Outer Blood-retinal Barrier Alteration Induced by Intraocular Ad vanced Glycation Endproduct

Advanced glycation end-product(AGE)is known as a factor causing diabetic retinopathy, but little is known about its effect on the function of outer blood-retinal barrier. To test whether AGE can increase the permeability of outer blood-retinal barrier, we injected glycated albumin into white rabbit eyes and observed the change of the fundus and of the outer blood-retinal barrier permeability. The rabbit retina in medullary ray was thickened in AGE-injected eyes. Intravenously injected microperoxidase, tracer molecule, was found in outer sensory retinal layer and outside of the retinal pigment epithelium in AGE-injected eyes. These results suggest that intraocularly injected AGE can increase the outer blood-retinal barrier permeability.

A Case of Relapsing Polychondritis / 대한피부과학회지

Relapsing polychondritis is a rare inflammatory disorder affecting the cartilaginous structures throughout the body. Although there is no pathognomonic laboratory tests, clinical features, when coupled with histopathologic findings, enable one to make a diagnosis of relapsing polychondritis. A 26-year-old man presented with purplish, swollen, and tender auricles and injected eyes. His symptoms had developed eight months ago and fluctuated irrespective of various medications such as corticosteroids and antibiotics. Histopathologic examination revealed loss of basophilic staining of the cartilage with some dissolution of its structures. Treatment was initiated with dapsone, However, the remission was too immediate to be considered as a effect of dapsone.

The Mechanism of Tissue Injury in the Animal Model of Experimental Retinal Vein Occlusion

We investigated the development of programmed cell death of apoptosis as a mechanism of cell death in experimental retinal vein occlusion of rats. We induced hemicentral retinal veinocclusion by photocoagulation 3 or 4 out of 6 retinal veins after infecting rose bengal intravenously.The eyes were enucleated sequentially between day one to day fourteen, and the retinas were examined after H&E and TUNEL staining. Exudative retinal detachment developed one day after vein occlusion and was reabsorbed completely by day 4. The number of ganglion cells in vein-occluded retina began to decrease one day after vein occlusion and continue to decrease until day fourteen. Many cells in ganglion cell layer and inner nuclear layer were stained positively by TUNEL staining. These results suggest that apoptosis is an important mechanism of cell death in early stage of experimental retinal vein occlusion.

Radiotherapy for Age-related Macular Degeneration Associated with Subfoveal Neovascular Membrane

The only effective treatment for subfoveal neovascular membrane in age-related macular degeneration is laser photocoagulation, which is associated with decreased visual acuity following treatment in most patients. Radiation treatment for subfoveal neovascular membrane has been tried, but its effectiveness and necessary dose are not determined yet. Twelve eyes with subfoveal neovascular membranes received X-ray radiation with the dose of 1980cGy or 1440cGy. After a minimum 6 month follow-up, 4 eyes had improved, 6 eyes had stable and 2 eyes had worsened visual acuity. To date no negative side effects have been observed. We could not find difference in visual outcome between two dose groups due to the small sample size. Regarding the poor natural course of age-related macular degeneration, these results suggest a possible beneficial effect of radiation treatment with total dose of 1980 or 1440cGy and justify the further treatments and evaluations of the radiotherapy.

Experimental Retianl Vein Occlusion in Albino Rats

The retinal vein occlusion is one of the most common, vision-threatening retinal diseases, and the establishment of animal model in rats will be of great help for further study. We occluded retinal veins with rose bengal dye injection followed by argon green laser photocoagulation in albino rats and confirmed the occlusion of veins with fluorescein angiography one hour after photocoagulation. We occluded half of an all of major retinal veins in 12 eyes, respectively. After 1-2 weeks of follow-up, histologic examinations were done. Eyes which underwent occlusion of all major retinal veins showed severe retinal atrophy and preretinal neovas-cularization developed in two eyes. Eyes which underwent occlusion of half of retinal veins showed relatively less damage and the number of retinal ganglion cells was significantly reduced in occluded area than that in control area (P=0.0033), which might represent the ischemic damage of inner retina. We expect that it will be possible to establish an animal model of retinal vein occlusion in albino rats using this method.

