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Purpose: Establishing the reliability of a new method to check the mean retinal and choroidal reflectivity and using it to find retinal and choroid changes in amblyopia., Methods: Design: Retrospective case-control. Population: 28 subjects of which 10 were healthy controls (20 eyes): 8 with refractive errors, 1 with strabismus, and 1 with both. 18 patients with unilateral amblyopia included: 7 anisometropic, 6 isoametropic, 1 strabismic, and 4 combined. Mean participants' age: 13.77 years ± 10.28. Observation procedures: SD-OCT and ImageJ. Main outcome measure: mean reflectivity of retinal and choroid layers. Amblyopic, fellow, and healthy eyes were compared., Results: The method of measuring reflectivity is good to excellent reliability for all regions of interest except the fourth. The mean reflectivity of the choriocapillaris and Sattler's layer in amblyopic eyes were significantly lower than in healthy eyes (p = 0.003 and p = 0.008 respectively). The RNFL reflectivity was lower than that of fellow eyes (p = 0.025). Post-hoc pairwise comparisons showed statistically significant differences between amblyopic and healthy eyes for choriocapillaris (p = 0.018) and Sattler's (p = 0.035), and between amblyopic and fellow eyes for RNFL (p = 0.039)., Conclusion: A decrease in reflectivity of the choriocapillaris and Sattler's in amblyopic compared to healthy eyes, and a decrease in reflectivity of the RNFL in the amblyopic compared to fellow eyes, indicate that the pathophysiology is partly peripheral and might be bilateral., Competing Interests: The authors have declared that no competing interests exist.

Purpose: To evaluate the efficacy of simultaneous laser in situ keratomileusis (LASIK) and small-aperture corneal inlay (KAMRA; AcuFocus, Inc) implantation in hyperopic presbyopic eyes at 5 years postoperatively., Methods: This was a retrospective single-center study of patients with hyperopia and presbyopia who underwent simultaneous LASIK and corneal inlay implantation by two experienced refractive surgeons. These patients were regularly observed for 5 years and evaluated with serial corneal tomographies and refractive assessments for uncorrected near visual acuity (UNVA), uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), distance-corrected near visual acuity (DCNVA), and manifest refraction spherical equivalent (MRSE)., Results: Twenty-four eyes of 24 patients were included. Mean age was 53.63 ± 4.11 years (range: 47 to 63 years) and mean preoperative MRSE was +1.52 ± 0.64 diopters (D) (range: +0.50 to +3.00 D). UNVA was 0.04 ± 0.06 logMAR at 1 month and 0.02 ± 0.05 logMAR (J1+ equivalent) at 5 years postoperatively. In comparison, preoperative DCNVA was 0.44 ± 0.20 (J5/J6 equivalent) (P < .001). At 5 years postoperatively, UDVA was 0.16 ± 0.18 logMAR (20/30 Snellen equivalent), and 23 of 24 eyes (95.8%) had UNVA of J3 or better. Two eyes (8.3%) lost one line of CDVA. One corneal inlay needed readjustment but none were explanted. Eight eyes (25%) developed regression in UNVA with hyperopic shift, which responded to a 3- to 4-month course of topical steroids, with 3 eyes showing patchy haze on the undersurface of the corneal inlay., Conclusions: Simultaneous LASIK and KAMRA inlay implantation, evaluated for 5 years postoperatively, shows some efficacy and predictability in improving UDVA and UNVA in hyperopic presbyopic eyes. However, late-onset regression with hyperopic shift, possible loss of CDVA, and occasional haze remain challenges. [J Refract Surg. 2020;36(8):498-505.]., (Copyright 2020, SLACK Incorporated.)

Objective: To report the 15-year trend in ophthalmic presentations to the emergency department (ED) at the only medical center in Lebanon that provides 24-hour ophthalmologic care., Methods: Retrospective review of 1967 patients presenting to the ED with eye-related complaints between September 1997 and August 1998 and between September 2012 and August 2013. Diagnoses were classified into 4 categories according to the International Society of Ocular Trauma and include penetrating eye injuries, nonpenetrating eye trauma, nontraumatic ophthalmic emergencies, and nontraumatic, nonurgent ophthalmic conditions., Results: One thousand sixty eye-related presentations out of 39,158 total ED visits (2.71%) presented in 1997 compared to 907 out of 46,363 in 2012 (1.96%). Penetrating and nonpenetrating eye emergencies decreased between 1997 and 2012 (7.17% to 4.19%, p = 0.003 and 52.64% to 29.00%, p < 0.001, resp.) while nonurgent cases increased from 30.19% to 53.47% ( p < 0.001). 57% of patients were covered by third-party guarantors in 1997 versus 73% in 2012., Conclusion: Our results demonstrate a significant increase in nonurgent cases in parallel with the proportion of third-party payers, an issue to be addressed by public health policies and proper resource allocation. A detailed nationwide review is needed to make solid recommendations for the management of ophthalmologic presentations in the ED.

Purpose: To evaluate the epithelial erosion incidence and refractive results in myopic eyes undergoing single-step transepithelial photorefractive keratectomy (TransPRK) compared with alcohol-assisted photorefractive keratectomy (PRK)., Methods: This was a retrospective nonrandomized comparative study conducted at the American University of Beirut Medical Center. A total of 189 eyes that had undergone single-step transepithelial PRK (TransPRK) were compared with 189 matched eyes that had undergone alcohol-assisted PRK over a follow-up of 1 year. The incidence and symptoms of epithelial erosion were evaluated in both treatment groups using a post hoc questionnaire administered to patients selected in the study. Visual and refractive outcomes, including vector analysis of astigmatism, and corneal higher-order aberrations were also compared at 1-year postoperatively., Results: Baseline characteristics were similar between 2 groups (P > 0.05). A slight difference was detected at 12-month follow-up in the refractive cylinder (P = 0.02) and difference vector (P = 0.01) between eyes that had undergone TransPRK versus alcohol-assisted PRK. All other visual and refractive outcomes were similar at 12-month follow-up between both groups. Of note, 9.9% of patients with alcohol-assisted PRK (10/101) reported to the clinic because of tearing and stabbing sensation within 1 week after contact lens removal as opposed to 1% (1/100) of the TransPRK group (P = 0.0097). Subclinical recurrent epithelial erosion symptoms occurred more frequently in alcohol-assisted PRK: soreness to touch, sharp pains, and eyelid sticking occurred in 26.0% versus 6.6%, 32.5% versus 7.9%, and 26.0% versus 6.6% among the patients who were treated with alcohol-assisted PRK versus those who were treated with TransPRK, respectively (P ≤ 0.002)., Conclusions: Single-step TransPRK for myopic eyes yields refractive results similar to those of alcohol-assisted PRK but shows a lesser incidence of early postoperative epithelial erosions and subsequent subclinical recurrent erosions.

