1.The effects of experimental ocular hypertension on the electroretinogram and ultrastructure of the retina in rabbits.
Dong He YOUN ; Young Ill KIM ; Jaeheung LEE ; Bong Leen CHANG ; Jin Hak LEE
Korean Journal of Ophthalmology 1987;1(1):1-7
Intragcular pressure (lOP) was artificially elevated and maintained in rabbits for up to 12 hours at levels 40, 60, 80, and 100 mmHg. Electroretinographic (ERG) responses showed gradual decline and later disappeared depending on the pressure. ERG responses were initially normal to supernormal at all lOP levels except 100 mmHg, and then showed gradual decline to extinction except in one eye of the 40 mmHg group. Ultrastrurtural damage was also pressure and time dependent. After 12 hours of the increased lOP, no damage to the ultrasfrurture of the retina was detected at 40mmHg, although the ERG was severely affected. Electron microscopic studies showed flattening of the pigment epithelium and swelling of mitochondria which appeared first at 60 mmHg; severe damage of mitochondria and the basal infoldings of the pigment epithelium at 80mmHg; and severe damage of all the retinal tissues at 100 mmHg. The critical duration of the elevated lOP which decreased the amplitude of the ERG was found to be 5 hours for 40 mmHg, 1 hour for 60 mmHg, and 30 minutes for 80 mmHg. The critical lOP which affected the ultrastrurture after 12 hours, lied between 40 and 60 mmHg.
Animals
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*Electroretinography
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Intraocular Pressure
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Ocular Hypertension/*physiopathology
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Pigment Epithelium of Eye/ultrastructure
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Rabbits
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Retina/physiopathology/*ultrastructure
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Time Factors
2.Detection of early visual field change in ocular hypertension using STATPAC.
Hyun Joon PARK ; Dong Myung KIM ; Dong Ho YOUN ; Chul HONG
Korean Journal of Ophthalmology 1990;4(1):16-22
Perimetric tests were performed on 32 ocular hypertensive eyes (17 patients) with the C-30-2 threshold program of the Humphrey Visual Field Analyzer. The global indices of 32 ocular hypertensive eyes were compared with those of 34 normal eyes (17 controls). None of the 34 normal eyes had visual field sensitivity loss. However, three out of 32 ocular hypertensive eyes, which is 0.4%, had visual field sensitivity loss. Of these three eyes, two eyes showed generalized depression (MD, P < 5%) and one eye showed paracentral scotoma.
Adolescent
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Adult
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Data Interpretation, Statistical
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Humans
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Intraocular Pressure
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Middle Aged
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Ocular Hypertension/*physiopathology
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*Software
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Visual Field Tests/*methods
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*Visual Fields
3.Detection of glaucomatous visual field defect using a screening program of Humphrey Field Analyzer.
Chul HONG ; Ki Yung SONG ; Dong Ho YOUN ; Woo Hyung PARK
Korean Journal of Ophthalmology 1990;4(1):23-25
To evaluate its clinical efficacy, we report the results of Armaly central field screening test in comparison with those of central 30-2 threshold test of Humphrey Field Analyzer. In 83 cases of normotensives, ocular hypertensives, and glaucoma patients with open-angle or narrow-angle enrolled in this study, a total of 143 eyes were examined. Fifty-four out of 61 patients (88.5%) and 73 out of 81 eyes (90.1%) with visual field defects were detected by the Humphrey Field Analyzer screening test. Eight eyes out of 81(9.9%) with visual field defects detected by the screening test were confirmed as false positive. All points of false positive were solitary, which tended to occur more frequently on superior visual field. A false negative of eight eyes out of 62 (12.9%) detected by the screening test was confirmed by the threshold test, which was more frequent on superior field and shown to be located more peripherally from the fixation point. There was no significant difference in either central sensitivity or age of the false positive and negative.
