Effect of Cryotherapy on Focal Adhesion Kinase in Retinal Pigment Epithelial Cells

PURPOSE: In the pathogenesis of proliferative vitreoretinopathy (PVR), retinal pigment epithelial (RPE) cells do not undergo apoptosis after separation from the basement membrane. In order to investigate the mechanism by which RPE cells resist apoptosis in PVR, the expression of focal adhesion kinase after cryotherapy was studied. METHODS: After lensectomy and vitrectomy was performed on rabbit eyes, a retinal tear was created. Cryotherapy was applied to the tear site one week after the tear creation. Rabbits were sacrificed at 1, 4 and 7 days after the tear formation and 30 minutes, 1, 4, 7, 9, 21 days after cryotherapy. Eyes were stained with anti-focal adhesion kinase (FAK) antibody. RESULTS: Expression of FAK increased after the tear formation and remained increased until 21days after cryotherapy. CONCLUSIONS: These data show that creation of a retinal tear and cryotherapy increases FAK expression and may contribute to resistance to apoptosis.

The Spontaneous Resolution of Idiopathic Macular Hole Diagnosed with OCT

PURPOSE: To report two cases of spontaneous resolution of macular hole stage 1 and 2, that were objectively diagnosed with OCT(optical coherence tomography). METHODS: Case 1-A 64-year-old woman without systemic disease visited Kong Eye Center complaining of decreasing visual acuity for 1 month. We diagnosed her case as macular hole stage 1, checked her regularly and detected spontaneous resolution of the macular hole after 6 months. We examined her using OCT before and after spontaneous resolution. Case 2-A 66-year-old man without systemic disease visited Kong Eye Center complaining of decreasing visual acuity for several months. We diagnosed his case as macular hole stage 2 and decided to perform an operation 3 weeks later. On admission, we detected spontaneous resolution of the macular hole. We examined him using OCT before and after spontaneous resolution. RESULTS: We could confirm the spontaneous resolution of stage 1 and 2 macular hole using OCT objectively. CONCLUSIONS: OCT is a useful tool in the diagnosis of macular hole and in the evaluation of various natural course of macular hole.

The Clinical Manifestations and Treatments of Parafoveal Telangiectasis

PURPOSE: To investigate the clinical manifestations and treatments of parafoveal telangiectasis. METHODS: Twenty-two eyes of fifteen patients diagnosed as parafoveal telangiectasis were selected who had visited Kong Eye Center from September 1999 to August 2003 complaining of decreasing visual acuity. Visual acuity was checked and fluorescein angiography and optical coherence tomography were done. Authors treated six eyes of six patients experienced decreasing visual acuity due to macular edema with argon laser photocoagulation and one eye of one patient accompanying with choroidal neovascularization with photodynamic therapy. RESULTS: Among fifteen patients, group 1 cases were eight (1B eight) and group 2 cases were seven by classification of Gass and Blodi. Visual acuity improved in two eyes of six eyes and maintained in four eyes of six eyes and optical coherence tomography showed decrease of macular edema in six eyes of six patients all after argon laser photocoagulation. Visual acuity improved and optical coherence tomography showed decrease of macular edema in one eye of one patient after photodynamic therapy. CONCLUSIONS: Group 1 cases were more than group 2 cases. Argon laser photocoagulation can be effectively used to treat decreasing visual acuity due to macular edema in parafoveal telangiectasis patients. Photodynamic therapy seems to be effective in parafoveal telangiectasis accompanied with choroidal neovascularization but we think that additional studies with more cases are needed.

Diagnosis and Treatment of Vitreomacular Traction Syndrome Using Optical Coherence Tomography

PURPOSE: To determine the benefit of optical coherence tomography (OCT) in the diagnosis of vitreomacular traction syndrome and evaluate the vitreoretinal interface before and after vitreous surgery. METHODS: Medical records of five patients with vitreomacular traction syndrome who had undergone vitrectomy were reviewed. Preoperative and postoperative visual acuity and preoperative and postoperative OCT were reviewed. In all patients OCT demonstrated posterior vitreous detachment and a focal adhesion of hyaloid membrane to macula with traction on the foveal retinal tissue. All of them underwent pars plana vitrectomy with peeling of poterior hyaloid face. RESULTS: Visual acuity improved in 4 eyes after the first vitrectomy. One eye developed postoperatively a macular hole, which was treated with the second vitrectomy and intravitreal gas tamponade with subsequent improvement in vision. In 4 eyes, OCT showed elimination of vitreous strand, relief of vitreous traction and restoration of normal foveal contour after vitrectomy. CONCLUSION: Optical coherence tomography is a useful tool in the diagnosis of vitreomacular traction syndrome and in the evaluation of status of vitreoretinal interface before and after vitrectomy. Following pars plana vitrectomy, vision improved and normal foveal contour was restored.

