A new class of frequency-selective surface filters (FSS) for terahertz (THz) applications is proposed and investigated both numerically and experimentally. A periodic FSS array of cross-shaped ...apertures is patterned on aluminum, deposited on thin foils of the low-loss cyclo-olefin polymer Zeonor. Apart from the fundamental filtering response of the FSS elements, we also observe very narrow-linewidth peaks with high transmittance, associated with guided-mode resonances in the dielectric substrate. The effect of the filter's geometrical parameters on its performance is systematically studied via finite-element method simulation and confirmed by time-domain spectroscopy characterization of the fabricated samples. Finally, thanks to the flexibility of the employed substrates, THz-FSS filters are also characterized in bent configuration, revealing a robust response in terms of the fundamental FSS passband filter and a high sensitivity of the GMR peaks. These features can be exploited in the design of novel THz filters or sensors.
To evaluate the efficacy and safety of using sodium hyaluronate 0.1% and carboxymethylcellulose 0.5% artificial tears for ocular discomfort and tear-film stability in eyes after cataract surgery.
...Twenty ophthalmic centers in Italy.
Prospective randomized case series.
This study enrolled patients scheduled for unilateral cataract surgery. After surgery, patients received artificial tears and a topical steroid-antibiotic (study group) or topical steroid-antibiotic alone (control group) and were assessed postoperatively at 1 and 5 weeks. Outcome measures were tear breakup time (TBUT), ocular surface disease index (OSDI), frequency of dry-eye symptoms evaluated using a visual analog scale (VAS), and corneal fluorescein staining.
The study comprised 282 patients. At 5 weeks, the mean TBUT was statistically significantly higher in the study group than in the control group (P = .0003). The mean OSDI score statistically significantly improved in both groups from 1 to 5 weeks (P < .0001 for both groups); however, there was no statistically significant difference between the groups at these timepoints. The artificial tears statistically significantly improved VAS-assessed dry-eye symptoms in the study group compared with the control group at 5 weeks (P < .001). The mean corneal fluorescein staining was significantly reduced in the study group compared with the control group at 5 weeks (P = .002 versus P = .05, respectively). No treatment-related adverse events were reported.
Sodium hyaluronate 0.1% and carboxymethylcellulose 0.5% ophthalmic solution was effective and well tolerated in reducing dry-eye disease symptoms and improving the clinical outcome after cataract surgery.
No author has a financial or proprietary interest in any material or method mentioned.
Background/aimsTomographic analysis of macular and peripapillary retinal nerve fibers layer (RNFL) thickness in patients with history of congenital (CC) and developmental cataract ...(DC).MethodsAnalysis of macular and RNFL thickness using a spectral-domain optical coherence tomography was performed. Retinal layers thickness was measured using the internal segmentation software. Measurements of affected (unilateral and bilateral), contralateral eyes and control eyes were compared.ResultsPatients with history of CC or DC (n = 13 and 11 respectively) and 35 healthy control subjects were enrolled. Thicker inner and outer nuclear layers (INL, ONL) and thicker ONL were found when CC and DC group when compared to controls respectively. Bilateral CC showed the most relevant differences. Slight thickening of CC inner retinal layers were found when compared to DC. Increased superonasal RNFL thickness was found in CC group when compared to DC and controls. Thickening of RNFL of contralateral unaffected eyes of unilateral CC were found when compared to controls.ConclusionSignificant macular and RNFL thickness changes between CC, DC patients and controls that partially involve also contralateral unaffected eyes of unilateral congenital cataract were found. CC and DC groups show significant differences only in inner retinal layers thickness. Our data suggest that early visual deprivation may influence retinal arrangements occurring during development involving predominantly the outer nuclear layer and para/perifoveal inner retinal layers, and confirm that early treatment of CC allow to achieve better long-term visual outcome. Moreover functional and structural data support the hypothesis that unilateral amblyopia is not exclusively an unilateral issue.
Tomographic analysis of macular and peripapillary retinal nerve fibers layer (RNFL) thickness in patients with history of congenital (CC) and developmental cataract (DC).
Analysis of macular and RNFL ...thickness using a spectral-domain optical coherence tomography was performed. Retinal layers thickness was measured using the internal segmentation software. Measurements of affected (unilateral and bilateral), contralateral eyes and control eyes were compared.
Patients with history of CC or DC (n = 13 and 11 respectively) and 35 healthy control subjects were enrolled. Thicker inner and outer nuclear layers (INL, ONL) and thicker ONL were found when CC and DC group when compared to controls respectively. Bilateral CC showed the most relevant differences. Slight thickening of CC inner retinal layers were found when compared to DC. Increased superonasal RNFL thickness was found in CC group when compared to DC and controls. Thickening of RNFL of contralateral unaffected eyes of unilateral CC were found when compared to controls.
