Desensitizing Inflation from the Planck Scale

A new mechanism to control Planck-scale corrections to the inflationary eta parameter is proposed. A common approach to the eta problem is to impose a shift symmetry on the inflaton field. However, this symmetry has to remain unbroken by Planck-scale effects, which is a rather strong requirement on possible ultraviolet completions of the theory. In this paper, we show that the breaking of the shift symmetry by Planck-scale corrections can be systematically suppressed if the inflaton field interacts with a conformal sector. The inflaton then receives an anomalous dimension in the conformal field theory, which leads to sequestering of all dangerous high-energy corrections. We analyze a number of models where the mechanism can be seen in action. In our most detailed example we compute the exact anomalous dimensions via a-maximization and show that the eta problem can be solved using only weakly-coupled physics.Comment: 34 pages, 3 figures

Spiral Inflation

We propose a novel scenario of primordial inflation in which the inflaton goes through a spiral motion starting from around the top of a symmetry breaking potential. We show that, even though inflation takes place for a field value much smaller than Planck scale, it is possible to obtain relatively large tensor-to-scalar ratio (r similar to 0.1) without fine tuning. The inflationary observables perfectly match Planck data

Vitrectomy with complete posterior hyaloid removal for ischemic central retinal vein occlusion: Series of cases

BACKGROUND: Central retinal vein occlusion (CRVO) is a common retinal vascular disorder with potentially complications: (1) persistent macular edema and (2) neovascular glaucoma. No safe treatment exists that promotes the return of lost vision. Eyes with CRVO may be predisposed to vitreous degeneration. It has been suggested that if the vitreous remains attached to the macula owing to a firm vitreomacular adhesion, the resultant vitreous traction can cause inflammation with retinal capillary dilation, leakage and subsequent edema6. The roll of vitrectomy in ischemic CRVO surgical procedures has not been evaluated. CASE PRESENTATION: This is a non comparative, prospective, longitudinal, experimental and descriptive series of cases. Ten eyes with ischemic CRVO. Vitrectomy with complete posterior hyaloid removal was performed. VA, rubeosis, intraocular pressure (IOP), and macular edema were evaluated clinically. Multifocal ERG (m-ERG), fluorescein angiography (FAG) and optic coherence tomography (OCT) were performed. Follow-up was at least 6 months. Moderate improvement of visual acuity was observed in 60% eyes and stabilized in 40%. IOP changed from 15.7 ± 3.05 mmHg to 14.9 ± 2.69 mmHg post-operative and macular edema from 976 ± 196 μm to 640 ± 191 μm to six month. The P1 wave amplitude changed from 25.46 ± 12.4 mV to 20.54 ± 11.2 mV. CONCLUSION: A solo PPV with posterior hyaloid removal may help to improve anatomic and functional retina conditions in some cases. These results should be considered when analyzing other surgical maneuvers

Functional benefits of a chorioretinal anastomosis at 2 years in eyes with a central retinal vein occlusion treated with ranibizumab compared with ranibizumab monotherapy

Objective: To evaluate the functional benefits (best corrected visual acuity (BCVA), central subfield thickness, injection loads, central venous pressure (CVP)) of a laser-induced chorioretinal anastomosis (L-CRA) in patients with central retinal vein occlusion (CRVO) treated with ranibizumab compared with ranibizumab monotherapy. Methods and Analysis: This is a post-hoc analysis of the 2-year randomised ranibizumab plus L-CRA for CRVO trial. Twenty-four patients (82.5%) developed a functioning or successful L-CRA; outcome effects were monitored in the monthly as-needed ranibizumab phase from months 7 to 24 and compared with the ranibizumab monotherapy group (n=29). Results: From months 7 to 24, the mean (95% CI) injection load for the functioning L-CRA group was 2.18 (1.57 to 2.78) compared with 7.07 (6.08 to 8.06) for the control group (p<0.0001). The mean BCVA was averaged across all timepoints between the control and functioning L-CRA groups (average difference=11.46 (3.16 to 19.75) letters, p=0.01). At 2 years, there was an 82.5% reduction in the odds of high CVP (greater or equal to central retinal artery diastolic pressure) for those with a successful L-CRA compared with controls (p<0.0001). Conclusion: For patients with CRVO, adding L-CRA as a causal-based treatment to conventional therapy reduced CVP and injection loads and offered improved BCVA.Trial registration number ACTRN12612000004864

Baseline central macular thickness predicts the need for retreatment with intravitreal triamcinolone plus laser photocoagulation for diabetic macular edema

