1.A Case of Macular Displacement after Surgical Reattachment of a Rhegmatogenous Retinal Detachment Induced with Penetrating Injury.
Tae Kwann PARK ; Dong Hee KIM ; Hyung Woo KWAK
Journal of the Korean Ophthalmological Society 2000;41(12):2755-2760
No Abstract Available.
Retinal Detachment*
;
Retinaldehyde*
2.The Assessment of Fixation Area and Prognostic Factors in Idiopathic Macular Holes after Vitrectomy with Microperimetry Using Scanning Laser Ophthalmoscope.
Hyung Kyu PARK ; Seung Young YU ; Hyung Woo KWAK
Journal of the Korean Ophthalmological Society 2002;43(9):1629-1634
PURPOSE: To evaluate the relation between recovery of visual function and microperimetric fixation area in eyes with idiophthic macular hole after vitrectomy. METHODS: We used SLO (Scanning laser microscope, Rodenstock, Germany) microperimetry to examine foveal retinal function and fixation area in 14 eyes with idiopathic macular hole following pars plana vitrectomy. The relation between those preoperative and postoperative best corrected visual acuity and fixation area was studied. RESULTS: The macular hole size was correlated with preoperative visual acuity (p=0.026) and the closure of hole was related to the size of fixation area (p=0.003). The postoperative visual acuity was related to symptom duration before the vitrectomy (p=0.03), but not related to preoperative macular hole size. The fixation area correlated with the postoperative best corected visual acuity (p=0.043) and the direction of movement was variable. In most eyes, fixation area was located above the horizontal meridian. CONCLUSIONS: The fixation area was correlated with postoperative visual acuity and we think functional macular hole closure as well as anatomical closure were useful parameter of the success of macular hole surgery.
Ophthalmoscopes*
;
Retinal Perforations*
;
Retinaldehyde
;
Visual Acuity
;
Vitrectomy*
3.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*
4.Normal Value for Microperimetry with the Scanning Laser Ophthalmoscope.
Sang Woong MOON ; Hyung Woo KWAK ; Seung Young YU
Journal of the Korean Ophthalmological Society 2000;41(3):677-683
Fundus perimetry is the device that provides visualization of the fundus and the precise localization of the stimuli on it. With the increasing importance of the direct fundus perimetry for certain focal retinal morphologic abnormalities, the scanning laser ophthalmoscope[SLO]has been utilized as a system to eliminate some of the classic technical problems in fundus perimetry. The aim of this study was to evaluate the normal light sensitivity values for microperimetryusing SLO system. Thirty eyes of thirty normal subjects were examined in 60 degrees image field using stimuli of variable intensity. The maximal retinal distance point which responded to stimulus was recorded, point which responded to stimulus was recorded, and the distance[millimeter]from the fovea was calculated by the Bennett formula. The maximum distance from the fovea at the given stimulus intensity was measured as follows :0.7596 +/-0.5262millimeter at 28decibel, 2.2050 +/-0.5878millimeter at 26decibel, 3.0571 +/-0.7151millimeter at 24decibel, 4.3690 +/-1.0973millimeter at 22decibel, and 5.6557 +/-1.3458millimeter at 20decibel. In conclusion, we were able to establish the normal range of light sensitivity in Microperimery examination. It may serve as the baseline for subsequent study of retinal pathology and functional evaluation as well as its treatment.
Ophthalmoscopes*
;
Pathology
;
Photophobia
;
Reference Values*
;
Retinaldehyde
;
Visual Field Tests
5.Evaluation in Various Aspect in Strabismus Patient.
Hyung Woo KWAK ; Bong Leen CHANG
Journal of the Korean Ophthalmological Society 1978;19(4):399-405
The author studied the 240 cases of strabismus patients in our OPD from 1972 to 1976. And the author observed the results of occlusion therapy in 55 cases of amblyopia with strabismus. The results are as follows: The sex distribution in exotropia patients showed a preponderance in female sex, the ratio male to female being 2:3. Concerning the refractive status, there were more hyperopia in esotropia and more myopia in exotropia. The amount of deviation was about the same at the near and distance, most patients had a basic type and distributed between 21-40 prism. Of all patients in whom a determination of the retina correspondence could be made, 70% showed NBC and 25 % showed ARC 5% showed variable. Ninety percent of the strabismic amblyopia patients was successfully treated by occlusion therapy. A positive correlation was not found between the duration of occlusion and the age at which occlusion was started. Amblyopes showed arrest of improvement after a certain period, about 3 to 4 months. The exotropia patients over the age of 7 showed good results by occlusion. The shorter the time between the age at which occlusion was started and the onset of strabismus, the better was the result. Strabismic amblyopia responded well to conventional occIusion.
Amblyopia
;
Esotropia
;
Exotropia
;
Female
;
Humans
;
Hyperopia
;
Male
;
Myopia
;
Retina
;
Sex Distribution
;
Strabismus*
6.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*
7.Evaluation of Macular Circulation in Patient with Diabetic Maculopathy using Scanning Laser Ophthalmoscope(SLO).
