Accuracy of IOL Power Calculation Formulas for AcrySof SN60WF versus Tecnis ZCB00 Intraocular Lenses

Purpose: To compare the accuracy of various intraocular lens power formulas for two monofocal hydrophobic foldable lenses, the AcrySof SN60WF and the Tecnis ZCB00. Methods: This retrospective study included 409 eyes from 409 patients who underwent uncomplicated cataract surgery (299 eyes with SN60WF and 110 eyes with ZCB00). Biometry was performed for all eyes with an IOLMaster 700. Predicted refraction from five different IOL power formulas (Barrett Universal II, Haigis, Hoffer-Q, Holladay 2, and SRK/T) was compared to postoperative refraction at one to three months for the following axial length strata: short eyes (<22.5 mm), medium eyes (22.5–25.5 mm), and long eyes (>25.5 mm). Results: In patients with medium eyes, there were no significant differences in the mean absolute error (MAE) and the percentage of eyes within ±0.5 D (%±0.5 D) between both IOLs. In short eyes, although MAE was similar between both lenses, %±0.5 D was significantly higher for Barrett Universal II in ZCB00 than in SN60WF (P = 0.01) while Hoffer-Q and Holladay 2 performed equally for both lenses. In long eyes, ZCB00 had a higher MAE than SN60WF for Barrett Universal II, Haigis, and Hoffer-Q. Additionally, in long eyes, the percentage of eyes within %±0.5 D was significantly higher for SN60WF than ZCB00 for all formulas (P < 0.001). Conclusion: Although there were no significant differences in the formula accuracy between these two lenses in medium eyes for all formulas and in short eyes for most formulas, the accuracy decreased significantly in long eyes for ZCB00 compared to SN60WF. The effect of IOL model on the postoperative outcomes should be further investigated

Etiology and Risk Factors for Infectious Keratitis in South Texas

Purpose: To determine the causative organisms and associated risk factors for infectious keratitis in South Texas. Methods: This retrospective study was performed at a tertiary teaching hospital system in South Texas. Medical records of all patients who presented with infectious keratitis from 2012 to 2018 were reviewed. Only patients with culture-proven bacterial, fungal, and Acanthamoeba keratitis were included. Results: In total, 182 eyes of 181 patients had culture-proven bacterial, fungal, or Acanthamoeba keratitis. The age of patients ranged from 3 to 93 years, with a mean of 48.3 ± 20.8 years. The most common etiologic agent was bacteria, with 173 bacterial cultures (95.1%) recovered, followed by 13 fungal cultures (7.1%), and 3 Acanthamoeba cultures (1.6%). Of the 218 bacterial isolates, coagulase-negative Staphylococcus was the most common (25.7%), followed by Pseudomonas aeruginosa (23.4%), Staphylococcus aureus (11.0%), and Moraxella (7.8%). Fusarium was the most common fungal isolate (46.2%). The most common risk factors for infectious keratitis included contact lens wear (32.4%), underlying corneal disease (17.6%), trauma (14.3%), and ocular surface disease (13.7%). Conclusions: Bacteria are the most common cause of infectious keratitis in this patient population, with coagulase-negative Staphylococcus and Pseudomonas as the most common isolates. The prevalence of culture-positive fungal keratitis is significantly lower than that of bacterial keratitis. Contact lens wear is the most common risk factor associated with infectious keratitis in South Texas

The Effect of Product Market on Dividend Policy and Firms’ Dividends

The present research is conducted to study the effect of product market power on dividend policy and firms’ dividends. In this regard, 83 firms were selected from 2011-2016. Lerner adjusted index was used as a measure of market power; next, the effect on the dividend policy and dividend was examined once the effect of control variables (firm size, profitability, growth opportunities, and firm retained earnings) is observed. Research data were analyzed using data paneling and corresponding tests. Research hypotheses were tested using logistic regression for the first research model, and using multivariate linear regression statistical analyses including Chow test, Hausman test, for the second research model, through Eviews9. Research results show that there is a positive significant relationship between market power and firms dividend policy at the probability 95%. In addition, there is also seen a significant relationship between market power and dividend

Tortuosity classification of corneal nerves images using a multiple-scale-multiple-window approach

