A Small-Molecule Fluorescence Probe for Nuclear ATP.

Fluorescence monitoring of ATP in different organelles is now feasible with a few biosensors developed, which, however, show low sensitivity, limited biocompatibility, and accessibility. Small-molecule ATP probes that alleviate those limitations thus have received much attention recently, leading to a few ATP probes that target several organelles except for the nucleus. We disclose the first small-molecule probe that selectively detects nuclear ATP through reversible binding, with 25-fold fluorescence enhancement at pH 7.4 and excellent selectivity against various biologically relevant species. Using the probe, we observed 2.1-3.3-fold and 3.9-7.8-fold higher nuclear ATP levels in cancerous cell lines and tumor tissues compared with normal cell lines and tissues, respectively, which are explained by the higher nuclear ATP level in the mitosis phase. The probe has great potential for studying nuclear ATP-associated biology.

Significance of Measuring Lumbar Spine 3-Dimensional Computed Tomography Hounsfield Units to Predict Screw Loosening.

BACKGROUND: Osteoporosis is a well-known risk factor of screw loosening. Classically, dual-energy x-ray absorptiometry (DEXA) scan is an easy and cost-effective method of detecting bone mineral density (BMD). However, T-score on DEXA scan can be overestimated in patients with degenerative changes of the spine. Our objective was to identify correlation between Hounsfield unit (HU) measured by 3-dimensional computed tomography (3D-CT) and screw loosening. METHODS: A total of 113 patients treated with lumbosacral spinal fusion were reviewed and categorized into a screw loosening group and a normal group to compare their average values of preoperative CT HU. Screw loosening was defined as radiolucent area around screw that was thicker than 1 mm with a "double halo sign". RESULTS: There were statistically significant differences in patient age and steroid use between screw loosening and non-loosening groups. There was no significant difference in BMD or T-score between the 2 groups. However, HU values measured in axial, coronal, and sagittal images were significantly different between the 2 groups. In the receiver operating characteristic for HU values measured in CT images, the greatest area under the curve was 0.774 and that was in case of Hounsfield unit measured by axial CT images from L1 to L4. CONCLUSIONS: Preoperative CT HU is associated with screw loosening. It can be a better predictor of screw loosening than DEXA scan. The best predictor of screw loosening in this study is the average value of HU from L1 to L4 in axial cut.

Engineered Surface Halide Defects by Two-Dimensional Perovskite Passivation for Deformable Intelligent Photodetectors.

As attractive photoactive materials, metal halide perovskites demonstrate outstanding performance in a wide range of optoelectronic applications. Among the various compositions studied, mixed-halide perovskites have a finely tunable band gap that renders them desirable for targeted applications. Despite their advantages, photoinduced halide segregation often deters the photoelectric stability of the materials. Herein, we adopt a strategy of post-treating the perovskite surface with an organic spacer to generate a two-dimensional (2D) perovskite passivating layer. Trap-assisted recombination pathways can be selectively modulated by passivating the surface halide defects that cause photoinduced halide segregation. Fluorescence lifetime imaging of flat and bent surfaces of perovskites reveals that the perovskite lattice tolerates mechanical strain via the neutralizing passivation of ionic halide defects. Upon bending, the photocurrent response of the flexible photodetector is maintained over 83% for 2D passivated perovskite and drops to 23% for pristine perovskite. A flexible photodetector array built with 2D passivated perovskite, in combination with a deep learning algorithm, demonstrates excellent accuracy in determining letters of the alphabet for both flat (>96%) and bent (>93%) states. The connection of chemically modified charge carrier dynamics and mechanical properties revealed in this study offers valuable guidance for developing next-generation optoelectronic applications.

Discrimination of Invasive Human Skin Tumor Using an Ultrafast ATP-Proton AND-Gate Probe.

Cancer cells undergo unscheduled proliferation resulting from dysregulation of the cell cycle, and hence, evaluation in tumor is of keen interest to examine the invasiveness and recurrence of cancer in the lesion. Molecular probes capable of discriminating actively growing tumor from resting ones remain unexplored despite their vast importance. Here, we describe a novel strategy to visualize invasive areas in tumor with a fluorescence probe that implements synergistic fluorescence response toward the slightly acidic environment of tumor and an ATP-abundant nature of actively growing cells. The probe has been designed for ultrafast detection of ATP with high specificity. We demonstrate its utility in visualizing invasive areas in tumor by distinguishing basal cell carcinomas and squamous cell carcinomas at their early stages by two-photon microscopy.

