ABSTRACT.Purpose: The purpose of this study was to evaluate the ability of different methods to induce choroidal neovascularization (CNV) in the domestic pig. Methods: A total of 26 Danish landrace pigs was used. A sample of 22 eyes in 12 pigs underwent retinal photocoagulation with a xenon lamp, six eyes in four pigs underwent retinal photocoagulation with a diode laser, and mechanical rupture of Bruch's membrane (BM) was induced in 12 pigs following surgical debridement of the retinal pigment epithelium without damage to the neuroretina. Results: All 12 pigs (100%) in the group with mechanical rupture of BM developed CNV. The induced membranes were morphologically similar to CNV membranes in humans. Induced CNV was found in 13 of 22 (54%) xenon lamp-treated animals and in five of six (83%) diode laser-treated animals. The CNV in these groups was small and the morphology of the induced lesions was dominated by retinal gliosis and retinal neovascularization, probably due to a marked destruction of the neuroretina. Conclusions: Surgical debridement of the retinal pigment epithelium followed by mechanical rupture of BM is a reproducible method of producing CNV in the domestic pig, whereas photocoagulation gives rise to glially derived subretinal fibrovascular membranes and primarily retinal neovascularization.

ABSTRACT.Purpose: To investigate the use of an ocular basement membrane as support material for transplanted porcine RPE cells. Methods: Porcine RPE cells were grown on bovine corneal extracellular matrix (ECM), isolated bovine-and porcine lens capsules, and tissue culture plastic. Cell density, and cell morphology were studied by phase contrast microscopy and transmission electron microscopy. Results: RPE cells grown on porcine anterior lens capsule and on ECM obtained better morphology and higher final cell density than cells grown on plastic and on bovine anterior lens capsule. It was possible to transplant the porcine anterior lens capsule to the subretinal space in pigs. Within two weeks of observation, the lens capsule was well tolerated in the subretinal space. Conclusion: The anterior lens capsule seems to be promising as support material for use in RPE cell-transplantation.

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Retinal and optic nerve oxygen tension increased with systemic administration of dorzolamide. The retinal vessels dilated, probably causing increased blood flow inducing the observed increase in RPO2. The increased oxygenation of retina by CAI may offer therapeutic possibilities in ischaemic diseases of the retina and optic nerve.

To determine visual outcome including the occurrence of radiation induced optic neuropathy (RION) as well as tumor control after fractionated stereotactic radiation therapy (FSRT) of benign anterior skull base meningiomas or pituitary adenomas. Thirty-nine patients treated with FSRT for anterior skull base meningiomas and 55 patients treated with FSRT for pituitary adenomas between January 1999 and December 2009 with at least 2 years follow-up were included. Patients were followed up prospectively with magnetic resonance imaging scans, visual acuity and visual field examinations. RION was found in four (10 %) patients with anterior skull base meningiomas and seven patients (13 %) with pituitary adenomas. The five-year actuarial freedom from 25 % RION visual field loss was 94 % following FSRT. Actuarial 2-, 5- and 10-year tumor control rates were 100, 88.4 and 64.5 % for anterior skull base meningiomas and 100, 98.2 and 94.9 % for pituitary adenomas, respectively. Patients with an impaired visual field function pre-FSRT were more likely to experience worsened function (p = 0.016). We found that RION, was a relatively uncommon event, in a large prospective cohort of patients that were systematically monitored following FSRT of benign anterior skull base tumors. Long term tumor control was favorable, especially for pituitary adenomas.

ABSTRACT.Purpose: To establish and characterize cultures of porcine retinal pigment epithelial (pRPE) cells in order to produce confluent monolayers of cells for transplantation. Methods: Primary pRPE cell cultures were established. Cell morphology was assessed by phase contrast and electron microscopy. Growth was determined by the crystal violet dye uptake assay. DNA synthesis and content were measured by incorporation of 3 H-thymidine and flow cytometry. Results: This primary culture resulted in cells with well-preserved morphology that could be propagated in up to six passages. The deterioration observed over time in cultures was not due to a constant high rate of cell turnover as postconfluency cell proliferation was limited. However, a large fraction of the cells had a high DNA content despite a lack of active DNA synthesis. Conclusions: The present method yields pRPE cells of high purity and proliferative capacity with preserved epithelial phenotype. However, aberrant DNA profiles and the deterioration of cell morphology observed over time in this graft material represent serious problems in RPE transplantation.

A significant protection against apoptosis of RPE cells grown on ECM compared to cells grown on uncoated plastic dishes was found after exposure to UV-A or DNR. This protection was found to be proportionally correlated to the anti-apoptotic protein Bcl-2 and inversely correlated to the expression of Bax. Furthermore a sustained induction and expression of c-Fos was found to correlate to a higher percentage of apoptotic cells of RPE cells grown on plastic. These findings demonstrate that ECM is of great importance for RPE cell survival during noxious stimuli and points out the essential role for a healthy Bruch's Membrane (BM) for RPE survival.