Adult
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Aged
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Evaluation Studies as Topic
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Female
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Glaucoma/*physiopathology
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Humans
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Male
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Middle Aged
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Ocular Hypertension/*physiopathology
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Predictive Value of Tests
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Vision Screening/*methods
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Visual Field Tests/*methods
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*Visual Fields
5.Current understanding of the treatment and outcome of acute primary angle-closure glaucoma: an Asian perspective.
Leslie P S ANG ; Leonard P K ANG
Annals of the Academy of Medicine, Singapore 2008;37(3):210-215
INTRODUCTIONPrimary angle-closure glaucoma (PACG) is a major cause of blindness among Asians. A better understanding of the disease will improve the treatment and outcome of this condition.
METHODSA literature review of all recent publications on PACG was carried out. Articles were retrieved using a key word search of MEDLINE, PubMed and Science Citation Index databases.
RESULTSFollowing laser peripheral iritodomy for acute angle-closure, Asians were found to have a higher tendency to develop a subsequent rise in intraocular pressure compared to Caucasians. Furthermore, the extent and severity of visual field damage was more severe in Asians than Caucasians, particularly in eyes that presented insidiously with chronic PACG. Prophylactic laser iridotomy in the contralateral eye was found to be highly effective in preventing acute angle-closure attacks.
CONCLUSIONPACG is more difficult to manage and is associated with more severe long-term visual morbidity in Asians than Caucasians. Regular follow-up of patients with PACG is important for the early detection of progression of the disease and visual field deterioration.
Asian Continental Ancestry Group ; European Continental Ancestry Group ; Glaucoma, Angle-Closure ; complications ; physiopathology ; surgery ; Humans ; Intraocular Pressure ; Iridectomy ; adverse effects ; Ocular Hypertension ; etiology ; Visual Fields
6.Correlation Between Frequency Doubling Technology Perimetry and Scanning Laser Polarimetry in Glaucoma Suspects and Glaucomatous Eyes.
Su Hyun KIM ; Hunei HONG ; Hee Jo KOO ; Sung jae YANG ; Hungwon TCHAH ; Michael S KOOK
Korean Journal of Ophthalmology 2004;18(2):89-99
The aim of this study was to determine the relationship between the frequency doubling technology (FDT) screening algorithm and parapapillary retinal nerve fiber layer (RNFL) thickness in the eyes of glaucoma suspects and patients with open angle glaucoma. FDT C20-1 screening program and a scanning laser polarimetry (SLP) system (GDx-NFA) was used to assess 53 glaucomatous eyes, 53 glaucoma suspects and 36 normal control eyes. In glaucomatous eyes, there were correlations between the FDT the screening algorithm and RNFL retardation values in several polarimetric indices, most significantly "inferior thickness" (r = -0.321, P = 0.029). In the eyes of glaucoma suspects, however, we observed no correlation between the FDT results and RNFL retardation values (r = 0.080, P > 0.05, "inferior thickness"). In glaucomatous eyes, the abnormal scores obtained with FDT screening program correlated negatively with RNFL retardation values, as measured by SLP. Despite poor correlation between the FDT abnormal score and RNFL retardation value in glaucoma suspects, detection of abnormality using the FDT screening protocol may aid in the assessment of early glaucomatous structural damage.
Comparative Study
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Glaucoma, Open-Angle/*diagnosis/physiopathology
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Humans
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Intraocular Pressure
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Lasers/diagnostic use
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Microscopy, Confocal
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Middle Aged
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Nerve Fibers/*pathology
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Ocular Hypertension/diagnosis/physiopathology
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Optic Nerve/*pathology
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Perimetry/*methods
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Retinal Ganglion Cells/*pathology
7.Optic disc and early glaucomatous visual field loss.