Ratiometric Detection of Hypochlorous Acid in Brain Tissues of Neuroinflammation and Maternal Immune Activation Models with a Deep-Red/Near-Infrared Emitting Probe.

Reactive oxygen species (ROS) produced by an inflammatory response in the brain are associated with various neurological disorders. To investigate ROS-associated neuroinflammatory diseases, fluorescent probes with practicality are in demand. We have investigated hypochlorous acid, an important ROS, in the brain tissues of neuroinflammation and maternal immune activation (MIA) model mice, using a new fluorescent probe. The probe has outstanding features over many known probes, such as providing two bright ratio signals in cells and tissues in deep-red/near-infrared wavelength regions with a large spectral separation, in addition to being strongly fluorescent, photo- and chemo-stable, highly selective and sensitive, fast responding, and biocompatible. We have found that the level of hypochlorous acid in the brain tissue of a neuroinflammatory mouse model was higher (2.7-4.0-fold) compared with that in normal brain tissue. Furthermore, the level of hypochlorous acid in the brain tissue of a MIA mouse model was higher (1.2-1.3-fold) compared with that in the normal brain tissue. The "robust" probe provides a practical tool for studying ROS-associated neurological disorders.

A Study on Hypoxia Susceptibility of Organ Tissues by Fluorescence Imaging with a Ratiometric Nitroreductase Probe.

Hypoxia, a condition of oxygen deficiency in tissues, features various diseases including solid tumor. Under hypoxia, several reductases such as nitroreductases are elevated. Based on this fact, we have investigated an indirect way to assess the hypoxia susceptibility of different organ tissues (mouse lung, heart, spleen, kidney, and liver) by detecting nitroreductase present within. Among the organs, the kidney showed a notable susceptibility to hypoxia, which was due to the renal medulla, not due to the renal cortex, as observed by ratiometric fluorescence imaging with a probe. The probe features ratiometric signaling, NIR-emitting, two-photon absorbing, and pH-insensitive emission properties, offering a practical tool for studying the nitroreductase activity and, furthermore, hypoxia-associated biological processes.

Open-Source Automatic Segmentation of Ocular Structures and Biomarkers of Microbial Keratitis on Slit-Lamp Photography Images Using Deep Learning.

We propose a fully-automatic deep learning-based algorithm for segmentation of ocular structures and microbial keratitis (MK) biomarkers on slit-lamp photography (SLP) images. The dataset consisted of SLP images from 133 eyes with manual annotations by a physician, P1. A modified region-based convolutional neural network, SLIT-Net, was developed and trained using P1's annotations to identify and segment four pathological regions of interest (ROIs) on diffuse white light images (stromal infiltrate (SI), hypopyon, white blood cell (WBC) border, corneal edema border), one pathological ROI on diffuse blue light images (epithelial defect (ED)), and two non-pathological ROIs on all images (corneal limbus, light reflexes). To assess inter-reader variability, 75 eyes were manually annotated for pathological ROIs by a second physician, P2. Performance was evaluated using the Dice similarity coefficient (DSC) and Hausdorff distance (HD). Using seven-fold cross-validation, the DSC of the algorithm (as compared to P1) for all ROIs was good (range: 0.62-0.95) on all 133 eyes. For the subset of 75 eyes with manual annotations by P2, the DSC for pathological ROIs ranged from 0.69-0.85 (SLIT-Net) vs. 0.37-0.92 (P2). DSCs for SLIT-Net were not significantly different than P2 for segmenting hypopyons (p > 0.05) and higher than P2 for WBCs (p < 0.001) and edema (p < 0.001). DSCs were higher for P2 for segmenting SIs (p < 0.001) and EDs (p < 0.001). HDs were lower for P2 for segmenting SIs (p = 0.005) and EDs (p < 0.001) and not significantly different for hypopyons (p > 0.05), WBCs (p > 0.05), and edema (p > 0.05). This prototype fully-automatic algorithm to segment MK biomarkers on SLP images performed to expectations on an exploratory dataset and holds promise for quantification of corneal physiology and pathology.

