To find out whether the cryotherapy for the treatment of the retinopathy of prematurity (ROP) causes structural changes of the extraocular muscle (EOM), and also whether the changes are related with the occurrence of strabismus. To examine the acute stage change, we conducted a transconjunctival cryotherapy around the superior rectus muscle of a rabbit and resected it 0, 3, 7, 14, and 28 days after the cryotherapy. In observing chronic changes, we first categorized patients who had an esotropia surgery into groups, one of which combined prematurity and cryotherapy and one group affected by prematurity but without having had cryotherapy. Then we compared the change of EOM with that of a fullterm infant group. In a rabbit, edema, acute inflammatory cells and a large amount of degenerated muscle fibers were observed immediately after the cryotherapy and on the 3rd day. On the 7th day, regenerated muscle fibers were observed and on the 14th day, the inflammatory cells decreased and the amount of regenerated muscle fiber increased. On the 28th day, abnormal findings were not observed any more and the muscle was found to be normal. When chronic changes of EOM in human on 1 1/2 to 8 1/2 years after cryotherapy, there were no abnormal findings observed in three groups. From the study, we can infer that cryotherapy can cause acute inflammation and necrosis of muscle fiber but such an acute change will improve and does not result in structural change in the long term. Therefore, the occurrence of strabismus in patients with ROP is considered to be attributable to reasons other than injury of EOM.
Animal ; Child ; Child, Preschool ; Cryotherapy/*adverse effects ; Human ; Infant ; Infant, Newborn ; Oculomotor Muscles/*surgery ; Rabbits ; Retinopathy of Prematurity/*pathology/*surgery ; Strabismus/*etiology

The relationship between the amount of posterior displacement of the retinal surface at the temporal disc margin and the reference height(HRef)in analyzing optic disc using Heidelberg Retina Tomograph(HRT;Heidelberg Engineering, Heidelberg, Germany)was evaluated. The displacement was measured as mean height of contour(MHC)in the temporal 40degrees C segment(20degrees C superior and 20degrees C inferior to the horizontal midline)of optic disc. HRef is a value representing the location of the standard reference plane. The accordances of HRef and stereometric parameters between right and left disc were also evaluated. MHC in the temporal 40 degrees C and nasal 40 degrees C segment, HRef, and stereometric parameters of optic disc were measured with the HRT in 244 eyes of 122 subjects. HRef was 0.376+/-0.099 mm in the right disc and 0.385+/-0.090 mm in the left disc. There was good correlation between HRef and MHC in the temporal 40degrees C segment(r=0.97, p<0.01), but poor in the nasal 40 degrees C segment(r=0.29, p<0.01). The accordances of HRef and stereometric parameters increased as the difference of MHC in the temporal 40degrees C segment between right and left disc decreased. HRef was affected by the amount of posterior displacement of the retinal surface at the temporal disc margin, which occurs in instances such as a tilted disc. We should find the method to adjust stereometric parameters to the amount of disc tilt.
Retina* ; Retinaldehyde*

To investigate the effects of platelet-derived growth factor(PDGF)and laminin on the proliferation and morphological change of retinal pigment epithelial(RPE)cells, RPE cells(5 10(3))were cultured on either plastic or laminin-coated 24-well-plates for 6 days. One percent fetal calf serum and PDGF(0, 10, 20 ng/ml)were added in the culture media. Morphological change and the numbers of attached RPE cells were assessed at the end of the culture, using image analyzer and MTT assay. In image analysis, as the PDGF concentration were increased, area(A), perimeter(P), normalized perimeter(NP), diameter(D), minimum size(MinS), maximum size(MaxS), and eccentricity of binary object(EF)were increased while circle filling(Cfil)was decreased. Compared with the cells cultured on plastic, the cells on the laminin showed increase in all the parameters except EF. The proliferative effect on RPE cells were increased on both plastic and laminin as PDGF concentration were increased(P<0.05). These results suggest that proliferation and morphologic change of RPE cells might be influenced by PDGF and laminin.
Culture Media ; Epithelial Cells* ; Extracellular Matrix ; Laminin* ; Plastics ; Platelet-Derived Growth Factor* ; Retinaldehyde*

