Using Electrochemical Impedance Spectroscopy as a Tool for Organic Coating Solute Saturation Monitoring

Electrochemical impedance spectroscopy (EIS) has been used to study the solute uptake for epoxy/phenolic (E/p) andepoxy/amine (E/a) thick-coated mild steel samples immersed for 160 days in 3.5 weight percent NaCl solution exposed to air. Samples with thicknesses of approximately 200 µm with an exposed surface area of 22.6 cm2 were used to follow solute saturation of the organic coating. Good agreement was obtained between the calculated and measured coating capacitance when, according to the diffusion equation, the coating capacitance was plotted against exposure time

Analysis of Scheimpflug Tomography Parameters for Detecting Subclinical Keratoconus in the Fellow Eyes of Patients with Unilateral Keratoconus in the Eastern Province of Saudi Arabia

Abdulaziz Al Somali,1 Hatim Najmi,2 Hend Alsawadi,2 Hassan Alsawadi,3 Assaf AlMalki,2 Mustafa Alhamoud,2 Hatlan Alhatlan,4 Nada Alwohaibi5 1Department of Ophthalmology, King Faisal University, Alahsa, Saudi Arabia; 2Department of Ophthalmology, Dhahran Eye Specialist Hospital, Dhahran, Saudi Arabia; 3Department of Electrical and Computer Engineering, King Abdulaziz University, Jeddah, Saudi Arabia; 4Department of Ophthalmology, King Fahad Hospital, Hofuf, Saudi Arabia; 5Cornea, External Diseases, and Refractive Surgery Fellow, Dhahran Eye Specialist Hospital, Dhahran, Saudi ArabiaCorrespondence: Hatim Najmi, Department of Ophthalmology, Dhahran Eye Specialist Hospital, Dhahran, Al Ameen 6927, Khobar, Eastern Province, 34446, Saudi Arabia, Tel +966533677784, Fax +966133583898, Email [email protected]: We compared the characteristics of subtle morphological changes in subclinical keratoconus (KC) and normal corneas using Scheimpflug tomography (Pentacam®) and assessed the efficacy of these parameters for distinguishing KC or subclinical KC from normal eyes.Patients and Methods: In this multicenter comparative study at Dhahran Eye Specialist Hospital and Al Kahhal Medical Complex in the Eastern Province of Saudi Arabia, we analyzed the Scheimpflug tomography charts of patients with topographically normal eyes and those with unilateral KC. Patients were divided into the normal (NL: patients considered for refractive surgery and with normal topographic/tomographic features, 129 eyes), KC (30 patients with manifest KC in one eye based on biomicroscopy and topographical findings), and forme fruste KC (FFKC: fellow eyes of patients in the KC group that met the NL group criteria) groups. Corneal morphological parameters were analyzed using the area under the receiver operating characteristic (ROC) curves (AUCs).Results: For distinguishing NL and KC groups, all measured corneal morphological parameters, except for flat keratometry, maximum Ambrósio relational thickness index, and minimum sagittal curvature, had AUCs > 0.75. The surface variance index yielded the largest AUC (0.999). For distinguishing NL and FFKC groups, all corneal morphological parameters had AUCs < 0.8. Total higher-order aberrations (RMS HOA) yielded the highest AUC, followed by Belin/Ambrỏsio Enhanced Ectasia total deviation (BAD-D), back elevation at the thinnest location, average pachymetric progression index (PPIave), and deviation of Ambrỏsio relational thickness (Da) (AUC 0.74– 0.78).Conclusion: The diagnostic performance of all tested topographic and tomographic parameters measured using Scheimpflug tomography for discriminating subclinical KC was fair at best, with the top parameters being RMS HOA, BAD-D, back elevation at the thinnest location, PPIave, and Da. Distinguishing between subclinical KC and healthy eyes remains challenging. Multimodal imaging techniques may be required for optimal early detection of subtle morphological changes.Plain language summary: Normal fellow eyes in patients with unilateral keratoconus were found to exhibit the mildest form of subclinical keratoconus. The parameters of these eyes were compared with those of normal eyes in the Saudi population using Scheimpflug tomography to detect early, subtle morphological changes. Most of the evaluated parameters were unsatisfactory in terms of their ability to discriminate between subclinical keratoconus and normal eyes, implying the need for multimodal imaging techniques for the optimal early detection of subclinical keratoconus.Keywords: ectatic corneal disease, forme fruste keratoconus, keratoconu

Metformin use among obese patients with prediabetes in Qassim, Saudi Arabia: An observational study

Background and aims: The high prevalence of prediabetes and diabetes mellitus and its secondary complications in Saudi Arabia is a major healthcare concern. Evidence suggests that despite evidence-based efficacy and safety, metformin is underutilized in prediabetic obese patients. Thus, the aim of this study was to investigate the use of metformin in prediabetic obese patients in the Qassim region of Saudi Arabia. Methods: Prediabetic patients' electronic health records were accessed and screened from 2017 to 2021. The inclusion criteria were patients with obesity (BMI ≥ 35) diagnosed with prediabetes, and who received metformin. Patients with chronic kidney disease and those using metformin for other diseases were excluded. The first major endpoint of this study was the rate of metformin use among obese, prediabetic individuals. The second major endpoint was the factors associated with metformin prescribing in our cohort. Descriptive statistics were used to report the primary and secondary outcomes. Data are presented as percentages, means, standard deviations (SDs), medians, and interquartile ranges, as appropriate. All analyses were conducted using Stata version 16.1. Results: A total of 304 prediabetic patients were included in this study after screening the records of 1,789 patients. The average age was found to be 40, and the majority were female (72%). The average BMI was found to be 39.4 kg/m2, while the average HbA1c was 5.8%. In the entire sample, only 25 (8.22%) obese patients received metformin for diabetes prevention. Among obese patients with a BMI ≥ 30, 19 patients (8.7%) received metformin. Metformin users had higher odds of being on statins (OR 2.72, 95% CI 1.01 to 7.36; p = 0.049). Conclusion: According to the study, metformin is not frequently prescribed to prediabetic obese individuals in the Qassim region of Saudi Arabia. This prevention strategy is a missed opportunity in the management of prediabetes in high-risk patients. Future studies are needed to investigate the root causes of the underuse of metformin and potential interventions to promote evidence-based practice in Saudi Arabia