Sung Min HYUNG ; Dong Myung KIM ; Dong Ho YOUN
Korean Journal of Ophthalmology 1990;4(2):82-91
In the early stages of glaucoma, the disc changes prior to visual field loss, so assessment of the optic disc is very important for the evaluation of the glaucoma patient. The aim of this study is to assess the glaucomatous disc and to look for the features of the optic disc that are commonly associated with early visual field loss. Forty-three eyes of 28 patients were included in this investigation. The criteria for inclusion were a cup/disc(C/D) ratio of more than 0.4 by direct ophthalmoscopy, no visual field defect with Goldmann perimetry, and open anterior chamber angle. Each optic disc was photographed with a Canon fundus camera with Polaroid 600 Plus film. Each photographic set was then examined stereoscopically for morphologic parameters: 1) comparison of vertical versus horizontal C/D ratio; 2) presence of nasal cupping; 3) presence of overpassing vessels; 4) presence of baring of circumlinear vessels; 5) presence of peripapillary atrophy; 6) ratio of the thinnest neuroretinal rim(NRR) width in the vertical sectors of the NRR width of the temporal sector. All subject's central visual fields were examined with an automated static perimeter, Humphrey program C30-2 with STATPAC. The C/D ratio estimated by direct ophthalmoscopy consistently showed a smaller C/D ratio than that found by the stereophotographic method. The parameter with the highest probability value to differentiate between the optic disc of the early visual field loss and the optic disc of normal subjects was "Ratio of the thinnest NRR width in the vertical sectors to the NRR width of the temporal sector < or = 85%". Although it has less resolving power than slide film, a stereo disc photograph with Polaroid film is a quick and simple method of recording changes, and the ratio of the thinnest NRR width in the vertical sectors to the temporal sector is a good predictive parameter for detection of early visual field loss.
Adolescent
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Adult
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Aged
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Child
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Female
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Fundus Oculi
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Glaucoma, Open-Angle/*pathology/physiopathology
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Humans
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Male
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Middle Aged
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Ocular Hypertension/*pathology/physiopathology
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Optic Disk/*pathology
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Photography
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Visual Field Tests
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*Visual Fields
8.Expression of the Na(+)-K(+)-2Cl(-)-Cotransporter 2 in the Normal and Pressure-Induced Ischemic Rat Retina.
Korean Journal of Ophthalmology 2012;26(3):203-211
PURPOSE: To evaluate the expression of the Na(+)-K(+)-2Cl(-)-cotransporter 2 (NKCC2) in the ischemic rat retina. METHODS: Retinal ischemia was induced by pressures 90 to 120 mmHg, above systemic systolic pressure. Immunohistochemistry and western blot analysis were performed. RESULTS: NKCC2 is expressed in the normal retina and its expression is increased by ischemia caused by intraocular pressure elevation. NKCC2 immunoreactivity was observed mainly in axon bundles of ganglion cells and horizontal cell processes in the retina. NKCC2 expression continuously increased with a peak value 3 days (to 415% of normal levels) after ischemic injury, and then gradually decreased to 314% of controls until 2 weeks post injury. The mean density of NKCC2-labeled ganglion cells per mm2 changed from 1,255 +/- 109 in normal retinas to 391 +/- 49 and 185 +/- 37 at 3 days and 2 weeks after ischemia, respectively (p < 0.05), implying cell death of ganglion cells labeled with NKCC2. CONCLUSIONS: Taken together, these results suggest that NKCC2, which is expressed in retinal ganglion and horizontal cells, may contribute to cell death by ischemic injury in the retina, although the molecular mechanisms involved remain to be clarified.
Animals
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Blotting, Western
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Disease Models, Animal
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Immunohistochemistry
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Intraocular Pressure
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Ischemia/etiology/*metabolism
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Male
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Microscopy, Confocal
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Ocular Hypertension/*complications/metabolism/physiopathology
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Rats
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Rats, Sprague-Dawley
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Retinal Diseases/etiology/*metabolism
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Retinal Ganglion Cells/*metabolism/pathology
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Sodium-Potassium-Chloride Symporters/*biosynthesis
9.Protective effects of progesterone against high intraocular pressure-induced retinal ischemia-reperfusion in rats.