Significant macular and RNFL thickness changes between CC, DC patients and controls that partially involve also contralateral unaffected eyes of unilateral congenital cataract were found. CC and DC groups show significant differences only in inner retinal layers thickness. Our data suggest that early visual deprivation may influence retinal arrangements occurring during development involving predominantly the outer nuclear layer and para/perifoveal inner retinal layers, and confirm that early treatment of CC allow to achieve better long-term visual outcome. Moreover functional and structural data support the hypothesis that unilateral amblyopia is not exclusively an unilateral issue.
Abstract
Dielectric singularities (DSs) constitute one of the most exotic features occurring in the effective permittivity of artificial multilayers called hyperbolic metamaterials (HMMs). Associated ...to DSs, a rich phenomenology arises that justifies the ever-increasing interest profuse by the photonic community in achieving an active control of their properties. As an example, the possibility to “canalize” light down to the nanoscale as well as the capability of HMMs to interact with quantum emitters, placed in their proximity, enhancing their emission rate (Purcell effect), are worth mentioning. HMMs, however, suffer of an intrinsic lack of tunability of its DSs. Several architectures have been proposed to overcome this limit and, among them, the use of graphene outstands. Graphene-based HMMs recently shown outstanding canalization capabilities achieving λ/1660 light collimation. Despite the exceptional performances promised by these structures, stacking graphene/oxide multilayers is still an experimental challenge, especially envisioning electrical gating of all the graphene layers. In this paper, we propose a valid alternative in which indium-tin-oxide (ITO) is used as an electrically tunable metal. Here we have numerically designed and analyzed an ITO/SiO
2
based HMM with a tunable canalization wavelength within the range between 1.57 and 2.74 μm. The structure feature light confinement of λ/8.8 (resolution of about 178 nm), self-focusing of the light down to 0.26 μm and Purcell factor of approximately 700. The proposed HMM nanoarchitecture could be potentially used in many applications, such as ultra-fast signal processing, high harmonic generation, lab-on-a-chip nanodevices, bulk plasmonic waveguides in integrated photonic circuits and laser diode collimators.
Objective
To compare the efficacy and safety of adalimumab versus infliximab in an open‐label prospective, comparative, multicenter cohort study of childhood noninfectious chronic uveitis.
Methods
...Thirty‐three patients (22 females, 11 males, median age 9.17 years) with refractory, vision‐threatening, noninfectious active uveitis were enrolled, and received for at least 1 year infliximab (5 mg/kg at weeks 0, 2, and 6, and then every 6–8 weeks) or adalimumab (24 mg/m2 every 2 weeks). The primary outcome was to assess, once remission was achieved, the time of a first relapse. Time to remission, time to steroid discontinuation, and the number of relapses were also considered.
Results
Sixteen children (12 with juvenile idiopathic arthritis JIA, 3 with idiopathic uveitis, and 1 with Behçet's disease) were recruited in the adalimumab cohort and 17 children (10 with JIA, 5 with idiopathic uveitis, 1 with early‐onset sarcoidosis, and 1 with Behçet's disease) were recruited in the infliximab group. Cox regression analysis did not show statistically significant differences between the two groups with regard to time to achieve remission and time to steroid discontinuation, whereas a higher probability of uveitis remission on adalimumab during the time of treatment was shown (Mantel‐Cox χ2 = 6.83, P < 0.001). At 40 months of followup, 9 (60%) of 15 children receiving adalimumab compared to 3 (18.8%) of 16 children receiving infliximab were still in remission on therapy (P < 0.02).
Conclusion
Even if limited to a relatively small group, our study suggests that over 3 years of treatment, adalimumab is more efficacious than infliximab in maintaining remission of chronic childhood uveitis.
Abstract Aim of the present study is to evaluate the relationship between genetic and phenotypic data in a series of patients affected by grade I and II of foveal hypoplasia with stable fixation and ...good visual acuity using multimodal imaging techniques. All patients underwent complete clinical and instrumental assessment including structural Optical Coherence Tomography (OCT), OCT Angiography and Adaptive Optics (AO) imaging. Central macular thickness (CMT), inner nuclear layer (INL), vessel density in superficial capillary plexus were the main variables evaluated with OCT technology. Cone density, cone spacing, cone regularity, cone dispersion and angular density were the parameters evaluated with AO. Genetic evaluation and trio exome sequencing were performed in all affected individuals. Eight patients (3 males and 5 females) with a mean age of 12.62 years (range 8–18) were enrolled. The mean best corrected visual acuity (BCVA) was 0.18 ± 0.13 logMAR, mean CMT was 291.9 ± 16.6 µm and INL was 26.2 ± 4.6 µm. The absence of a foveal avascular zone (FAZ) was documented by examination of OCT-A in seven patients in the superficial capillary plexus. However, there was a partial FAZ in the deep plexus in patients P5 and P8. Of note, all the patients presented with major retinal vessels clearly crossing the foveal center. All individuals exhibited a grade I or II of foveal hypoplasia. In 5 patients molecular analyses showed an extremely mild form of albinism caused by compound heterozygosity of a TYR pathogenic variant and the hypomorphic p.Ser192Tyr;Arg402Gln haplotype. One patient had Waardenburg syndrome type 2A caused by a de novo variant in MITF. Two patients had inconclusive molecular analyses. All the patients displayed abnormalities on OCT-A. Photoreceptor count did not differ from normal subjects according to the current literature, but qualitative analysis of AO imaging showed distinctive features likely related to an abnormal pigment distribution in this subset of individuals. In patients with foveal hypoplasia, genetic and multimodal imaging data, including AO findings, can help understand the physiopathology of the foveal hypoplasia phenotype. This study confirms that cone density and visual function can both be preserved despite the absence of a pit.