Purpose: To assess central corneal thickness (CCT) and corneal haze in keratoconus eyes following corneal cross-linking (CXL)., Design: Prospective noncomparative case series., Methods: Forty patients (44 eyes) with keratoconus that had serial evaluation for CCT, following CXL, using high-definition optical coherence tomography (HD-OCT), ultrasound pachymetry (USP), and dual Scheimpflug tomography. CCT was measured at baseline, then at 2 weeks and 1, 3, 6, and 12 months postoperatively., Results: The mean baseline CCT measurements were 470.02 μm, 469.79 μm, and 466.66 μm using the HD-OCT, the USP, and dual Scheimpflug tomography, respectively (P = .91). Following CXL, the mean CCT measurements by dual Scheimpflug, at all follow-up periods, were lower compared to mean baseline reading (P < .003). The mean CCT measurements by the HD-OCT and USP were similar to baseline readings except for the thicker readings at the 2-week follow-up visit. Overall, the mean CCT obtained by the USP was similar to that obtained by the HD-OCT throughout the 12-month period. However, the mean CCT measurements obtained by dual Scheimpflug tomography were statistically and clinically significantly lower than those obtained by both HD-OCT and USP at all follow-up visits., Conclusions: USP and HD-OCT showed better agreement in CCT readings at all visits, and may better estimate the true CCT following CXL as compared to dual Scheimpflug tomography. The lower mean CCT post-CXL as measured by the latter seems to be correlated with the amount of haze that develops after cross-linking., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Great discrepancies are often encountered between the distance fixation and the near-fixation esodeviations and exodeviations. They are all attributed to either anomalies of the AC/A ratio or anomalies of the fusional convergence or divergence amplitudes. We report a case with pseudoconvergence insufficiency and another one with pseudoaccommodative convergence excess. In both cases, conv./div. excess and insufficiency were erroneously attributed to anomalies of the AC/A ratio or to anomalies of the fusional amplitudes. Our purpose is to show that numerous factors, other than anomalies in the AC/A ratio or anomalies in the fusional conv. or divergence amplitudes, can contaminate either the distance or the near deviations. This results in significant discrepancies between the distance and the near deviations despite a normal AC/A ratio and normal fusional amplitudes, leading to erroneous diagnoses and inappropriate treatment models.

Photorefractive keratectomy (PRK) was the first excimer laser procedure developed to treat refractive errors. The safety and efficacy of PRK established it as one of the most performed corneal refractive procedures worldwide. With the introduction of laser in situ keratomileusis (LASIK), and more recently keratorefractive lenticule extraction (KLEx) procedures, many corneal surgeons favor these newer corneal procedures as the first choice due to faster visual rehabilitation and less discomfort during the early postoperative period. Importantly, however, PRK remains a viable alternative for most corneal refractive candidates and there are many situations in which PRK remains the refractive procedure of choice. This review addresses the technical evolution of PRK—mechanical epithelial debridement versus alcohol-assisted epithelial removal versus excimer laser-assisted epithelial debridement (transepithelial) PRK—and reports the PRK refractive outcomes compared to other keratorefractive laser procedures. The corneal wound response associated with each PRK technique and the indications, limitations, and complications of PRK are reviewed to aid refractive surgeons to best position PRK in their overall practice. [J Refract Surg. 2024;40(10):e754–e767.] [ABSTRACT FROM AUTHOR]

Irritable bowel syndrome (IBS) is a gastrointestinal functional disorder characterized by unclear underlying mechanisms. Several theories propose that hyperactivation of the hypothalamic–pituitary–adrenal (HPA) axis leads to elevated cortisol levels and increased sensitivity of gut wall receptors. Given the absence of prior literature on this topic, our study aimed to investigate the potential for diagnosing IBS based on morphological changes in the pituitary gland, specifically its volume and grayscale intensity. Additionally, we aimed to assess whether factors such as gender, age, and body mass index influence these parameters. This retrospective study involved 60 patients, examining the volume and grayscale characteristics of their pituitary glands in the presence of IBS. Our findings revealed a positive correlation between pituitary gland volume and IBS diagnosis, although no significant correlation was observed with grayscale intensity. Due to the limited existing research and the small sample size of our study, further investigation with a larger cohort is warranted to validate these results. [ABSTRACT FROM AUTHOR]

Purpose. To discuss an unusual presentation of ocular toxocariasis. Methods. Case report. Results. A 40-year-old woman presented with decreased vision in the left eye with a long history of recurrent red eye from uveitis. Eosinophilia and positive ELISA titers for Toxocara canis favored the diagnosis of ocular toxocariasis. Over 3 months, an anterior scleral mass had a rapid growth raising the possibility of medulloepithelioma, which rarely can mimic uveitic syndromes. Surgical plan changed from local excision to enucleation. Histopathology demonstrated a large homogeneous mass of chronic inflammatory cells with inflammation of the overlying thinned out sclera, medial rectus insertion, and limbal cornea. The triad of peripheral granuloma, eosinophilia, and positive blood serology established the diagnosis of ocular toxocariasis. Conclusions. Ocular toxocariasis can mimic ocular malignancy such as medulloepithelioma in adults and rarely presents as an anterior scleral mass.

