Lens Mass Research Articles

TDCOSMO

Strong-lensing time delays enable the measurement of the Hubble constant (H0) independently of other traditional methods. The main limitation to the precision of time-delay cosmography is mass-sheet degeneracy (MSD). Some of the previous TDCOSMO analyses broke the MSD by making standard assumptions about the mass density profile of the lens galaxy, reaching 2% precision from seven lenses. However, this approach could potentially bias the H0 measurement or underestimate the errors. For this work, we broke the MSD for the first time using spatially resolved kinematics of the lens galaxy in RXJ1131−1231 obtained from the Keck Cosmic Web Imager spectroscopy, in combination with previously published time delay and lens models derived from Hubble Space Telescope imaging. This approach allowed us to robustly estimate H0, effectively implementing a maximally flexible mass model. Following a blind analysis, we estimated the angular diameter distance to the lens galaxy Dd = 865−81+85 Mpc and the time-delay distance DΔt = 2180−271+472 Mpc, giving H0 = 77.1−7.1+7.3 km s−1 Mpc−1 – for a flat Λ cold dark matter cosmology. The error budget accounts for all uncertainties, including the MSD inherent to the lens mass profile and line-of-sight effects, and those related to the mass–anisotropy degeneracy and projection effects. Our new measurement is in excellent agreement with those obtained in the past using standard simply parametrized mass profiles for this single system (H0 = 78.3−3.3+3.4 km s−1 Mpc−1) and for seven lenses (H0 = 74.2−1.6+1.6 km s−1 Mpc−1), or for seven lenses using single-aperture kinematics and the same maximally flexible models used by us (H0 = 73.3−5.8+5.8 km s−1 Mpc−1). This agreement corroborates the methodology of time-delay cosmography.

Testing cosmology with double source lensing

Double source lensing provides a dimensionless ratio ofdistance ratios, a “remote viewing” of cosmology throughdistances relative to the gravitational lens, beyond theobserver. We use this to test the cosmological framework,particularly with respect to spatial curvature and thedistance duality relation. We derive a consistency equationfor constant spatial curvature, allowing not only theinvestigation of flat vs curved but of theFriedmann-Lemaître-Robertson-Walker framework itself.For distance duality, we demonstrate that the evolution ofthe lens mass profile slope must becontrolled to ≳ 5 times tighter fractional precisionthan a claimed distance duality violation.Using LensPop forecasts of double source lensingsystems in Euclid and LSST surveys we also explore constraintson dark energy equation of state parameters and anyevolution of the lens mass profile slope.

Cellular activity of autophagy and multivesicular bodies in lens fiber cells during early lens development in rbm24a mutant of zebrafish: Ultrastructure analysis

Use of zebrafish as animal model for various diseases during early developmental stages has been exponentially increased with the aim to achieve the best representative results in this transparent fish. Recent studies documented that Rbm24a mutant causes cataract formation and resulted in blindness using the zebrafish model. Therefore, correct interpretation of studies that aimed for molecular approaches, a description of comparative and in-depth analysis of development of lens in wildtype and mutant is crucial to obtain the correct conclusion. In this study, we use a gold standard method the Transmission Electron Microscopy (TEM) to analysis the lens development in rbm24a mutant zebrafish. Firstly, we compare the cellular structures at 16–20 h post fertilization (hpf), the lens placode in ectoderm indicated delay lens development in rbm24a mutant than wildtype (siblings) zebrafish. At 33 hpf, loosely appeared lens fiber cells showed heterogenous electron density with numbers of mitochondria in lens of rbm24a mutant, revealed the influence of gene mutation in lens development. A detail ultrastructure of lens of rbm24a mutant also presented at 33 hpf. Comparatively in wildtype (siblings) at 33 hpf, lens exhibited homogenous electron density in tightly packed lens fiber cells with few mitochondria. Furthermore, to characterize the lens in rbm24a mutant we obtained data of cellular structures on 25 hpf and 1.5 days’ post fertilization (dpf). At 25 hpf in mutant zebrafish, the detached solid sphere lens mass from ectoderm showed karyorrhexis, mitophagy and vesicles (also multivesicular bodies), these cellular structures supposed to hamper the development of future fiber cells. Moreover, at 1.5 dpf in mutant, nuclear excisosome, multilamellar bodies and irregular shaped mitochondria in heterogenous electron dense cytoplasm of lens fiber cells, collectively shown affected lens transparency. In summary the ultrastructure results of lens of rbm24a mutant zebrafish expand our knowledge and give reflection of different cellular activities like autophagy, apoptosis, vesicles (multivesicular bodies) and nuclear excisosomes which play their role in transparency achievement.