The visual results of laser photocoagulation for subfoveal choroidal neovascular membrane (CNVM) has not always been satisfactory. The surgical removal of the neovascular membrane may be another treatment option. To investigate the prognosis and risk factors of this surgery, we analyzed the results of surgical removal of subfoveal CNVM (23 eyes), subfoveal hemorrhage with CNVM (6 eyes), and subfoveal hemorrhage alone (6 eyes). The mean follow-up period was 17.7 months (range 2 to 47 months). The mean preoperative membrane size was 0.89 disc diameter and the mean postoperative retinal pigment epithelial (RPE) defect size was 1.33 disc diameter. Visual improvement was observed in 13 out of the 23 eyes (56.5%) with sufoveal CNVM, four out of the six eyes (66.6%) with subretinal hemorrhage and CNVM, and five out of the six eyes (83.3%) with subretinal hemorrhage only. The visual outcome of subfoveal CNVM surgery was related to the presence of a subfoveal RPE defect (p = 0.005) rather than to the size of the RPE defect. No recurrence of neovascular membrane was observed during the follow up period. In conclusion, surgical removal may be a good alternative treatment for subfoveal CNVM.
Choroidal Neovascularization/surgery* ; Choroidal Neovascularization/diagnosis ; Choroidal Neovascularization/complications ; Comparative Study ; Female ; Fluorescein Angiography ; Fovea Centralis/surgery ; Fovea Centralis/pathology ; Fundus Oculi ; Human ; Laser Coagulation* ; Male ; Middle Age ; Pigment Epithelium of Eye/pathology ; Prognosis ; Retinal Hemorrhage/surgery ; Retinal Hemorrhage/diagnosis ; Retinal Hemorrhage/complications ; Retrospective Studies ; Risk Factors ; Visual Acuity

We investigated fifteen men and twenty one women, who were diagnosed to have asteroid hyalosis between June, 1997 and November, 1997 at Seoul National University Hospital. After obtaining their medical history a complete eye examination was performed. Specimen was examined by light microscope in one case. Funduscopic examination revealed bilateral involvement in 5 cases. Twenty six patients were diabetic and 12 were hypertensive. There was a significant association with diabetes. Light microscopic exam showed variable sized spherical structures with brown rim. Further decrease in visual acuity due to asteroid hyalosis was not observed in 35 cases in which follow-up exams were possible. In conclusion, asteroid hyalosis rarely caused visual loss and were likely to be monocular and to occur in old age.
Female ; Follow-Up Studies ; Humans ; Male ; Seoul ; Visual Acuity

The authors investigated macular circulation in a group of 27 patients(54 eyes) with diabetes melitus to evaluate the change of macular blood flow according to the grade of retinopathy, the status of glucose control and the duration of diabetes. Blood volume, flow and velocity on macular area were measured by Heidelberg Retinal Flowmeter(HRF, Heidelberg Engineering). Paticents with moderate or severe diabetic retinopathy showed a significant increase in macular blood flow than patients with less degree of diabetic retinopathy(502.45+/-223.58 AU vs, 355.19+/-123.84 AU, p=0.003). Both blood volume and velocity were also significantly increased in the patients with more advanced diabetic retinopathy. Macular blood flow was increased in the patients with higher fasting blood glucose, although the statistical significance was in borderline(473.12+/-238.57 AU vs, 362.14+/-103.22 AU, p=0.066). These results show that macular blood flow increases in the diabetic patients with more advanced diabetic retinopathy, suggesting that the increase in the macular blood flow may play a role in the development of diabetic macular microangiopathy.
Blood Glucose ; Blood Volume ; Diabetic Retinopathy ; Fasting ; Glucose ; Humans ; Retinaldehyde

The purpose of this study was to evaluate the usefulness of retinal nerve fiber layer [RNFL] photography and Heidelberg Retina Tomograph [HRT, Heidelberg, Germany] in early detection of glaucoma. Among 2802 people who underwent routine health checkup at. Seoul National University Hospital from July I to Decernber 31, 1996, forty-nine persons were included whose IOP was above 21mmHg or cup/disc ratio was 0.5 or greater. RNFL photography, HRT and automated perimetry [Humphrey Field Analyzer, program C30-2] were performed. Twelve eyes were diagnosed as glaucoma and one sye as glaucoma suspect. Four eyes with glaucoma had RNFL defect with normal visual field and 7 eyes with glaucoma had both RNFL defect and glaucomatous visual field defect. Of 26 eyes suggested as glaucoma by FSM classification of HRT, only 8 eyes met the diagnostic cri-teria of glaucoma of this study. Among 21 eyes with decreased hump height in HRT only 7 eyes were diagnosed as glaucoma. RNFL photography increased the detection rate for glaucoma by 50% over that with visual field test. only. RNFL photography will be a valuable method for early detection of glaucorna while HRT may play a suppleinentary role.
Classification ; Glaucoma* ; Humans ; Nerve Fibers* ; Photography ; Retina ; Retinaldehyde* ; Seoul ; Visual Field Tests ; Visual Fields

