The association of 2D materials and ferroelectrics offers a promising approach to tune the optoelectronic properties of atomically thin Transition Metal Dichalcogenides (TMDs). In this work, the ...combined effect of ferroelectricity and light on the optoelectronic properties of monolayer (1L)‐MoS2 deposited on periodically poled lithium niobate crystals is explored. Using scanning micro‐photoluminescence, the effect of excitation intensity, scanning direction, and domain walls on the 1L‐MoS2 photoluminescence properties is analyzed, offering insights into charge modulation of MoS2. The findings unveil a photoinduced charging process dependent on the ferroelectric domain orientation, in which light induces charge generation and transfer at the monolayer‐substrate interface. This highlights the substantial role of light excitation in ferroelectrically‐driven electrostatic doping in MoS2. Additionally, the work provides insights into the effect of the strong, nanometrically confined electric fields on LiNbO3 domain wall surfaces, demonstrating precise control over charge carriers in MoS2, and enabling the creation of deterministic p‐n homojunctions with exceptional precision. The results suggest prospects for novel optoelectronic and photonic application involving monolayer TMDs by combining light‐matter interaction processes and the surface selectivity provided by ferroelectric domain structures.
The interplay between ferroelectricity and light on the optoelectronic properties of monolayer MoS2 on periodically poled lithium niobate crystals is investigated. A light‐induced charging process dependent on ferroelectric domain orientation is shown, along with precise control over MoS2 charge carriers provided by the nanometrically confined electric fields on the domain walls, enabling creation of deterministic p‐n homojunctions with exceptional precision.
To study the outcome of botulinum toxin (BTX) treatment (group 1) in partially accommodative esotropia with high accommodative convergence/accommodation (AC/A) ratio, in comparison with bilateral ...medial rectus muscles recessions and posterior fixation (group 2).
In a retrospective comparative study, children aged 3-8 years old treated between 2011 and 2016, with partially accommodative esotropia with high AC/A ratio, deviation at distance of 10 prism diopters or more, and at least 1 year of follow-up, were included. Visual acuity, alternate prism and cover test, stereoacuity, biomicroscopy, and cycloplegic retinoscopy were carried out at initial, baseline visit, 6 months and 1 year after BTX injection or surgery. Main outcome variables were deviation at distance and near, improvement in stereoacuity, and percentage of success. We used multiple regression or proportional odds analysis to control for potential confounding variables.
Of 95 patients, 84 were eligible, 48 children in group 1 and 36 in group 2. Deviation and stereoacuity were similar in the two groups at 6 months, but significantly better in the BTX group at 1 year (median distance deviation 0 prism diopters vs 5 prism diopters, p<0.01), although differences were not clinically relevant. Percentage of success was also significantly better only at 1 year (93% vs 72%, p = 0.01). Change in distance-near disparity was not significantly different in the two groups in the period of study.
Botulinum toxin could be superior to, or as effective as surgery, at middle term, in the treatment of partially accommodative esotropia with high AC/A ratio.
Introduction
Anterior segment ischemia may occur when three or more rectus muscles are operated in the same eye. Our purpose was to investigate the efficacy of rectus muscle stretching as a ...vessel-sparing weakening technique, in comparison with a retrospectively collected series of patients.
Methods
Non-operated patients with an indication of medial rectus muscle weakening surgery (deviation up to 20 PD, prism diopters) who could cooperate with topical or sub-Tenon’s anesthesia. Clinical workup included routine complete ophthalmological evaluation. One double-needle 6/0 Mersilene suture was used on each side of the muscle at 4 mm distance of the insertion and pulled/stretched to insert in the sclera 3–5 mm posterior to the muscle locking passes. Main outcome measure was distance deviation at 2 months after surgery (alternate prism and cover test).
Results
Seven patients with esotropia of 12–20 PD, recruited in a 20-month period, were included. Preoperative median deviation was 20 PD, whereas postoperative median deviation was 4 PD (range 0–8 PD). On a visual pain scale (1–10) median pain score was 3 (range 2–5). Remarkable postoperative complications did not occur. Significant differences with a retrospectively collected series of patients’ data, treated with standard medial rectus recession, were not observed.
Conclusions
Preliminary data indicate that stretching of a rectus muscle has some weakening effect, that could be useful to correct small-angle strabismus, and may be suggested as a vessel-sparing technique when two rectus muscles have previously been operated in the same eye.
Trial Registration
ClinicalTrials.gov NCT05778565.
To study the effect of small-incision cataract surgery on the optical aberrations of the cornea.