Stellar prospects for FRB gravitational lensing

ABSTRACTGravitational lensing of fast radio bursts (FRBs) offers an exciting avenue for several cosmological applications. However, it is not yet clear how many such events future surveys will detect nor how to optimally find them. We use the known properties of FRBs to forecast detection rates of gravitational lensing on delay time-scales from microseconds to years, corresponding to lens masses spanning 15 orders of magnitude. We highlight the role of the FRB redshift distribution on our ability to observe gravitational lensing. We consider cosmological lensing of FRBs by stars in foreground galaxies and show that strong stellar lensing will dominate on microsecond time-scales. Upcoming surveys such as DSA-2000 and CHORD will constrain the fraction of dark matter in compact objects (e.g. primordial black holes) and may detect millilensing events from intermediate mass black holes (IMBHs) or small dark matter halos. Coherent all-sky monitors will be able to detect longer-duration lensing events from massive galaxies, in addition to short time-scale lensing. Finally, we propose a new application of FRB gravitational lensing that will measure directly the circumgalactic medium of intervening galaxies.

A Binary Origin for the First Isolated Stellar-mass Black Hole Detected with Astrometric Microlensing

The Milky Way is believed to host hundreds of millions of quiescent stellar-mass black holes (BHs). In the last decade, some of these objects have been potentially uncovered via gravitational microlensing events. All these detections resulted in a degeneracy between the velocity and the mass of the lens. This degeneracy has been lifted, for the first time, with the recent astrometric microlensing detection of OB110462. However, two independent studies reported very different lens masses for this event. Sahu et al. inferred a lens mass of 7.1 ± 1.3 M ⊙, consistent with a BH, while Lam et al. inferred 1.6–4.2 M ⊙, consistent with either a neutron star or a BH. Here, we study the landscape of isolated BHs formed in the field. In particular, we focus on the mass and center-of-mass speed of four subpopulations: isolated BHs from single-star origin, disrupted BHs of binary-star origin, main-sequence stars with a compact object companion, and double compact object mergers. Our model predicts that most (≳70%) isolated BHs in the Milky Way are of binary origin. However, noninteractions lead to most massive BHs (≳15–20 M ⊙) being predominantly of single origin. Under the assumption that OB110462 is a free-floating compact object, we conclude that it is more likely to be a BH originally belonging to a binary system. Our results suggest that low-mass BH microlensing events can be useful to understand binary evolution of massive stars in the Milky Way, while high-mass BH lenses can be useful to probe single stellar evolution.

Observability of lensing of gravitational waves from massive black hole binaries with LISA

The gravitational waves emitted by massive black hole binaries in the Laser Interferometer Space Antenna (LISA) band can be lensed. Wave-optics effects in the lensed signal are crucial when the Schwarzschild radius of the lens is smaller than the wavelength of the radiation. These frequency-dependent effects can enable us to infer the lens parameters, possibly with a single detection alone. In this work, we assess the observability of wave-optics effects with LISA by performing an information-matrix analysis using analytical solutions for both point-mass and singular isothermal sphere lenses. We use gravitational-waveform models that include the merger, ringdown, higher harmonics, and aligned spins to study how waveform models and source parameters affect the measurement errors in the lens parameters. We find that previous work underestimated the observability of wave-optics effects and that LISA can detect lensed signals with higher impact parameters and lower lens masses.

