The Role of VEGF and Bruch's Membrane in the Development Choroidal Neovascularization

A major cause of blindness in elderly people is choroidal neovascularizapathogenesis and stimulating factor of CNV is not clearly understood. Vascular endothelial growth factor(VEGF)is a major stimulating factor for retinal neovascularization in ischemic retinopathy such as diabetic retinopathy, retinopathy of prematurity. But it is not known if VEGF is a stimulating factor for CNV. In this study, we have treated VEGF transgenic mice and C57BL/6 mice with laser. Different laser parameter for damage to retina pigment epithelium(RPE)only and for break of Bruch's membrane were used each. We were not able to induce CNV with only RPE damage. CNV wes induced when the break of Bruch's membrane was made and there was profuse CNV in VEGF transgenic mice rather than C57BL/6. These data suggest that the damage of Bruch's membrane may be the prerequisition for CNV formation and VEGF is the important stimulating factor for CNV.

Neurotropic Effect of Basic Fibroblast Growth Factor on Laser Wound

In order to analyze the potential role of basic fibroblast growth factor (bFGF)on retinal wound after laser photocoagulation, we studied the expression of GFAP and the morphologic changes in the retina of pigmented rats. A multiline krypton laser was used to produce laser lesions. After irradiation, eyes were intravitreally injected with 1 microliter vehicle or 1 microgram of bFGF in l microliter of vehicle. And we examined the expression of GFAP at 1 day, 3 days, 7 days and 14 days after treatment.We also measured the size of defect in outer nuclear layer at 7 days after laser. The results were as follows : 1. GFAP immunoreactivity of M ü ller cell begins to appear within 24 hours in whole retina area.It sharply increases until 7 days and then decreases slowly. 2. bFGF stimulates the expression of GFAP and it is statistically significant(p<0.05) 3. BFGF prevents cell death of photoreceptor in the laser lesions(p<0.05 ) From these results, we concluded that bFGF stimulates Müller cell reactivity after laser phtocoagulation and prevents photoreceptor loss. These results may be important to understand the healing mechanism of laser phtocoagulation and to minimize the complications of laser phtocoagulation.

The rapeutic Effects of Low Dose Triple Agents Steroid, Cyclosporine and Azathiprineon Refractory Uveitis

Immunosuppressive agent has been used as a therapeutic agent for Endogeneous posterior uveitis[EPU]. But serious side effect of steriod or cyclosporine and frequent recurrence of ocular inflammation warrant the addition of other immunosuppressive agents. In this study, we evaluated the therapeutic effectiveness of low dose triple therapy using steroid, cyclosporine and azathioprine when combination therapy with steroid and cyclosporine had failed. We reviewed the records of 10 Behcet's patients[18 eyes]and 2 sympathetic ophthalmia patients[2 eyes]who had been resistant to steroid and cyclosporine combination therapy. The median follow up duration of triple therapy was 16.3 months. Recurrence, severity of inflammation, systemic manifestations associated with Behcet's disease, and side effect of therapeutic agents were evaluated. There was a significantly decrease in the frequency[0.37/month during pretriple therapy and 0.14/month after triple therapy]and severity of ocular inflammation[p<0.01]. The frequency and severity of systemic manifestations also decreased. Visual acuity remained stable in 7 eyes[35%]and improved in 13 eyes[65%]. No serious side effects or newly developed side effect were developed during triple therapy except reversible mild anemia in 1 patient. The results of our study suggest that triple agent immunosuppressive therapy is well tolerated and appears to be effective for the severe uveitis which is refraction to steroid and cyclosporine combination therapy.

Assessment of Idiopathic Macular Hole Surgery by Heidelberg Retina Tomograph

For the evaluation of preoperative and postoperative factors effecting the results of vitrectomy as a treatment of full thickness macular hole, we estimated the three dimensional morphology of macular hole using the HRT [Heidelberg retina tomography]and investigated every patient's history and operation method. Pars plana vitrectomy, epiretinal and internal limiting membrane removal, and C3F8 injection were performed in 19 patients[19 eyes]with full thickness macular holes. Anatomic success was seen in 12 eyes[63.2%]and was statistically related with preoperative hole area, volume and depth. Functional success was seen in 6 eyes[31.6%]and was significantly related with preoperative hole volume and depth, marginal detachment area and volume, hole diameter and hole area. In addition, anatomic success was statistically related with internal limiting membrane removal[p<0.01], stage and preoperative visual acuity [p<0.05]. Functional success was significantly related with preoperative visual acuity, internal limiting membrane removal[p<0.01], stage and duration of the disease[p<0.05]. We conclude that preoperative HRT is a useful method in deciding the operative indications and also in predicting the outcomes.