Jong Hyeok LEE ; Sun Wook KIM ; Hyung Woo KWAK
Journal of the Korean Ophthalmological Society 1999;40(6):1574-1581
In the condition of diabetic retinopathy, the vascular changes are localized primarily in the retinal capillaries and are presumed to promote angiogenesis. To investigate the change of retinal blood flow velocities and morphological parameters in diabetic retinopathy, we measured perifoveal capillary blood velocities(v) and the size of foveal avascular zones(FAZ). Thirteen patients with diabetic maculopathy and nine healthy volunteers were included in this study. The scanning laser technique in conjunction with an image analysing system were used to assess the morphological and hemodynamic changes in diabetic retinopathy. Diabetic maculopathy group showed a slower capillary blood velocity than normal group(2.44+/-0.39mm/sec vs2.75+/-0.61 mm/sec, p>0.18). The foveal avascular zone was significantly larger in diabetic maculopathy group than in normal group(313.5+/-64.6micrometervs. 238.9+/-93.8micrometer, p<0.05). This results indicate that the retinal microcirculation is altered in diabetic patients compared with healthy subjects. These alterations may be due to the change of the capillary wall and blood viscosity in diabetic patients. The determination of these parameters can be utilized in monitoring the progress of diabetic maculopathy.
Blood Flow Velocity
;
Blood Viscosity
;
Capillaries
;
Diabetic Retinopathy
;
Healthy Volunteers
;
Hemodynamics
;
Humans
;
Microcirculation
;
Retinaldehyde
8.Evaluation of clinically applied visual evoked potential (VEP) in ophthalmological and neurological diseases.
Korean Journal of Ophthalmology 1987;1(1):26-30
VEPs weie recorded in 222 cases of different disease groups and in 42cases of the control group using a Nicolet CA 1000 system. The latency time of N1, P1, N2, and P2 from the prominent surface peak and the P1-N2 amplitude at full field pattern reversal VEP. The score of each disease group was compared with those of the control group. The results are as follows; 1. Functional amblyopia, optic neuritis, and optic nerve atrophy patients presented a significant derrease in amplitude in comparison to normal subiects. 2. In the P1 implicit time, optic neuritis, and optic nerve atrophy patients presented a marked delay. Functional amblyopia patients presented a moderate delay while other disease group patients presented normal to mild delays. 3. More than half of the optic neuritis and optic nerve atrophy patients presented a detraction of the P1 wave form.
Adolescent
;
Adult
;
Amblyopia/*diagnosis
;
Brain Diseases/*diagnosis
;
Child
;
Diagnosis, Differential
;
*Evoked Potentials, Visual
;
Humans
;
Middle Aged
;
Optic Atrophy/*diagnosis
;
Optic Neuritis/*diagnosis
;
Time Factors
9.The Neuroprotective Effect of Intravitreal Melatonin Injection in Pressure-induced Retinal Ischemia.
Seung Joon LEE ; Won Sub SON ; Hyung Woo KWAK
Journal of the Korean Ophthalmological Society 2001;42(4):638-646
PURPOSE: The authors sought to determine the neuroprotective effect of melatonin in a model of ischemic injury in rabbit retina. METHODS: Ischemia was induced by high intraocualr pressure. A dose of 100 microgram of melatonin or dimethyl sulfoxide(DMSO) alone was injected intravitreally just after the induction of ischemia. After 7 and 14 days, the neuroprotective effect of melatonin on ischemic retina was examined with light microscope and transmission electron microscope. RESULTS: The authors found reduction of cytoplasm of retinal ganglion cell(RGC), vacuole formation, chromatin condensation and rupture of nuclear membrane in ischemia-injured eyes treated with DMSO alone. But in melatonin treated eyes, we found that RGC layer's thickness and number of RGC reduced and destruction of cytoplasmic organells and nuclear damage were minimal. The partial recovery of wave is noted in melatonin-treated eyes after ischemia induction. CONCLUSIONS: The melatonin(100 microgram) protected the rabbit retina from high intraocular pressure-induced ischemic injury when administered intravitreally. Melatonin may be useful to decrease neuronal damage in the retina as a result of ischemic injury. But further investigations are neccesary to decide effective concentration, route and time of administration.
Chromatin
;
Cytoplasm
;
Dimethyl Sulfoxide
;
Ganglion Cysts
;
Ischemia*
;
Melatonin*
;
Neurons
;
Neuroprotective Agents*
;
Nuclear Envelope
;
Retina
;
Retinaldehyde*
;
Rupture
;
Vacuoles
10.Clinical Observation on Reconstruction of the Contracted Anophthalmic Socket by the Dermis-fat Graft.
Jung Hyoo MOON ; Hyung Woo KWAK
Journal of the Korean Ophthalmological Society 1987;28(6):1365-1370
The various method have been used in reconstruction of the anophthalmic socket. Dermis-fat graft as an orbital implant is a relatively new approach. Dermis-fat graft restores the volume lost by enucleation, gives additional conjunctival lining and is permanent, with a minimal chance of absorption. Dermis-fat graft was used in reconstruction of an ophthalmic socket in our hospital. We found it successful procedure in case of primary enucleation, because it is permanent and it preserves the conjunctiva.
Absorption
;
Conjunctiva
;
Orbital Implants
;
Transplants*