Light curves and colours of the ejecta from Dimorphos after the DART impact.

On 26 September 2022, the Double Asteroid Redirection Test (DART) spacecraft struck Dimorphos, a satellite of the asteroid 65803 Didymos1. Because it is a binary system, it is possible to determine how much the orbit of the satellite changed, as part of a test of what is necessary to deflect an asteroid that might threaten Earth with an impact. In nominal cases, pre-impact predictions of the orbital period reduction ranged from roughly 8.8 to 17 min (refs. 2,3). Here we report optical observations of Dimorphos before, during and after the impact, from a network of citizen scientists' telescopes across the world. We find a maximum brightening of 2.29 ± 0.14 mag on impact. Didymos fades back to its pre-impact brightness over the course of 23.7 ± 0.7 days. We estimate lower limits on the mass contained in the ejecta, which was 0.3-0.5% Dimorphos's mass depending on the dust size. We also observe a reddening of the ejecta on impact.

The efficacy, sensitivity, and specificity of in vivo laser confocal microscopy in the diagnosis of meibomian gland dysfunction.

PURPOSE: To evaluate the efficacy, sensitivity and specificity of confocal microscopy (CM) parameters: meibomian gland (MG) acinar longest diameter (MGALD), MG acinar shortest diameter (MGASD), inflammatory cell density (ICD), and MG acinar unit density (MGAUD) in the diagnosis of MG dysfunction (MGD). DESIGN: Prospective, controlled, single-center study. PARTICIPANTS: Twenty MGD patients (9 males, 11 females; mean age, 63.5+/-16.5 years) and 26 age- and gender-matched control subjects (13 males, 13 females; mean age, 53.2+/-15.7 years) were recruited. METHODS: All subjects underwent slit-lamp examinations, tear film break-up time (BUT) measurements, assessment of tear evaporation rate from the ocular surface (TEROS), vital stainings, Schirmer test, meibography, MG expressibility, and CM of the MG. Data were compared between the 2 groups using the Mann-Whitney and chi-square tests. MAIN OUTCOME MEASURES: The correlation between the clinical findings of tear functions, vital staining scores, and the 4 CM parameters were tested by Spearman's correlation coefficient by rank test. Receiver operating characteristic curve technique was used to evaluate the sensitivity, specificity, and cutoff values of CM parameters. RESULTS: The mean tear film BUT, vital staining scores, TEROS values, MG expressibility, and MG dropout grades by meibography were significantly worse in MGD patients compared with controls (P<0.001). The mean values of the MGALD, MGASD, ICD, and MGAUD in MGD patients were significantly worse than those observed in the controls with CM. All CM parameters showed a strong, significant correlation with tear functions, ocular surface vital stainings, MG expressibility, and MG dropout grades. The cutoff values for MGALD, MGASD, ICD, and MGAUD in the diagnosis of MGD were 65 microm, 25 microm, 300 cells/mm2, and 70 glands/mm2, respectively. The sensitivity and specificity values of these parameters under these cutoff values were 90% and 81% for MGALD, 86% and 96% for MGASD, 100% and 100% for ICD, 81% and 81% for MGAUD. CONCLUSIONS: Confocal microscopy has the potential to diagnose the simple MGD with high sensitivity and specificity. The CM-based diagnostic parameters correlated significantly and strongly with the status of the ocular surface disease. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Strip meniscometry: a new and simple method of tear meniscus evaluation.

PURPOSE: To investigate the applicability and efficacy of a new and simple method of quantification of the volume of tear meniscus, termed "strip meniscometry," in the diagnosis of the dry eye syndromes in a prospective controlled study. METHODS: One hundred eyes of 50 patients with dry eye (19 males; 31 females) aged between 18 and 76 years (mean, 54.3 years), as well as 80 eyes of 40 normal subjects aged from 15 to 70 years (mean, 50.8 years; 12 males, 28 females) were recruited in this study. The patients and the control subjects underwent strip meniscometry for 5 seconds, tear film lipid layer interferometry, tear film break-up time measurement, and ocular surface vital staining with fluorescein and rose bengal dyes and the Schirmer-1 test. RESULTS: Strip meniscometry scores correlated with tear quantity and stability, ocular surface staining scores, and lipid layer interferometry grades and improved after 2 weeks of punctal plug occlusion. CONCLUSIONS: Strip meniscometry is a swift, noninvasive, promising new method that is expected to find application in the diagnosis and evaluation of the outcome of treatment of dry eye syndromes.

Development of Definitive and Reliable Grading Scales for Meibomian Gland Dysfunction.

PURPOSE: To develop and validate grading scales for meibomian gland dysfunction (MGD) that allow consistent diagnosis of MGD and are suitable for clinical studies. DESIGN: Development and validation study of grading scales. METHODS: Lid margin and meibomian gland photographs were taken in the multicenter, prospective cross-sectional study for MGD and control subjects. New grading scales for MGD signs (abnormal lid margin findings of vascularity, plugging of gland orifices, lid margin irregularity, lid margin thickening, partial glands, and gland dropout) in both upper and lower eyelids were developed. Three MGD experts, 3 general ophthalmologists, and 3 non-physicians independently tested the scales by evaluating photographs. The levels of interrater and intrarater agreement for each grading scale were estimated with the use of kappa statistics. RESULTS: Thirty-eight patients with MGD and 20 control subjects were enrolled and photographed. New grading scales were developed using a total of 226 photographs. The interrater kappa values for MGD experts and for general ophthalmologists and non-physicians with reference to an MGD expert ranged from 0.36 to 0.87 (median of 0.66), 0.41 to 0.73 (0.60), and 0.30 to 0.77 (0.59), respectively. Those for intrarater reliability for 2 MGD experts ranged from 0.49 to 0.93 (0.82). CONCLUSIONS: New grading scales for MGD signs were developed and found to have appropriate inter- and intrarater reliabilities for grading MGD. These grading scales are suitable for MGD diagnosis and application to multicenter trials.