OGLE-2018-BLG-0584 and KMT-2018-BLG-2119: Two microlensing events with two lens masses and two source stars

Aims. We conducted a systematic investigation of the microlensing data collected during the previous observation seasons for the purpose of re-analyzing anomalous lensing events with no suggested plausible models. Methods. We found that two anomalous lensing events, OGLE-2018-BLG-0584 and KMT-2018-BLG-2119, cannot be explained with the usual models based on either a binary-lens single-source (2L1S) or a single-lens binary-source (1L2S) interpretation. We tested the feasibility of explaining the light curves of the events with more sophisticated models by adding either an extra lens (3L1S model) or a source (2L2S model) component to the 2L1S lens system configuration. Results. We find that a 2L2S interpretation explains the light curves of both events well and that for each event there are a pair of solutions resulting from the close and wide degeneracy. For the event OGLE-2018-BLG-0584, the source is a binary composed of two K-type stars and the lens is a binary composed of two M dwarfs. For KMT-2018-BLG-2119, the source is a binary composed of two dwarfs of G and K spectral types and the lens is a binary composed of a low-mass M dwarf and a brown dwarf.

Light Curves and Polarizations of Gravitationally Lensed Kilonovae

Kilonovae are generally believed to originate from the ejecta of binary neutron stars (NSs) or black hole–NS mergers. Free neutrons might be retained in the outermost layer of the ejecta to produce a precursor via β decay. During the propagation of kilonovae to observers, a small percentage of them might be gravitationally lensed by foreground objects. In this paper, three lens models, i.e., the point-mass model, the singular isothermal sphere (SIS) model, and the Chang–Refsdal model, were taken into consideration to explore the light curves and polarizations of gravitationally lensed kilonovae. We found that, if the time delay between two images exceeds the ejecta-heating timescale for the lens mass ∼1010 M ⊙ in the SIS model, a tiny bump-like signal will be generated in the light curve, and the total luminosity will be magnified in all cases. The polarization of lensed kilonovae is significantly enhanced in most cases. Future detections of lensed kilonovae will impose constraints on the morphology of the ejecta and aid in the determination of the nature of compact object mergers and the search for strong gravitational lenses.

Evolving Morphology of Resolved Stellar Einstein Rings

We consider strong gravitational lensing by nearby stars. Using our wave-optical treatment of lensing phenomena, we study Einstein rings that may form around nearby stellar lenses. It is remarkable that these rings are bright and large enough to be detected and resolved by existing instruments. Such lensing events have durations of hours or days, with peak light amplification lasting for several minutes. Many such events may be predicted using the Gaia astrometric catalog. Serendipitous discoveries are also possible. Fortuitous alignments can be used to confirm or discover and study exoplanets. For lenses that have dense stellar regions in their background, these events may occur several time a year, warranting their continuous or recurrent monitoring. Resolved imaging and spectroscopy of the evolving morphology of an Einstein ring offers knowledge about both the lens and the source. The angular size of the Einstein ring amounts to a direct measurement of the lens mass. The changing orientation of the major and minor images of the source offers astrometric information related to the mutual orientation of the objects. The event duration, when the full ring is present, helps to determine the source’s size. The sky position of planetary lensing events constrains the planet’s orbit. Spectroscopy of the ring allows for direct investigations of the source. The frequency and predictability of these events and the wealth of information that can be obtained by imaging motivate observational campaigns using existing facilities and/or construction of new instruments dedicated to the search and study of Einstein rings that are forming around nearby stars. As a specific example, we consider a predicted 2028 lensing of a red giant by α Centauri A and discuss the relevant science campaign.

