ABSTRACT
A new tangential gamma-ray spectrometer has been developed for fast ion measurements in deuterium and deuterium-tritium plasmas of the Joint European Torus (JET). The instrument is based on a LaBr3 crystal with a photo-multiplier tube and replaces a pre-existing bismuth germanate detector, providing enhanced energy resolution and a counting rate capability in the MHz range. The line of sight is equipped with a LiH attenuator, which reduces the background due to 14 MeV neutron interactions with the crystal by more than two orders of magnitude and enables the observation of gamma-ray emission from confined α particles in JET deuterium-tritium plasmas. Thanks to its tangential line of sight, the detector can distinguish co- and counter-passing ions. The performance of the instrument is demonstrated through the results of recent JET fast ion experiments in deuterium plasmas.
Subject(s)
Intracranial Hemorrhages/complications , Retinal Hemorrhage/complications , Vision Disorders/diagnosis , Vision Disorders/etiology , Vitreous Hemorrhage/complications , Calcinosis/complications , Calcinosis/diagnosis , Delayed Diagnosis , Female , Fluorescein Angiography , Humans , Intracranial Hemorrhages/diagnosis , Middle Aged , Retinal Hemorrhage/diagnosis , Syndrome , Time Factors , Vitreous Hemorrhage/diagnosisABSTRACT
INTRODUCTION: The purpose of our study was to evaluate the progression of lamellar corneal grafts after endothelial keratoplasty by Descemet stripping automated endothelial keratoplasty (DSAEK) and the effect of their characteristics on the clinical and functional results. MATERIALS AND METHODS: This was a prospective study in which 74 patients who had undergone endothelial keratoplasty by DSAEK were included. The corneal grafts were obtained from a French tissue bank and were delivered in a preservation medium containing a deturgescent agent (Corneajet® or Stemalpha 3®). Pachymetry of the corneal graft was measured ex vivo by ultrasonic pachymetry prior to dissection, then after the 1st or 2nd cut as necessary. Corrected visual acuity in logMAR, total graft pachymetry, measured by anterior segment OCT (Spectralis® HRA+SDOCT, Heidelberg engineering, Inc., Heidelberg, Germany) and corneal density (Pentacam®, Oculus, Inc., Wetzlar, Germany) were obtained for each patient preoperatively, at D5, M1, M3, M6, M9 and M12. RESULTS: Overall, 74 corneal grafts, from donors of mean age 69.7±13.3 years (37 to 92 years) were transplanted into 67 patients aged 70.3±12.1 years. Predissection pachymetry was statistically significantly thicker in the case of short deturgescence time (r=-0.383, P=0.001). For the same deturgescence time, predissection pachymetry was statistically significantly thicker in the Stemalpha 3® medium (691±89µm for Corneajet® vs. 760±100µm for Stemalpha 3®, P=0.01), with the same final pachymetry (168±31µm vs. 166±25µm, P=0.833). Graft pachymetry and total corneal pachymetry decreased significantly between the preoperative measurement and M12 (168±29µm vs. 92±57µm, P=0.0008 et 665±124µm vs. 566±73µm, P=0.027 respectively). Preoperative endothelial cell density (2938±418 cells/mm2) did not correlate with postoperative visual acuity. There was a positive correlation between visual acuity at D5 and donor age (r=0.3, P=0.04). Postoperative visual acuity correlated positively with preoperative visual acuity (P<0.05). Corneal densitometry was statically higher than normal postoperative densitometry. Corneal density at M1 correlated positively with time since obtaining the donor tissue (r=0.373, P=0.043). There was no significant difference between the sub-groups of over or under 130µm. Seven patients experienced graft failure with no statistically significant graft risk factor. DISCUSSION: The preservation medium affects predissection pachymetry with no consequence on clinical results. In our study, preoperative visual acuity and donor age were correlated with visual acuity after DSAEK. CONCLUSION: Although donor age was associated with better visual acuity at D5, the other donor characteristics had no effect on clinical results.
Subject(s)
Corneal Diseases/diagnosis , Corneal Diseases/surgery , Descemet Stripping Endothelial Keratoplasty/methods , Endothelium, Corneal/transplantation , Tissue Donors , Adult , Aged , Aged, 80 and over , Corneal Pachymetry , Corneal Transplantation/methods , Female , Follow-Up Studies , France , Graft Survival , Humans , Male , Middle Aged , Prognosis , Treatment Outcome , Young AdultABSTRACT
In order to complete the exploitation of the JET ITER-like Wall and to take full benefit from deuterium-tritium experiments on JET, a set of diagnostic system refurbishments or upgrades is in progress. These diagnostic enhancements focus mainly on neutron, gamma, fast ions, instabilities, and operations support. These efforts intend to provide better spatial, temporal, and energy resolution while increasing measurement coverage. Also previously non-existing capabilities, such as Doppler reflectometry is now available for scientific exploitation. Guaranteeing diagnostic reliability and consistency during the expected DT conditions is also a critical objective of the work and systems being implemented. An overview of status and scope of the ongoing projects is presented.
ABSTRACT
PURPOSE: To evaluate the effectiveness of a hyperosmolar medication in corneal edema. METHODS: This was a prospective randomized study, performed in patients with post-operative corneal edema. Two groups were created: group 1 treated with hypertonic eye drops of 5% sodium chloride with 0.15% sodium hyaluronate in addition to the usual post-operative treatment for 1 month; group 2 without treatment for edema. Visual acuity, pachymetry and corneal density were measured at 1 day, 1 week, 1 month, 3 months and 6 months following surgery. RESULTS: Forty-four patients were included in group 1 and 42 in group 2. Visual acuity was significantly better in group 1 than in group 2 at 7 days (0.84 logMAR vs 1.55 logMAR, P=0.019 CI 95% [-1.298;-0.128]) and was no longer different at one month, three and six months. Pachymetry decreased significantly in 7 days in group 1 (decrease of 17%, P=0.04, CI 95% [1.987; 258.305]), compared to group 2 (P=0.8, CI 95% [-132.9; 161.8]), but the difference between the 2 groups was not statistically significant (P=0.11, CI 95% [-16; 19.1]). Corneal density was also not significantly different between the two groups. CONCLUSION: Five percent sodium chloride hypertonic eye drops show a statistically significant reduction in post-operative corneal edema as shown by the improvement in visual acuity at one week and the downward trend in pachymetry.
