Comparison of cytotoxic, apoptotic and oxidative properties of Akacid plus and chlorhexidine in corneal epithelial cell culture.

PURPOSE: This study aims to compare the cytotoxic, apoptotic, and oxidative effects of a new cationic disinfectant, Akacid Plus, with chlorhexidine, on the human corneal epithelial cell line. METHODS: Time-dependent cytotoxicity studies were performed with the Alamar Blue method. Apoptotic activity was investigated by flow cytometric methods. Reactive oxygen species levels were measured with the ROS cellular test kit. BAX, BCL2 and caspase 3, 9, 12 mRNA expressions were evaluated by PCR, as well as BAX and BCL2 protein expressions by Western-Blot. RESULTS: At the fifth minute of the treatment, the viability was 68.15% with Akacid Plus and 43.95% with chlorhexidine. At the 15th minute, no significant difference was observed with both solutions. In the apoptotic evaluation, Akacid Plus significantly increased the early and late apoptotic activity in the cell line (p < 0.0001), while a significant increase was observed in late apoptosis and necrosis levels with chlorhexidine (p < 0.001). Chlorhexidine also induced gene expression of BAX, BCL2, caspase 3, 9 and BAX proteins (p < 0.05), while reducing protein expression of BCL2 (p < 0.001). Akacid Plus induced the gene expressions of BCL2, CASP3 and caspase 9, reduced gene expressions of BAX and caspase 12 and protein expression of BCL2 (p < 0.05). No significant difference was observed in the ROS level with both solutions (p > 0.05). CONCLUSION: Due to the widespread use of cationic polymers in ophthalmology, this new molecule with high antimicrobial activity and relatively low cytotoxicity may be of interest for clinical use. Further investigations are necessary to fully understand the ophthalmologic potential of this solution.

Choroidal vascular changes in non-alcoholic fatty liver disease.

INTRODUCTION: The most common cause of death in nonalcoholic fatty liver disease (NAFLD) is cardiovascular disease. Choroidal microvascular structure in the eye may be a predictor of systemic vascular disease. We aimed to evaluate the effects of NAFLD on the choroidal microvascular structure using enhanced depth optical coherence tomography (EDI-OCT). MATERIAL AND METHODS: This prospective study was conducted by evaluating a total of 96 patients, 52 with steatosis and 44 without steatosis. After anthropometric measurements and ultrasonography were performed in the Gastroenterology Clinic, venous blood samples were taken for biochemical examinations. Then, all patients underwent an eye examination by an ophthalmologist. Subfoveolar choroidal thickness (SFCT) values of the cases were measured with EDI-OCT. Choroid vascular index (CVI) measurements were obtained by dividing the subfoveal choroidal area in the EDI-OCT images into luminal and stromal areas using the image binarization technique (ImageJ). In statistical analysis, the chi-square test was used to compare categorical data, and the independent t-test and Mann-Whitney U test were used to compare quantitative data. RESULTS: The mean age of those with fatty liver was 41±15.7 years, and of those without fatty liver it was 46 ± 10.7 years. There was nostatistically significant difference between the groups in terms of age (p = 0.064). Body mass index (BMI), waist circumference (WC), glucose, uric acid, alanine aminotransferase (ALT), gamma glutamyl transpeptidase (GGT), total cholesterol (TC), ferritin, insulin, and Homestatic Model Assesment - Insuline Restistance (HOMA-IR) were statistically significantly higher in the NAFLD group. On the other hand, there was no statistically significant difference between the groups in terms of low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol, triglyceride, and aspartate aminotransferase (AST) values. The mean SFCT was measured as 280.26 ± 23.68 microns in the NAFLD group, and 308.96 ± 18.57 microns in the control group. There was no statistically significant difference in SFCT between the groups (p = 0.077). CVI measurements were 0.63 and 0.65, respectively, and they were significantly lower in the group with NAFLD (p = 0.045). CONCLUSIONS: This is the first study in the literature to compare patients with and without ultrasonographic fatty liver in terms of choroidal vascular changes. We found that the choroidal vascular index decreased in NAFLD. This result proves that NAFLD causes changes at the microvascular level and is a multisystemic disease.

Investigation of changes in retinal vascular parameters and choroidal vascular index values during the early recovery period of COVID-19: The COVID-OCTA study.

BACKGROUND: COVID-19 effects microvasculature in many tissues. This study investigated whether the choroidal structure is also affected. METHODS: This cross-sectional study included 80 patients with COVID-19 and the same number of age- and gender-matched healthy individuals. All participants' right eye measurements were examined. Optical coherence tomography angiography (OCTA) was used for imaging. Otherwise, two independent researchers used the Choroidal vascular index (CVI) for choroidal parameters calculation. RESULTS: Superior and deep flow values were lower in the COVID-19 group than in the control group, and vascular density (VD) values were lower in all regions in this group. Except for the superior mean VD, there was no statistically significant difference (p = 0.003). However, the COVID-19 group had significantly lower subfoveal choroidal thickness (SFChT) measurements than the control group (p = 0.001). In addition, no significant difference was observed between the groups in evaluating mean CVI values (p>0.05). CONCLUSION: Noninvasive diagnostic tools such as OCTA and EDI-OCT can be used to monitor early changes in diseases affecting microvessels, such as from COVID-19.