Photometric redshift estimation of strongly lensed galaxies

Context.Around 105strongly lensed galaxies are expected to be discovered with upcoming wide-field surveys such asEuclidand the LSST. Utilising these large samples to study the inner structure of lens galaxies requires source redshifts, which are needed to turn lens models into mass measurements. However, obtaining spectroscopic source redshifts for large samples of strong lenses is prohibitive with the current capacity of spectroscopic facilities.Aims.As an alternative to spectroscopy, we study the possibility of obtaining source photometric redshifts (photo-zs) for large samples of strong lenses. We pay particular attention to the problem of blending between the lens and the source light.Methods.Our strategy consists of deblending the source and lens light by simultaneously modelling the lens galaxy and the background source in all available photometric bands, and then feeding the derived source colours to a template-fitting photo-zalgorithm. We describe the lens and the source light with a Sérsic profile, and the lens mass with a singular isothermal ellipsoid. We first test our approach on a simulated sample of lenses. Then, we apply it to 23 real systems with broad-band photometry from the Hyper Suprime-Cam survey.Results.We identify the deviations of the lens light from a Sérsic profile and the contrast between the lens and source image as the main drivers of the source colour measurement error. Although the former is challenging to measure directly for real lenses, we find the latter to be sufficient for evaluating the accuracy of a measured source colour. We split the real sample based on the ratio Λ of the lens to source surface brightness measured at the image locations. In the Λ < 1 regime, the photo-zoutlier fraction is 20%, and the accuracy of photo-zestimation is limited by the performance of the template-fitting process. In the opposite regime, the photo-zoutlier fraction is 75%, and the errors from the source colour measurements dominate the photo-zuncertainty.Conclusions.Measuring source photo-zs for lenses with Λ < 1 poses no particular challenges compared to the isolated galaxy case. For systems with significant lens light contamination, however, improvements in the description of the surface brightness distribution of the lens are required: a single Sérsic model is not sufficiently accurate.

Detection of H i 21 cm emission from a strongly lensed galaxy at z ∼ 1.3

ABSTRACT We report the first 5σ detection of H i 21 cm emission from a star-forming galaxy at redshift z ∼ 1.3 (nearly 9 billion years ago) using upgraded Giant Metrewave Radio Telescope (uGMRT). This is the highest redshift H i detection in emission from an individual galaxy to date. The emission is strongly boosted by the gravitational lens, an early-type elliptical galaxy, at redshift z ∼ 0.13. The measured H i mass of the galaxy is $M_{\rm H\, \small {\rm I}} = (0.90 \pm 0.14 \pm 0.05) \times 10^{10}\, \mathrm{M}_{\odot }$, which is almost twice the inferred stellar mass of the galaxy, indicating an extended structure of the H i gas inside the galaxy. By fitting 2D Gaussian to the H i signal at the peak of the spectral line, we find the source to be marginally resolved with the position angle consistent with the emission being tangential to the critical curve of the lens mass distribution. This indicates that the solid angle of the approaching H i line flux comes very close to the inner lens caustic and results in very high magnification. These results, for the first time, demonstrate the feasibility of observing high-redshift H i in a lensed system with the modest amount of telescope time and open up exciting new possibilities for probing the cosmic evolution of neutral gas with existing and upcoming low-frequency radio telescopes in the near future.

Angular structure and gravitational imaging

AbstractIn gravitational imaging, the mass model for the main lensing galaxy is one of the main sources of systematic uncertainty. We use subhalo detection models with increasing levels of angular complexity in the lens mass model to analyse 100 HST mock observations. We find that perturbations of just 1% are enough to cause a 20% false positive subhalo detection rate, with order 3 multipoles having the strongest effect. The area in an observation where a substructure can be detected drops by a factor of 10 if multipoles up to 3 per cent amplitude are included in the lens model. The mass of the smallest detectable substructure however is not affected. We find a detection limit of M>108.2M⊙ at 5σ in all models. In order for strong lensing searches for dark matter objects to remain reliable in the future, angular structure beyond the elliptical power-law must be included.

