Brian J. Lee

Observation of contemporaneous optical radiation from a gamma-ray burst

The origin of γ-ray bursts (GRBs) has been enigmatic since their discovery. The situation improved dramatically in 1997, when the rapid availability of precise coordinates, for the bursts allowed the detection of faint optical and radio afterglows — optical spectra thus obtained have demonstrated conclusively that the bursts occur at cosmological distances. But, despite efforts by several groups, optical detection has not hitherto been achieved during the brief duration of a burst. Here we report the detection of bright optical emission from GRB990123 while the burst was still in progress. Our observations begin 22 seconds after the onset of the burst and show an increase in brightness by a factor of 14 during the first 25 seconds; the brightness then declines by a factor of 100, at which point (700 seconds after the burst onset) it falls below our detection threshold. The redshift of this burst, z ≈ 1.6 (refs 8, 9), implies a peak optical luminosity of 5× 1049 erg s−1. Optical emission from γ-ray bursts has been generally thought to take place at the shock fronts generated by interaction of the primary energy source with the surrounding medium, where the γ-rays might also be produced. The lack of a significant change in the γ-ray light curve when the optical emission develops suggests that the γ-rays are not produced at the shock front, but closer to the site of the original explosion.

Prompt Optical Observations of Gamma-Ray Bursts

The Robotic Optical Transient Search Experiment (ROTSE) seeks to measure simultaneous and early afterglow optical emission from gamma-ray bursts (GRBs). A search for optical counterparts to six GRBs with localization errors of 1 deg2 or better produced no detections. The earliest limiting sensitivity is mROTSE>13.1 at 10.85 s (5 s exposure) after the gamma-ray rise, and the best limit is mROTSE>16.0 at 62 minutes (897 s exposure). These are the most stringent limits obtained for the GRB optical counterpart brightness in the first hour after the burst. Consideration of the gamma-ray fluence and peak flux for these bursts and for GRB 990123 indicates that there is not a strong positive correlation between optical flux and gamma-ray emission.

A Search for Early Optical Emission from Short- and Long-Duration Gamma-Ray Bursts

Gamma-ray bursts of short duration may harbor vital clues to the range of phenomena producing bursts. However, recent progress from the observation of optical counterparts has not benefited the study of short bursts. We have searched for early optical emission from six gamma-ray bursts using the telephoto array on the Robotic Optical Transient Search Experiment I. Three of these events were of short duration, including GRB 980527, which is among the brightest short bursts yet observed. The data consist of unfiltered CCD optical images taken in response to Burst and Transient Source Experiment triggers delivered via the GRB Coordinates Network. For the first time, we have analyzed the entire 16° × 16° field covered for five of these bursts. In addition, we discuss a search for the optical counterpart to GRB 000201, a well-localized long burst. Single-image sensitivities range from 13th to 14th magnitude around 10 s after the initial burst detection and from 14 to 15.8 mag 1 hr later. No new optical counterparts were discovered in this analysis suggesting short-burst optical and gamma-ray fluxes are uncorrelated.

Risk Factors for Developing Thyroid-Associated Ophthalmopathy Among Individuals With Graves Disease