Clinical Studies in Patients with HLA-B 27 Positive Uveitis

It is well known that HLA-B 27-associated uveitis is mostly anterior uveitis and has systemic manifestations.20 Patients [27 eyes]followed up at department of Ophthalmology of Kangnam St.Mary`s hospital, Catholic University Medical College from November 1989 to June 1998, were studied to delineate the clinical manifestations, treatments and prognosis in patients with HLA-B 27-associated uveitis.An HLA B27 associated systemic disorder was present in 10 patients, all of whom were ankylosing spondylitis. Systemic manifestations occurred in 19 patients included oral ulcer in 7 patients, genital ulcer in 3 patients, arthralgia in 16 patients, and skin lesion in 3 patients.Among the total 27 eyes, anterior uveitis was noted in 23 eyes and posterior segment involvement occurred in 4 eyes.The findings of posterior segment involvement included retinal vasulitis in 2 eyes and chorioretinitis in 1 eyes.Severe vitritis occurred in 1 eyes.Most of anterior uveitis was treated with topical steroid eyedrops and periocular steroid injections.In 3 eyes of posterior segment involvement, systemic steroid therapy was required for control of inflammation.After treatment, visual acuity in 23 eyes among 27 eyes was 20/40 or better.And, visual acuity in 4 eyes of posterior segment involvement was 20/25 or better following medical treatment.In conclusion, although HLA-B 27-associated uveitis was mostly related to anterior uveitis, posterior segment manifestations may be occurred in some patients;these patients may require the use of aggressive systemic immunosuppressive therapy to control inflammation and preserve vision.

The Relationship between Plasma PAI-1 Antigen Concent ration and Diabetic Retinopathy in NIDDM Patients

To examine the relationship between plasma plasminogen activator inhibitor-1[PAI-1]antigen concentration and diabetic retinopathy in non-insulin dependent diabetic patients, PAI-1 antigen levels and some fibri-nolytic parameters were studied in 89 non-insulin dependent diabetic patients[mean age 59.8 +/-11.3 years]and 25 normal adults as control[meanage 52.8 +/-14.7 years]. The diabetic patients were classified as three subgroups: no DR[n=34], NPDR[n=29]and PDR[n=26]according to the degree of retinopathy.The PAI-1 antigen concentration was measured by enzyme immunoassay[Innotest PAI Ag kit].The diabetic patients had a significantly higher mean PAI-1 antigen level [34.56 +/-17.80ng/milliliter ]compared to a control group[20.35 +/-15.78 ng/milliliter ][p<0.05].Plasma PAI-1 antigen level was significantly lower in diabetic patients with PDR[27.39 +/-15.54 ng/milliliter ]than in diabetics with no DR[36.87 +/-23.31 ng /milliliter ]or NPDR[39.43 +/-2 0.17 ng/milliliter ][p<0.05], probably because of more extensive systemic endothelial damage. These results support the hypothesis that impaired fibrinolysis due to elevated PAI-1 is associated with the development of retinopathy, and therefore the levels of PAI-1 can be used as useful indicator for the development and progression of proliferative retinopathy.