Cytotoxic, Apoptotic, and Oxidative Effects of Preserved and Preservative-Free Brimonidine in a Corneal Epithelial Cell Line.

Purpose: This study aims to compare the cytotoxic, apoptotic, and oxidative effects of preserved and preservative-free forms of brimonidine 0.15% on the human corneal epithelial cell (HCEC) line. Methods: Time-dependent cytotoxicity studies were performed with the Alamar Blue method. For apoptotic studies, PE Annexin V and 7-amino-actinomycin (7-AAD) staining and flow cytometry were performed. Messenger RNA (mRNA) expressions of Bax, Bcl-2, and caspase-3, -9, -12, and protein expressions of Bax and Bcl-2 were evaluated by quantitative real-time polymerase chain reaction and Western blot method, respectively. Results: Cell viability was 76.4% with the preserved solution and 36.05% with the preservative-free solution at the fifth minute. No significant difference was observed with either solution at the 15-min mark, whereas cell viability did not change significantly after 1 h. In the apoptosis evaluation, it was observed that the preservative-free solution increased the early apoptotic activity to a greater degree (P < 0.05). Preservative-free solution also induced gene expression of proapoptotic Bax, caspase-9 and -12, and protein expression of Bax while reducing the protein expression of anti-apoptotic Bcl-2 (P < 0.0001). Preserved solution induced only the gene expression of caspase-12, and reduced the protein expression of Bcl-2 (P < 0.0001). No significant difference was observed in the reactive oxygen species (ROS) levels of either solution compared with the control group (P > 0.05). Conclusion: It was demonstrated that the preserved solution is less cytotoxic to the HCEC line in the early period, has less early apoptotic activity, and does not significantly increase ROS levels.

Comparison of refractive outcomes using Scheimpflug Holladay equivalent keratometry or IOLMaster 700 keratometry for IOL power calculation.

PURPOSE: This study aims to compare postoperative refractive error results using Pentacam (Oculus Optikgeräte GmbH) Holladay equivalent keratometry readings (EKR) or IOLMaster 700 (Carl Zeiss Meditec AG) keratometry (K) values in IOL power calculation. MATERIAL AND METHODS: This retrospective study included 54 eyes of 31 patients who underwent cataract surgery. Preoperative biometric measurements of all patients were obtained using IOLMaster 700 followed by Pentacam measurements. IOLMaster 700 K measurements on horizontal (K1) and vertical (K2) axes and EKR measurements on 2 mm (EKR2mm), 3 mm (EKR3mm) and 4.5 mm (EKR4.5 mm) corneal zones were recorded. EKR4.5 mm value and IOLMaster 700 K values were used in Holladay-II, SRK/T, Haigis, and Hoffer-Q formulas to calculate predictive refractive error (PRE). Absolute refractive error (ARE) was calculated as the absolute difference between actual postoperative refractive error (APRE) and PRE values. RESULTS: Mean age was 72.2 ± 8.3 (51-87) years and mean IOL power was 21.5 ± 2.9 D (18-23 D). There was no significant difference between PRE values when IOLMaster 700 K measurements and EKR4.5 mm K measurements were used in Holladay-II, SRK/T, Haigis, and Hoffer-Q formulas (p = 0.571, p = 0.833, p = 0.165, p = 0.347, respectively). There was no significant difference between APRE and ARE values (p = 0.124). According to mean ARE results, the closest estimate was achieved when the IOLMaster 700 K values were used in the Holladay-II formula (p = 0.271). CONCLUSION: IOLMaster 700 K measurement and Pentacam EKR4.5 mm measurements can be used interchangeably. IOLMaster 700 K values yielded the most predictive measurement of the refractive result using the Holladay-II formula.

Antiproliferative and anti-apoptotic effect of astaxanthin in an oxygen-induced retinopathy mouse model.

OBJECTIVE: To evaluate the impact of intravitreal (IV) and intraperitoneal (IP) astaxanthin (AST) injections on neovascular development (ND), retinal morphology, and apoptotic activity in a C57BL/6J mouse model with hyperoxia-induced retinopathy (HIR). DESIGN: C57BL/6J mouse model. METHODS: Two negative control groups (n = 6 each; one of which received IV sterile dimethyl sulfoxide [DMSO]) of C57BL/6J-type mice were exposed to room air. The HIR groups included 36 C57BL/6J-type mice exposed to 75% ± 2% oxygen from postnatal day (PD) 7 to PD 12. On PD 12, these mice were randomized into 6 groups (n = 6 each): 2 HIR control groups (one of which received IV-DMSO), 2 IV-AST groups (10 and 100 µg/mL), and 2 IP-AST groups (0.5 and 5 mg/kg). We measured ND by counting neovascular tufts in cross sections and examined histological, ultrastructural changes via light and electron microscopy. Apoptosis was detected using terminal deoxynucleotidyl transferase-mediated nick end-labeling. RESULTS: No ND was detected in the negative control groups. ND levels were not significantly different between high- and low-dose AST for either means of administration. However, ND levels were significantly lower in the AST groups, regardless of delivery, compared to the control groups. The means of delivery (IP versus IV) also yielded significant differences in ND. The incidence of mitochondrial dysmorphology and apoptosis were lower in groups receiving AST. CONCLUSIONS: AST seems to suppress ND and has anti-apoptotic activity in the HIR mouse model.