IMPORTANCE Thyroid-associated ophthalmopathy (TAO) is a common and debilitating manifestation of Graves disease (GD). Presently little is known about factors that may increase the risk of developing TAO among patients with GD. OBJECTIVE To identify risk factors associated with the development of TAO among individuals with newly diagnosed GD. DESIGN, SETTING, AND PARTICIPANTS In this longitudinal cohort study, all beneficiaries 18 years of age or older with newly diagnosed GD who were continuously enrolled in a large nationwide US managed care network and who visited an eye care professional 1 or more times from 2001 to 2009 were identified. International Classification of Diseases, Ninth Revision, Clinical Modification billing codes were used to identify those who developed manifestations of TAO. Multivariable Cox regression was used to determine the hazard of developing TAO among persons with newly diagnosed GD, with adjustment for sociodemographic factors, systemic medical conditions, thyrotropin levels, and medical and surgical interventions for management of hyperthyroidism. MAIN OUTCOMES AND MEASURES Manifestations of TAO measured by hazard ratios (HRs) with 95% CIs. RESULTS Of 8404 patients with GD who met the inclusion criteria, 740 (8.8%) developed TAO (mean follow-up, 374 days since initial GD diagnosis). After adjustment for potential confounders, surgical thyroidectomy, alone or in combination with medical therapy, was associated with a 74% decreased hazard for TAO (adjusted HR, 0.26 [95% CI, 0.12-0.51]) compared with radioactive iodine therapy alone. Statin use (for ≥60 days in the past year vs <60 days or nonuse) was associated with a 40% decreased hazard (adjusted HR, 0.60 [CI, 0.37-0.93]). No significant association was found for the use of nonstatin cholesterol-lowering medications or cyclooxygenase 2 inhibitors and the development of TAO. CONCLUSIONS AND RELEVANCE If prospective studies can confirm our finding that a thyroidectomy and statin use are associated with substantially reduced hazards for TAO among patients with GD, preventive measures for this burdensome manifestation of GD may become a reality.

Exposed porous orbital implants treated with simultaneous secondary implant and dermis fat graft.

Purpose: To describe a technique for simultaneous secondary orbital implantation and dermis fat graft placement for exposed porous implants with significant conjunctival insufficiency. Design: Retrospective review of 4 consecutive cases. Methods: Charts were reviewed for type and size of exposed porous implant, size of conjunctival defect, history of previous reconstruction for exposure, size and type of implant placed, follow-up interval, complications, ability to retain prosthesis, and cosmesis. Results: Four patients underwent simultaneous dermis fat graft placement and secondary implantation for exposed and completely avascular orbital implants. The rectus muscles were advanced over the new implant to act as the host bed for the dermis fat graft. All patients tolerated a new prosthesis well, with adequate motility and cosmesis. Conclusions: Simultaneous secondary implantation and dermis fat graft placement may adequately address avascular porous implant exposure with significant conjunctival insufficiency.

Periocular Epithelioid Hemangioma: Response to Bevacizumab and Vascular Pathogenesis

Epithelioid hemangioma (EH), also known as angiolymphoid hyperplasia with eosinophilia, may affect the eyelids and orbit, mimic idiopathic orbital inflammation, and respond poorly to corticosteroids.1,2 We describe a patient with chronic, bilateral orbital EH unresponsive to corticosteroids. Histopathologic analysis showed lobular vascular proliferations containing plump endothelial cells with surrounding mixed leukocytic infiltrates diagnostic of EH.3 Successful treatment consisted of surgical debulking and intralesional bevacizumab. Periocular EH lesions of 2 additional patients treated by debulking also showed prominent lobular vascular proliferations, highlighting them as the basis of this benign tumor. We conclude that EH is primarily a vascular tumor that can respond to bevacizumab.

An Untriggered Search for Optical Bursts

We present an untriggered search for optical bursts with the Robotic Optical Transient Search Experiment (ROTSE-I) telephoto array. Observations were taken that monitor an effective 256 deg2 field continuously over 125 hr to mROTSE = 15.7. The uniquely large field, moderate limiting magnitude, and fast cadence of ~10 minutes permit transient searches in a new region of sensitivity. Our search reveals no candidate events. To quantify this result, we simulate potential optical bursts with peak magnitude mp at t = 10 s, which fade as f = , where αt < 0. Simple estimates based on observational evidence indicate that a search of this sensitivity begins to probe the possible region occupied by gamma-ray burst (GRB) orphan afterglows. Our observing protocol and image sensitivity result in a broad region of high detection efficiency for light curves to the bright and slowly varying side of a boundary running from [αt,mp] = [-2.0, 6.0] to [-0.3, 13.2]. Within this region, the integrated rate of brief optical bursts is less than 1.1 × 10-8 s-1 deg-2. At ~22 times the observed GRB rate from BATSE, this suggests a limit on θopt/θγ 5, where θopt and θγ are the optical and gamma-ray collimation angles, respectively. Several effects might explain the absence of optical bursts, and a search of the kind described here but more sensitive by about 4 mag should offer a more definitive probe.

