Selcuk Kara

Protective Effect of Hesperetin and Naringenin against Apoptosis in Ischemia/Reperfusion-Induced Retinal Injury in Rats

Purpose. Hesperetin and naringenin are naturally common flavonoids reported to have antioxidative effects. This study was performed to investigate whether either hesperetin or naringenin has a protective effect against apoptosis on retinal ischemia/reperfusion (I/R) injury. Methods. Retinal I/R was induced by increasing the intraocular pressure to 150 mmHg for 60 minutes. Thirty-three male Wistar albino rats were randomised into 5 groups named control, I/R + sham, I/R + solvent (DMSO), I/R + hesperetin, and I/R + naringenin. Animals were given either hesperetin, naringenin, or the solvent intraperitoneally immediately following reperfusion. Thickness of retinal layers and retinal cell apoptosis were detected by histological analysis, tunel assay, and immunohistochemistry assay. Results. Hesperetin and naringenin attenuated the I/R-induced apoptosis of retinal cells in the inner and outer nuclear cells of the rat retina. Retinal layer thickness of the naringenin treatment group was significantly thicker than that of the hesperetin, sham, and solvent groups (P < 0.05). Conclusions. Hesperetin and naringenin can prevent harmful effects induced by I/R injury in the rat retina by inhibiting apoptosis of retinal cells, which suggests that those flavanones have a therapeutic potential for the protection of ocular ischemic diseases.

Quercetin protects the retina by reducing apoptosis due to ischemia-reperfusion injury in a rat model

PURPOSE This study aimed to investigate the effect of quercetin on apoptotic cell death induced by ischemia-reperfusion (I/R) injury in the rat retina. METHODS Twenty-four rats were divided into four equal groups: control, ischemic, solvent, and quercetin. I/R injury was achieved by elevating the intraocular pressure above the perfusion pressure. Intraperitoneal injections of 20 mg/kg of quercetin and dimethyl sulfoxide (DMSO) were performed in the quercetin and solvent groups, respectively, immediately prior to I/R injury, and the researchers allowed for the retinas to be reperfused. Forty-eight hours after injury, the thicknesses of the retinal ganglion cell layer (RGCL), inner nuclear layer (INL), inner plexiform layer (IPL), outer plexiform layer (OPL), and outer nuclear layer (ONL) were measured in all groups. Moreover, the numbers of terminal deoxynucleotidyl transferase dUTP nick-end-labeled [TUNEL (+)] cells and caspase-3 (+) cells in both INL and ONL were evaluated in all groups. RESULTS The administration of quercetin was found to reduce the thinning of all retinal layers. The mean thickness of INL in the quercetin and ischemic groups was 21 ± 5.6 µm and 16 ± 6.4 µm, respectively (P<0.05). Similarly, the mean thickness of ONL in the quercetin and ischemic groups was 50 ± 12.8 µm and 40 ± 8.7 µm, respectively (P<0.05). The antiapoptotic effect of quercetin in terms of reducing the numbers of both TUNEL (+) cells and caspase-3 (+) cells was significant in INL. The mean number of TUNEL (+) cells in INL in the ischemic and quercetin groups was 476.8 ± 45.6/mm2 and 238.72 ± 251/mm2, respectively (P<0.005). The mean number of caspase-3 (+) cells in INL of ischemic and quercetin groups was 633.6 ± 38.7/mm2 and 342.4 ± 36.1/mm2, respectively (P<0.001). CONCLUSION The use of quercetin may be beneficial in the treatment of retinal I/R injury because of its antiapoptotic effect on the retinal layers, particularly in INL.

Comparison of transcanalicular diode laser dacryocystorhinostomy and external dacryocystorhinostomy in patients with primary acquired nasolacrimal duct obstruction.

To compare the success, complication, and patient discomfort rates of transcanalicular diode laser dacryocystorhinostomy (TCDL‐DCR) and external dacryocystorhinostomy (EX‐DCR) surgeries performed in patients with primary acquired nasolacrimal duct obstruction.

The protective effects of dexmedetomidine against apoptosis in retinal ischemia/reperfusion injury in rats.

Abstract Objective: Dexmedetomidine is an alpha 2 adrenoceptor agonist and can be used for postoperative sedation, analgesia and anesthesia-sparing properties. Furthermore, the neuroprotective effects against ischemia/reperfusion (I/R) injury in the central nervous system have been shown in experimental studies. This study aimed to investigate the protective effects of dexmedetomidine against apoptosis in retinal I/R injury in the rat. Materials and methods: Retinal I/R injury was induced by transient elevation of intraocular pressure. Eighteen animals were divided into three groups (n = 6): sham, I/R and treatment. The I/R injury and protective effects of the dexmedetomidine were evaluated by retinal thickness determined by histological sections, terminal deoxynucleotidyl transferase-mediated biotin-deoxyuridine triphosphate nick-end labeling (TUNEL) and immunohistochemistry of caspases 3. Results: A decrease in the retinal thickness and an increase in the apoptotic cells were found to be statistically significant in I/R and treatment groups when compared with the control group. However, in comparison with the I/R group we realized that the administration of dexmedetomidine reduced the thinning of retinal thickness and also decreased the number of caspases 3 and TUNEL-positive cells. Conclusion: Dexmedetomidine is protective against apoptosis in retinal I/R injury in rats.