Roderick O&#39;Day,1 Daniel Barthelmes,1 Meidong Zhu,1 Tien Yin Wong,2,3 Ian L McAllister,4 Jennifer J Arnold,5 Mark C Gillies11Clinical Ophthalmology and Eye Health, The University of Sydney, Sydney, NSW, Australia; 2Singapore Eye Research Institute, National University of Singapore, Singapore; 3Center for Eye Research Australia, The University of Melbourne, Melbourne, VIC, Australia; 4Lions Eye Institute, The University of Western Australia, Perth, WA, Australia; 5Marsden Eye Specialists, Sydney, NSW, AustraliaPurpose: To identify baseline characteristics that predict the number of treatments with intravitreal triamcinolone acetonide (IVTA) plus laser photocoagulation needed to treat diabetic macular edema over a 2-year period.Methods: Individual data from 42 eyes of 42 participants treated with IVTA plus laser photocoagulation for diabetic macular edema during a prospective, randomized, double-masked, placebo-controlled trial were used for this post hoc analysis. Baseline characteristics &ndash; age, gender, best-corrected visual acuity, glycosylated hemoglobin, phakic status, intraocular pressure, and central macular thickness (CMT) &ndash; were correlated with the number of IVTA plus laser treatments received during the 2 years of this study.Results: The median number of treatments received over the 2-year period was 2.5 (interquartile range 1.0&ndash;3.0), with 21 (50%) eyes needing three or more treatments. Eyes that received more IVTA plus laser treatments had a higher mean baseline CMT and eyes with a higher baseline CMT were more likely to receive three or more treatments (odds ratio 5.13, 95% confidence interval 1.75&ndash;15.04, P=0.003 per 100 &micro;m increase in CMT). No significant relationship was found between other baseline characteristics and the number of IVTA plus laser treatments received.Conclusion: Higher baseline CMT was strongly linked with receiving more IVTA plus laser treatments. These patients may be at higher risk of developing dose-dependent steroid-related adverse events, cataract progression, and intraocular pressure rise.Keywords: diabetic macular edema, intravitreal triamcinolone, central macular thicknes

Macular Atrophy in Neovascular Age-Related Macular Degeneration A Randomized Clinical Trial Comparing Ranibizumab and Aflibercept (RIVAL Study)

PURPOSE: To investigate differences in the development of macular atrophy (MA) over 24 months between treat-and-extend (T&E) ranibizumab and aflibercept in patients with neovascular age-related macular degeneration (nAMD). DESIGN: A phase 4 randomized, partially masked, multicenter study. PARTICIPANTS: Individuals 50 years of age or older diagnosed with active, treatment-naïve subfoveal choroidal neovascularization secondary to nAMD with baseline best-corrected visual acuity (BCVA) of 23 logarithm of minimum angle of resolution letters or more. METHODS: Patients were randomized 1:1 to receive either intravitreal injections of ranibizumab 0.5 mg or aflibercept 2.0 mg and were treated according to the same reading center-guided T&E regimen after 3 initial monthly injections. MAIN OUTCOME MEASURES: The primary outcome was mean change in square root area of MA from baseline to month 24. Key secondary outcomes included number of injections and mean change in BCVA from baseline to months 12 and 24. RESULTS: Two hundred seventy-eight patients were included in the analysis (ranibizumab 0.5 mg, n = 141; aflibercept 2.0 mg, n = 137). Mean change in square root area of MA from baseline to month 24 was +0.36 mm (95% confidence interval [CI], 0.27-0.45 mm) for ranibizumab and +0.28 mm (95% CI, 0.19-0.37 mm) for aflibercept (treatment difference, +0.08 mm [95% CI, -0.05 to 0.21 mm]; P = 0.24). The proportion of patients with MA increased from 7% (10/141) to 37% (43/117) for ranibizumab and from 6% (8/137) to 32% (35/108) for aflibercept from baseline to month 24. The average number of injections received per year was similar between both groups: 9.6 (95% CI, 9.2-10.0) for ranibizumab and 9.5 (95% CI, 9.1-9.9) for aflibercept. The mean change in BCVA from baseline to month 24 was +6.6 letters (95% CI,4.7-8.5 letters) for the ranibizumab group and +4.6 letters (95% CI, 2.7-6.6 letters) for the aflibercept group ( P = 0.15). Rates of adverse events (AEs) were similar between both groups. CONCLUSIONS: No significant differences in the rate of development or growth of MA over 24 months were observed between ranibizumab and aflibercept in nAMD patients treated using an identical T&E regimen