External dacryocystorhinostomy outcomes in sarcoidosis patients

Purpose: To determine surgical outcomes after external dacryocystorhinostomy (DCR) surgery in patients with sarcoidosis. Methods: We retrospectively reviewed the charts of all patients with sarcoidosis who underwent external DCR surgery between January 2001 and January 2010. Clinical data reviewed included patient demographics, immunosuppressive therapies, biopsy results, use of intraoperative triamcinolone, and postoperative outcomes and complications. Success was defined as resolution of epiphora. Results: External DCR was performed on 13 sides of 9 patients with sarcoidosis. Four patients were systemically immunosuppressed with methotrexate or plaquenil, and 4 patients used inhaled corticosteroids only. Intraoperative biopsy in 10 cases (9 patients) revealed non-necrotizing granulomatous inflammation (8 cases) and chronic inflammation (2 cases). Silicone stents were removed at a mean of 2.9 months. Initial DCR surgery was successful in 10 of 13 (87%) surgeries with an average follow up of 31 months (range, 14 to 48 months). None of the 5 surgeries (4 patients) with intralesional triamcinolone injections failed, compared with 3 of 8 (38%) surgeries without intralesional triamcinolone. Of the 3 failures, 2 early failures (3 months) were successfully treated with balloon catheter dilation. In the one patient with a late failure (47 months), subsequent balloon catheter dilation failed. All 3 patients who experienced failures used inhaled corticosteroids only. In contrast, 4 of the 6 patients with successful surgery were systemically immunosuppressed. Complications such as punctal erosion, wound necrosis, or cerebrospinal fluid leak did not occur. Conclusions: External DCR surgery successfully treats nasolacrimal duct obstruction associated with sarcoidosis. Intralesional triamcinolone may improve the success rate without added complications. Long-term success may be less in patients not receiving systemic immunosuppressive therapy.

Results from Gamma-Ray Optical Counterpart Search Experiment: A Real Time Search for Gamma-Ray Burst Optical Counterparts

The Gamma-Ray Optical Counterpart Search Experiment (GROCSE) has searched for contemporaneous optical counterparts to gamma-ray bursts (GRBs) using an automated rapidly slewing wide field of view optical telescope at Lawrence Livermore National Laboratory. The telescope was triggered in real time by the Burst and Transient Source Experiment (BATSE) data telemetry stream as processed and distributed by the BATSE COordinates DIstribution NEtwork (BACODINE). GROCSE recorded sky images for 28 GRB triggers between 1994 January and 1996 June. The analysis of the 12 best events is presented here, half of which were recorded during detectable gamma-ray emission. No optical counterparts have been detected to limiting magnitudes mV ≤ 8.5 despite nearly complete coverage of burst error boxes.

External dacryocystorhinostomy surgery in patients with Wegener granulomatosis.

Purpose: To determine surgical outcomes after external dacryocystorhinostomy (DCR) surgery in patients with Wegener granulomatosis (WG). Methods: The authors retrospectively reviewed the charts of consecutive patients with WG who underwent primary or secondary external DCR surgery between January 2001 and January 2010. Clinical data reviewed included patient demographics, systemic disease involvement and immunosuppression therapy, intraoperative biopsy findings, and postoperative outcomes and complications. Success was defined as resolution of epiphora. Results: Sixteen primary external DCRs were performed on 9 patients with WG, and 2 secondary external DCRs were performed on 2 patients. At the time of surgery, all patients with WG were on systemic immunosuppressive agents including methotrexate, rapamycin, sirolimus, tacrolimus, azathioprine, cyclophosphamide, rituximab, and prednisone, and no patients received increased corticosteroids after surgery. Intraoperative biopsy in patients with WG revealed chronic inflammation (4 patients) and fibrosis (1 patient). Silicone stents were removed at an average of 5.8 months (range, 3–12 months). All surgeries were successful in resolving epiphora with an average follow up of 3.5 years (range, 10 months–6 years) and no complications. Conclusions: Primary and secondary external DCR surgery successfully treats nasolacrimal duct obstruction in patients with WG on systemic immunosuppression.