Purpose: To compare the objective visual quality of moderate-to-high myopia corrected by small incision lenticule extraction (SMILE) and transepithelial photorefractive keratectomy (TransPRK) at a 1,050-Hz ablation frequency, assisted by Smart-Pulse technology (SCHWIND eye-tech-solutions). Methods: This study involved 123 patients (123 eyes) with moderate-to-high myopia between July 2020 and January 2021. They were categorized into the SMILE group (67 patients, 67 eyes) and the TransPRK group (56 patients, 56 eyes). Follow-ups were conducted at 6 months postoperatively to record the logarithm of the minimum angle of resolution visual acuity, and the Strehl ratio and higher order aberrations were measured using the Sirius anterior segment analysis device (SCHWIND eye-tech-solutions) under a 6-mm pupil diameter at various postoperative intervals. Results: At 1 week and 1 month postoperatively, the uncorrected distance visual acuity (UDVA) in the SMILE group was superior to that in the TransPRK group (P <.05 for both). At 1 week and 1 month postoperatively, the Strehl ratio value in the SMILE group was higher than that in the TransPRK group (P <.05 for both). At 1, 3, and 6 months postoperatively, coma was greater in the SMILE group than in the TransPRK group (P <.05 for all). Spherical aberrations were lower in the SMILE group than in the TransPRK group at 3 and 6 months postoperatively (P <.05). At 6 months postoperatively, UDVA was −0.09 ± 0.08 and −0.11 ± 0.05 logMAR in the SMILE and TransPRK groups, respectively, which exceeded their preoperative corrected distance visual acuity of −0.05 ± 0.04 and −0.09 ± 0.08 logMAR (all P <.001). Compared with preoperative values, the Strehl ratio, total higher order, coma, and spherical aberration differences were significantly increased postoperatively in both groups (all P <.001). Conclusions: Both surgical methods improved UDVA and each had its advantages. The visual quality of SMILE was superior at 1 week and 1 month postoperatively (Strehl ratio values were higher than those of the TransPRK group), and its spherical aberration was lower than that of the TransPRK group at 3 and 6 months; TransPRK with SmartPulse technology with a 1,050-Hz ablation frequency showed that coma was significantly lower than that of the SMILE group at 1, 3, and 6 months postoperatively. [J Refract Surg. 2024;40(7):e490–e498.] [ABSTRACT FROM AUTHOR]

In this paper, we focus on the strong product of the pentagonal networks. Let Rn be a hexagonal network composed of 2n pentagons and n quadrilaterals. Let P2n denote the graph formed by the strong product of Rn and its copy R' n. By utilizing the decomposition theorem of the normalized Laplacian characteristics polynomial, we characterize the explicit formula of the multiplicative degree-Kirchhoff index completely. Moreover, the complexity of P2n is determined. [ABSTRACT FROM AUTHOR]

Purpose: To assess the safety and efficacy of treatment and secondarily determine the topographic changes, visual outcomes, and demarcation line depth after high-fluence pulsed light accelerated cross-linking (ACXL) in pediatric patients (younger than 18 years) with progressive keratoconus. Methods: This retrospective analysis included 32 eyes (25 children, aged 11 to 18 years), with progressive keratoconus treated with high-energy epithelium-off pulsed light ACXL (7.2 J/cm2, 15 mW/cm2, 12 minutes, 2 seconds on/1 second off). Corrected distance visual acuity (CDVA), Scheimpflug tomography, and anterior optical coherence tomography measurements were recorded preoperatively and 1, 2, and 3 years postoperatively. Results: A total of 32 eyes were included. Significant CDVA improvement, pachymetry, and maximum keratometry reduction were found at all follow-up visits. Mean keratometric values remained stable, and astigmatism showed a mild worsening (< 0.25 D) with statistical significance at 1 and 3 years. Total aberration showed discordant results and coma aberration had a slight improvement without statistical significance. The demarcation line depth was 265 ± 26 μm. Three patients developed mild haze without visual acuity loss. None of the patients underwent a second CXL procedure. Conclusions: In pediatric patients, high-fluence epithelium-off pulsed light ACXL appears to be a safe and effective procedure to halt the progression of keratoconus, slightly improving the CDVA and keratometric values. [J Refract Surg. 2024;40(3):e148–e155.] [ABSTRACT FROM AUTHOR]

A connected graph G of diameter diam (G) ≥ ℓ is ℓ -distance-balanced if | W xy | = | W yx | for every x , y ∈ V (G) with d G (x , y) = ℓ , where W xy is the set of vertices of G that are closer to x than to y. We prove that the generalized Petersen graph GP(n, k) is diam (G P (n , k)) -distance-balanced provided that n is large enough relative to k. This partially solves a conjecture posed by Miklavič and Šparl (Discrete Appl Math 244:143–154, 2018). We also determine diam (G P (n , k)) when n is large enough relative to k. [ABSTRACT FROM AUTHOR]

Purpose: To observe and understand the structural changes in choroidal vessels in eyes with hyperopic anisometropic amblyopia using swept-source optical coherence tomography angiography (SS-OCTA). Methods: A total of 44 patients were enrolled in this study: 22 children with hyperopic anisometropic amblyopia and 22 age-matched controls. SS-OCTA was used to scan the 6*6 mm macular area of their eyes. The average choroidal thickness (CT) and choroidal capillary flow area (CC) in a 3 mm diameter area centered on the macular area were obtained. The choroidal vascularity volume (CVV) was automatically extracted and 3D reconstructed by inbuild software, and the three-dimensional choroidal vascularity index (3D-CVI) was calculated. The effect of amblyopia on the choroidal vessel structure was assessed using generalized linear estimating equations (GEEs) corrected for axial length, sex, age, and best-corrected visual acuity. Results: The CC was greater in amblyopic eyes than in fellow eyes (P = 0.014) but was not significantly different from that in control eyes (P = 0.963). After correcting for sex, age, axial length, and visual acuity using GEEs, the mean CT in the amblyopic eyes was greater than that in the fellow eyes (P = 0.030) but was not significantly different from that in the control eyes (P = 0.160). The 3D-CVI in amblyopic eyes was higher than that in control eyes (P = 0.038) but was not significantly different from that in fellow eyes (P = 0.407). The three-dimensional choroidal vascularity volume (3D-CVV) was higher in amblyopic eyes than in fellow eyes (P = 0.046) and control eyes (P = 0.023). Conclusions: We found that eyes with hyperopic anisometropic amblyopia demonstrated higher CT, CC and 3D-CVV values than the contralateral eyes after correction, while the 3D-CVI was unchanged. Compared with control eyes, amblyopic eyes had higher 3D-CVV and 3D-CVI values but similar CT and CC values. Amblyopic eyes may have different choroidal vascular structures from fellow and control eyes. [ABSTRACT FROM AUTHOR]

