method for RPE cells will provide a good in-vitro model for the studies of biochemistry, cellular function of the RPE cell, as well as its clinical application in eye disease.
Adenine
;
Biochemistry
;
Cell Culture Techniques
;
Cell Separation
;
Chorea
;
Epidermal Growth Factor
;
Epithelial Cells*
;
Ethanolamine
;
Eye Diseases
;
Hydrocortisone
;
Insulin
;
Melanins
;
Retinaldehyde*
;
Transferrin
8.Echocardiographic Observation in Patients with Mitral Valve Prolapse.
Wee Hyun PARK ; Hyoung Woo LEE ; Hyo Suk KIM ; Kyu Sik KWAK ; Jae Eun JUN ; Hi Myung PARK
Korean Circulation Journal 1984;14(1):73-79
Twenty-one cases of mitral valve prolapse (MVP) diagnosed by M-mode echocardiograms were studied in regard to the underlying or associated conditions, types of MVP, and dimensions of the cardiac structures and parameters reflecting cardiac performance determined by echocardiograms. In 9 cases, MVP was thought to be idiopathic origin. Associated conditions in the remainder were 5 cases of congenital heart disease, 2 cases of rheumatic myocarditis, 1 case each of aortic valve disease, ischemic heart disease and hyperthyroidism, and 2 cases of undiagnosed cardiac conditions. There were 2 cases of buckling type of MVP and in the remainder hammock type. In these 2 patients with hammock type of MVP, mitral valve echoes were seen in the left atrium during systole in 1 case, and diastolic anterior displacement of posterior mitral leaflet in the other. In 9 cases of idiopathic MVP, cardiac dimensions and parameters reflecting cardiac performance as determined from echocardiograms showed no significant differences from those of 27 normal controls.
Aortic Valve
;
Echocardiography*
;
Heart Atria
;
Heart Defects, Congenital
;
Humans
;
Hyperthyroidism
;
Mitral Valve Prolapse*
;
Mitral Valve*
;
Myocardial Ischemia
;
Myocarditis
;
Systole
9.Evaluation of Chorioretinal Toxicity of Steroid after Intrachoroidal Injection in Rabbit.
Hyung Woo KWAK ; Jong Geun SHIN ; Jae Myung KIM
Journal of the Korean Ophthalmological Society 1995;36(5):787-792
To determine the ocular toxicity after intrachoroidal steroid injection in the rabbit eye, 0.15ml(40 mg/ml) triamcinolone acetonide, 0.15ml(40 mg/ml) methylprednisol one acetate and 0.15ml balanced salt solution(as controls) were injected into the choroid. The results were shown normal in fundus examination, electroretinography, and electron microscopy throughout the two weeks course of the experiment. From these result, it would appear that intrachoroidal 6 mg steroid injection demonstrated the lack of ocular toxicity.
Choroid
;
Electroretinography
;
Microscopy, Electron
;
Pathology
;
Triamcinolone
;
Triamcinolone Acetonide
10.Effects of Antimetabolites on Proliferation of Rabbit Retinal Pigment Epithelial Cells.
Ho Kyum KIM ; Hyung Woo KWAK ; Jae Myung KIM
Journal of the Korean Ophthalmological Society 1996;37(4):602-607
Inspite of technical advances, the need for pharmacologic treatment of proliferative vitreoretinopathy was increased. In order to evaluate the antiproliferative effect of various antimetabolites to the rabbit retinal pigment epithelial cell, we treated cultured rabbit retinal pigment epithelial cell with different concentration of drugs to perform dose inhibition studies. We found that the antimetabolites inhibited the proliferation of rabbit retinal pigment epithelial cell in a dose dependent and a time dependent manner. The drug concentration required for 50% inhibition of cell growth (ID50) were found to be as follows (BCNU; 6.51 mg/L, 5-FU ; 8.94 mg/L, Daunorubicin; 0.03mg/L, Mitomycin-C; 0.26mg/L).
Antimetabolites*
;
Daunorubicin
;
Epithelial Cells*
;
Fluorouracil
;
Mitomycin
;
Retinaldehyde*
;
Vitreoretinopathy, Proliferative