Adhesive forces between the retina and the retinal pigment epithelium, which is mainta ined by active mechanisms unique for living animals, deteriorates rapidly after death and leads to spontaneous retinal detachment. Change of retinal adhesiveness in rabbits after death was investigated using a new method. Retinal detachment was induced by applying various levels of aspiration power from 0 to 1OO mmHg to the vitreous cavity using a vitrectomy instrument immediately after the rabbit was killed without enucleation. And the time required for creating the retinal detachment was measured. Retinal adhesiveness deteriorated and spontaneous retinal detachment occurred 28 minutes and 35 seconds after death confirming the active adhesion between the retina and the retinal pigment epithelium before death Increase of aspiration power led to shortening of time required for creating retinal detachment. From aspiration powers of 0 to 100 mmHg, the common logarithm of time required for retinal detachment was inversely proportional to the aspiration power [IogY = 1.45215 - 0.01113X, (R2=0.99041), X: aspiration power (mmHg), Y: time required for creating retinal detachment (minutes)]. Thus, presumed time of retinal detachment could be estimated between the aspiration powers of 0 to 100 mmHg.
Adhesiveness ; Adhesives* ; Animals ; Postmortem Changes* ; Rabbits ; Retina* ; Retinal Detachment ; Retinal Pigment Epithelium* ; Retinaldehyde* ; Vitrectomy

Posterior instability of the shoulder is far less common than anterior or multidirectional instability. There is still controversy in the diagnosis and treatment of recurrent posterior instability, and many treatment protocols have been advocated. However the failure rate as high as 50% was reported. The purpose of this study is to introduce characteristic physical findings of posterior instability, to present our operative techniques, and to report the efficacy of a superior shift of the postero-inferior capsule in the treatment of recurrent posterior instability. From June 1995 to September 1996, five patients, six shoulders underwent postero-inferior capsular shift for posterior instahility and were evaluated at an average of 17 months(ranged from 9 to 26 months) after operation. The average age was 22.4 years. Preoperatively, mean scores of pain, stability and function according to American Shoulder and Elbow Society (ASES) scoring system were 21, 9, and 16 points respectively and mean overall ASES score was 46 points. After surgery, the average range of motion was 175 of forward elevation and 74 of external rotation and internai rotation in back was up to the sixth thoracic level. Postoperative mean scores of pain, stability and function were 29, 34 and 25 points respectively and mean overall ASES score was 88.5 points. No patient had a recurrence of posterior instability. All patients had satisfactory results with significant improvement in stability and function except one case who had multidirectional instability that mainly involved the posterior component
Clinical Protocols ; Diagnosis ; Elbow ; Humans ; Range of Motion, Articular ; Recurrence ; Shoulder*

The early ultrastructural changes of basement membrane thickening and degeneration of the pericyte were noted in retinal capillaries in diabetic patients. However no early ultrastructural changes were reported in diabetic iris capillary. The authors studied the ultrastructural features of basement membrane of iris capillaries which were obtained during cataract surgery in five diabetic patients and compared with those obtained in five nondiabetic patients. The endothelium basal lamina, pericyte basal lamina and membrane-like pericyte matrix in didabetic iris capillaries were thicker than those in nondiabetic Iris capillaries. The thickening of pericyte basal lamina is more prominant than the endothelium basal lamina in diabetes. The duration of diabetes had no relationship to endothelium basal lamina but, showed statistically significant relationship to thickness of pericyte bascal lamina and pericyte matrix.
Basement Membrane* ; Capillaries* ; Cataract ; Endothelium ; Humans ; Iris* ; Pericytes ; Retinaldehyde

Ascorbic acid, which is toxic to retinal pigment epithelial cells in vitro, can stimulate fibrotic tissue formation. This study investigated the influence of ascorbic acid on endotoxin-induced fibrosis. Experimental vitreal fibrosis was induced in the rabbit by injecting endotoxin with or without ascorbic acid into the vitreous, and compared the degree of fibrosis. Inflammation induced by 1 microgram of endotoxin first appeared on day 1, remained on day 3. On day 7, organized membrane was developed. The striking decrease in ascorbic acid occurred after the intravitreal injection of endotoxin. In a series of experiment in which ascorbic acid were used, endotoxin produced less inflammatory response compared to the control. Rabbits which were injected 1 microgram of endotoxin (with or without ascorbic acid) had shown significant vitreal fibrosis. Even though the high conentration of ascorbic acid can provide extacellular protection for the ocular tissues during ocular inflammation, It was not effective in preventing the formation of membrane.
Ascorbic Acid* ; Epithelial Cells ; Fibrosis* ; Inflammation ; Intravitreal Injections ; Membranes ; Rabbits ; Retinaldehyde ; Strikes, Employee