Alterations in Iris Structure and Pupil Size Related to Alpha-1 Adrenergic Receptor Antagonists Use: Implications for Floppy Iris Syndrome

PURPOSE To evaluate structural alterations of iris and pupil diameters (PDs) in patients using systemic α-1-adrenergic receptor antagonists (α-1ARAs), which are associated with intraoperative floppy iris syndrome (IFIS). METHODS Eighty-eight eyes of 49 male were evaluated prospectively. Patients were assigned to 2 different groups. Study group included 23 patients taking any systemic α-1ARAs treatment, and control group included 26 patients not taking any systemic α-1ARAs treatment. All patients underwent anterior segment optical coherence tomography to evaluate iris thickness at the dilator muscle region (DMR) and at the sphincter muscle region (SMR). The PD was measured using a computerized infrared pupillometer under scotopic and photopic illumination. RESULTS The study group included 46 eyes of 23 patients and the control group included 42 eyes of 26 patients. Most treated patients were on tamsulosin (16/23). Mean age was similar in the study and control groups (61.9±7.1 vs. 60.3±8, 2 years, nonsignificant). DMR (506.5±89.4 vs. 503.6±83.5 μm), SMR (507.8±78.1 vs. 522.1±96.4 μm) and the DMR/SMR ratio (1.0±0.15 vs. 0.99±0.23 μm) was similar in the study and control groups and these differences were nonsignificant. Scotopic PDs were also similar in both groups (3.99±1.11 vs. 3.74±1.35, nonsignificant). A significantly reduced photopic PD (2.89±0.55 vs. 3.62±0.64, P<0.001) and an increased scotopic/photopic PD (1.42±0.44 vs. 1.02±0.30, P<0.001) were found in the study group. CONCLUSIONS Evaluating PD alterations might be more useful than evaluating iris structural alterations in predicting IFIS. There is still a need for a reliable method that will determine the possibility of IFIS.

Ocular penetration of topically applied 1% daptomycin in a rabbit model.

PURPOSE To evaluate the ocular penetration of daptomycin, a new antibiotic agent targeted against Gram-positive organisms. METHODS Thirty-two New Zealand white rabbits were divided into 4 equal groups. One drop of 50 μL 1% daptomycin was administered to group 1. In group 2, 1 drop of 1% daptomycin was administered after the corneal epithelium was scraped. In group 3, 1 drop of 1% daptomycin was administered every 15 min for 1 h (keratitis protocol). In group 4, the keratitis protocol was applied after the corneal epithelium was scraped. In groups 1 and 2, aqueous humor samples were collected 30 min, 1 h, and 2 h after the single drop under general anesthesia. All the animals in groups 3 and 4 were humanely killed. Cornea, aqueous humor, and vitreous samples were collected 1 and 2 h after the last drop. Daptomycin concentrations were measured by high-performance liquid chromatography. RESULTS Each group comprised 8 rabbits. Daptomycin was not detected in the aqueous humor in groups 1 and 2. In group 3, the mean values at 1 h in the aqueous humor and cornea, respectively, were 1.90±0.15 μg/mL and 3.93±0.67 μg/g, and at 2 h were 1.71±0.42 μg/mL and 4.13±0.46 μg/g. In group 4, the mean values at 1 h were 5.19±0.50 μg/mL and 7.10±0.35 μg/g, and at 2 h were 4.96±0.47 μg/mL and 7.22±0.34 μg/g. Daptomycin was not detected in vitreous samples in groups 3 and 4. CONCLUSIONS Single-drop administration does not yield a detectable daptomycin concentration in aqueous humor in neither nonscraped nor scraped group. In the multiple-drop regimen, daptomycin seems to penetrate well into the aqueous humor and cornea both in nonscraped and scraped groups. However, this concentration may not cover the minimum inhibitory concentration (MIC) of organisms such as Enterococcus fecalis.