Recipient Factors Associated With Graft Detachment of a Subsequent Eye in Sequential Descemet Membrane Endothelial Keratoplasty.

PURPOSE: To evaluate the recipient factors associated with graft detachment in the subsequent eye of patients who underwent sequential Descemet membrane endothelial keratoplasty (DMEK). METHODS: A retrospective, consecutive case series with 158 eyes of 79 patients who underwent DMEK surgeries in both eyes between October 2013 and April 2019 for treatment of Fuchs endothelial dystrophy. The main outcome measure was the presence of graft detachment (any amount of detachment) at postoperative 1 week in the subsequent eye. Preoperative, intraoperative, and postoperative factors were evaluated for association with graft detachment. RESULTS: Of 79 patients (158 eyes) with a mean follow-up of 11.7 ± 8.4 months, 18 patients (36 eyes) developed graft detachment in both eyes 1 week postoperatively. The risk of detachment in the subsequent eye was increased when the first eye had any amount of detachment [odds ratio = 2.8; 95% confidence interval (CI) = 1.1-7.3; P = 0.037]. When the first eye had a clinically significant detachment (>30% detached), the risk of detachment occurring in the subsequent eye was greater (odds ratio = 15.7; 95% CI = 1.8-134.5; P = 0.012). This risk of graft detachment in the subsequent eye increased 33% for every 5% increase in the detachment percentage in the first eye (odds ratio = 1.3; 95% CI = 1.1-1.6; P = 0.008). CONCLUSIONS: The presence of graft detachment after DMEK increases the risk of graft detachment in subsequent DMEK in the contralateral eye. Modification in perioperative care and surgical technique in the contralateral eye, such as a larger gas bubble, use of SF6 20%, and combining cataract surgery, may be needed when graft detachment occurs after DMEK in the first eye.

Measurement Reliability for Keratitis Morphology.

PURPOSE: To evaluate the reliability of manual annotation when quantifying cornea anatomical and microbial keratitis (MK) morphological features on slit-lamp photography (SLP) images. METHODS: Prospectively enrolled patients with MK underwent SLP at initial encounter at 2 academic eye hospitals. Patients who presented with an epithelial defect (ED) were eligible for analysis. Features, which included ED, corneal limbus (L), pupil (P), stromal infiltrate (SI), white blood cell (WBC) infiltration at the SI edge, and hypopyon (H), were annotated independently by 2 physicians on SLP images. Intraclass correlation coefficients (ICCs) were applied for reliability assessment; dice similarity coefficients (DSCs) were used to investigate the area overlap between readers. RESULTS: Seventy-five MK patients with an ED received SLP. DSCs indicate good to fair annotation overlap between graders (L = 0.97, P = 0.80, ED = 0.94, SI = 0.82, H = 0.82, WBC = 0.83) and between repeat annotations by the same grader (L = 0.97, P = 0.81, ED = 0.94, SI = 0.85, H = 0.84, WBC = 0.82). ICC scores showed good intergrader (L = 0.98, P = 0.78, ED = 1.00, SI = 0.67, H = 0.97, WBC = 0.86) and intragrader (L = 0.99, P = 0.92, ED = 0.99, SI = 0.94, H = 0.99, WBC = 0.92) reliabilities. When reliability statistics were recalculated for annotated SI area in the subset of cases where both graders agreed WBC infiltration was present/absent, intergrader ICC improved to 0.91 and DSC improved to 0.86 and intragrader ICC remained the same, whereas DSC improved to 0.87. CONCLUSIONS: Manual annotation indicates usefulness of area quantification in the evaluation of MK. However, variability is intrinsic to the task. Thus, there is a need for optimization of annotation protocols. Future directions may include using multiple annotators per image or automated annotation software.

Refractive approaches to visual rehabilitation in patients with keratoconus.