Presbyopia can be defined as the refractive state of the eye in which, due to a physiological decrease in the ability to accommodate, it is not possible to sustain vision without fatigue in a prolonged manner, along with difficulty focusing near vision. It is estimated that its prevalence in 2030 will be approximately 2.1 billion people. Corneal inlays are an alternative in the correction of presbyopia. They are implanted beneath a laser-assisted in situ keratomileusis (LASIK) flap or in a pocket in the center of the cornea of the non-dominant eye. The purpose of this review is to provide information about intraoperative and postoperative KAMRA inlay complications in the available scientific literature. A search was conducted on PubMed, Web of Science, and Scopus with the following search strategy: ("KAMRA inlay" OR "KAMRA" OR "corneal inlay pinhole" OR "pinhole effect intracorneal" OR "SAICI" OR "small aperture intracorneal inlay") AND ("complication" OR "explantation" OR "explanted" OR "retired"). The bibliography consulted shows that the insertion of a KAMRA inlay is an effective procedure that improves near vision with a slight decrease in distance vision. However, postoperative complications such as corneal fibrosis, epithelial iron deposits, and stromal haze are described. [ABSTRACT FROM AUTHOR]

Background: Many researchers have noticed that there is an increasing trend of Bielschowsky acquired comitant esotropia (ACE) in recent years related to excessive near work, but the exact pathogenesis and treatment methods have not been reported yet. Therefore, we aimed to characterize the clinical features of this ACE in adults and to evaluate the efficacy of botulinum toxin (BTX) injections in these patients.Methods: This was a prospective consecutive case series of 47 patients with Bielschowsky ACE. BTX was injected bilaterally into the medial rectus muscle of 45 patients, and twenty-seven of them (27/45) completed 10 months of follow-up after their last injection. Angle of deviation, fusion, stereopsis, subjective assessment of diplopia were documented before and after BTX treatment, and repeated measures data were compared by the Wilcoxon signed-rank test or Analysis of variance. The relationship between BTX dosage and corrected esotropia was explored by the Regression analysis. Meanwhile, possible risk factors for ACE including time spent on near work, refraction error, patients' personality, glasses wearing habits and duration of symptoms were recorded and analyzed with General Linear Models.Results: The patients aged 32.32 ± 10.96 (range 15-53) years spent 8.34 ± 2.38 h on near work each day, and most myope habitually removed their glasses at near. Their chief complaint was distance diplopia, with more significant esotropia at distance (around 20 PD) than at near. This series of patients also exhibited perfectionist tendencies. However, most patients achieved orthophoria after BTX treatment, only with a mild residual esotropia (+ 3.96 ± 5.79 PD), which left them asymptomatic most of the time.Conclusion: This group of ACE patients was characterized by diplopia with more significant esotropia at distance. Besides excessive near-work, habitually removing myopic glasses and perfectionist tendencies may also contribute to this type of ACE. Fortunately, bilateral BTX injection safely and effectively reduced the esotropia with complete resolution of symptoms, especially for those treated at an early stage. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate 10 years of KAMRA corneal inlay explantation and associated visual outcomes. Patients and Methods: Single-site retrospective chart review of 22 cases of AcuFocus KAMRA Inlay (ACI7000PDT) explantation (range 1 week– 1 year). Uncorrected distance visual acuity (UDVA), uncorrected near visual acuity (UNVA), corrected distance visual acuity (CDVA), and manifest refraction at 1 day, 1 week, 1 month, 3 months, 6 months, and 1 year post-explantation were reviewed. Results: The explantation rate was 8.2% across 10 years. All patients underwent KAMRA explantation due to dissatisfaction with their vision including blurry near vision, impaired night vision, decreased vision in dim lighting, streaks or halos, haze, and double vision. Mean UDVA pre-implant was − 0.01± 0.13 logMAR (logarithm of the minimal angle of resolution), 0.30± 0.22 logMAR pre-explant, and 0.16± 0.15 logMAR post-explant (n=20). Mean UNVA pre-implant was 0.37± 0.09 logMAR, 0.38± 0.13 logMAR pre-explant, and 0.42± 0.21 logMAR post-explant (n=20). Mean CDVA pre-implant was − 0.01± 0.04 logMAR and 0.05± 0.11 logMAR post-explant (n=17). Mean CDVA pre-explant was 0.04± 0.07 logMAR and 0.04± 0.11 logMAR post-explant (n=19). Significant differences were observed between pre-implant and post-explant UDVA (p=0.009), and between pre-explant and post-explant UDVA (p=0.02). All patients (100%) had 20/20 or better CDVA pre-implant but decreased to 73.7% post-explant. Sixty percent (12/20) of the patients lost UDVA Snellen acuity lines post-explant. MRSE was − 0.31± 0.29 D pre-implant and +0.26± 0.77 D post-explant (p=0.007) with note of a hyperopic shift. The hyperopic shift in 31.6% (6/19) of patients did not resolve after explantation. Post-explant residual corneal haze occurred in 72.7% (16/22) of patients. Conclusion: Although the KAMRA corneal inlay is a removable device, patients may experience residual corneal haze, hyperopic shift, and deficits in UDVA after explantation compared to pre-implantation UDVA. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to evaluate the outcomes of astigmatic correction by single-step transepithelial photorefractive keratectomy (TransPRK) and femtosecond-assisted laser in-situ keratomileusis (Femto-LASIK) surgeries.Methods: A total of 218 subjects received TransPRK or Femto-LASIK surgery for the treatment of myopia and astigmatism (-2.25 to -0.25 D). Refraction errors and uncorrected (UDVA) and corrected distance visual acuity (CDVA) were examined before and at 3 months after surgery. Astigmatism changes were assessed by vector analysis.Results: Preoperative parameters of the TransPRK group were similar to the Femto-LASIK group. UDVA and CDVA at 3 months were similar between both groups. Manifest refraction (MR) spherical equivalent in the TransPRK group (0 ± 0.20 D) was slightly lower compared with the Femto-LASIK group at 3 months (0.11 ± 0.25 D, P = 0.001). MR cylinder was -0.06 ± 0.19 D in the TransPRK group and -0.02 ± 0.15 D in the Femto-LASIK group at 3 months (P = 0.135). The index of success (IS) was 0.15 ± 0.36 in the TransPRK group and 0.06 ± 0.17 in the Femto-LASIK group (P = 0.125). The correction index (CI) was 1.03 ± 0.19 in the TransPRK group and 1.01 ± 0.11 in the Femto-LASIK group (P = 0.815).Conclusion: For low to moderate myopic astigmatism, TransPRK provided a comparable astigmatic treatment effect as Femto-LASIK. Myopic astigmatism was both slightly overcorrected after TransPRK and Femto-LASIK surgeries. [ABSTRACT FROM AUTHOR]

