Explore the vast range of titles available.

We empirically advocate for UK regulators to increase the volume limit of 15% outstanding shares on open market repurchases. Our main framework initially tests the determinants of share repurchases based on their size, Small, Medium and Large. The findings reveal that consistent with extant literature, the payout is primarily determined by its capability of distributing excess cash to shareholders and signaling undervaluation. We then check the viability of increasing the volume limit by testing new levels at 2.50% increments, up to 30%. The results indicate that any increase does not broadly change the determinants’ relationship with the payout, rather increased efficiency is realized at every interval, with the 20% and 30% levels being the most favorable.

To identify corneal epithelial- and stromal-thickness distribution patterns in keratoconus using spectral-domain optical coherence tomography (SD-OCT). We analyzed SD-OCT findings in 20 confirmed cases of keratoconus (group 1) and in 20 healthy subjects with corneal astigmatism ≥ 2 D (group 2). Epithelial and stromal thicknesses were measured at 11 strategic locations along the steepest and flattest meridians, previously located by corneal topography. Vertical mirrored symmetry superimposition was used in the statistical analysis. The mean maximum keratometry measurements in groups 1 and 2 were 47.9 ± 2.9 D (range, 41.8-52.8) and 45.6 ± 1.1 D (range, 42.3-47.5), respectively, with mean corneal cylinders of 3.3 ± 2.2 D (range, 0.5-9.5) and 3.6 ± 1.2 D (range, 2.0-6.4), respectively. The mean epithelial thickness along the steepest meridian in group 1 was the lowest (37.4 ± 4.4 µm) at 1.2 mm inferotemporally and the highest (59.3 ± 4.4 µm) at 1.4 mm supranasally from the corneal vertex. There was only a small deviation in thickness along the steepest meridian in group 2, as well as along the flattest meridians in both groups. The stromal thickness distribution in the two groups was similar to the epithelial, while the stromal thickness was generally lower in group 1 than in group 2. SD-OCT provides details about the distribution of corneal epithelial and stromal thicknesses. The epithelium and stroma in keratoconic eyes were thinner inferotemporally and thicker supranasally compared with control eyes. The distribution pattern was more distinct in epithelium than in stroma. This finding may help improve the early diagnosis of keratoconus. ClinicalTrials.gov NCT02023619.

PURPOSE: To study the corneal epithelial and stromal thickness profile changes after photorefractive keratectomy (PRK) for myopia. METHODS: Retrospective analysis of the postoperative corneal epithelial and stromal thickness profile changes in 46 left eyes of 46 patients treated with PRK for myopia. Corneal and epithelial thickness maps within the central 6 mm were obtained by anterior segment spectral-domain optical coherence tomography preoperatively and at 1, 3, and 6 months postoperatively. Stromal thickness was calculated by subtracting the epithelial thickness from the total corneal thickness. Correlations between postoperative thickness changes and the amount of correction, treatment zone, and preoperative epithelial thickness were analyzed. RESULTS: Compared to preoperative values, the central 2 mm and the paracentral 2- to 5-mm zone epithelium was 5.20 ± 3.43 and 5.72 ± 3.30 Compared to preoperative values, the central 2 mm and the paracentral 2- to 5-mm zone epithelium was 5.20 ± 3.43 and 5.72 ± 3.30 µ m thicker, respectively, at 3 months postoperatively ( P < .05). No significant difference was detected between 3 and 6 months postoperatively. The stromal thickness did not change between 1 and 6 months postoperatively. The spherical equivalent (SE) changed from −2.82 ± 1.54 diopters (D) preoperatively to −0.06 ± 0.42 D at 1 month postoperatively, and remained stable thereafter. There was a trend toward greater epithelial thickening with a larger amount of programmed SE correction, smaller treatment zone, and thinner preoperative epithelium. No correlation between epithelial thickness change and postoperative change in refraction was detected. CONCLUSIONS: The corneal epithelial thickness increased after PRK up to 3 months postoperatively. It was affected by the amount of myopia treated, treatment zone, and preoperative epithelial thickness. The postoperative epithelial thickening did not affect the refractive outcomes. [[ J Refract Surg. 2015;31(7):446–453.]