PURPOSE OF REVIEW: As keratoconus is a chronic disease affecting young people, vision-related quality of life is often significantly impaired in patients with this disease. However, successful management of keratoconus, including visual rehabilitation strategies, can improve quality of life in these patients. This review will describe clinical approaches that improve vision-related quality of life in patients with stable keratoconus. RECENT FINDINGS: Several types of contact lenses including scleral lenses have been used successfully to manage keratoconus. Eyes with severe keratoconus, even those in which fitting with other types of lenses is challenging, can be successfully fitted with scleral lenses. Although laser ablative procedures, such as photorefractive keratectomy (PRK) have been traditionally contraindicated in patients diagnosed with or suspected of having keratoconus, PRK has been attempted to partially correct refractive errors in keratoconus. Although phototherapeutic keratectomy and radial keratotomy have been reported to be used in eyes with keratoconus, effectiveness and safety results have varied. Implantation of phakic intraocular lenses and intraocular lenses, including toric intraocular lenses, which primarily correct regular astigmatism, with cataract extraction or refractive lens exchange can improve vision-related quality of life in patients with keratoconus by significantly reducing cylinder while improving uncorrected visual acuity. SUMMARY: Appropriate selection and application of treatment options based on consideration of multiple factors will help patients with keratoconus, improving their vision-related quality of life and delaying or avoiding keratoplasty.

Prosthetic Replacement of the Ocular Surface Ecosystem (PROSE) for Visual Rehabilitation in Limbal Stem Cell Deficiency.

OBJECTIVES: To evaluate the clinical outcomes of patients with limbal stem cell deficiency (LSCD) who were fitted with the Prosthetic Replacement of the Ocular Surface Ecosystem (PROSE) scleral device. METHODS: In this retrospective, interventional case series, we reviewed the charts of 31 eyes of 19 consecutive patients clinically diagnosed with LSCD who were evaluated for the PROSE device. Clinical data were reviewed before PROSE evaluation and at the last available follow-up. The main outcomes measures were best-corrected distance visual acuity (CDVA) and modified ocular involvement score (OIS), graded using a previously described system for corneal findings. RESULTS: Corrected distance visual acuity improved from 0.86±0.50 logarithm of the minimal angle of resolution (Snellen equivalent, 20/145) at baseline to 0.46±0.44 (Snellen equivalent, 20/58) with PROSE at the last follow-up (mean, 25.1±18.0 months; P<0.0001). In 27 eyes (87.1%) CDVA improved, with 22 eyes (71.0%) gaining 2 or more lines of Snellen acuity. When categorized by disease severity, CDVA improved in less severe eyes (stage 1) and more severe eyes (stage 2 or 3; P=0.049 and P=0.00009, respectively). Total OIS was not significantly different between baseline and last follow-up (P=0.754); however the epithelial defect score was significantly less (P=0.034). Twenty-four of 31 eyes (77.4%) continued wearing the PROSE device, with a mean daily wearing time of 10.0±4.6 hrs. CONCLUSIONS: In patients with LSCD, vision improved and the OIS remained stable with PROSE, suggesting that the device could be considered for visual rehabilitation in this population.

Far-red/near-infrared emitting, two-photon absorbing, and bio-stable amino-Si-pyronin dyes.

Organic fluorophores emitting in the far-red/near-infrared (NIR) wavelength region are in great demand for minimal autofluorescence and reduced light scattering in deep tissue or whole body imaging. Currently, only a few classes of far-red/NIR fluorophores are available including widely used cyanine dyes, which are susceptible to photobleaching and form nonfluorescent aggregates. Even rare are those far-red/NIR emitting dyes that have two-photon imaging capability. Here we report a new class of far-red/NIR-emitting dyes that are photo-stable, very bright, biocompatible, and also two-photon absorbing. The introduction of an electron-withdrawing group such as N-acyl or N-alkoxycarbonyl groups on the C-10-amino substituent of the new julolidine-derived amino-Si-pyronin dyes (ASiPj), which emit in the far-red region, causes large bathochromic shifts, leading to NIR-emitting amino-Si-pyronin dyes (NIR-ASiPj) having high cellular stability. Furthermore, the ASiPj-NIR-ASiPj couple offers a novel ratiometric bioimaging platform with a large spectral gap, as demonstrated here with a boronate-containing NIR-ASiPj derivative that is converted to the corresponding ASiPj dye upon reaction with hydrogen peroxide.