Non-syndromic inherited retinal dystrophies (IRDs) such as retinitis pigmentosa or Leber congenital amaurosis generally manifest between early childhood and late adolescence, imposing profound ...long-term impacts as a result of vision impairment or blindness. IRDs are highly heterogeneous, with often overlapping symptoms among different IRDs, and achieving a definite diagnosis is challenging. This narrative review provides a clinical overview of the non-syndromic generalized photoreceptor dystrophies, particularly retinitis pigmentosa and Leber congenital amaurosis. The clinical investigations and genetic testing needed to establish a diagnosis are outlined, and current management approaches are discussed, focusing on the importance of the involvement of an interdisciplinary team from diagnosis and initial care to long-term follow-up and support.
The effective management of IRDs requires a multidisciplinary, and ideally interdisciplinary, team of experts knowledgeable about IRDs, with experienced professionals from fields as diverse as ophthalmology, neuropsychiatry, psychology, neurology, genetics, orthoptics, developmental therapy, typhlology, occupational therapy, otolaryngology, and orientation and mobility specialties. Accurate clinical diagnosis encompasses a range of objective and subjective assessments as a prerequisite for the genetic testing essential in establishing an accurate diagnosis necessary for the effective management of IRDs, particularly in the era of gene therapies. Improvements in genome sequencing techniques, such as next-generation sequencing, have greatly facilitated the complex process of determining IRD-causing gene variants and establishing a molecular diagnosis. Genetic counseling is essential to help the individual and their family understand the condition, the potential risk for offspring, and the implications of a diagnosis on visual prognosis and treatment options. Psychological support for patients and caregivers is important at all stages of diagnosis, care, and rehabilitation and is an essential part of the multidisciplinary approach to managing IRDs. Effective communication throughout is essential, and the patient and caregivers' needs and expectations must be acknowledged and discussed.
As IRDs can present at an early age, clinicians need to be aware of the clinical signs suggesting visual impairment and follow up with multidisciplinary support for timely diagnoses to facilitate appropriate therapeutic or rehabilitation intervention to minimize vision loss.
Oculocutaneous albinism is an autosomal recessive disorder characterized by the presence of typical ocular features, such as foveal hypoplasia, iris translucency, hypopigmented fundus oculi and ...reduced pigmentation of skin and hair. Albino patients can show significant clinical variability; some individuals can present with only mild depigmentation and subtle ocular changes. Here, we provide a retrospective review of the standardized clinical charts of patients firstly addressed for evaluation of foveal hypoplasia and slightly subnormal visual acuity, whose diagnosis of albinism was achieved only after extensive phenotypic and genotypic characterization. Our report corroborates the pathogenicity of the two common TYR polymorphisms p.(Arg402Gln) and p.(Ser192Tyr) when both are located in trans with a pathogenic TYR variant and aims to expand the phenotypic spectrum of albinism in order to increase the detection rate of the albino phenotype. Our data also suggest that isolated foveal hypoplasia should be considered a clinical sign instead of a definitive diagnosis of an isolated clinical entity, and we recommend deep phenotypic and molecular characterization in such patients to achieve a proper diagnosis.
Abstract
We experimentally demonstrate the possibility to modulate the second harmonic (SH) power emitted by nonlinear AlGaAs metasurfaces embedded in a liquid crystal (LC) matrix. This result is ...obtained by changing the relative in-plane orientation between the LC director and the linear polarization of the light at the excitation wavelength. According to numerical simulations, second-harmonic is efficiently radiated by the metasurfaces thanks to the sizeable second-order susceptibility of the material and the resonant excitation of either electric or magnetic dipole field distributions inside each meta-atom at the illuminating fundamental wavelength. This resonant behavior strongly depends on the geometric parameters, the crystallographic orientation, and the anisotropy of the metasurface, which can be optimized to modulate the emitted SH power by about one order of magnitude. The devised hybrid platforms are therefore appealing in view of enabling the electrical control of flat nonlinear optical devices.
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