The role of recombinant lysine-plasminogen and recombinant urokinase and sulfur hexafluoride combination in inducing posterior vitreous detachment.

PURPOSE: To determine the optimal method of generating plasmin in vitreous using recombinant lysine-plasminogen and recombinant urokinase and to determine its efficacy in inducing posterior vitreous detachment when combined with sulfur hexafluoride. METHODS: Plasmin concentration of the rabbit vitreous after separate and combined intravitreal administrations of recombinant lysine-plasminogen and recombinant urokinase was tested in 78 rabbits to determine the optimal method of administration. The safety and efficacy of these agents and sulfur hexafluoride in inducing complete posterior vitreous detachment (total separation of the vitreous apart from vitreous base) were also evaluated. RESULTS: The highest plasmin concentration in vitreous was measured 10 minutes after injection. Intravitreal administration of recombinant lysine-plasminogen and recombinant urokinase did not cause any toxicity findings up to concentrations of 100 microg and 200 IU, respectively, on funduscopy, electroretinography, and histopathologic studies. When combined with sulfur hexafluoride injection, separate intravitreal administrations of 75 microg/0.1 mL of recombinant lysine-plasminogen and 15 IU/0.1 mL of recombinant urokinase induced complete posterior vitreous detachment in 75% of the eyes compared with 13% in eyes that received sulfur hexafluoride injection combined with balanced salt solution, recombinant lysine-plasminogen, or recombinant urokinase. CONCLUSIONS: Plasmin was effectively generated in the vitreous after separate intravitreal administrations of recombinant lysine-plasminogen and recombinant urokinase. When combined with intravitreal gas injection, this method of plasmin production induced complete posterior vitreous detachment in 75% of the eyes.

Ocular photodynamic therapy in choroidal neovascularization complicating idiopathic central serous chorioretinopathy.

Two consecutive patients with idiopathic central serous chorioretinopathy and decreased vision subsequent to subfoveal choroidal neovascular membranes were treated with photodynamic therapy applied using the protocol of the Treatment of Age-Related Macular Degeneration with Photodynamic Therapy Study Group. Main outcome measures included best-corrected visual acuity, biomicroscopic appearance, and leakage on fluorescein and indocyanine green angiography. Photodynamic therapy offered anatomical, angiographic, and functional improvement. After an initial complete response, the patients required re-treatment at 3 and 4 months, respectively. Cessation of leakage with improvement in visual acuity occurred, but subretinal fibrosis posed a possible limitation for full functional recovery. Although choroidal neovascular membranes complicating idiopathic central serous chorioretinopathy portend a poor visual prognosis, the overall response to photodynamic therapy was favorable.

The role of scleral buckle in experimental posterior penetrating eye injury.

PURPOSE: Although episcleral buckles are frequently placed as an additional procedure to vitreoretinal surgery, little is known about their independent effect after ocular trauma. The authors created a posterior penetrating ocular injury model to evaluate the isolated role of primary episcleral buckle placement. METHODS: Twenty eyes underwent surgery. The penetrating injury consisted of two 5-mm circumferential incisions placed five clock hours apart and 8 mm behind the limbus. A segmental episcleral buckle was placed over a randomly chosen injury site after wound closure. The degrees of fibrous proliferation, traction, and the presence of retinal detachment were evaluated on follow-up examinations. After enucleation and initial fixation, tissue sectioning was performed, and the greatest dimension of the fibrous proliferation at both wound sites was measured with a caliper. RESULTS: Two eyes were excluded from the study. Three eyes developed a retinal detachment; the remaining 15 eyes showed varying degrees of proliferation and traction on the retina. The greatest dimension of the fibrous proliferation at the buckle site (1.22 +/- 1 mm) was significantly different from that at the nonbuckle site (2 +/- 1.45 mm, P = 0.01). CONCLUSIONS: Primary episcleral buckle placement at the time of surgical repair reduces vitreous traction from the buckle site and decreases the degree of fibrovascular proliferation.