Safety of Long-Term Storage and Shipping of Prestripped, Prestained, and Preloaded Descemet Membrane Endothelial Keratoplasty Tissue.

PURPOSE: The purpose of this study was to determine the safety of long-term storage and shipping of prestripped, prestained, and preloaded Descemet membrane endothelial keratoplasty (pDMEK) grafts. METHODS: A total of 33 cadaveric corneas were prestripped, prestained, and preloaded using modified Jones tube injectors as pDMEK. The corneas were masked to groups that were prepared <9 hours (control), 48 hours, and 72 hours before unloading and analysis. The 48- and 72-hour tissues were shipped by airfreight on each day before arrival to simulate domestic and international shipping. The corneas were then stained using Calcein AM vital dye (Molecular Probes, Eugene, OR) and imaged using an inverted confocal microscope. Primary outcome measures were endothelial cell loss (ECL, %) and sustainability of staining. MetaMorph software (Molecular Devices, Downingtown, PA) was used to quantify ECL, and staining was evaluated subjectively using all-or-none rating. RESULTS: There was no difference in the mean ECL for the control, 48-hour, and 72-hour groups, which were 25.1% ± 8.8%, 26.4% ± 17.5%, and 19.2% ± 11.5%, respectively (P = 0.45; Kruskal-Wallis test). In all tissues of each group, no loss of staining was identified at each time point of analysis. CONCLUSIONS: ECL in pDMEK tissue prepared 48 and 72 hours in advance and shipped using standard methods is similar to that in pDMEK tissue prepared on the same day. These findings support the safety of domestic and international shipping of pDMEK grafts.

Novel Image-Based Analysis for Reduction of Clinician-Dependent Variability in Measurement of the Corneal Ulcer Size.

PURPOSE: To assess variability in corneal ulcer measurements between ophthalmologists and reduce clinician-dependent variability using semiautomated segmentation of the ulcer from photographs. METHODS: Three ophthalmologists measured 50 patients' eyes for epithelial defects (EDs) and the stromal infiltrate (SI) size using slit-lamp (SL) calipers. SL photographs were obtained. An algorithm was developed for semiautomatic segmenting of the ED and SI in the photographs. Semiautomatic segmentation was repeated 3 times by different users (2 ophthalmologists and 1 trainee). Clinically significant variability was assessed with intraclass correlation coefficients (ICCs) and the percentage of pairwise measurements differing by ≥0.5 mm. Semiautomatic segmentation measurements were compared with manual delineation of the image by a corneal specialist (gold standard) using Dice similarity coefficients. RESULTS: Ophthalmologists' reliability in measurements by SL calipers had an ICC from 0.84 to 0.88 between examiners. Measurements by semiautomatic segmentation had an ICC from 0.96 to 0.98. SL measures of ulcers by clinical versus semiautomatic segmentation measures differed by ≥0.5 mm in 24% to 38% versus 8% to 28% (ED height); 30% to 52% versus 12% to 34% (ED width); 26% to 38% versus 10% to 32% (SI height); and 38% to 58% versus 14% to 34% (SI width), respectively. Average Dice similarity coefficients between manual and repeated semiautomatic segmentation ranged from 0.83 to 0.86 for the ED and 0.78 to 0.83 for the SI. CONCLUSIONS: Variability exists when measuring corneal ulcers, even among ophthalmologists. Photography and computerized methods for quantifying the ulcer size could reduce variability while remaining accurate and impact quantitative measurement endpoints.

Visual Outcome and Patient Satisfaction of Low-Power-Added Multifocal Intraocular Lens.