Four patients underwent surgery for idiopathic epiretinal membrane at macula. The follow-up was from 5 to 8 months. The epiretinal membrane was removed by vitreous surgical technique with sutherland scissors and forceps. By electron microscopic study of the membrans, four typical cells(fibrous astrocytes, macrophages, fibrocytes and myofibroblast-like cells) were found in one case and hyalocytes in another case. In all cases visual acuity improved by more than 2 lines in Snellen chart.
Astrocytes ; Epiretinal Membrane* ; Follow-Up Studies ; Humans ; Macrophages ; Surgical Instruments ; Visual Acuity

Ascorbic acid in aqueous humor, the concentration is 15-69 times higher than in plasma, protects ocular tissues from free radicals as an antioxidant and absorbs ultraviolet rays. It is regarded that the concentration of ascorbic acid in the vitreous body is greater than in the plasma, but there is no knowledge about it's role and relationships to retinal disease. We measured the concentrations of ascorbic acid in plasma, aqueous humor, vitreous and subretinal fluid in 10 patients with rhegmatogenous retinal detachment who were treated with scleral encircling by high performance liquid chromatography. The average concentrations of ascorbic acid in plasma, anterior chamber aqueous humor, vitreous, and subretinal fluid were 30.8 +/- 7.5 micro gram/ml, 157.4 +/- 2.5 micro gram/ml, 195.3 +/- 7.5 micro gram/ml, and 178.5 +/- 2.5 micro gram/ml respectively. The ascorbic acid concentrations in intraocular fluids were 5-6 times higher than in plasma.
Anterior Chamber ; Aqueous Humor ; Ascorbic Acid* ; Chromatography, Liquid ; Free Radicals ; Humans ; Plasma ; Retinal Detachment* ; Retinal Diseases ; Retinaldehyde* ; Subretinal Fluid* ; Ultraviolet Rays ; Vitreous Body

Trichoepithelioma. so named by Jarisch(1894), is a rare benign neoplasm of the skin on face and eyelid. The solitary type which is the most usual form seen in the eyelid occurs mainly in adult, on the other hand multiple type begin to appear at adolescence or puberty as a dominantly inherited condition. A 21 year-old korean female was found to have trichoepithelioma in her left lower eyelid mangm.
Adolescent ; Adult ; Eyelids ; Female ; Hand ; Humans ; Puberty ; Skin ; Young Adult

We experienced a case of D3 proliferative vitreoretinopathy complicated with a shortened retina in a 31-year-old male which was managed using 360-degrees circumferential retinotomy technique and a case of D1 proliferative vitreoretinopathy complicated with a shortened retina in a 26-year-old female which was managed using 260-degrees circumferential retinotomy technique. We report these cases with a review of the literature
Adult ; Female ; Humans ; Male ; Retina* ; Vitreoretinopathy, Proliferative

PURPOSE: To evaluate the pre-operative and the intra-operative factors including marginal fibrosis affecting the result of vitrectomy for macular hole. METHODS: The medical records of the patient who had been operated for idiopathic full-thickness macular hole from January 1997 to July 2000 were investigated retrospectively. RESULTS: Hole closure, as the implication of anatomical success, was seen in 28 eyes (84.8%) at 1 month after surgery and 23 eyes (69.7%) at the end of follow-up period. And the improvement of two or more Snellen line, as the implication of functional success, was seen in 17 eyes (51.5%). The smaller size of the hole was well correlated with higher rate of anatomical success (P=0.001). And there was a good correlation of higher anatomic success rate with the lack of marginal fibrosis around the hole (P=0.001). CONCLUSIONS: There must be more efforts and investigations on proper management of marginal fibrosis, which might help to improve the result of macular hole surgery.
Fibrosis* ; Follow-Up Studies ; Humans ; Medical Records ; Retinal Perforations* ; Retrospective Studies ; Vitrectomy

Pneumatic retinopexy is a new procedure that is effective in treating the uncomplicated cases of rhegmatogenous retinal detachments. The procedure of pneumatic retinopexy is composed of cryotherapy(photocoagulation), intraocular gas injection and postoperative positioning. The advantages of this procedure are less tissue damage, no hospitalization, reduced expense and minimal complication. For these reasons, this procedure has become popular retinal detachment surgeons. Peports of associated complications are still limited. The authors experienced one case of choroidal detachment after intraocular gas(SF6 gas) injection in rhegmatogenous retinal detachment in pseudophakic eye.
Choroid* ; Hospitalization ; Retinal Detachment