Evaluation of choroidal thickness in patients with obstructive sleep apnea/hypopnea syndrome

Purpose: To compare the subfoveal choroidal thickness (SFCT) of patients with different severities of obstructive sleep apnea/hypopnea syndrome (OSAHS) and normal controls via enhanced depth imaging optical coherence tomography (EDI-OCT). Methods: In this retrospective, case-control study, 49 eyes from 49 patients that had undergone polysomnography were included. SFCT of the horizontal and vertical line scans were manually measured for all eyes based on EDI-OCT images. Two separate analyses were performed according to different apnea/hypopnea index (AHI) groupings. Initial testing was conducted using non-OSAHS, mild OSAHS (5≤AHI<15), moderate OSAHS (15≤AHI<30), and severe OSAHS (AHI≥30) patient groupings, while secondary testing used non-OSAHS, mild OSAHS (5≤AHI<15), and moderate/severe OSAHS (AHI≥15) patient groupings. Results: The mean SFCT was 314.5 μm in the non-OSAHS patients (n=14), 324.5 μm in the mild OSAHS patients (n=15), 269.3 μm in the moderate OSAHS patients (n=11), and 264.3 μm in the severe OSAHS patients (n=9). SFCT between the four groups revealed no significant differences despite a trend towards slight thinning in the severe group (P=0.08). When the moderate and severe groups were merged and compared with the mild OASHS and non-OSAHS groups, SFCT of the moderate/severe group was found to be significantly thinner than that of the mild group (P=0.016). A negative significant correlation was found between SFCT and AHI in OSAHS patients (r=0.368, P=0.033). Conclusions: In patients with moderate/severe OSAHS, EDI-OCT revealed a thinned SFCT. Other accompanying systemic or ocular diseases may induce perfusion and oxygenation deficiency in eyes of OSAHS patients. Further studies are required in order to determine the exact relationships between ocular pathologies and clinical grades of OSAHS.

Evaluation of Macular Ganglion Cell-inner Plexiform Layer and Choroid in Psoriasis Patients Using Enhanced Depth Imaging Spectral Domain Optical Coherence Tomography

ABSTRACT Purpose: To evaluate changes in the thickness of the central macula, macular ganglion cell-inner plexiform layer (mGCIPL), and subfoveal choroid in patients with psoriasis using spectral domain optical coherence tomography (SD-OCT). Methods: The measurements of macular, mGCIPL thicknesses and subfoveal choroidal thickness (SFCT) obtained by SD-OCT of psoriasis patients (n = 46). These measurements were compared with those of 50 healthy controls. Results: The macular, mGCIPL, and choroidal thicknesses did not differ between the controls and psoriatic subjects (p>0.05). When the patients were divided into two distinct groups, only the SFCT was significantly thicker in the severe psoriasis group compared with the mild psoriasis group (p = 0.003). Conclusions: These findings suggest that choroidal alterations are seen without macular changes in patients with psoriasis. Severe psoriasis appears to be related to increases in SFCT as a consequence of possible inflammatory cascades that are part of the disease’s pathogenesis.

Bacterial contamination of needles used for intravitreal injections: comparison between 27-gauge and 30-gauge needles.

Abstract Purpose: To compare the contamination rate between 27-gauge and 30-guage needles used for intravitreal injection (IVT). Methods: Patients undergoing IVT injections were enrolled prospectively. Injections were performed with 27- or 30-gauge needles. All needle tips were collected and placed in brain–heart infusion broth. The contamination rates of needles were compared. Results: A total of 109 patients participated in the study and a total of 126 IVT injections were performed. Injections were performed by 27-gauge (49%) and 30-gauge (51%) needle. No patient developed endophthalmitis. The overall contamination rate of the used needles were 13% for 27-guage and 29% for 30-guage (p = 0.022). However, this difference was nonsignificant after Bonferronis correction was applied. The most common bacteria isolated from the used needles are coagulase-negative Staphylococcus (CNS). Conclusion: The results suggest that the needle bore size seems not to be a risk factor for contamination during IVT injection.

Fibrin glue coating of the surgical surfaces may facilitate formation of a successful bleb in trabeculectomy surgery

Trabeculectomy is commonly conducted when medical therapy fails to control intraocular pressure (IOP). The success of trabeculectomy for the treatment of glaucoma depends on the wound-healing response at the subconjunctival filtering bleb site. Postoperative scar formation is a serious problem in this surgery. Current strategies to counteract scarring include local antimetabolite treatment, which is associated with severe side effects, limiting its application. Therefore, additional means to safely modulate wound healing are desirable. In ophthalmic surgery, fibrin glue is used mainly for sealing and hemostatics purpose. Fibrin glue coating of tenon face of conjunctiva, scleral surface, reverse face of scleral flap and scleral bed with insoluble fibrin glue can halt both ooze bleeding and vascular leakage. By retarding the first step of wound healing, less postoperative inflammation may occur. Additionally aqueous humor flows through a fibrin glue coated interface. Therefore, we hypothesize that fibrin glue coating of the surgical surfaces in trabeculectomy surgery may yield less subconjunctival fibrosis and more successful bleb. To the best of our knowledge, no basic research has yet been performed regarding fibrin glue coating for halting the vascular leakage and easing the aqueous drainage into subconjunctival space in glaucoma surgery.