PURPOSE: To evaluate visual outcome and patient satisfaction following implantation of multifocal intraocular lenses (IOLs) with a +1.5 diopters (D) addition compared with monofocal IOLs. METHODS: This prospective, nonrandomized, comparative case series involved 48 eyes (24 patients) who underwent cataract surgery with implantation of low-power-added multifocal IOLs (LS313-MF15; multifocal group) and 48 eyes (24 patients) with conventional monofocal IOLs (CTS204; monofocal group). Visual acuity (VA), defocus curves, refraction, contrast sensitivity, glare, ocular optical quality, and scores in questionnaire were assessed 6 months postoperatively. RESULTS: Uncorrected VA at intermediate and near distance tended to be better in the multifocal group, with significant differences at 50 cm (P=0.03). The defocus curve showed significantly different VA at vergences of -1.5 and -2.0 D (P=0.02 and P=0.03, respectively). Results of postoperative refraction, contrast sensitivity, glare, and optical quality were similar (P>0.05), although coma-like aberration was higher in the multifocal group (P=0.04). Despite of similar levels of visual disturbances (P>0.05), disturbances in activities and spectacle use at intermediate working distance were significantly less frequent in the multifocal group (P=0.03 and P=0.04, respectively). Multifocal group showed significantly greater overall satisfaction (P=0.02). CONCLUSIONS: Low-power-added multifocal IOLs yielded better intermediate and near vision without increasing optical phenomena compared with monofocal IOLs.

Effects of subconjunctival administration of anti-high mobility group box 1 on dry eye in a mouse model of SjÓ§gren's syndrome.

PURPOSE: Extracellular high mobility group box 1 (HMGB1) acts as a damage associated molecular pattern molecule through the Toll-like receptor to promote autoreactive B cell activation, which may be involved in the pathogenesis of SjÓ§gren's syndrome. The aim of this study was to investigate the effect of subconjunctival administration of anti-HMGB1 on dry eye in a mouse model of SjÓ§gren's syndrome. METHODS: Ten weeks-old NOD.B10.H2b mice were subconjunctivally injected with 0.02 to 2 µg of anti-HMGB1 antibodies or PBS twice a week for two consecutive weeks. Tear volume and corneal staining scores were measured and compared between before- and after-treatment. Goblet cell density was counted in PAS stained forniceal conjunctiva and inflammatory foci score (>50 cells/focus) was measured in extraorbital glands. Flow cytometry was performed to evaluate the changes in BrdU+ cells, IL-17-, IL-10-, or IFNγ-secreting cells, functional B cells, and IL-22 secreting innate lymphoid cells (ILC3s) in cervical lymph nodes. The level of IL-22 in intraorbital glands was measured by ELISA. RESULTS: Injection of 2 µg or 0.02 µg anti-HMGB1 attenuated corneal epithelial erosions and increased tear secretion (p<0.05). Goblet cell density was increased in 0.2 µg and 2 µg anti-HMGB1-treated-mice with marginal significance. The inflammatory foci score, and the number of BrdU+ cells, IL-17-, IL-10-, IFNγ-secreting cells, and functional B cells did not significantly change following anti-HMGB1 treatment. Surprisingly, the percentage of ILC3s was significantly increased in the draining lymph nodes (p<0.05), and the expression of IL-22 was significantly increased in the intraorbital glands (p<0.05) after administration of 2 µg anti-HMGB1. CONCLUSION: This study shows that subconjunctival administration of anti-HMGB1 attenuates clinical manifestations of dry eye. The improvement of dry eye may involve an increase of ILC3s, rather than modulation of B or plasma cells, as shown using a mouse model of SjÓ§gren's syndrome.

Diagnosis of corneal limbal stem cell deficiency.