Retinal Nerve Fiber Layer Thicknesses in Three Different Optic Nerve Head Size Groups Measured by Cirrus Spectral Domain Optical Coherence Tomography.

OBJECTIVES: To compare the retinal nerve fiber layer (RNFL) thicknesses in three different optic nerve head (ONH) size groups measured by Cirrus spectral domain optical coherence tomography (OCT). MATERIALS AND METHODS: Between January and March 2013, 253 eyes of 253 healthy subjects were enrolled in this study (mean age: 42.7±7.4 years [28-62 years]; 121 men and 132 women). The patients were divided into 3 groups according to ONH size: 77 patients in the "small ONH" group (ONH area <1.63 mm2), 90 patients in the "medium ONH" group (ONH area 1.63-1.97 mm2), and 86 patients in the "large ONH" group (ONH area >1.97 mm2). RESULTS: There were significant differences in superior (p=0.008), inferior (p=0.004) and average RNFL thickness (p=0.001) between the small, medium and large ONH groups. Positive correlations between ONH size and inferior/average RNFL thicknesses were significant but very weak (r=0.150, p=0.017 and r=0.157, p=0.013 respectively). CONCLUSION: RNFL thickness as measured by Cirrus OCT is positively correlated with ONH size and the differences in RNFL thickness were statistically significant between groups. This correlation and difference may be the result of a varying distance between the circular scan and the ONH margin.

Non-Contact and Contact Tonometry in Corneal Edema.

PURPOSE: To compare the intraocular pressure (IOP) values by Goldmann applanation tonometry (GAT) and Reichert 7 CR noncontact tonometry (R7CR-NCT) in patients with postsurgical corneal edema and to examine the impact of postoperative corneal edema on these values. METHODS: Forty-six patients with grade 4 and 5 cataracts were included in this study. Intraocular pressure was measured using GAT and R7CR-NCT before and 1 day after phacoemulsification. Central corneal thickness (CCT) was determined before and after surgery to quantify postsurgical corneal edema. The R7CR-NCT provided a Goldmann-correlated IOP (IOPg) and corneal-compensated IOP (IOPcc). RESULTS: The CCT increased significantly 1 day after surgery (the mean preoperative CCT, 543.5 ± 25.4 µm; the mean postoperative CCT, 681.5 ± 19.8 µm; p < 0.001), a mean increase of 26.7%. The preoperative R7CR-NCT measurements (the mean IOPcc, 18.8 ± 5.6 mm Hg; the mean IOPg, 17.8 ± 4.5 mm Hg) were significantly higher than GAT measurements (the mean GAT-IOP, 16.0 ± 3.4 mm Hg) (p < 0.001). On postoperative day 1, the R7CR-NCT measurement (the mean IOPcc, 27.0 ± 9.8 mm Hg; the mean IOPg, 25.1 ± 8.9 mm Hg) were significantly higher than GAT measurements (the mean GAT-IOP, 18.3 ± 7.9 mm Hg) (p < 0.001). The difference between postoperative R7CR-NCT and GAT-IOP values were significantly higher than the difference between preoperative R7CR-NCT and GAT-IOP values (p < 0.001 for both IOPcc to GAT-IOP and IOPg to GAT-IOP). The difference between postoperative IOPcc and GAT-IOP was significantly correlated to the change in CCT (r = 0.526, p < 0.001). Similarly, the difference between postoperative IOPg and GAT-IOP was significantly correlated to the change in CCT (r = 0.536, p < 0.001). CONCLUSIONS: The R7CR-NCT IOP values were high in patients with postsurgical intensive corneal edema. Consequently, the difference between R7CR-NCT IOP and GAT-IOP increased in edematous corneas.

Bilateral corneal infiltrates and uveitis in a pediatric patient with presumed ocular sarcoidosis.

PURPOSE: To report a pediatric case with presumed ocular sarcoidosis presented with bilateral corneal infiltrates and uveitis. DESIGN: Single case report. METHODS: A 9-year-old girl presented with a 1-month history of blurred vision and redness in both eyes. Ophthalmologic evaluation revealed midstromal infiltrates in cornea, granulomatous anterior uveitis, vitritis, snowball opacities, and localized perivenous exudates. RESULTS: She was treated with topical and oral steroids. During steroid tapering, oral cyclosporine A therapy was added. CONCLUSION: In patients with corneal infiltrates and uveitis, sarcoidosis should be considered in the differential diagnosis.