Classify in vivo confocal microscopy corneal images by tortuosity is complicated by the presence of variable numbers of fibres of different tortuosity level. Instead of designing a function combining manually selected features into a single coefficient, as done in the literature, we propose a supervised approach which selects automatically the most relevant combination of shape features from a pre-defined dictionary. To our best knowledge, we are the first to consider features at different spatial scales and show experimentally their relevance in tortuosity modelling. Our results, obtained with a set of 100 images and 20 fold cross-validation, suggest that multinomial logistic ordinal regression, trained on consensus ground truth from 3 experts, yields an accuracy indistinguishable, overall, from that of experts when compared against each other

Two-dimensional plane for multi-scale quantification of corneal subbasal nerve tortuosity

Purpose To assess the performance of a novel system for automated tortuosity estimation and interpretation. Methods: A supervised strategy (driven by observers' grading) was employed to automatically identify the combination of tortuosity measures (i.e., tortuosity representation) leading to the best agreement with the observers. We investigated 18 tortuosity measures including curvature and density of inflection points, computed at multiple spatial scales. To leverage tortuosity interpretation, we propose the tortuosity plane (TP) onto which each image is mapped. Experiments were carried out on 140 images of subbasal nerve plexus of the central cornea, covering four levels of tortuosity. Three experienced observers graded each image independently. Results: The best tortuosity representation was the combination of mean curvature at spatial scales 2 and 5. These tortuosity measures were the axes of the proposed TP (interpretation). The system for tortuosity estimation revealed strong agreement with the observers on a global and per-level basis. The agreement with each observer (Spearman's correlation) was statistically significant (αs = 0.05, P < 0.0001) and higher than that of at least one of the other observers in two out of three cases (ρOUR = 0.7594 versus ρObs3 = 0.7225; ρOUR = 0.8880 versus ρObs1 = 0.8017, ρObs3 = 0.7315). Based on paired-sample t-tests, these improvements were significant (P < 0.001). Conclusions: Our automated system stratifies images by four tortuosity levels (discrete scale) matching or exceeding the accuracy of experienced observers. Of importance, the TP allows the assessment of tortuosity on a two-dimensional continuous scale, thus leading to a finer discrimination among images

Peripheral Ulcerative Keratitis: A Review

Peripheral ulcerative keratitis (PUK) is a rare but serious ocular condition that is an important clinical entity due to its ophthalmological and systemic implications. It is characterized by progressive peripheral corneal stromal thinning with an associated epithelial defect and can be associated with an underlying local or systemic pro-inflammatory condition, or present in an idiopathic form (Mooren ulcer). Associated conditions include autoimmune diseases, systemic and ocular infections, dermatologic diseases, and ocular surgery. Cell-mediated and autoantibody- mediated immune responses have been implicated in the pathogenesis of PUK, destroying peripheral corneal tissue via matrix metalloproteinases. Clinically, patients with PUK present with painful vision loss, a peripheral corneal ulcer, and often adjacent scleritis, episcleritis, iritis, or conjunctivitis. Diagnostic evaluation should be focused on identifying the underlying etiology and ruling out conditions that may mimic PUK, including marginal keratitis and Terrien marginal degeneration. Treatment should be focused on reducing local disease burden with topical lubrication, while simultaneously addressing the underlying cause with antimicrobials or anti-inflammatory when appropriate. Existing and emerging biologic immunomodulatory therapies have proven useful in PUK due to autoimmune conditions. Surgical treatment is generally reserved for cases of severe thinning or corneal perforation

Psychosocial Predictors of Cognitive Impairment in the Elderly: A Cross-Sectional Study

Objective: Cognitive impairment is a major public health problem among elderly population. The aim of this study was to assess some psychosocial predictors of cognitive impairment (age, education, living alone, smoking, depression and social support) in the Iranian elderly population. Method: A total of 1612 elderly (over 60 years) were enrolled in this cross-sectional study. Cognitive function was assessed using Mini Mental State Examination (MMSE). In addition, data from psychological tests and demographic characteristics were analyzed. Results: Older age, low education level, living alone, smoking, depressive symptoms, and lower social support were associated with an increased risk of cognitive impairment. Ages 70 to 74 (OR = 3.47; 95% CI, 2.13-5.65), 75 to79 (OR = 3.05; 95% CI, 2.11-4.41) and 80 to 85 (OR = 5.81; 95% CI, 2.99-11.22) and depression symptoms (OR = 1.64; 95% CI, 1.27-2.13) were significant positive predictors, whereas social support with scores ranging from 26 to 30 (OR =0. 32; 95% CI, 0.16-0.62) and 31 to 33 (OR =0.29; 95% CI, 0.14-0.61) and more than 5 years of education (OR = 0.19; 95% CI, 0.14-0.27) were the negative predictors of cognitive impairment. Conclusion: The findings suggest older age and depression as positive predictive factors and higher education level and social support as negative predictive factors of cognitive impairment in the elderly population