To determine the measurement reliability of CorVis ST, a dynamic Scheimpflug analyser, in virgin and post-photorefractive keratectomy (PRK) eyes and compare the results between these two groups. Forty virgin eyes and 42 post-PRK eyes underwent CorVis ST measurements performed by two technicians. Repeatability was evaluated by comparing three consecutive measurements by technician A. Reproducibility was determined by comparing the first measurement by technician A with one performed by technician B. Intraobserver and interobserver intraclass correlation coefficients (ICCs) were calculated. Univariate analysis of covariance (ANCOVA) was used to compare measured parameters between virgin and post-PRK eyes. The intraocular pressure (IOP), central corneal thickness (CCT) and 1st applanation time demonstrated good intraobserver repeatability and interobserver reproducibility (ICC ≧ 0.90) in virgin and post-PRK eyes. The deformation amplitude showed a good or close to good repeatability and reproducibility in both groups (ICC ≧ 0.88). The CCT correlated positively with 1st applanation time (r = 0.437 and 0.483, respectively, p<0.05) and negatively with deformation amplitude (r = -0.384 and -0.375, respectively, p<0.05) in both groups. Compared to post-PRK eyes, virgin eyes showed longer 1st applanation time (7.29 ± 0.21 vs. 6.96 ± 0.17 ms, p<0.05) and lower deformation amplitude (1.06 ± 0.07 vs. 1.17 ± 0.08 mm, p < 0.05). CorVis ST demonstrated reliable measurements for CCT, IOP, and 1st applanation time, as well as relatively reliable measurement for deformation amplitude in both virgin and post-PRK eyes. There were differences in 1st applanation time and deformation amplitude between virgin and post-PRK eyes, which may reflect corneal biomechanical changes occurring after the surgery in the latter.

PURPOSE: To evaluate the safety, efficacy, and predictability of IntraLase (Abbott Medical Optics) femtosecond laser–assisted compared to microkeratome-assisted myopic LASIK. METHODS: A comprehensive literature search of Cochrane Library, PubMed, and EMBASE was conducted to identify relevant trials comparing LASIK with IntraLase femtosecond laser to LASIK with microkeratomes for the correction of myopia. Meta-analyses were performed on the primary outcomes (loss of ≥2 lines of corrected distance visual acuity [CDVA], uncorrected distance visual acuity [UDVA] 20/20 or better, manifest refraction spherical equivalent [MRSE] within ±0.50 diopters [D], final refractive SE, and astigmatism), and secondary outcomes (flap thickness predictability, changes in higher order aberrations [HOAs], and complications). RESULTS: Fifteen articles describing a total of 3679 eyes were identified. No significant differences were identified between the two groups in regards to a loss of ≥2 lines of CDVA (Fifteen articles describing a total of 3679 eyes were identified. No significant differences were identified between the two groups in regards to a loss of ≥2 lines of CDVA ( P =.44), patients achieving UDVA 20/20 or better ( P =.24), final UDVA ( P =.12), final mean refractive SE ( P =.74), final astigmatism ( P =.27), or changes in HOAs. The IntraLase group had more patients who were within ±0.50 D of target refraction ( P =.05) compared to the microkeratome group, and flap thickness was more predictable in the IntraLase group ( P <.0001). The microkeratome group had more epithelial defects ( P =.04), whereas the IntraLase group had more cases of diffuse lamellar keratitis ( P =.01). CONCLUSIONS: According to the available data, LASIK with the IntraLase femtosecond laser offers no significant benefits over LASIK with microkeratomes in regards to safety and efficacy, but has potential advantages in predictability.

Background The primary objective of this investigation was to compare the nominal central ablation depth with the achieved central corneal stromal ablation depth after StreamLight transepithelial photorefractive keratectomy (tPRK) for myopia with WaveLight® laser by Alcon Laboratories, TX, USA. Methods This ambispective study encompassed a retrospective analysis of 40 eyes who underwent treatment for myopia and astigmatism, followed by a prospective examination conducted 6–9 months postoperatively. Pre- and postoperative Avanti spectral-domain optical coherence tomography (SD-OCT; Optovue Inc., CA, USA) provided stromal and epithelial thickness maps. The difference between pre- and postoperative central stromal thicknesses at the corneal vertex was used to calculate the achieved stromal thickness ablation depth. This value was then compared with the corresponding central nominal depth on the laser ablation planning map. Results A total of 40 eyes (OD/OS:18/22) of 40 patients (31.4 ± 9.2 years) were available for evaluation. The mean treated spherical equivalent was − 2.98 ± 1.46 D. The mean nominal and achieved central stromal ablation depths were 51.22 µm and 59.67 μm, respectively, showing a mean stromal excessive ablation of 16.50%. The mean pre- and postoperative central epithelial thicknesses were 53.74 μm and 59.31 μm, respectively, showing a mean postoperative thickness increase of 10.46%. This increase in the epithelial thickness rendered the mean postoperative pachymetry reduction to 54.11 μm, only 2.33% greater than the mean nominal ablation depth. Conclusions The study revealed a central stromal ablation 16.50% greater than the nominal ablation depth. This excessive stromal removal was largely compensated for by the increase in epithelial thickness, resulting in a mean difference between the nominal ablation depth and the achieved central corneal pachymetry reduction of only 2.33%. This significant excessive central stromal ablation must be taken into consideration in the calculation of the residual stromal thickness.