Corneal topography was measured before and after cataract surgery on 70 eyes of 70 patients. Monofocal ...foldable IOLs were implanted after phacoemulsification through a clear-cornea, 3.5-mm incision without suture. Corneal aberrations, up to the fifth order and 6-mm pupil, were calculated by ray-tracing from the corneal topography. Pre- and postoperative aberrations were compared in each patient and the optical changes induced by surgery investigated.
The root mean square of the wave aberration slightly increased on average after surgery (pre, 0.65 +/- 0.46 microm; post, 0.85 +/- 0.63 microm). Most aberration terms were similar, averaged across the 70 patients, before and after surgery (spherical aberration: pre, 0.32 +/- 0.12 microm, and post, 0.34 +/- 0.19 microm; astigmatism: pre, 0.9 +/- 0.8 D, and post, 1.1 +/- 1.0 D; coma: pre, 0.27 +/- 0.18 microm, and post, 0.32 +/- 0.33 microm). However, in each patient, there were changes after surgery in the magnitude (either increasing or decreasing) and/or orientation of aberrations. The mean induced astigmatism was -1.0 +/- 0.9 D at the orientation of the surgical meridian. Induced trefoil also showed a predominant pattern at this direction. Patients with nasal incisions experienced larger changes.
Small-incision surgery does not systematically degrade the optical quality of the anterior corneal surface. However, it introduces changes in some aberrations, especially in nonrotationally symmetric terms such as astigmatism, coma, and trefoil. The incision site plays a main role in the corneal changes after surgery.
To investigate the best location of clear-cornea incision in phacoemulsification, depending on preexisting corneal astigmatism.
Randomized clinical trial and noncomparative interventional case ...series.
A total of 574 patients in five stages were assigned to the following incisions: superior or temporal (n = 89), superior (n = 141), superior or superior plus relaxing (n = 102), nasal or temporal (n = 156), and incisions based on applying conclusions of preceding and current studies (n = 86). Visual acuity, refraction, biomicroscopy, keratometry, and videokeratography (Fourier analysis) were performed before and after phacoemulsification and intraocular lens implantation (3.5-mm incision). main outcome measures: Corneal refractive and surface regularity index change between preoperative and 6-month postoperative examination. Visual acuity at 6 months.
In patients without corneal astigmatism, corneal changes induced were greater in superior than temporal incision. After a superior incision (preoperative steep axis at 90 degrees), a shift of the axis 90 degrees away was less likely with at least 1.5 diopters of astigmatism. A perpendicular relaxing limbal incision decreased corneal changes. Nasal incision induced greater corneal change than temporal incision (preoperative steep axis at 180 degrees). A shift of this axis 90 degrees away was more likely with astigmatism < 0.75 diopters in temporal incision and < 1.25 diopters in nasal incision.
Superior incision is recommended with at least 1.5 diopters of astigmatism and steep axis at 90 degrees. Temporal incision is recommended with astigmatism < 1.5 diopters and steep axis at 90 degrees, negligible astigmatism, or astigmatism < 0.75 diopters and steep axis at 180 degrees. Nasal incision is recommended with at least 0.75 diopters of astigmatism and steep axis at 180 degrees.
Purpose To compare the efficacy and sensory outcome of pharmacologic and optical penalization in the treatment of moderate to mild amblyopia. Design Randomized clinical trial. Methods In an ...institutional setting, two- to 10-year-old children with strabismic or anisometropic amblyopia (visual acuity in the amblyopic eye at least 20/60) who were cooperative to measure visual acuity using the logarithm of the minimum angle of resolution (logMAR) crowded Glasgow acuity cards were randomized into two groups of therapy (n = 35 in each group), 1% atropine, and optical penalization with positive lenses, after stratification by cause of amblyopia. Visual acuity was tested by the logMAR crowded Glasgow acuity cards, after retinoscopic refraction, and deviation angle were measured by the simultaneous prism and cover or Krimsky test. Stereoacuity was determined using the Titmus fly test and Randot preschool or Randot circles stereoacuity test. Change in visual acuity of the amblyopic eye and in interocular difference of visual acuity after six months of amblyopia therapy was the main outcome measure; stereoacuity at six months of therapy was a secondary outcome measure. Results Thirty-one and 32 children completed the outcome examination in the atropine and optical penalization group, respectively. Average improvement in visual acuity of the amblyopic eye was larger in the atropine than in the optical penalization group (3.4 and 1.8 logMAR lines, respectively), as well as average improvement in interocular difference of visual acuity (2.8 and 1.3 logMAR lines, respectively). Better stereoacuity, but nonsignificantly different, was detected in the atropine group. Conclusions Atropine penalization may be considered more effective than optical penalization with positive lenses.