Na LU ; Chao LI ; Yuan CHENG ; Ai-Lin DU
Journal of Southern Medical University 2008;28(11):2026-2029
OBJECTIVETo investigate the protective effect of progesterone against high intraocular pressure-induced ischemia-reperfusion (IR) injury.
METHODSTwenty-four SD rats were randomly divided into normal control, IR model, dimethyl sulfoxide (DMSO) solvent treatment group, and progesterone treatment group. In the latter 3 groups, retinal IR injury was induced by intraocular injection of saline. In the progesterone group, intraperitoneal injections of 4 mg/kg progesterone were administered 30 min before and 2 h after ischemia, and an equivalent volume of DMSO was used in the DMSO group. The content of malondialdehyde (MDA) and superoxide dismutase (SOD) activity were measured by spectrophotometer after the treatment, and the pathological changes of the retina were observed by transmission electron microscope and light microscope.
RESULTSSix hours after reperfusion, the content of MDA in the model group was significantly higher than that in the normal control group (P<0.01), but lower than that in progesterone treatment group (P<0.01); reverse changes in SOD activity was observed. In the model group, the inner nuclear layer and nerve fiber layer became thinner with obvious cellular pathologies including nuclear condensation, mitochondria vacuolization and endocytoplasmic reticulum swelling. Progesterone treatment markedly alleviated these pathologies in the inner nuclear layer and nerve fiber layer of the retina.
CONCLUSIONProgesterone offers protection of the retina against IR injury in SD rats by increasing SOD activity and decreasing MDA content in the retina.
Animals ; Dimethyl Sulfoxide ; Female ; Ischemia ; etiology ; pathology ; Male ; Malondialdehyde ; metabolism ; Ocular Hypertension ; complications ; Progesterone ; pharmacology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; etiology ; prevention & control ; Retina ; metabolism ; Retinal Vessels ; physiopathology ; Superoxide Dismutase ; metabolism
10.Congenital Aniridia: Long-term Clinical Course, Visual Outcome, and Prognostic Factors.
Ji Woong CHANG ; Jeong Hun KIM ; Seong Joon KIM ; Young Suk YU
Korean Journal of Ophthalmology 2014;28(6):479-485
PURPOSE: To describe the clinical course of congenital aniridia and to evaluate prognostic factors for visual outcome after long-term follow-up. METHODS: The medical records of 120 eyes from 60 patients with congenital aniridia were retrospectively reviewed. The prevalence and clinical course of ophthalmic characteristics, systemic disease, refractive errors, and visual acuity were assessed. Prognostic factors for final visual outcomes were analyzed. RESULTS: Aniridic keratopathy developed in 82 (69%) of 119 eyes. Macular hypoplasia was observed in 70 eyes of 35 patients (91%). Cataract was observed in 63 of 120 eyes (53%). Nystagmus was present in 41 patients (68% of 60 patients) at the initial visit but decreased in five patients (8% of 60 patients). Ocular hypertension was detected in 19 eyes (20% of 93 eyes), six (32% of 19 eyes) of which developed secondarily after cataract surgery. The mean changes in spherical equivalent and astigmatism during the follow-up period were -1.10 and 1.53 diopter, respectively. The mean final visual acuity was 1.028 logarithm of minimal angle of resolution. Nystagmus and ocular hypertension were identified as prognostic factors for poor visual outcome. CONCLUSIONS: Identification of nystagmus and ocular hypertension was important to predict final visual outcome. Based on the high rate of secondary ocular hypertension after cataract surgery, careful management is needed.
Adolescent
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Adult
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Aniridia/*diagnosis/physiopathology
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Cataract/diagnosis
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Child
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Child, Preschool
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Corneal Diseases/diagnosis
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Eye Abnormalities/diagnosis
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Eye Diseases/*diagnosis/physiopathology
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Follow-Up Studies
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Humans
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Infant
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Infant, Newborn
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Nystagmus, Pathologic/diagnosis
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Ocular Hypertension/diagnosis
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Prognosis
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Retina/abnormalities
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Retrospective Studies
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Visual Acuity/*physiology
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Young Adult