Histopathology of Conjunctivochalasis Compared to Normal Conjunctiva

Purpose: To evaluate the histopathologic changes in the conjunctiva of patients with conjunctivochalasis (CCh) compared to age-matched controls. Methods: This cross-sectional, controlled study included 27 eyes of 27 patients with CCh and 16 eyes of 16 age-matched controls. A biopsy of the bulbar conjunctiva was performed along the temporal lower lid margin before cataract surgery in both groups. Histopathologic evaluation of the specimens was done with light microscopy using staining with hematoxylin/eosin, periodic acid Schiff, and van Gieson elastic stain. Various histopathologic features of the conjunctival epithelium and stroma were compared between the two groups. Results: The mean age of patients was 62.4 ± 6.9 years in the CCh group and 65.1 ± 6.3 years in the control group (P = 0.54). No significant differences were noted between the two groups in terms of conjunctival epithelial changes including papillomatosis, epithelial clefts, epithelial goblet cells, or infiltration of inflammatory cells. Mean thickness of the conjunctival stroma was 0.21 ± 0.08 mm in the CCh group and 0.26 ± 0.21 mm in the control group (P = 0.10). For the conjunctival stroma, there were no significant differences between the two groups in terms of elastosis, fibrosis, lymphangiectasia, or infiltration of inflammatory cells. Conclusion: No noticeable differences were found in the histopathologic features by light microscopy between eyes with CCh and those of age-matched controls. Therefore, the primary pathology of CCh may not be within the conjunctiva itself. Instead, loose attachment of the conjunctiva to the underlying tissue may be the reason for the redundant folds in the bulbar conjunctiva

Effects of Corneal Nerve Density on the Response to Treatment in Dry Eye Disease

Purpose To evaluate whether levels of corneal subbasal nerve fiber length (SNFL) in dry eye disease (DED) could prognosticate the level of improvement in signs and symptoms after treatment. Design Phase IV, double-masked, randomized clinical trial. Participants Sixty patients with meibomian gland dysfunction-associated DED and 27 age-matched controls. Methods Patients with DED were randomized to receive topical artificial tears, loteprednol etabonate 0.5%, or loteprednol etabonate 0.5%/tobramycin 0.3% twice daily for 4 weeks. At baseline, in vivo confocal microscopy of central cornea was performed in both eyes. Patients with DED were divided into 2 subgroups, those with low baseline SNFL and those with near-normal baseline SNFL (the cut-off point: mean SNFL in controls minus 2 standard deviations). Clinical signs and symptoms at baseline and after 4 weeks of treatment were compared between the subgroups with low and near-normal SNFL for all therapeutic groups. Main Outcome Measures Symptom questionnaires, corneal fluorescein staining (CFS), conjunctival staining with lissamine green, tear break-up time, Schirmer’s test, and SNFL. Results In patients with DED, baseline SNFL (17.06 ± 5.78 mm/mm2) was significantly lower than in controls (23.68 ± 3.42, P=0.001). In the artificial tear and loteprednol groups, although no significant improvement in any sign or symptom was noted in patients with low baseline SNFL (<16.84 mm/mm2), subjects with near-normal baseline SNFL (≥16.84 mm/mm2) showed significant improvement in both symptoms and corneal fluorescein staining (CFS) score (all P<0.05). In the loteprednol/tobramycin group, no significant change was evident for any sign or symptom in either subgroup of low or near-normal baseline SNFL. Conclusions Significant improvements in CFS and patient symptomatology after DED treatment were evident only in the subgroup with near-normal corneal SNFL. Consideration of SNFL may thus assist in explaining the variability of patients’ response to DED therapy