Retinal angiomatous proliferation: clinical characteristics and treatment options

A new form of exudative age-related macular degeneration (ARMD), retinal angiomatous proliferation (RAP), has been described in which neovascularization begins in the deep retina, extends through the subretinal space, and eventually communicates with choroidal neovascularization. Case series. Common clinical features of RAP include small multiple intra-retinal hemorrhages, intra-retinal edema, vascularized pigment epithelial detachments (PEDs), and retinal choroidal anastomosis (RCA). Fluorescein angiography (FA) reveals ill-defined, occult choroidal neovascularization. Indocyanine green (ICG) angiography is useful in early stages because ’hot spots’ can be detected before clinical or FA characteristics are present. Optical coherence tomography (OCT) is useful in illustrating some of the clinical and FA characteristics. The use of photodynamic therapy (PDT), combined with intravitreal triamcinolone injection, was successful in stabilizing the RAP lesion in one case discussed in this report. Retinal angiomatous proliferation is a newly recognized entity of exudative age-related macular degeneration with its own set of clinical, FA, ICG angiography, and OCT features. Experimental treatments such as the use of PDT combined with intravitreal triamcinolone injection demonstrate potential success with this entity. The biggest hope appears to be anti-angiogenic factors currently in clinical trials for the treatment of exudative ARMD

Parametric characterization of penumbra reduction for aperture-collimated pencil beam scanning (PBS) proton therapy

Recently, a commercial treatment planning system (TPS) has implemented aperture collimators for PBS dose calculations which can serve to reduce lateral penumbra. This study characterized the variation in magnitude of lateral penumbra for collimated and un-collimated PBS fields versus the parameters of air gap, depth, and range shifter thickness. Comparisons were performed in a homogenous geometry between measured data and calculations made by a commercial TPS. Beam-specific target volumes were generated for collimated and un-collimated PBS fields and optimized for various range shifter thicknesses and air gaps. Lateral penumbra (80%-20% distance) was measured across each target volume to characterize penumbra variation with depth and air gap. An analytic equation was introduced to predict the reduction in lateral penumbra between un-collimated and collimated PBS treatments. Calculated penumbra values increased with depth across all combinations of range shifters for a constant air gap. At 2 cm depth, the reductions in penumbra due to the aperture were 2.7 mm, 3.7 mm and 4.2 mm when using range shifter thicknesses of 0 cm, 4.0 cm and 7.5 cm, respectively. At a depth of approximately 20 cm and air gap of 5 cm, differences between penumbras of collimated and un-collimated beams were less than 1 mm. Penumbra reductions for the collimated beams were largest at small air gaps. All TPS-calculated penumbra values derived in this study were within 1 mm of film measurement values. Finally, the analytic equation was tested using a clinical CT scan, and we found good dosimetric agreement between the model predictions and the result calculated by the TPS. In conclusion, application of collimators to PBS fields can sharpen penumbra by several mm and are most beneficial for shallow targets. Furthermore, measurements indicate that the dose calculation accuracy in the penumbra region of PBS-collimated fields is adequate for clinical use

Factors associated with reduced visual acuity during long-term follow-up of patients with idiopathic central serous chorioretinopathy

To investigate factors associated with reduced visual acuity during long-term follow-up of patients with idiopathic central serous chorioretinopathy (ICSC). Retrospective consecutive case series that included patients with ICSC who were younger than 50 years of age at the time of initial examination and were followed up for > or =3 years. The mean follow-up for 101 involved eyes of 61 patients was 9.8 years (median, 8.0 years). Eyes were stratified into two groups based on visual acuity at the final examination: Group 1, visual acuity of 2040 or better; and Group 2, visual acuity of worse than 2040. Findings identified as potential risk factors for reduced vision at the final follow-up examinations for Group 1 versus Group 2 included the following: macular retinal pigment epithelium atrophy (90.8% versus 96.0%, respectively; P = 0.68); persistent pigment epithelial detachment or persistent subretinal fluid (5.3% versus 28.0%, respectively; P = 0.004); recurrences (39.5% versus 68.0%, respectively; P = 0.020); laser treatment (28.9% versus 32.0%, respectively; P = 0.80); and submacular choroidal neovascularization (0.0 versus 8.0%, respectively; P = 0.059). Factors associated with reduced visual acuity during long-term follow-up of patients with ICSC included persistent pigment epithelial detachment and/or subretinal fluid, recurrences, and submacular choroidal neovascularization

Spectral Characterization of a Blue-Enhanced

In this paper, we report on spectral response data and gamma ray spectroscopy measurements using two newly developed silicon photodetectors that are designed to have enhanced sensitivity in the blue spectral region. The enhanced sensitivity is a result of our newly developed ion implantation profile used to create the active area of the photodetector. The quantum efficiency of the new photodetectors (without any optimized antireflective coating) has been measured to be 40% at a wavelength of 420 nm. Gamma ray spectroscopy experiments have been performed using a thallium doped cesium iodide, [CsI(Tl)], and a cerium doped lutetium oxy-orthosilicate, (LSO) crystal excited by a Cs or 22 Na source and read out by the new photodetectors. We have measured an energy resolution of 7.7% and 22.7% full-width at half-maximum (FWHM) for the 662-keV gamma rays from a Cs for the CsI(Tl) and LSO scintillator crystal respectively. We intend to use the photodetectors, in the form of a detector array optically coupled to CsI(Tl) or LSO, in the development of a new scintillator detector module for use in positron emission tomography (PET)

Recommendation on Design, Execution, and Reporting of Animal Atherosclerosis Studies A Scientific Statement From the American Heart Association

Animal studies are a foundation for defining mechanisms of atherosclerosis and potential targets of drugs to prevent lesion development or reverse the disease. In the current literature, it is common to see contradictions of outcomes in animal studies from different research groups, leading to the paucity of extrapolations of experimental findings into understanding the human disease. The purpose of this statement is to provide guidelines for development and execution of experimental design and interpretation in animal studies. Recommendations include the following: (1) animal model selection, with commentary on the fidelity of mimicking facets of the human disease; (2) experimental design and its impact on the interpretation of data; and (3) standard methods to enhance accuracy of measurements and characterization of atherosclerotic lesion