This meta-analysis review compares the primary and secondary outcomes of transepithelial photorefractive keratectomy (TPRK) to the conventional photorefractive keratectomy (PRK), in terms of efficacy, predictability, safety, and patient perspectives. A total of 1711 eyes with PRK (811 eyes) and TPRK (900 eyes) from 12 studies were included through bibliographic searches. The main outcomes were efficacy, predictability, and safety parameters, and the secondary outcomes included visual and patient-reported parameters. The effect measures were weighted mean differences with 95% confidence intervals (CI) which were derived from the random-effects model of the meta-analysis to account for possible heterogeneity. TPRK procedure presents a comparable status in the main outcome and a very dominant significance in all the secondary outcomes in this meta-analysis. This study updates the evidence of the accuracy of TPRK procedure for surgical correction of all refractive errors and was deemed safer with less surgical time required and an early healing time. [ABSTRACT FROM AUTHOR]

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A simple and reliable method for quantifying Fusarium head blight (FHB), a widespread disease of barley, would enhance our capacity in identifying resistance sources and highly aggressive isolates. A detached head assay (DHA) was used to reliably assess: (i) resistance of two barley cultivars, Arabi Aswad (AS) and Arabi Abiad (AB) with different susceptibility to FHB and (ii) aggressiveness in a set of 16 fungal isolates of four Fusarium species. The two inoculated cultivars showed different responses in FHB incidence (DI) and severity (DS) using spray and point inoculation on detached barley heads, respectively. On AB, susceptible under several experimental conditions, inoculation with different Fusarium species resulted in significantly higher DI and DS, compared with AS, which showed Fusarium resistance. Furthermore, the values of DI and DS were significantly correlated with the previous findings generated under several experimental conditions. The use of this simple and reliable method in barley breeding programs can speed up the process of identification of sources of resistance to multiple FHB isolates. To our best knowledge, this is the first in-depth report investigating the usefulness of DHA for distinguishing susceptibility of barley plants and aggressiveness of diverse Fusarium species from a breeder's point of view. [ABSTRACT FROM AUTHOR]

Ocular rosacea is a chronic potentially sight-threatening inflammatory condition, which can occur in approximately 20% of patients without skin involvement. However, an accurate diagnosis of ocular rosacea has not been defined yet due to its rather nonspecific symptoms and clinical findings. Therefore, this article updates the current recommendations for diagnosis and treatment of ocular rosacea and the previously published consensus recommendations from the ROSCO expert panel on the management of rosacea. [ABSTRACT FROM AUTHOR]

Whistler-mode waves are one of the most intense electromagnetic waves in the planetary magnetospheres. These waves are responsible for energetic electron losses into the atmosphere and for electron acceleration up to relativistic energies. Generation of whistler-mode waves is typically attributed to the thermal electron anisotropy. The anisotropy corresponding to the marginal stability for whistler-mode waves has been derived for a single-component Maxwellian plasma, but this criterion does not always work in the Earth's magnetosphere where whistler-mode waves are generated by an energy-confined, strongly anisotropic electron population. This study aims to generalize the marginal stability equation for multi-component plasma with a small, but strongly anisotropic, electron population. New analytical equations for the marginal stability have been derived from the linear analysis. We have also discussed applicability of the derived equations for different electron populations in the Earth's magnetosphere. [ABSTRACT FROM AUTHOR]

PURPOSE: To evaluate management of keratoconic eyes with anterior stromal necrosis overlying the intracorneal ring segment (ICRS), by either ICRS explantation alone or exchange with corneal allogenic intrastromal ring segments (CAIRS). METHODS: Among 643 Intacs SK (Additional Technology, Inc) inserted at one institutional center, 16 eyes (15 patients) with overlying spontaneous anterior stromal necrosis were identified. Data included size of stromal defect and refractive and topographical findings before ICRS insertion, before anterior stromal necrosis, and 6 months after intervention. RESULTS: The 10-year incidence of anterior stromal necrosis after femtosecond laser–assisted ICRS insertion was 5.5%. Eight eyes underwent ICRS removal only and 8 eyes had ICRS exchanged with CAIRS. In the first group, CDVA worsened from 0.14 before melt to 0.28 logMAR after removal (P =.10), simulated keratometry (SimK) and maximum axial keratometry (Kmax) increased from 44.73 to 46.34 diopters (D) (P =.14) and from 49.23 to 52.26 D (P =.14), respectively, and coma worsened from 0.87 to 1.52 D (P =.02). In the CAIRS group, CDVA of 0.16 before melt improved to 0.11 logMAR postoperatively (P >.99), and topographic indices stabilized with SimK, Kmax, and coma mildly altering from 45.31 to 45.44 D (P >.99), from 49.25 to 49.64 D (P >.99) and from 0.87 to 0.81 D (P >.99), respectively. Whether the ICRS were explanted or exchanged, the visual and topographic mean values were better than those reported before ICRS implantation, whereas higher order aberrations in eyes without CAIRS regressed to levels before ICRS insertion. At the site of melt, thinnest residual stromal thickness averaged 327 µm with ICRS removal and 490 µm with CAIRS. Eyes with larger melt areas resulted in less optimal results with CAIRS implantation. CONCLUSIONS: Early experience in the management of anterior stromal necrosis by exchange of polymethylmethacrylate ICRS with CAIRS seems to avoid stromal thinning and confer better visual and topographic results, which were more pronounced with thicker segments. The benefit of CAIRS in large stromal melts needs to be investigated. [J Refract Surg. 2022;38(4):256–263.] [ABSTRACT FROM AUTHOR]