To assess the tear film and meibomian gland (MG) features in a Norwegian cohort of patients with primary Sjögren´s syndrome (pSS) and in age- and gender-matched control subjects. Thirty-four female patients with pSS (age 52.9±11.9 years) and 32 female control subjects (age 49.0±11.5 years) were recruited. After completion of Ocular Surface Disease Index (OSDI) questionnaire and McMonnies Dry Eye Questionaire, participants underwent measurements of tear osmolarity, tear break-up time (TBUT), ocular surface and corneal staining, Schirmer I test, corneal sensitivity, MG expressibility evaluations, and lid margin morphology examination using slitlamp microscopy. Non-contact infrared meibography images were assessed by computer-assisted analysis. The MG loss, calculated as (tarsal area-MG area)/tarsal area, was evaluated in both upper (UL) and lower lids (LL). Compared to the control group, pSS patients demonstrated higher MG loss in both UL (33.8±13.2% vs. 24.4±8.5%, p< 0.01) and LL (52.5±15.7% vs. 43.0±9.6%, p<0.05), as well as higher lid abnormality score (0.8±0.8 vs. 0.2±0.6, p< 0.01). Furthermore, pSS patients showed higher OSDI and McMonnies questionnaire scores, elevated osmolarity, shorter TBUT, shorter blink interval, less wetting in Schirmer I test, more ocular surface staining and more corneal staining. MG loss in UL correlated negatively with TBUT (r = -0.386, p = 0.029) in the pSS group, whereas MG loss in LL correlated negatively with TBUT (r = -0.380, p = 0.035) in the control group. Significantly elevated dry eye symptoms and signs were found in the pSS group compared with the control group, which might be attributed to both decreased aqueous tear production and increased tear evaporation.

PURPOSE: To evaluate a combination of topography-guided custom ablation and corneal collagen cross-linking (CXL) in a single procedure for the treatment of keratectasia. METHODS: Twelve eyes of 12 patients with keratectasia were treated with topography-guided custom ablation and CXL. Topography-guided custom ablation was performed using a transepithelial technique with the iVIS Suite 1 kHz flying spot excimer laser. Collagen cross-linking was performed immediately after topography-guided custom ablation, according to standard protocol. Postoperative follow-up examinations were performed at 1, 3, 6, and 12 months. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refractive change, corneal topography, and pachymetry were analyzed pre- and postoperatively. RESULTS: Mean UCVA increased from 20/1000 preoperatively to 20/125 12 months postoperatively. Mean BSCVA increased from 20/57 to 20/35, with no loss of lines of visual acuity. Mean astigmatism was reduced from 5.40±2.13 diopters (D) to 2.70±1.44 D, and keratometric asymmetry decreased from 6.38±1.02 D to 2.76±0.73 D. Only minor changes in posterior corneal surface elevation and stability of refraction were found, confirming that no progression of ectasia occurred during the observation time. CONCLUSIONS: A combination of topography-guided custom ablation and CXL improved patients' visual, refractive, and topography outcomes and halted the progression of keratectasia within the observation period of 12 months. This method may postpone or eliminate the need for corneal transplantation in suitable cases with keratectasia. [J Refract Surg. 2010;26:145–152.]

Ticks are significant vectors of pathogens in human and veterinary medicine and have been identified as (re)emerging health threats. The primary objective of this study was to collect new data on the fauna of hard ticks within the region of Istria with a focus on spatial distribution using a geographical information system (GIS). All tick specimens were collected over three years (2020–2023), and this research included all 41 self-government units of Istria and Brijuni Islands National Park. Ticks were collected using the flagging/dragging method and manually from hosts (humans, domestic, or wild animals). In addition, morphological identification using tick keys was performed. The obtained data were used to create maps and feed models and to predict risk assessments. Collected data reveal the predominant presence of Ixodes ricinus, accounting for (n = 446) or 48.1% of the tick population. Rhipicephalus sanguineus (Ixodida: Ixodidae) follows with (n = 253) or 27.23%, and Hyalomma marginatum represents (n = 136) or 14.64% of the tick species collected using the host method in the region. Tick–host relationships are complex and influenced by a range of ecological and environmental factors. The results of this research will contribute to a better understanding, identification, and prediction of the changes in their geographic ranges and help in the prevention and control of zoonosis transmitted to humans by ticks. The obtained results mapped using GIS support the first study on the spatial distribution of ticks in the region of Istria in Croatia.