Search for Dark Matter decay signals in the Galactic Halo with the MAGIC telescopes

MAGIC is a system of two Cherenkov telescopes located in the Canary island of La Palma. A key part of MAGIC Fundamental Physics program is the search for indirect signals of Dark Matter (DM) from different sources. In the Milky Way, DM forms an almost spherically symmetric halo, with a density peaked towards the center of the Galaxy and decreasing toward the outer region. We search for DM decay signals from the Galactic Halo, with a special methodology developed for this work. Our strategy is to compare pairs of observations performed at different angular distances from the Galactic Center, selected in such a way that all the diffuse components cancel out, except for those coming from the DM. In order to keep the systematic uncertainty of this novel background estimation method down to a minimum, the observation pairs have been acquired during the same nights and follow exactly the same azimuth and zenith paths. We collected 20 hours of data during 2018. Using half of them to determine the systematic uncertainty in the background estimation of our analysis, we obtain a value of 4.8% with no dependence on energy. Accounting for this systematic uncertainty in the likelihood analysis based on the 10 remaining hours of data collected so far, we present the limit to TeV DM particle with a lifetime of $10^26$ s in the $mathrmbarb$ decay channel

Cystoid macular edema following cataract surgery.

CYSTOID MACULAR EDEMA FOLLOWING CATARACT SURGERY Alberto Rossetti and Daniele Doro Cystoic macular edema (CME) is the most common cause of unexpected visual loss following cataract surgery. CME occurring in aphakic eyes with intraretinal fluorescein angiographic cystoid spaces has been termed the Irving-Gas syndrome. After extracapsular extraction chronic CME with permanent visual loss is estimated to occur in approximately 1% of patients. The majority of cases occur between 4 and 12 week after cataract surgery. Predisposing factors are intraoperative complication ( e.g. vitreous loss or vitreous traction at the wound, severe iris trauma), diabetic retinopathy, and pre-existing epiretinal membrane. The authors describe the pathogenesis , the diagnosis, the symptoms , the prevention and the medical therapy of CME

Retained intravitreal lens fragments after phacoemulsification : complications and visual outcome in vitrectomized and non vitrectomized eyes

I.F. 2.07

Intraocular Pressure and Conjunctival Hyperaemia with Bimatoprost Every 48 Hours Versus Every 24 Hours

Purpose: To evaluate the efficacy and tolerability of a reduced rate of bimatoprost administration. Methods: Diurnal intraocular pressure (IOP) was recorded at 10 a.m., 2 p.m. and 6 p.m. in 40 eyes of twenty Caucasian patients (age range 56-75 years), with ocular hypertension or primary open angle glaucoma, at baseline and four weeks later. The right eye received daily bimatoprost, and in the left eye bimatoprost was administered every 48 hours at 8 p.m. Bulbar conjunctival hyperaemia was assessed by direct observation by a masked observer at baseline and at week 4 and was graded as none, minimal, mild, or moderate or severe (0 to 4). Results: Baseline mean diurnal IOP in the right eye significantly (P<0.001) decreased from 25.4±2.8 to 17.8±1.8 mmHg 14 to 22 hours after daily bimatoprost. Baseline mean diurnal IOP in the left eye significantly (P<0.001) decreased from 25.2±2.0 to 19.0±1.7 mmHg 38 to 46 hours post-dose. The reduction in the right eye was significantly greater than in the left (P=0.02). The average conjunctival hyperaemia after bimatoprost every 24 and 48 hours was graded as 2.4±1.0 and 1.8±0.8 respectively and this difference was significant (P<0.01). Conclusion: Bimatoprost every 48 hours was less effective than daily bimatoprost (24.6 vs. 30% IOP decrease), but caused less short term conjunctival hyperaemia. This off label dose schedule may be proposed to patients complaining of ocular redness especially in the first weeks of treatment

Ultrasound biomicroscopy examination of anterior uveal tumors: information on location and size only?

The aim of the study was to assess whether ultrasound biomicroscopy (UBM) examination of anterior uveal tumors could help in tissue differentiation. Five anterior uveal tumors in five patients underwent UBM (Paradigm P45, 50 MHz) examination prior to fine needle aspiration (FNA) of the lesion; two melanomas, one nevus, one metastatic carcinoma, and one bilateral iris lymphoma were cytologically diagnosed. Only UBM information was obtained from four small non-growing lesions consistent with iris nevi. Four ciliary body pigmented tumors elevated by 4 to 6 mm were examined both with UBM and immersion standardized echography (Cinescan S, Quantel Medical). UBM showed high reflective iris subsurface in all iris nevi. Of the FNA verified iridociliary pigmented tumors, the iris pigment epithelium was found to be indistinct in iridociliary melanoma only. Iridociliary melanoma, nevus and metastatic carcinoma showed angle invasion and similar acoustic pattern and reflectivity on UBM examination. Multiple iris masses were imaged in lymphoma and metastatic carcinoma. Two ciliary body low to medium reflective and two ciliary body high reflective tumors on standardized echography, consistent with ciliary body melanoma and melanocytoma, were plagued or observed for four and thirteen years; UBM was informative for superficial margins and angle invasion only. In conclusion, UBM was very useful for location and size of small anterior uveal tumors, but could not help in tissue differentiation of iridociliary tumors. Multiple iris lesions were found in iridociliary lymphoma or metastatic carcinoma only. Standardized echography allowed for tissue differentiation in at least 4-mm thick ciliary body pigmented tumors