In this study, we present the first observations from the Magnetospheric Multiscale (MMS) mission of the Kelvin–Helmholtz instability (KHI) at the dusk-flank magnetopause during southward interplanetary magnetic field conditions on September 23, 2017. The instability criterion for the KHI was fulfilled for the plasma parameters observed throughout the event. An analysis of the boundary normal vectors based on the application of the timing method onto the magnetic field and the electron density data and the minimum directional derivative method onto the magnetic field data shows signatures of surface waves in the plane parallel to the velocity shear. A comparison to 2D fully kinetic simulations demonstrates reasonable consistencies with the formation of surface waves generated by the KH instability, as well as the structures of rolled-up KH waves. The observations further indicated low density faster than sheath plasma as an indicator of rolled-up vortices, which is also consistent with the simulations. All of these results show that the observed waves and vortices are most likely generated by the KH instability. High-time resolution MMS measurements further demonstrate kinetic-scale electric field fluctuations on the low-density side of the edges of surface waves. Detailed comparisons with the simulations suggest that the observed fluctuations are generated by the lower-hybrid drift instability excited by the density gradient at the edges of these surface waves. These secondary effects can lead to a flattening of the edge layers, indicating the connection between kinetic and larger scales within the KH waves and vortices. [ABSTRACT FROM AUTHOR]

One of the most serious risks from COVID-19 is a financial crisis for a company. Governments and central banks have used both fiscal and monetary tools on a large scale to alleviate the financial crises of companies. We build a cross-sectional model to explore who obtained more bank loans after the outbreak of COVID-19. Using data from China's listed companies, we find that real estate companies and state-owned companies obtained more bank loans. In addition, there is no evidence that industries more severely affected by the virus obtained more bank loans. Our findings demonstrate that the misallocation of credit in China worsened after the outbreak of COVID-19. [ABSTRACT FROM AUTHOR]

The reciprocal complementary Wiener index is a Wiener like molecular descriptor. It was introduced in the chemical graph theory and has shown to be useful. Reciprocal complementary Wiener index of a graph G is defined as RCW(G) = ∑ {u,v}⊆V (G) 1/ 1 + D − dG(u, v), where D is the diameter of a graph G and dG(u, v) is the distance between the vertices u and v. The aim of this paper is to determine new inequalities involving the reciprocal complementary Wiener index (RCW) and characterize graphs extremal with respect to them. [ABSTRACT FROM AUTHOR]

In this paper, we consider the main eigenvalues of connected chain graphs. We provide some properties of the eigenvectors corresponding to the main eigenvalues, upper and lower bounds on the number of main eigenvalues in connected chain graphs as well as examples that show that these bounds are attainable. As a consequence, we show that, for any positive integer k there exists a chain graph with k main eigenvalues. We also prove that there is no connected controllable chain graph. Our results make a bridge between the spectral properties of tridiagonal matrices and of chain graphs. [ABSTRACT FROM AUTHOR]

Purpose: To assess the results of simultaneously performed femtosecond laser–assisted Keraring intrastromal corneal ring–segment insertion and corneal collagen cross-linking for the treatment of keratoconus. Patients and Methods: In this retrospective, noncomparative, interventional study, 30 eyes of 24 progressive-keratoconus patients of both sexes aged 18– 36 years old with poor best-corrected visual acuity (BCVA) and intolerance to contact lenses were included. All patients had been subjected to complete preoperative and postoperative ophthalmological examinations — unaided VA, BCVA, refraction, Pentacam, and contrast sensitivity examinations at 3-month, 6-month, and 1-year follow-ups. Results: Mean unaided VA had changed significantly from 0.649± 0.239 logMAR preoperatively to 0.514± 0.222 (P=0.014), 0.419± 0.162 (P< 0.001), and 0.379± 0.142 (P< 0.001) logMAR at the three follow-up visits, respectively. Mean BCVA had changed significantly from 0.326± 0.144 logMAR preoperatively to 0.231± 0.140 (P=0.006) at 1-year follow-up. Mean spherical equivalent refraction had decreased significantly at 6-month (P=0.0298) and 1-year follow-up (P=0.0081). Mean steep keratometry (K2) had also significantly reduced from 51.89± 3.81 D to 49.87± 4.57 D (P=0.034) at 6 months and 49.40± 4.39 D (P=0.011) at 1 year. Mean refractive and keratometric astigmatism had significantly decreased at all follow-up visits. Conclusion: At 1-year follow-up, keraring intrastromal corneal ring–segment insertion assisted by femtosecond laser performed simultaneously with corneal collagen cross-linking resulted in an improvement in visual, refractive, and topographic outcomes, which may suggest it is an effective treatment of keratoconus. [ABSTRACT FROM AUTHOR]

Purpose. To compare the clinical outcomes of aberration-free all surface laser ablation (ASLA) with and without the use of smart pulse technology (SPT) in high myopia. Methods. This study retrospectively analyzed 138 eyes (138 patients, only the right eye was selected) treated for high myopia (spherical equivalent ≥−6.00 diopters) using aberration-free ASLA (non-SPT group; 85 eyes) and aberration-free ASLA assisted by SPT (SPT group; 53 eyes). Examinations such as visual acuity, refraction, and haze were performed before the 12-month follow-up. Corneal epithelial healing time was assessed in the first postoperative day. Visual acuity and refraction examination were performed at 7 days and 1, 3, 6, and 12 months postoperatively. Corneal haze was evaluated in 1, 3, 6, and 12 months. Safety, efficacy, and corneal wavefront aberrations were assessed 12 months after the treatment. Results. At 12 months postoperatively, 60% versus 40% of eyes achieved 20/16 Snellen lines or better, and 92% versus 82% of eyes achieved 20/20 Snellen lines or better visual acuity in the SPT and the non-SPT groups, respectively. The average postoperative epithelial healing time was 3.75 ± 1.00 days in the SPT group and 3.73 ± 1.30 days in the non-SPT group (P ≥ 0.05). The safety and the efficacy index of the SPT group were better than those of the non-SPT group in the follow-ups. The attempted spherical equivalent before the surgery and the achieved spherical equivalent at 12 months were comparable between the two groups. Regarding the aberrations, the results of Coma 90° in the SPT group were better than those in the non-SPT group (P ≤ 0.05), but the increase of RMS HOAs (root mean square higher order aberrations), Coma 0°, and spherical aberration postoperatively had no statistical difference between the two groups (P ≥ 0.05). Conclusions: Both aberration-free ASLA with and without SPT showed favorable safety, effectiveness, and predictability within 12 months for high myopia. And, ASLA using SPT might have potential advantages in the long-term visual quality. [ABSTRACT FROM AUTHOR]