A Search for Predicted Astrometric Microlensing Events by Nearby Brown Dwarfs* *Released.

Gravitational microlensing has the potential to provide direct gravitational masses of single, free-floating brown dwarfs, independent of evolutionary and atmospheric models. The proper motions and parallaxes of nearby brown dwarfs can be used to predict close future alignments with distant background stars that cause a microlensing event. Targeted astrometric follow up of the predicted microlensing events permits the brown dwarf’s mass to be measured. Predicted microlensing events are typically found via searching for a peak threshold signal using an estimate of the lens mass. We develop a novel method that finds predicted events that instead will lead to a target lens-mass precision. The main advantage of our method is that it does not require a lens-mass estimate. We use this method to search for predicted astrometric microlensing events occurring between 2014 and 2032 using a catalog of 1225 low-mass star and brown-dwarf lenses in the Solar Neighborhood of spectral type M6 or later and a background source catalog from DECaLS Data Release 9. The background source catalog extends to g = 23.95, providing a more dense catalog compared to Gaia. Our search did not reveal any upcoming microlensing events. We estimate the rate of astrometric microlensing event for brown dwarfs in the Legacy Survey and find it to be low ∼10−5 yr−1. We recommend carrying out targeted searches for brown dwarfs in front of the Galactic Bulge and Plane to find astrometric microlensing events that will allow the masses of single, free-floating brown dwarfs to be measured.

Brown dwarf companions in microlensing binaries detected during the 2016–2018 seasons

Aims. With the aim of finding microlensing binaries containing brown dwarf (BD) companions, we investigate the microlensing survey data collected during the 2016–2018 seasons. Methods. For this purpose, we first modeled lensing events with light curves exhibiting anomaly features that are likely to be produced by binary lenses. We then sorted out BD companion binary-lens events by applying the criterion that the companion-to-primary mass ratio is q ≲ 0.1. With this procedure, we identify six binaries with candidate BD companions: OGLE-2016-BLG-0890L, MOA-2017-BLG-477L, OGLE-2017-BLG-0614L, KMT-2018-BLG-0357L, OGLE-2018-BLG-1489L, and OGLE-2018-BLG-0360L. Results. We estimated the masses of the binary companions by conducting Bayesian analyses using the observables of the individual lensing events. According to the Bayesian estimation of the lens masses, the probabilities for the lens companions of the events OGLE-2016-BLG-0890, OGLE-2017-BLG-0614, OGLE-2018-BLG-1489, and OGLE-2018-BLG-0360 to be in the BD mass regime are very high with PBD > 80%. For MOA-2017-BLG-477 and KMT-2018-BLG-0357, the probabilities are relatively low with PBD = 61% and 69%, respectively.

TDCOSMO

The largest source of systematic errors in the time-delay cosmography method likely arises from the lens model mass distribution, where an inaccurate choice of model could in principle bias the value of H0. A Bayesian hierarchical framework has been proposed which combines lens systems with kinematic data, constraining the mass profile shape at a population level. The framework has been previously validated using a small sample of lensing galaxies drawn from hydro-simulations. The goal of this work is to expand the validation to a more general set of lenses consistent with observed systems, as well as confirm the capacity of the method to combine two lens populations: one which has time delay information and one which lacks time delays and has systematically different image radii. For this purpose, we generated samples of analytic lens mass distributions made of baryons+dark matter and fit the subsequent mock images with standard power-law models. Corresponding kinematics data were also emulated. The hierarchical framework applied to an ensemble of time-delay lenses allowed us to correct the H0 bias associated with model choice to find H0 within 1.5σ of the fiducial value. We then combined this set with a sample of corresponding lens systems which have no time delays and have a source at lower z, resulting in a systematically smaller image radius relative to their effective radius. The hierarchical framework has successfully accounted for this effect, recovering a value of H0 which is both more precise (σ ∼ 2%) and more accurate (0.7% median offset) than the time-delay set alone. This result confirms that non-time-delay lenses can nonetheless contribute valuable constraining power to the determination of H0 via their kinematic constraints, assuming they come from the same global population as the time-delay set.