Effect of Ascorbic Acid on Experimental Retinal Vein Occlusion

The retinal vein occlusion is one of the most common vision-threatening retinal diseases, and both the hemi-central and central retinal vein occlusion might induce severe visual loss. There have been many studies on the role of abnormally produced oxygen free radicals and excitatory amino acids in the mechanism of ischemic retinal injury. Many free radical scavengers, such as superoxide dismutase (SOD), catalase, and EGB 761 were reported to reduce the extent of ischemic retinal injury in animal experiments. Ascorbic acid is also a well-known free radical scavenger, but its in vivo therapeutic effects on retinal ischemia has not been studied, yet. We induced experimental retinal vein occlusion in 48 albino rat eyes; half of major veins in 24 eyes (group A) and total veins in 24 eyes (group B), with rose bengal dye injection followed by argon-green laser photocoagulation. The occlusion of veins was confirmed with fluorescein angiography. We injected ascorbic acid intraperitoneally just after venous occlusion in 12 eyes for each group. Rats were sacrificed after I week (group A) or 2 weeks (group B) following experiment and histological examination was done. In both groups, inner retina was less damaged than outer retina. The density of retinal ganglion cells was reduced to a less degree in eyes of rats treated with ascorbic acid in group A(P=0.0318). These data support the idea that the reactive free adicals are involved in the mechanism of ischemic retinal injury and thus the ascorbic acid may attenuate the ischemic retinal damage.

Experimental Exudative Retinal Detachment in Albino Rats

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.

Clinical Characteristics of Branch Retinal Vein Occlusion with Vitreous Hemorrhage

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.

Mitomycin C in anterior chamber tube shunt to a surgical membrane

To increase the success rate of intraocular pressure control in recalcitrant glaucoma, anterior chamber tube shunt to a surgical membrane (ACTSSM) surgery using silicone tube and expanded polytetrafluoroethylene (e-PTFE) can be performed. Applying mitomycin C (MMC) during ACTSSM surgery may increase the success rate by decreasing the fibroblast proliferation and collagen in the fibrous capsule. To evaluate the effects of MMC on the fibrous capsule formed after ACTSSM surgery, operations were performed on 18 white rabbits. Nine rabbits were treated with 0.04% MMC solution on the episclera for 5 minutes before ACTSSM (group A) and the others were not treated (group B). At postoperative 2, 4 and 8 weeks successively, 6 eyes of the 3 rabbits were enucleated from each group. Light microscopic examinations were performed after hematoxylin

Horizontal Incornitancy After Monocular Recession-Resection Surgery

Horizontal incomitancy is a difference of deviation angle between right and left gaze and monocular recession-resection operation may cause horizontal incomitancy. We reviewed 85 patients of intermittent exotropia without oblique dysfunction and vertical deviation who underwent monocular recession-resection operation. The preoperative horizontal in comitancy was 1.0 delta in average with a range of 0 delta to 5 delta. The postoperative horizontal incomitancy after 7 months (mean) was 4.8 delta in average with a range of 0 delta to 17 delta. The postoperative remained deviation and horizontal incomitancy were significanty smaller in the group of patients who had fusion with worth 4-dot test (p

Television and Myopia

To investigate the relationship between the watching television and myopia, 301 middle school students of different school grade and sex were given questionnaires of the average television watching period per a day and examined the degree of myopia by the manifest refraction. The results showed that no statistically significant correlation existed between the degree of myopia and the television watching period, however the degree of myopia progresses with advancing school grade. From this results, we concluded that the usual television watching is not related to the degree of myopic refractive changes.

Two-Wall Orbital Decompression for Endocrine Exophthalmos

We reviewed 17 cases with dysthyroid exophthalmos in 13 patients which were treated with antral-ethmoidal decompression surgery. Transantral approaches were done in 6 orbits of 3 patients and transfornix approaches were done in 11 orbits of 10 patients. The amount of postoperative retroplacement of the globe was 4.3mm in average and ranged from 1mm to 9mm during the average follow-up period of 14.9 months. All patients with compressive optic neuropathy improved in visual acuity by 3 or 4 lines of Hahn test chart. In most patients the restriction of ocular motility was improved and exposure keratitis decreased The cosmetic results were also satisfactory. The postoperative complications were induced diplopia in 2 cases and permanent infraorbital anesthesia in 1 case. The detailed surgical procedures and results were presented and reviewed.