Background: Corneal collagen cross-linking (CXL) has recently become the preferred practice in the management of progressive keratoconus and other corneal ectasias as it has been proven to be successful in halting progression of the disease with an excellent safety and efficacy profile. However, there is a known variation regarding the response to CXL, depending on several parameters related either to the treatment protocol, patient characteristics, or corneal biomechanical properties. In fact, continuing progression of keratoconus has been noted in some cases despite prior treatment with CXL. Methods: The aim of this article is to provide an updated review of all published results on repeated-CXL, focusing on the indications and the efficacy of repeated treatment and highlighting possible explanations of progression after primary CXL. Conclusions: The diagnosis of primary treatment failure should always be made based on specific clinical and imaging criteria, with repeated and consistent measurements, in order to exclude pseudoprogression. In cases of confirmed progression, physicians need to decide whether repeating CXL could be an option to enhance corneal stability without any complications. [ABSTRACT FROM AUTHOR]

Let G be a graph. The Steiner distance of W ⊆ V (G) is the minimum size of a connected subgraph of G containing W. Such a subgraph is necessarily a tree called a Steiner W-tree. The set A ⊆ V (G) is a k-Steiner general position set if V (T B) ∩ A = B holds for every set B ⊆ A of cardinality k, and for every Steiner B-tree T B . The k-Steiner general position number sgp k (G) of G is the cardinality of a largest k-Steiner general position set in G. Steiner cliques are introduced and used to bound sgp k (G) from below. The k-Steiner general position number is determined for trees, cycles and joins of graphs. Lower bounds are presented for split graphs, infinite grids and lexicographic products. The lower bound for the latter product leads to an exact formula for the general position number of an arbitrary lexicographic product. [ABSTRACT FROM AUTHOR]

Let T be a tree on n vertices and algebraic connectivity α (T). The trees on n ≥ 45 vertices and α (T) ≥ 5 - 21 2 have already been completely characterized. In case of α (T) ≥ 2 - 3 , it was proved that this set of trees can be partitioned in six classes, C i , 1 ≤ i ≤ 6 , ordered by algebraic connectivity, in the sense that α (T i) > α (T j) whenever T i ∈ C i , T j ∈ C j , and 1 ≤ i < j ≤ 6. In this work, we extend both results by studying four classes of trees, C i , 7 ≤ i ≤ 10. We prove that, for n ≥ 45 , 2 1 - cos π 7 ≤ α (T) < 5 - 21 2 if and only if T ∈ C 9 ∪ C 10 . Moreover, the set of trees with 2 1 - cos π 7 ≤ α (T) < 2 - 3 can be partitioned in the classes C i , 7 ≤ i ≤ 10 , also ordered by algebraic connectivity. [ABSTRACT FROM AUTHOR]

Background The corneal cross-linking procedure has been proven to be an effective method to treat and stabilize keratoconus progression, but early vision rehabilitation is still needed in patients. Aim The aim was to compare the results of the combined CXL and intrastromal corneal ring segment implantation procedure to that of the cross-linking-alone procedure in terms of visual acuity, refraction, and some corneal topographic parameters in keratoconic patients. Design This was a prospective, comparative, and interventional study. Patients and methods This study was carried out on 44 keratoconic patients (60 eyes) of both sexes who ranged from 18 to 36 years. Thirty eyes were subjected to the CXL-alone procedure and 30 eyes were subjected to the combined procedure. Measurements were performed in all patients preoperatively and at 3, 6 months, and 1 year postoperatively including unaided visual acuity, best-corrected visual acuity, refractive, and topographic outcomes. Results Through the entire study period, both procedures were safe and effective in treating and stabilizing keratoconus progression. Furthermore, the combined group showed additional improvements over the CXL group for the following: UDVA at 3 months (P=0.0028), best-corrected visual acuity at 1 year (P=0.011), refractive and keratometric astigmatism at all follow-up visits and corneal asphericity at 3 months (P=0.013) and 6 months (P=0.0221) of follow-up. No severe intraoperative or postoperative complications were observed during the entire study period in either group. Conclusions The combined procedure is safe and effective for earlier improvement of visual and refractive outcomes in addition to the corneal stabilizing effect. [ABSTRACT FROM AUTHOR]

Fusarium head blight (FHB) is consistently one of the most important barley diseases worldwide. This study aimed to evaluate the pathogenicity of 16 isolates of four Fusarium species under controlled conditions and their genetic variability using 22 random amplified polymorphic DNA (RAPD) markers. Pathogenic variation was characterized based on disease development rates and disease index on two Syrian barley landraces with varying resistance to FHB, Arabi Aswad (AS) and Arabi Abiad (AB). Significant differences in intra- and inter-Fusarium species pathogenicity and in susceptibility between the above-mentioned cultivars were highlighted. Overall, the two barley landraces showed moderately susceptible to moderately resistance levels to fungal infection and FHB spread within the head. Quantitative traits showed significant correlation with previous data generated in vitro and under field conditions, suggesting that growth chamber indices can predict fungal pathogenicity and quantitative disease resistance generated under various experimental conditions. Based on PCR amplification with seven different primers, the isolates showed genetic variation. Dendrogram generated by cluster analysis based on RAPD markers data showed two main groups, suggesting that a possible clonal origin could exist in the four Fusarium species. RAPD fingerprints are not useful to distinguish the 16 Fusarium isolates with different levels of pathogenicity. [ABSTRACT FROM AUTHOR]

Due to the spread of coronavirus disease 2019 (COVID-19), business environmental uncertainty, a restricted flow of personnel and materials, and changes in consumer demand have impacted business operations and financial performance. This study investigates the relationship between COVID-19, customer concentration, and sustainable growth based on data from listed companies in China. The results reveal that COVID-19 has had a negative impact on sustainable growth, but customer concentration can mitigate this negative association. By emphasizing the moderating effect of customer concentration on the relationship between COVID-19 and sustainable growth, this study provides new insights for firms who are seeking to mitigate the negative shocks of COVID-19 and promote sustainable development. [ABSTRACT FROM AUTHOR]

We have developed novel topological techniques to generate distance degree vector sequences (DDS) and distance degree scalar sequences(SS) of tensor and Cartesian products of graphs. We establish that the tensor products of two distance degree regular graphs is distance degree regular. We apply the mathematical techniques thus developed for both tensor and Cartesian products to enumerate 13 C NMR signals and intensity patterns through the partitioning of equivalence classes accomplished by the use of distance degree vector sequences. In particular the techniques are applied to several nano materials such as carbon nanotori, monocyclic cylindrical nanotubes and zig–zag polyhex carbon nanotubes. It is shown that DDS sequences satisfactorily partition carbon vertices into equivalence classes for these nanomaterials. We also demonstrate applications of the developed techniques to diagrammatic representations of energy decompositions in molecular interactions. [ABSTRACT FROM AUTHOR]