The effect of gravitational lensing on fast transient event rates

ABSTRACT Fast cosmological transients such as fast radio bursts (FRBs) and gamma-ray bursts (GRBs) represent a class of sources more compact than any other cosmological object. As such, they are sensitive to significant magnification via gravitational lensing from a class of lenses which are not well constrained by observations today. Low-mass primordial black holes are one such candidate which may constitute a significant fraction of the Universe’s dark matter. Current observations only constrain their density in the nearby Universe, giving fast transients from cosmological distances the potential to form complementary constraints. Motivated by this, we calculate the effect that gravitational lensing from a cosmological distribution of compact objects would have on the observed rates of FRBs and GRBs. For static lensing geometries, we rule out the prospect that all FRBs are gravitationally lensed for a range of lens masses and show that lens masses greater than 10−5M⊙ can be constrained with 8000 unlocalized high-fluence FRBs at 1.4GHz, as might be detected by the next generation of FRB-finding telescopes.

First JWST observations of a gravitational lens

We present our lens mass model of SMACS J0723.3−7327, the first strong gravitational lens observed by the James Webb Space Telescope (JWST). We use data from the Hubble Space Telescope and the Multi Unit Spectroscopic Explorer (MUSE) to build our ‘pre-JWST’ lens model and then refine it with newly available JWST near-infrared imaging in our JWST model. To reproduce the positions of all multiple lensed images with good accuracy, the adopted mass parameterisation consists of one cluster-scale component, accounting mainly for the dark matter distribution, the galaxy cluster members, and an external shear component. The pre-JWST model has, as constraints, 19 multiple images from six background sources, of which four have secure spectroscopic redshift measurements from this work. The JWST model has more than twice the number of constraints: 30 additional multiple images from another 11 lensed sources. Both models can reproduce the multiple image positions very well, with a δrms of 0.​​″39 and 0.​​″51 for the pre-JWST and JWST models, respectively. The total mass estimates within a radius of 128 kpc (roughly the Einstein radius) are 7.9−0.2+0.3 × 1013 M⊙ and 8.7−0.2+0.2 × 1013 M⊙ for the pre-JWST and JWST models, respectively. We predict with our mass models the redshifts of the newly detected JWST sources, which is crucial information, especially for systems without spectroscopic measurements, for further studies and follow-up observations. Interestingly, one family detected with JWST is found to be at a very high redshift, z > 7.5 (68% confidence level), and with one image that has a lensing magnification of |μ| = 9.5−0.8+0.9, making it an interesting case for future studies. The lens models, including magnification maps and redshifts estimated from the model, are made publicly available, along with the full spectroscopic redshift catalogue from MUSE.

KMT-2017-BLG-0673Lb and KMT-2019-BLG-0414Lb: Two microlensing planets detected in peripheral fields of KMTNet survey