Surgical Results of Vitrectomy for Longstanding Idiopathic Macular Hole: Factors Affecting Postoperative Prognosis

Results of vitrectomy as treatment of full thickness(stage 3,4) macular hole were reported large variability and difference n anatomical and funtional success rate. So many surgeons fely difficulty in expectation of postoperative results before operation on stage 3,4. To use decision of proper operation time & effective treatment and expect the postoperative results before operation, after anatomical & functional factor affecting postoperative results & prognosis were arranged, relationship of these data after vitrectomy were evaluated. Pars plana vitrectomy in 25 patients(25 eyes) with stage 3(8 eyes) and stage 4(17 eyes) macular hole was performed. Functional success was seen in 7 eye(28%) and Anatomical success was seen in 12 eyes(48%). Preoperative factors such an stage of macular hole, preoperative visual acuity, size or macular hole, and sex were not found any association with postoperative functional & anatomical success rate. the group that had completely attached hole after vitrectomy and small preoperative cuff size(<1.0mm) were showed improvement of visual acuity compared with the other group. But these results were statistically not significant. And patients (5 eyes) with additional removal of ILM with PVD or memb peeling were showed good anatomical success rate(80%), but no difference of postoperative visual acuity compared with the other group. Although preoperative fluid cuff size and around hole and completely closure of hole after surgery were statistically not significant, highly correlated with postoperative visual acuity compared with the other factor. But long-term follow-up & recruitment of additional cases are required to consider as one of the significant factor on deciding operation time & expecting postoperative result.

Clinical Evaluation for Patients with Retinal Detachment Caused by Macular Hole

We investigated the surgical outcomes in 19 eyes with retinal detachment(RD)caused by macular hole only. 15 eyes were high-myopic(>-8.0Ds), and the mean preoperative axial-length was 28.30 mm. As an initial treatment method, simple gas injection was done to 2 eyes, and pars plana vitrecto-my(PPV), air-fluid exchange and subretinal fluid drainage with intravitreal tamponade were performed in 17 eyes. The retina of 2 eyes with simple gas injection was not attached because of persistent vitreoretinal traction. PPV with intravitreal tamponade was successful in 12 of 17 eyes with a single operation, and reoperation was effective in 3 eyes of the failed 5 eyes. We conclude that, in case of retinal detachment caused by macular hole, the success rate can be improved by PPV with complete removal of vitreoretinal traction along with the long-lasting intravitreal tamponade.

Clinical Effect of Nd -YAG Synechiolysis

Patients who had posterior synechiae associated with uveitis,IOL mplantation, vitrectomy, underwent Nd-YAG synechiolysis had been treated with topical corticosteroids and surgical iridectomy. Even minimal dilatation of the pupil by Nd YAG synechiolysis enable the patient to read and the surgeon to postpone cataract surgery and evaluate optic disc or fundus. Also, pupil block may be treated by detaching the synechiae.18 Patients (20 eyes) with posterior synechiae underwent Nd-YAG synechiolysis at Kangnam St.Mary's Hospital from November 1997 to August 1998. An average of 17.14 +/-6.43mJ laser were used. The average prelaser pupil size was 3.78 +/-0.98 mm ;postlaser, 5.13 +/-1.27 mm.This change was statistically significant (p<0.01). Microhyphema and pigment dispersion developed in 4 eyes. However,no significant long-term complications occurred, and there were no obvious lenticular damage and pupil abnormality. Because this laser treatment is relatively safe and offers some possibility of visual improvement, we recom-mend Nd-YAG synechiolysis,but only if performed by an experienced laser microsurgeon.

Corneal Endothelial change following Par Plana Vitrectomy with Expanding Gas

We performed prospective study of corneal endothelial damage associated with expanding gas during pars plana vitrectomy in 33 patients. A total of 16 eyes were performed vitrectomy with lens removal(intact anterior capsule), only 6 eyes in the gas treated group and 10 eyes in the control group. Among 19 eyes underwent vitrectomy without lens removal, 10 eyes treated with the expanding gas, which was not performed in the other 9 patients. The corneal endothelium was examined with a noncontact specular microscopy preoperatively and 3 months postoperatively. Endothelial changes were analyzed by comuterized morphometric data of individual cells and represented cell density, coefficient of variation, and hexaponality. The mean endothelial cell loss was 2.73% in 9 phakic eyes which underwent vitrectomy without expanding gas and 5.99% in 10 phakic eyes which underwent vitrectomy with expanding gas. In aphakic eyes, vitrectomy was comvined with lensectomy and expanding gas, the mean endothelial cell loss was 6.81%. The changes of endothelial cell density and hexagonality were not statistically significant. But coefficient of variation in aphakic eyes with vitrectomy using expanding gas was higher compared with other groups. As our results, although the difference of coefficient of expanding gas during vitrectomy in aphakic eyes seems to be safe. Because during vitrectomy with expanding gas in aphakic eyes.