PURPOSE OF REVIEW: A state of limbal stem cell deficiency (LSCD) can be secondary to a number of etiologies, resulting in either a reduction in the total number of limbal stem cells or an abnormality in stem cell function. Initially, the epithelium becomes irregular and hazy; however, this condition may progress to persistent corneal epithelial defects, stromal scarring, ulceration, and even perforation. Since LSCD secondary to a variety of etiologies may be reversible, and various factors are prognostic of disease progression, timely diagnosis is important. This review will describe current knowledge of diagnostic techniques for LSCD and understanding of epithelial stem cell function. RECENT FINDINGS: Conjunctivalization, regarded as the most reliable clinical finding diagnostically, can be identified as late staining of epithelium with fluorescein. While identifying loss of the palisades of Vogt by slit-lamp examination, can provide a high suspicion of LSCD, but this is not diagnostic. Impression cytology is a simple, noninvasive technique that aids in the diagnosis of LSCD, but a negative result also cannot rule out the diagnosis. Recent findings have also shown that imaging techniques including in-vivo confocal microscope and optical coherent tomography can also aid in diagnosing LSCD; however, several challenges remain before these techniques become standard diagnostic methods in clinical practice. Meanwhile, determination of the absence of limbal epithelial crypts and focal stromal projections using image reconstruction techniques may assist in the diagnosis of LSCD. Furthermore, histologic markers may help not only to improve sensitivity and specificity of conventional techniques in diagnosis of LSCD, but also to identify human limbal stem cells and determine their number and function in LSCD. SUMMARY: Efforts to develop and improve techniques for diagnosing LSCD are ongoing. Increased knowledge of limbal stem cells and components of their niches may not only help in understanding the pathogenesis of LSCD but may improve its diagnosis, thereby ameliorating the prognosis of patients with this devastating disease.

The Likelihood of Reaching Substantial Clinical Benefit After an Interlaminar Dynamic Spacer for Chronic Low Back Pain: A Clinical and Radiologic Analysis of a Prospective Cohort.

OBJECTIVE: Chronic low back pain (CLBP) often causes disabling pain that impairs a patient's quality of life. Surgical treatment is recommended for patients who do not respond to conservative treatments lasting more than 6 months. The purpose of this study is to present results after the use of an interlaminar dynamic spacer for CLBP. METHODS: We enrolled consecutive patients with CLBP irresponsive to more than 6 months of conservative treatment into the present study. Included patients underwent an interlaminar dynamic spacer insertion without direct decompression. We assessed radiographic parameters and health-related quality of life (HRQoL) data included visual analog scale back/leg pain and Oswestry Disability Index scores. Substantial clinical benefit achievement was assessed. RESULTS: Thirty-five patients (average age, 47.8 years; 21 female) were included. The mean preoperative symptom duration was 29.6 months. Surgeries involved 1-level (n = 18) and 2-levels (n = 17) procedures. Operative levels included L4-5 (n = 8), L5-S1 (n = 10), L3-4-5 (n-2), and L4-5-S1 (n = 15). The average follow-up period was 16.6 months. After the procedure, all radiographic parameters (including disc height, segmental extension angle, and foraminal area) improved significantly. All preoperative HRQoL parameters improved significantly at the final follow-up. Substantial clinical benefit achievement was observed in 75.8% of the cases on the Oswestry Disability Index, and in 72.7% and 84.8% of the cases on the visual analog scale back and leg pain, respectively. CONCLUSIONS: An interlaminar dynamic spacer significantly improves HRQoL scores in patients with CLBP who do not respond to conservative treatment. Although encouraging, these results should be confirmed with studies assessing a larger cohort and a longer follow-up.

Multifocal Intraocular Lens Results in Correcting Presbyopia in Eyes After Radial Keratotomy.

OBJECTIVES: To report results of multifocal intraocular lens (IOL) implantation in 2 patients with refractive error and presbyopia after previous radial keratotomy (RK). METHODS: A refractive multifocal IOL with rotational asymmetry (LS313-MF30; Oculentis, Berlin, Germany) was implanted. RESULTS: The first patient was a 60-year-old man with myopia who underwent unilateral RK 20 years before. His uncorrected distance visual acuity (UDVA) was 20/400, and his distance corrected near vision was J9 in both eyes. Six months after bilateral surgery, his binocular UDVA and uncorrected near visual acuity (UNVA) improved to 20/20 and J1, respectively, although he experienced diurnal fluctuation. The second patient was a 55-year-old woman with hyperopia who underwent bilateral RK 18 years before. Uncorrected distance visual acuity was 20/25 in both eyes, but UNVA was between J9 and J10. Three months after unilateral surgery, UDVA and UNVA of the postsurgical eye improved to 20/20 and J1, respectively. Neither patient reported any significant photic phenomena, and both were satisfied with the results of treatment. CONCLUSIONS: The desirable clinical outcomes and levels of satisfaction expressed by these patients indicate that surgery using this particular multifocal IOL may benefit presbyopic patients with previous RK.