Photo-occlusion

An argon laser (filtered to deliver only at 488 nm) was used to release the liposomes content for purposes of angiography. The power of the laser was increased gradually until a bright fluorescent bolus was observed. Typically, this was achieved with a power of 16mW applied on a 600-pm spot for a duration of 200 msec. In the case of photo-occlusion (described later), a diode laser emitting at 675 nm was used to activate the photosensitizer. The delivery of both laser beams was controlled by shutters activated by a computer. 

POTENTIAL THERAPEUTIC APPLICATIONS OF LTD Laser-Targeted Photo-Occlusion... 

Nishiwaki H, Zeimer R, Goldberg MF, D Anna SA, Vinores SA, Grebe R. Laser targeted photo-occlusion of rat choroidal neovascularization without collateral damage. Photochem Photobiol 2002 75 149-158. 

Grebe R, Asrani S, Zou S, et al. Effects on the RPE following choriocapillaris occlusion induced by laser targeted photo-occlusion and conventional photodynamic therapy. Invest Ophthalmol Vis Sci/ARVO 1996 37(3) S976 (abstract). 

When comparing them with the photos obtained with the help of generally known Kato method (10). one can see beside similarity of general picture ofrubber distribution also difference membranes between occluded polystyrene and rubber particles in our picture are much thicker. In our opinion it can be explained by the fact that when being worked out one can see only contracted with osmium-tetroxide rubber and in fig. 1 b membranes be-tween occlusions represent rubber together with the intermediate layer, consisting of graft polymer of poly(styrene-gr-bu tadiene). 

Figure 3 In the BVOS, grid laser was applied to the area of retinal leakage and ischemia. Successful treatment could lead to resolution of macular edema and improvement in visual acuity. (A) Baseline photo and (B) corresponding fluorescein angiogram. (C) Follow-up fluorescein angiogram with resolution of leakage laser spots stain. Abbreviation BVOS, Branch Vein Occlusion Study.

To take standard photos, a horizontal reference plane was set for each maxillary plaster model. This was a triangular plane defined by the occlusal plane at the maxillary midline and the distobuccal cusp of the left and right maxillary first molars. 

Skin Of four prospective, randomized, controlled trials in healthy volunteers at two independent research facilities, two examined phototoxicity after 24 hours of drug exposure under occlusion (combined n = 51), and two examined photoallergenicity after a 3-week, six-dose induction phase (combined n = 72) followed by challenge [43 ]. There were no phototoxic or photo-allergic reactions with tretinoin 0.05% in a new gel formulation. These findings are... 

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