Aims. We investigate the microlensing data collected during the 2017–2019 seasons in the peripheral Galactic bulge fields with the aim of finding planetary signals in microlensing light curves observed with relatively sparse coverage. Methods. We first sort out lensing events with weak short-term anomalies in the lensing light curves from the visual inspection of all non-prime-field events, and then test various interpretations of the anomalies. From this procedure, we find two previously unidentified candidate planetary lensing events KMT-2017-BLG-0673 and KMT-2019-BLG-0414. It is found that the planetary signal of KMT-2017-BLG-0673 was produced by the source crossing over a planet-induced caustic, but it was previously missed because of the sparse coverage of the signal. On the other hand, the possibly planetary signal of KMT-2019-BLG-0414 was generated without caustic crossing, and it was previously missed due to the weakness of the signal. We identify a unique planetary solution for KMT-2017-BLG-0673. However, for KMT-2019-BLG-0414, we identify two pairs of planetary solutions, for each of which there are two solutions caused by the close-wide degeneracy, and a slightly less favored binary-source solution, in which a single lens mass gravitationally magnified a rapidly orbiting binary source with a faint companion (xallarap). Results. From Bayesian analyses, it is estimated that the planet KMT-2017-BLG-0673Lb has a mass of 3.7−2.1+2.2 MJ, and it is orbiting a late K-type host star with a mass of 0.63−0.35+0.37 M⊙. Under the planetary interpretation of KMT-2010-BLG-0414L, a star with a mass of 0.74−0.38+0.43 M⊙ hosts a planet with a mass of ~3.2–3.6 MJ depending on the solution. We discuss the possible resolution of the planet-xallarap degeneracy of KMT-2019-BLG-0414 by future adaptive-optics observations on 30 m class telescopes. The detections of the planets indicate the need for thorough investigations of non-prime-field lensing events for the complete census of microlensing planet samples.

Testing strong lensing subhalo detection with a cosmological simulation

ABSTRACT Strong gravitational lensing offers a compelling test of the cold dark matter paradigm, as it allows for subhaloes with masses of ∼109 M⊙ and below to be detected. We test commonly used techniques for detecting subhaloes superposed in images of strongly lensed galaxies. For the lens we take a simulated galaxy in a ∼1013 M⊙ halo grown in a high-resolution cosmological hydrodynamical simulation, which we view from two different directions. Though the resolution is high, we note the simulated galaxy still has an artificial core which adds additional complexity to the baryon dominated region. To remove particle noise, we represent the projected galaxy mass distribution by a series of Gaussian profiles which precisely capture the features of the projected galaxy. We first model the lens mass as a (broken) power-law density profile and then search for small haloes. Of the two projections, one has a regular elliptical shape, while the other has distinct deviations from an elliptical shape. For the former, the broken power-law model gives no false positives and correctly recovers the mass of the superposed small halo; however, for the latter we find false positives and the inferred halo mass is overestimated by ∼4–5 times. We then use a more complex model in which the lens mass is decomposed into stellar and dark matter components. In this case, we show that we can capture the simulated galaxy’s complex projected structures and correctly infer the input small halo.

MANAGEMENT CASE OF POST PHAKIC INTRAOCULAR LENS IMPLANT IN HIGH MYOPIA WITH COMPLICATED CATARACT AFTER VITRECTOMY: POST SURGERY CHALLENGES

Introduction: To highlight the therapeutic dilemma in managing complications in high myopia patient with complicated cataract after vitrectomy who previously had refractive surgery.
 Case Report: A 37-years old man, presented with half the right eye view was being blocked by a black curtain for one week before admission. He had a history of high myopia on both eyes and underwent phakic intraocular lens (PIOL) implantation 12 years ago. Presenting visual acuity (VA) of the right eye was hand motion (HM). Retinal detachment (RD) on inferior side, and clear lens with anterior chamber (AC) PIOL were found in the examination. Patient underwent vitrectomy, endolaser, and silicone oil in the next four days. A sudden severe pain with red-eye was found one month after surgery, intraocular pressure (IOP) was increased to 43 mmHg, the lens was white opaque with lens material seen in AC. 
 Discussion: The diagnosis of traumatic cataract and lens-particle-induced glaucoma was made. Lens mass evacuation surgery was performed after initial antiglaucoma medication. Posterior capsule rupture was found intraoperatively with only a small amount of lens mass remaining. Visual acuity result after the second surgery is still dissatisfied with the presence of rubeosis iridis, with the possibility of retinal re-detachment was still present.
 Conclusion: High myopia still poses a greater risk of ocular complications. It can be corrected by refractive surgery, with expensive cost and it will not prevent potential future ocular problems. Repeated assessment before and after refractive surgery procedure is mandatory in order to prevent sight-threatening complications of high myopia which might lead to other blinding complications.