To model incisional axis and perpendicular corneal profile pattern changes in 2.2-mm corneal incision phacoemulsification.
Sixty-seven eyes of 67 patients were included in this prospective, ...interventional, before-after paired design study. Power vector components were obtained from keratometry (IOLMaster; Carl Zeiss Meditec, Göttingen, Germany) and topography corneal height data with the Pentacam HR (Oculus Optikgeräte, Wetzlar, Germany) preoperatively and at 6 months postoperatively. Second- to sixth-order curve fitting polynomial functions of the corneal profile in the incisional and perpendicular axes were created using Matlab (The Mathworks, Inc., Natick, MA). Multivariate regression analysis was run to study the influence of potential predictors. Correlation of changes in corneal elevation and corneal radius with astigmatic parameters was also obtained.
Significant changes occurred only in the J(0) (P = .004) and M (P = .001) parameters. R(2) was high with all of the fitted polynomials (0.98 to 0.99) and although the smallest root mean square error was obtained with sixth-degree polynomials (0.63 to 1.13), they were more badly conditioned and redundant than quadratic polynomials. Corneal flattening changes were obtained on axis, which was the most frequent pattern (n = 52, 77%), but were significantly larger in the incisional side than the non-incisional side (P = .001) and only coupled with perpendicular axis steepening in 23 patients. In the non-incisional side on axis, corneal steepening was a relatively frequent pattern (n = 22 patients, 33%). Predictors studied for profile pattern of change were only near significance. Corneal radius of curvature changes were significantly correlated with astigmatic parameters.
Polynomial curve fitting is adequate for corneal biomechanical modeling of curvature and profile changes in the incisional and perpendicular axes of a 2.2-mm incision for phacoemulsification.
To study the induced refractive change caused by different 2.8-mm corneal incision locations in phacoemulsification.
One hundred ten patients were randomly assigned to nasal or temporal incision or ...to superior incision, depending on preexisting astigmatism. The authors fulfilled visual acuity, refraction, keratometry, and eye scanner analysis before and after phacoemulsification. Outcome measures were induced corneal refractive change (Fourier power vector analysis), index of surface variance (ISV) change, and visual acuity at 6 months. A comparative interventional case series was used for the study design.
Induced refractive change caused by different incision locations showed differences in parameter J0 (JCC at axis 0 degrees ), which was smaller after temporal than after nasal or superior incision, with marginal clinical significance and influence in uncorrected visual acuity. ISV changes did not differ between incisional groups.
Small differential effects of incisions by location may be useful, depending on preexisting astigmatism. Temporal incisions are recommended for negligible astigmatism, whereas nasal and superior incisions are preferable when the steep axis is located at approximately 180 degrees and 90 degrees, respectively. (ClinicalTrials.gov number, NCT00742950).
To examine the agreement and relationship between refractive and corneal astigmatism in a population of pseudophakic eyes.
Patients of age at least 40 years, visual acuity 20/40 or better, and no ...ocular disease were included (n = 111). Refractive astigmatism was obtained by subjective refraction. Corneal astigmatism was measured by automated keratometry and Scheimpflug scanning analysis. All refractive values were converted to power vector components J0 and J45 for comparison and regression analysis of refractive versus corneal astigmatism. Main outcome measures were refractive and corneal astigmatism components.
Median single Jackson cylinder (J) was similar in refractive 0.37 diopter (D), keratometric (0.46 D), and Pentacam astigmatism (0.49 D) (P = 0.157). Median J0 astigmatic component was slightly negative, indicating against-the-rule (ATR) astigmatism, in refractive and Scheimpflug, but not in keratometric astigmatism (refractive J0: -0.10 D; keratometric J0: 0.05 D; Pentacam J0: -0.08 D) (P = 0.049). J45 astigmatic component was nearly zero and similar with the 3 methods (P = 0.416). Refractive and keratometric J0 were significantly correlated (r = 0.7, P < 0.01), as well as the corresponding J45 values (r = 0.65, P < 0.01). Refractive and Pentacam astigmatic components were worse correlated (J0: r = 0.36, P = 0.01; J45: r = 0.45, P < 0.01). Keratometric and Pentacam astigmatic components were also significantly correlated (J0: r = 0.58, P < 0.01; J45: r = 0.51, P < 0.01).
Mean internal ATR astigmatism, which comes mainly from the posterior corneal surface, adds to anterior corneal astigmatism, resulting in ATR refractive astigmatism. Correlation between refractive and corneal astigmatism components is better when keratometric data are used.
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