Analysis of Typing in Patients with Uveitis in Korean Population

In order to evaluate association of particular HLA typing with certain uveitis in Korean population, HLA antigens were analyzed in 114 uneitis patients(acute anterior uveitis: 32 cases, Behcet`s disease: 25 cases, intermediate uveitis: 19 cases, Vogt-Koyanagi-Harada (V-K-H) syndrome: 10 cases, retinal vasculitis: 12 cases, Eale`s disease: 3 cases, posterior uveitis: 9 cases, pan.uveitis: 4 cases). The stronger association between acute anterior uveitis and HLA-B27 was statistically significant, and this result was similar to reports in other ethnic groups. Also, the association between V-K-H syndrome and HLA-DR4 showed same results. But the high frequency of HLA-DR7 in the patients with V-K-H syndrome was unque in patients of Korean popjlation and statistically significant. The association between HLA-A2 and posterior uveitis was high in patients of Korean population and statistically significant. Behcet`s disease was stronger association with HLA-B51 but not statistically significant and much weaker association than reports in Japanese group. Although many similarities of associations between particular uveitis and HLA typing were detected as compared with other ethnic groups, distinctive HLA associations were demonstrated in Korean population. Additional cases and long-term follow-up are required to confirm the association with HLA typing and the relationship with prognosis including clinical and laboratory variabilities.

Postoperative Endophthalmitis Following Intraocular Surgery

No abstract available.

Culture of Bovine Retinal Pigment Epithelium: Topographical Differences of Morphology and Growth Rate in Vitro

Cell cultures of adults bovine retinal pigment epithelium(RPE) were propagated from central and peripheral regions of the same eyes to study the topographical differences in cell growth and to compare the differences in growth rate between two areas. The results obtained were as follows: A regional variation in the morpholgy was observed between the RPE from central and that from peripheral regions. Retinal pigment epithelium from central region attached to culture dish more slowly(average 4 days) than those from peripheral region(average 3.5 days) The growth rate of retinal pigment epithelium declined with serial passage in culture. The growth rate of retinal pigment epithelium from peripheral region at the first generation was highest. And there was a statistical difference in growth rate with passing in generation(P<0.05). This study reveals that growth rate and cell activity of RPE from central region are lower than from peripheral region.

CMV Papillitis in Renal Transplant Recipient

Cytomegalovirus(CMV) ocular infection is one of the common ocular complications seen in immunocompromised condition, such as AIDS or organ transplant recipient receiving immunosuppressive drugs, CMV papillitis is known to be care. CMV papillitis has, however, a poor visual prognosis because the treatment is more resistant to than that of CMV retinitis. We report a case of CMV papillitis after the renal transplantation which has good result with long-term ganciclovir administration.

Proliferative Effect of Serum on Bovine Retinal Pigment Epithelial Cell Culture

The retinal pigment epithelium(RPE) is one of the most important cell layers in the visual system and is vital to the integrity of the rod and cone outer segments. It has many complex functions, such as absorption of light, storage and conversion of vitamin A esters and formation of acid- mucopolysaccharide complex. As serum in the vitreous cavity stimulates the migration and proliferation of RPE cells, serum is necessary to grow RPE cells in culture. Bovine RPE cells were cultured with various concentrations of fetal bovine serum(FBS 0%, 5%, 10%, 20%, 40%) to evaluate their effects on RPE cell growth. FBS stimulated the proliferation of bovine RPE ells in a dose-dependent manner, with maximal proliferation at 20% FBS. This proliferative effect, however, was suppressed at the highest concentration(40% FBS).

Central Retinal Vein Occlusion in Multiple Myeloma Associated with Hyperviscosity Syndrome

Multiple myeloma is a malignant proliferation of the atypical plasma cells which usually involves antibody synthesis in the immune system. Systemic manifestations include anemia, renal failure, osteoporosis, immune deficiency symptom. Ophthalmolgically this disease involves cornea, conjunctiva, uvea, iris, ciliary body, retinal vessels, extraocular muscles and optic nerve. The authors experienced a case of multiple myeloma with hyperviscosity syndrome who presented with central retinal vein occlusion in both eye.

