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.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*
4.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*
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.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
9.The Effect Intravitreal Dexamethasone and Antibiotic Therapy after Vitrectomy.
Jung Hyoo MOON ; Hyung Woo KWAK ; Mi Ae LEE ; Jae Myung KIM
Journal of the Korean Ophthalmological Society 1999;40(2):459-469
Bacterial endophthalmitis is an ocular emergency that requires rapid diagnosis and therapeutic decision making. The introdection of intravitreal injection of antibiotics has been a major advancement because it has resulted in a marked improvement in visual outcome. The intravitreal injection of steroids may be potentially useful in the treatment of endophthalmitis and other ocular inflammatory diseases. Forty eyes of pigmented rabbits were used, and divided into two groups. Group I was eyes without vitrectomy. In the right eye, 100 microliter of 1mgvancomycin, 400 microliter amikacin and 400 microliter dexamethasone injected was done. Group II was eyes with vitrectomy and lensectomy. At 2 weeks after lens and vitreous removal, rabbit eyes received an injection of a combination of 1mg vancomycin, 400 microliter amikacin and 400 microliter dexamethasone in right eye and BSS in left eye. The effect of combination injection was examined by light and transmission, scanning electron microscope at 3 days, 1 week, 2 weeks and 6 weeks following injection. The injection of combination without vitrectomy produced no toxicity. After injections of either combination or BSS after vitrectomy, macrophages were observed on the surface of retinal pigment epithelium and disorganized outer segments. This finding seems to be produced by vitrectomy procedure rather than drug toxicity. These results supports the hypothesis that the injection of these combinations is not toxic to aphakic/vitrectomized eyes.
Amikacin
;
Anti-Bacterial Agents
;
Decision Making
;
Dexamethasone*
;
Diagnosis
;
Drug-Related Side Effects and Adverse Reactions
;
Emergencies
;
Endophthalmitis
;
Intravitreal Injections
;
Macrophages
;
Rabbits
;
Retinal Pigment Epithelium
;
Steroids
;
Vancomycin
;
Vitrectomy*
10.A Study on the Changes in Blood-Retinal Barrier After Vitreal Injection of Silicone Oil in Rabbits.
In Sik CHA ; Kyung Hyun JIN ; Hyung Woo KWAK ; Jae Myung KIM
Journal of the Korean Ophthalmological Society 1986;27(5):781-787
The blood-retinal barrier, that outward movement from the eye into the blood appears to predominate and the penetration into the eye of only a few important metabolic products is allowed, is particularly tight non-leaky junction on blood ocular barrier. In order to investigate the extent of destruction in blood retinal barrier after injection of silicone oil in the vitreous of the rabbit, author serially studied the change of fluorescein concentration in vitreous using the HPLC, ERG changes, and histopathologic changes of the retina. The results were belows, 1. The changes of fluorescein concentration in the vitreous showed increasing tendency, with time. The concentration of fluorescein were 0.008 micro/ml in 1st week, 0.069 micro/ml in 2nd week, 0.058 micro/ml in 3rd week, 0.325 micro/ml in 4th week, respectively. 2. The amplitude of photopic b wave in normal rabbit was lower than that of scotopic b wave, but there wasn't significant difference in latency between photopic and scotopic b wave. The amplitudes of b wave in silicone oil injected eyes showed lower voltage than that of normal eyes. 3. The amplitudes of b wave in silicone oil injected eyes were 210 micro V at 1st week, 150 micro V at 2nd week, 72 micro V at 3rd week, 63 micro V at 4th week in average. They showed prominent decrease in voltage from 1st week to 3rd week, but decreased slightly from 3rd week to 4th week. 4. Histopathologically, the retinal changes of the silicone oil injected eyes in 3rd week showed increased cellularity in ganglion cell layer and presented many vacuoles. In 4th week, ganglion cells were decreased but vacuoles were more increased in number.
Blood-Retinal Barrier*
;
Chromatography, High Pressure Liquid
;
Fluorescein
;
Ganglion Cysts
;
Rabbits*
;
Retina
;
Retinaldehyde
;
Silicone Oils*
;
Vacuoles