Forty three eyes with vitreous hemorrhage caused by branch retinal vein occlusion had been underwent pars plana vitrectomy and followed-up over 6 months. The eyes were classified into 4 groups according to intraoperative fundus findings-group 1; vitreous hemorrhage only, group 2; vitreous hemorrhage with fibrovascular proliferation, group 3; vitreous hemorrhage with traction retinal detachments, group 4; vitreous hemorrhage with rhegmatogenous retinal detachments. Analysis was focused on the clinical characteristics and postoperative outcome in each group. The durations of vitreous hemorrhage were longer significantly in group 2 and group 3. The vision improved postoperatively in 35 of 43 eyes(81.3%). The percentage of postoperative visual improvements was 100%(18 of 18 eyes) in group 1, 85.7%(12 of 14 eyes) in group 2, 66.6%(4 of 6 eyes) in group 3, and 20$(1 of 5 eyes) in group 4. The preoperative ultrasono-graphic findings of retinal status were accorded with intraoperative retinal findings in 74.4% of eyes.
Retinal Detachment ; Retinal Vein Occlusion* ; Retinal Vein* ; Retinaldehyde* ; Traction ; Ultrasonography ; Vitrectomy ; Vitreous Hemorrhage*

To establish animal model of exudative retinal detachment in Sprague Dawley albino rats and to elucidate the possible role of retinal vein in the induction of exudative retinal detachments, rose bengal photosensitive dye was injected intravenously and argon laser was applied. In group A(10 eyes), laser was applied on intervascular retinal areas linearly. In group B (12 eyes), laser was applied on major retinal veins. In group C(4 eyes), laser was applied on major retinal arteris. In group D(3 eyes), laser was applied on major retinal veins without rose bengal dye and in group E(26 eyes), only the rose bengal dye was perfused. And in group F(3 eyes), normal eyes were fixed for negative controls. Exudative bullous retinal detachment occurred only in group B and these resutls were confirmed in histological examinations. In control groups (D and E), tissue injuries were not found. In conclusion, exudative retinal detachment could be induced by occlusion of retinal veins in albino rats and the abnormalities of retinal venous blood flow were required for the induction of exudative retinal detachment.
Animals ; Argon ; Models, Animal ; Rats* ; Retinal Detachment* ; Retinal Vein ; Retinaldehyde* ; Rose Bengal

We examined excitotoxicity, putatively a major mechanism of ischemic neuronal death, in primary rat retinal cultures. Retinal cultures were prepared from newborn rats (day 1 or 2). Exposure of these cultures (DIV8-10)to NMDA or kainate induced neuronal death. Furthermore, MK-801 or CNQX each partially attenuated glutamateinduced neuronal death, suggesting that both NMDA and kainate receptors mediate it. Thy-1(+) retinal ganglion neurons, like neurons as a whole, were equally injured by NMDA and by kainate. However, GABA(+) or calbindin (+) neurons of the inner nuclear layer were resistant to NMDA, but highly vulnerable to kainate. These neurons may have AMPA/kainate receptors that are highly permeable to Ca2+, as they take up cobalt with kainate stimulation. These results suggest that the AMPA/kainate receptor, rater than the NMDA receptor, may mediate this pattern of selective neurnonal death.
6-Cyano-7-nitroquinoxaline-2,3-dione ; Animals ; Calbindins ; Cell Death* ; Cobalt ; Dizocilpine Maleate ; GABAergic Neurons ; Ganglion Cysts ; Humans ; Infant, Newborn ; Kainic Acid ; N-Methylaspartate ; Neurons ; Rats ; Receptors, Kainic Acid ; Retinal Neurons* ; Retinaldehyde*