Purpose. To analysis the multimodal imaging of a group of patients diagnosed clinically with atypical juvenile ocular toxocariasis (OT). Methods. In this case series study, we examined 9 young patients diagnosed with atypical OT. Routine ophthalmological examinations, fundus photography, optical-coherence tomography (OCT), fluorescein angiography (FFA), and B-mode ultrasound were performed. A questionnaire was used to record whether the patients were newly diagnosed and whether they had a history of exposure to a cat and dog. Aqueous humor and serum samples were taken for serological tests. Results. In all the patients, yellow-and-white dot-shaped lesions and perivascular white sheath were seen in the fundus. Heterogeneous changes including hyper-reflection in the disrupted neuroretina, hyper-reflection in the outer retinal layer, high-reflection mass on the surface of the neuroretina accompanied with reflective attenuation, and high-reflection mass involving the entire neuroretina or high-reflection mass in the vitreous body were noticed in OCT images. On FFA, seven of these patients (77.8%) showed leakage of fluorescein in the small- and medium-branch veins of the retina, and a "bristle-like" change indicated increased permeability of the vessels. B-mode ultrasound showed proliferative membranes and proliferative bands (33.3%), as well as spotted opacity in the vitreous (66.7%). The antibodies to Toxocara canis in the aqueous humor and serum were positive, and the Goldmann–Witmer coefficient was significantly increased in 6 out of 7 patients. Conclusions. Multimodality images are useful in the diagnosis of atypical juvenile OT, which could be easily overlooked and misdiagnosed. [ABSTRACT FROM AUTHOR]

PURPOSE: To evaluate and compare corneal haze as determined by optical coherence tomography (OCT) after corneal cross-linking (CXL) for the treatment of mild to moderate keratoconus with or without mitomycin C (MMC) application. METHODS: This was a retrospective analysis of 87 eyes of 72 patients with mild to moderate keratoconus. The first group (n = 44 eyes) underwent CXL between June 2013 and January 2015 and the second group (n = 43 eyes) underwent CXL with MMC (CXL+MMC) between February and December 2015, both following the Dresden protocol. Patients were evaluated preoperatively and at 1, 3, 6, and 12 months postoperatively. Main outcome measures were corneal reflectivity and haze reflectivity measured by a specially developed OCT image analysis software. RESULTS: Anterior corneal reflectivity at 1 month and 1 year postoperatively was 14.79 ± 4.68 and 25.97 ± 15.01 (Anterior corneal reflectivity at 1 month and 1 year postoperatively was 14.79 ± 4.68 and 25.97 ± 15.01 (P <.001), and 13.88 ± 4.39 and 18.41 ± 9.25 (P =.025) for the CXL and CXL+MMC groups, respectively. The reflectivity of the anterior stromal haze region at 1 month and 1 year postoperatively was 23.15 ± 5.91 and 33.14 ± 16.58 (P =.005), and 20.58 ± 7.88 and 27.14 ± 12.80 (P =.049) for both groups, respectively. The changes in simulated keratometry from preoperatively to postoperatively were similar in both groups. The CXL+MMC group showed larger maximum keratometry flattening: 53.41 ± 6.88 diopters (D) preoperatively and 49.44 ± 5.66 D 1 year postoperatively versus 52.27 ± 5.78 and 50.91 ± 4.25 D for CXL alone (P =.008). CONCLUSIONS: MMC application following CXL significantly increases corneal haze. Similar studies need to be performed on simultaneous CXL and photorefractive keratectomy to evaluate the role of MMC in haze formation in such procedures. [[J Refract Surg. 2021;37(2):83–90.] [ABSTRACT FROM AUTHOR]

Objective. To establish a porcine eye model for manual sub-Bowman layer photorefractive keratomileusis (SBPRK), which is a reformed surface ablation refractive surgery that results in preserving the corneal Bowman layer (BL). Methods. The SBPRK group consisted of eleven eyes of 8 healthy pigs with BL flaps by mechanical technique followed by laser ablation. Regarding the remaining 5 eyes, 3 random eyes had transepithelium photorefractive keratectomy (TransPRK) (the TransPRK group), while the other 2 eyes were untreated (the blank control group). All the pigs were followed up for 8 weeks. Slit-lamp biomicroscopy and optical coherence tomography (OCT) were examined before the surgeries and at 1 week, 4 weeks, and 8 weeks after the surgeries. Results. In a few days after the surgery, 3 eyes of the SBPRK group were excluded from the study because of poor healing of the corneal flaps. At the 1st postoperative week, one eye had an irregular defect of about 3 mm in the central corneal epithelium area; the cornea of the other 7 eyes had just light edema with intact epithelium just like the cornea of the TransPRK group. At the 4th week, in the SBPRK group, the cornea was slightly hazy (haze stage 1). While in the TransPRK group, the cornea was hazier (haze stage 2). At the 8th week, in the SBPRK group, both corneas were almost transparent, and the edges of the BL flaps could not be clearly seen. Meanwhile, in the TransPRK group, the corneal haze became lighter and thinner. OCT showed that, in the SBPRK group, there was high reflection in the BL layer, and it was obvious at 1 week postoperation, decreased at 4 weeks, and calmed down at 8 weeks. However, in the TransPRK group, the high reflection diffused in the anterior corneal stroma at 1 week postoperation, enhanced at 4 weeks, and weakened at 8 weeks. Conclusions. Preserving the BL while conducting surface refractive surgery may result in less haze than TransPRK. However, further study is still needed, and this technique still requires refining until it becomes a standard clinical procedure. [ABSTRACT FROM AUTHOR]

This paper investigates market reaction to the novel corona virus (COVID-19) pandemic. Using a sample of Chinese listed firms, we find that market reaction to the COVID-19 outbreak is more intense in firms within the industries that are vulnerable to the virus, and those with high institutional investors. Furthermore, firms with larger scale, better profitability and growth opportunity, higher combined leverage, and less fixed assets experience less adverse impact of the COVID-19 outbreak than other firms. [ABSTRACT FROM AUTHOR]