Intracorneal blood removal six weeks after canaplasty

In a 71-year-old patient with bilateral open-angle glaucoma, intracorneal blood was found after a canaloplasty procedure in the right eye. Six weeks after surgery on ultrasound biomicroscopy examination, liquified blood and blood clots could be observed nasally in the deep corneal stroma close to the Descemet's membrane. The intracorneal blood was washed out with balanced saline solution following deep corneal incision and lamellar dissection. Descemet's membrane was reattached with air injection into the anterior chamber. Two months later, visual acuity improved to 20/50, intraocular pressure was 16 mm Hg without medication and confocal microscopy showed deep stromal folds and limited endothelial cell loss. Viscoelastic entering the cornea at Schwalbe's line and reflux of blood from the collector channels to Schlemm's canal can account for corneal hematoma. Even six weeks after canaloplasty, successful blood removal could be fulfilled without rupturing the Descemet's membrane

High-resolution ultrasonography in central serous chorioretinopathy

PURPOSE: To investigate the use of high-resolution ultrasonography for detecting choroidal layer abnormalities in eyes with central serous chorioretinopathy (CSC). DESIGN: Prospective observational case series. METHOD: Optical coherence tomography (OCT) and high-resolution ultrasonography with a 20-MHz immersion probe were performed bilaterally in 10 patients, of whom 5 were affected by unilateral active CSC and 5 by unilateral cystoid macular edema (CME). Ten age-matched control subjects were also investigated. RESULTS: Both OCT and high-resolution ultrasonography showed a macular elevation in eyes with CSC and CME. High-resolution ultrasonography has shown evidence of a nonechogenic linear band under the retinal pigment epithelium in patients affected by CSC. This could be found in neither patients with CME or in control subjects. CONCLUSION: High-resolution ultrasonography can detect a nonechogenic space consistent with hyperpermeability of choroidal capillaries in eyes with active CSC. Shadowing by an altered retinal pigment epithelium cannot be ruled out, however

Long-term follow-up with optical coherence tomography and microperimetry in eyes with metamorphopsia after macula-off retinal detachment repair

PURPOSE: to report the long-term sequential morphological and functional results in eyes with metamorphopsia after retinal detachment (RD) repair. PATIENTS AND METHODS: in six eyes of six patients aged 58.7 \ub1 11.0 years with metamorphopsia after successful buckling surgery for macula-off RD, best-corrected visual acuity (BCVA), fundus biomicroscopy, Amsler grid test, time-domain optical coherence tomography (TD-OCT) and central 12\ub0 microperimetry (MP-1) were performed at months 1, 3, 6, 12, and 18. At 5 to 6 years after surgery all patients underwent also spectral domain (SD)-OCT. RESULTS: three eyes slowly recovered pre-RD BCVA. In the remaining three eyes-with good final BCVA-the interrupted junction line between photoreceptor cell inner and outer segments (IS/OS) was progressively less evident after RD surgery; and the external limiting membrane was preserved on SD-OCT examination. In all eyes post-operative metamorphopsia faded with time, but fully disappeared in 6 years only in two eyes without photoreceptor abnormalities. One of the two eyes with subretinal fluid up to 6 months and IS/OS disruption had central dense scotoma with relatively unstable fixation on MP-1 and persistent metamorphopsia. Macular sensitivity (MS) increased from 9.7 \ub1 7.1 at month 1 to 13.5 \ub1 5.6 dB at the final check, and was weakly (r=0.33) correlated with post-operative BCVA and OCT abnormalities. CONCLUSION: long-standing metamorphopsia can occur after successful macula-off RD repair even without detectable photoreceptor disruption on OCT. Post-operative BCVA recovery weakly correlates with increasing MS, and late restoration of the photoreceptor layer may be observed. PMID: 20948555 [PubMed - indexed for MEDLINE

Bilateral optic neuropathy and intraretinal deposits after pars plana vitrectomy in amyloidosis

Pathological examination of material from a nonextensive pars plana vitrectomy (PPV) in the right eye provided a diagnosis of nonfamilial amyloidosis in a 68-year-old woman, who presented with bilateral glass wool-like vitreous opacities. Genetic testing revealed a Tyr114Cys mutation in the transthyretin gene. Six months after PPV, perimetry showed intense constriction with a temporal island and central scotoma in the right eye. An extensive PPV was performed in the left eye. Spectral domain optical coherence tomography evidenced bilateral epimacular amyloid deposits and unreported reflective spots within the inner retina. One year later, visual acuity had decreased to 20/400 in the left eye, with mild vitreous opacity, pale cupped optic disc and inferior altitudinal field defect. Bilateral diurnal intraocular pressure, transiently increased after PPV, never exceeded 16 mmHg with medication. Our patient presented optic nerve blood supply impairment, due to amyloidosis, which caused optic atrophy. Epiretinal and intraretinal deposit detection could aid in diagnosing patients with suspected amyloidosis