[Comparison of 12 Months Outcome of As-needed Intravitreal Aflibercept or Ranibizumab for the Treatment of Naïve Patients with Age-related Macular Degeneration].

PURPOSE: To compare pro re nata (PRN) intravitreal injections of aflibercept (IVA) and ranibizumab (IVR) in patients with treatment naïve age-related macular degeneration (AMD). MATERIAL AND METHODS: We analyzed 42 eyes that receive 3 times monthly IVA as introduction phase and subsequently received PRN retreatment at the recurrence. As the control, 56 eyes received the same IVR treatments as the IVA criteria. We statistically analyzed chronological changes of VA and the first recurrence following introduction phase by comparing the findings of the 2 groups. RESULTS: There was no difference in the IVA and the IVR in baseline visual acuity (VA) and the mean number of injections during 12 months. Compared to the IVR, the IVA showed better improved VA from baseline at each time point, especially, there was a statistically significant difference in 6 months after introduction (p = 0.041). The IVA proved to have a shorter period until the first recurrence and a lower remission maintenance rate following introduction phase than the IVR. The improvement of VA above 0.2 logMAR was significantly related to cases involving polypoidal choroidal vasculopathy, greatest linear dimension and baseline VA. CONCLUSIONS: The improvement of VA in anti-VEGF therapy for AMD was influenced by the disease type or pathology rather than the choice of therapeutic agents.

[Measurement of depth dose distribution using plastic scintillator].

We propose a new method to measure the depth dose distribution in matter. The method is to use organic plastic scintillator as a phantom, which has the effective atomic number close to that of human soft tissue, and to measure the position distribution of the scintillation light by a wavelength analyzer through a thread of plastic optical fiber. The purpose of this study is to examine possibility to measure the depth dose distribution with the proposed method. We carried out the following three measurements. First, we measured the effective field of view (FOV); the plastic optical fiber accepts the light from the FOV. Then, we measured the dose dependence of the amount of emission light. Finally, the light distribution in the depth direction by the present method was compared to the depth dose distribution by the ionization chamber. The results are as follows. The angular range of FOV is 7.03 degrees +/- 0.21 degrees The dose dependence shows a good linearity. In other words, the amount of emission light is proportional to the absorbed dose. Both of the light and the dose distributions are proportional each other, and they show the same attenuation in the region deeper than 15 mm. From these results, we conclude that the present method can be used for the measurement of the depth dose distribution in matter.