A Case of Acquired Brown Syndrome Following Scleral Buckling

PURPOSE: To present a case of the acquired Brown syndrome caused by scleral buckling. METHODS: A 58-year-old man presented with floaters in his right eye which had developed 20days before. Rhegmatogenous retinal detachment with a retinal tear at the location of 2 o' clock was diagnosed. Radial scleral buckling was performed. Ten days after surgery, he was unable to elevate his right eye in adduction, and right superior oblique muscle overaction was presented. RESULTS: Acquired Brown syndrome caused by scleral buckling has not been documented in Korea to our knowledge. Therefore, we report this case with review of related literatures.

Leiomyoma in the Ciliary Body Resected Ab Externo

A leiomyoma of the ciliary body is a rare tumor that is thought to arise from the neural crest tissue.It is difficult to differentiate this tumor from a uveal melanoma either clinically or pathologically. We performed a complete removal or the mass that had been suspected clinically as an intraocular inflammation or a malignant melanoma.However, it was diagnosed as a leiomyoma by immunohistochemistry and electron microscopy.

The Necessity of Topical Corticosteroid After Excimer Laser Photorefractive Keratectomy

The effect of topical steroid application on clinical results of 215 eyes(126 patients) performed with excimer laser photorefractive keratectomy (PRK) from July 1993 to July 1994 was evaluated, postopertively. The range of myopia was between -2.5 and -11.5 diopter and followed for 9 months after PRK with Summit Omnimed(TM). Topical corticosteroid or non-steroidal antiinflammatory drug (NSAID) was not applied for one month after operation in all cases. After one month, in cases of 115 eyes showing myopic regression of more than -1 diopter or stromal haziness of more than grade 1(delayed steroid group; DSG), 0.1% fluorometholone was applied 4 times daily for 4 weeks, then tapered according to the planned schedule. 46.5% (100 eyes, non-steroid group;NSG) did not show the myopic regression nor stromal haziness without treatment of fluorometholone throughout the follow-up period. Uncorrected visual acuity, spherical equivalent and corneal haziness were evaluated 1, 2, 4, 8, 12, 24, 36 week after operation. 73%(73 eyes) of NSG and 27%(30 eyes) of DSG showed a myopia less than 6.0 diopters preoperatively. The proportion of male was 36% in NSG and 50.4% in DSG. 88.1% of male high myopia(>6.0 diopters) needed 0.1% fluorometholone, while 17.6% of female moderate and mild myopia(

Analysis of the Penetrating Ocular Injuries Involving the Posterior Segment

We analyzed retrospectively 39 cases of 39 patients who had undergone surgery for penetrating ocular injury involving posterior segment to investigate the effect of pars plana vitrectomy on visual outcome and anatomical success. Patients who received surgery between January, 1990 to October, 1994 were included. The patients who underwent pars plana vitrectomy were classified to 'vitrectomy group', and those who had not undergone vitrectomy were classified to 'primary repair group'. There were no significant differences in severity of ocular injury between the two groups. The vitrectomy group had significantly better result in functional success(visual result) and the anatomical success. Success rates of the two groups were compared in the presence of poor prognostic factors, including initial visual acuity worse than hand motion, hyphema more than 50%, vitreous hemorrhage, retinal detachment, laceration longer than 7mm, located more than 6mm posterior to the limbus. Vitrectomy group showed better results in the presence of each factor.

Evaluation of Antiproliferative Agents in Tissue Culture Model

The authors investigated the effect of single intraoperative exposure of mitomycin C(MMC), 5-fluorouracil(5-FU), and cyclosporine A(Cs A) on the glaucoma filtering surgery. Human Tenon's fibroblasts were cultured and exposed to various concentrations of each drug for 5 minutes. Cell viability was measured using MTT assay, and cell proliferation was studied by 3H-thymidine uptake test. None of MMC(up to 0.04%), 5-FU(up to 40mg/ml), Cs A(up to 20micro gram/ml) was cytocidal. However, both MMC and 5-FU inhibited proliferation of fibroblasts significantly, but not Cs A. We concluded that MMC and 5-FU improve the results of filtering surgery not by direct cytocidal effect, but by the inhibition of proliferation. As for Cs A, longer exposure time and higher concentrations were needed to have similar effect on cellular viability and proliferation.

Retinal Detachment Following Scleral Fixation of Posterior Chamber Intraocular Lens

The authors reviewed retrospectively retinal detachment(RD)s following posterior chamber intraocular lens(PC-IOL) implantation by transscleral suture fixation. One hundred twenty-two transscleral fixations of PC-IOL were performed from January, 1990 to December, 1992. The follow-up periods for this series ranged from 12 to 42 months. Six retinal detachments developed in this series. and the incidence of RD was 4.9%. There was no statistical difference between the primary operation group(unplanned posterior capsule rupture during extracapsular cataract extraction, lens dislocation/subluxation) and the secondary operation group(already aphakia after previous cataract surgery). The predisposing factors to RD were myopic eye(p=0.03), postoperative vitreous hemorrhage(p=0.001). In cases with RD, the locations of transscleral fixation sutures almost coincided with the meridians of the retinal breaks. The contributing factors to increased incidence of RD were thought to be vitreous loss during operations, vitreous traction by suturing needle or haptics of IOL, proliferative change by vitreous hemorrhage.