A Case of Nanophthalmos

Nanophthalmos is a rare disease that results from arrested development of the globe after closure of the embryonic fissure and is characterized by a small eye with thickened sclera, uveal effusion, non-rhegmatogenous retinal detachment and narrow angle glaucoma. Treatments include medical, laser and surgical theraphy for glaucoma, and surgical treatments like scleral resection, anterior sclerotomy and vortex vein decompression surgery for the drainage of the uveal effusion, etc. We experienced a case of nanophthalmos with narrow angle glaucoma and choroidal effusion in 34 year-old male patients. Anterior sclerotomy for the drainage of the uveal effusion was performed and the scleral tissue obtained. Histopathologic study on the sclera showed abnormal collagen fibers.

Punctate Inner Choroidopathy

Punctate inner choroidopathy is a clinical disorder of unknown etiology that affects the retinal pigment epithelium and inner choroid resulting in visual loss. Punctate inner choroidopathy is characterized by multiple tiny punctate yellowish-white lesions in the deep retina of posterior pole. There is often an associated serous retinal detachment and subretinal neovascular membrane. The lesions are characterized by small punctate hyperfluorescent in the early phase and leak or stain in the late phase by fluorescein angiography. The authors experienced a case of suspected punctate inner choroidopathy associated with decreased visual acuity in a 24 year-old female and reviewed the available literatures regrading the disease.

A Clinical Study on Rhegmatogenous Retinal Detachment by Macular Involvement

We reviewed charts of 148 patients(148 eyes) who were diagnosed with rhegmatogenous retinal detachment and operated from January 1994 to December 1995 and followed for at least 3 months postoperatively at kangnam St. Mary's hospital. We compared preoperative findings, surgical methods, ultimate anatomic success and visual outcome by macular involvement, and evaluated the causes of decrease in visual acuity after operation. Fifty four eyes were A group without involved macula and 94 eyes were B group with involved macula. There were no differences betwetm the two groups according to age, sex distribution, preoperative refractive error and location of retinal breaks. In the eyes with detached macular(B group), the duration and the extent of retinal detachment and the numbers of retinal breaks were more than those of A Group. Postoperatively 52 eyes(96.3%) with spared macular and 84 eyes(89.4%) with detached macular were anatomically reattached. Forty two eyes(77.8%) with spared macula achived visual acuity of 0.3 or better, in contrast to 2.5 eyes(26.6%) with detached macula. The most common causes of decrease in visual acuity after operation were proliferative vitreoretinopathy, macular pucker, cystoid macular edma and subretinal hemorrhage.

Effects of 5-fluorouracil on culture of Bovine Retinal Pigment Epithelial cells

Inspite of technical advances, long term retinal reattachment of proliferative vitreoretinopathy following the successful surgery is often disturbed by the occurrence of cell proliferation and traction. A variety of antimetabolite or anticancer drugs have been tried to use for testing their antiproliferative effects on proliferative vitreoretinopathy. To evaluate the antiproliferative property of 5-FU, we treated with the different concentration of 5-FU(0.5, 1, 5, 10 mg/L) on cultured bovine retinal pigment epithelial cells and performed dose inhibition studies. We also examined the 5-FU treated bovine retinal pigment epithelial cells by inverted microscope daily to evaluate the morphologic change for 5 days. The results were as follows; 1. 5-FU inhibited proliferation of bovine pigment epithelial cells in a dose dependent and a time dependent manner. 2. The drug concentration required for 50% inhibition of cell growth(ID50) was found to be 1.87 mg/L. 3. As the drug concentration increased, the cell density gradually decreased and the degenerative changes such as irregular shape of cells, cytoplasmic vaculoes and cell debris were aggravated. In 10 mg/L of 5-FU treated well, disruption of cell membrane and cell death were noted from the first day of incubation. These results show that 5-FU has a potent antiprolifertive effects in retinal pigment epithelial cell and toxic effet in high dose.