Evaluation of choroidal and retinal thickness measurements in adult hemodialysis patients using spectral-domain optical coherence tomography

Purpose: To assess the effect of hemodialysis on retinal and choroidal thicknesses using spectral-domain optical coherence tomography (SD-OCT). Methods: In this prospective interventional study, 25 hemodialysis patients (17 male, 8 female) were enrolled. All participants underwent high-speed, high-resolution SD-OCT (lambda=840 mm; 26.000 A-scans/s; 5 mu m resolution) before and after hemodialysis. Choroidal thickness was measured perpendicularly from the outer edge of the retinal pigment epithelium to the choroid-sclera boundary at the fovea and at five additional points: 500 mu m and 1000 mu m nasal to the fovea and 500 mu m, 1000 mu m, and 1500 mu m temporal to the fovea. Two masked physicians performed the measurements. Choroidal and retinal thicknesses before and after hemodialysis were compared. Results: The median choroidal thicknesses before and after hemodialysis were 182 mu m (range, 103-374 mu m) and 161 mu m (range, 90-353 mu m), respectively (P0.05). Systolic arterial pressure, diastolic arterial pressure, mean arterial pressure, heart rate, and ocular perfusion pressure significantly decreased after hemodialysis (P<0.001). Intraocular pressure did not vary significantly (P=0.540). Conclusion: Hemodialysis seems to cause a significant decrease in choroidal thickness, whereas it has no effect on retinal thickness. This significant decrease in choroidal thickness might be due to the extensive fluid absorption in hemodialysis, which could result in decreased ocular blood flow

Postconditioning Ozone Alleviates Ischemia-Reperfusion Injury and Enhances Flap Endurance in Rats

Introduction: Muscle-flap transferring is a routine approach utilized in reconstructive operations; however, flap morbidity is often a source of post-operative difficulty. Ischemia-Reperfusion Injury (IRI) is an important contributor to the viability of flaps after transferring. The goal of this research was for assess the probable useful impacts of ozone on flap survival in a rat muscle-flap design. Materials and Methods: We examined the effects of postconditioning ozone administration on viability of pedicled composite flaps. Twenty-eight Wistar rats were randomized into four groups: sham-operated (S), ischemia-reperfusion (IR), sham-operated + ozone (O), IR + ozone (IR + O), respectively. The animals were sacrificed on the eighth day. In a general histological evaluation, flap tissues were examined with a light microscope, and apoptotic cells were counted. The Apoptotic Index (AI) was then calculated. Flap-tissue samples were sent for analyses of malondialdehyde (MDA), catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and protein carbonyl (PCO), and blood samples were sent for analyses of Total Oxidant Score (TOS), and Total Antioxidant Capacity (TAC). Data were evaluated statistically using the Kruskal–Wallis test. Results: The histomorphometric score was remarkably greater in O (p = .002). The AI was greater in IR (p = .002). The antioxidant parameters values as regards SOD, GSH-Px, CAT, and TAC were found to be greater in O (p < .005). The oxidant parameters values as regards MDA, PCO, TOS were found to be greater in IR (p < .005). Discussion: The current research indicates that ozone application can attenuate the muscle-flap injury brought about by IR through triggering the increase of the antioxidant capacity