The Effects of Lens Extraction Surgery on Intraocular Pressure and Anterior Segment Parameters in Primary Angle-Closure Glaucoma.

Objectives: To investigate the effects of phacoemulsification with intraocular lens implantation (phaco+IOL) surgery on intraocular pressure (IOP) and anterior segment parameters in patients with cataract and primary angle-closure glaucoma (PACG). Materials and Methods: Fifty-five patients with PACG undergoing phaco+IOL surgery were evaluated in terms of best corrected visual acuity (BCVA), IOP, anterior chamber depth (ACD), aqueous depth (AD), and lens thickness (LT) measured by optical biometry preoperatively and at the 6-month postoperative visit. They were compared with 34 healthy age-and gender-matched cataract patients who underwent phaco+IOL surgery. Results: Preoperative evaluation revealed higher IOP, shorter axial length, shallower ACD and AD, and greater LT in the PACG group (p<0.001 for all). Postoperative evaluation in the PACG group showed an increase in BCVA, a significant decrease in IOP, an increase in ACD and AD, and a decrease in LT (p<0.001 for all). Additionally, a reduction in the average number of antiglaucomatous medications used postoperatively was observed in the PACG group (p<0.001). The changes in IOP, ACD, AD, and LT between preoperative and postoperative assessments were significantly greater in the PACG group compared to the control group (p<0.0001 for all). Conclusion: Phaco+IOL surgery in PACG patients leads to a significant increase in ACD compared to the control group and allows better control of IOP with fewer antiglaucomatous medications after surgery.

Evaluation of retinal vascular and structural alterations in pediatric idiopathic intracranial hypertension patients without papilledema.

PURPOSE: The aim of this study was to evaluate retinal structural and microvascular alterations using optical coherence tomography-angiography (OCTA) in pediatric idiopathic intracranial hypertension (IIH) patients with regressed papilledema. METHODS: This study included 40 eyes of 21 IIH patients and 69 eyes of 36 healthy controls. Radial peripapillary capillary (RPC) vessel density and peripapillary retinal nerve fiber layer (RNFL) thickness were evaluated by XR Avanti AngioVue OCTA (Optovue, Fremont, CA, USA). The data were obtained from measurement zones that are automatically divided into two equal hemispheres (superior and inferior) and eight quadrants (superior-temporal, superior-nasal, inferior-temporal, inferior-nasal, nasal-superior, nasal-inferior, temporal-superior, temporal-inferior). Initial cerebrospinal fluid (CSF) pressure, grade of papilledema, and duration of follow-up were recorded. RESULTS: There were significant differences in RPC vessel densities and RNFL thicknesses between the study groups (p Ëƒ 0.05). Significantly higher RPC vessel density measurements were observed in the patient group for the whole image, peripapillary, inferior-hemi, and whole nasal quadrants (p < 0.05). Except for the temporal-superior, temporal-inferior, inferior-temporal, and superior-temporal quadrants, the RNFL in all regions was significantly thicker in the IIH group than in the control group (p Ë‚ 0.001). CONCLUSIONS: RNFL thickness and RPC vessel density were significantly different between the IIH patient and control groups, suggesting that retinal microvascular and subclinical structural changes that were potentially secondary to CSF pressure can persist after the resolution of papilledema. However, our results should be confirmed by further longitudinal studies investigating the progress of these alterations to determine their effects on peripapillary tissues.

Evaluation of ocular microvascular characteristics in smokers and patients with chronic obstructive pulmonary disease using an optical coherence tomography angiography.

PURPOSE: To investigate retinal microvascular changes in patients with chronic obstructive pulmonary disease (COPD) using optical coherence tomography angiography (OCTA) and to compare these values with those of smokers and healthy non-smokers. METHODS: This study was performed on 38 eyes of 38 patients with COPD, 30 eyes of 30 smokers, and 31 eyes of 31 healthy non-smokers. Foveal avascular zone (FAZ) area, superficial (SCP) and deep (DCP) capillary plexus (whole image, fovea, parafovea, and perifovea) and radial peripapillary capillary (RPC) vessel densities (whole image, peripapillary, and inside disc) were evaluated via OCTA device (Optovue, Fremont, CA, USA). The forced expiratory volume in the first second (FEV1)/forced vital capacity (FVC) ratio and FEV1 values of patients with COPD were recorded. RESULTS: There were statistically similar values in smoking pack-years between the smoker and COPD groups (p = 0.059). Entire SCP and DCP vessel densities were significantly different among the all groups (p < 0.05); for these parameters, the control group had the highest and the COPD group had the lowest vessel density values. Significantly decreased RPC vessel densities in all regions were detected in the COPD group compared with the other groups. Multiple regression analysis showed significant positive correlations between the FEV1 and the SCP, DCP, and RPC vessel densities (for all, p < 0.05). CONCLUSIONS: This study detected lower vessel densities in patients with COPD than in smokers and healthy controls and reported decreased vessel density measurements with increasing COPD severity. COPD patients with or without a history of smoking may benefit from higher prioritization in terms of ophthalmic screening to prevent ocular complications.

Long-term evaluation of posterior corneal surface parameters after accelerated corneal cross-linking with a comparison with uncross-linked keratoconic eyes.

PURPOSE: To evaluate the 36 months changes in posterior corneal surface parameters in keratoconic eyes after accelerated corneal cross-linking and to compare the data with uncross-linked progressive and non-progressive keratoconic eyes. METHODS: Thirty five cross-linked, 30 uncross-linked progressive, and 30 uncross-linked non-progressive keratoconic eyes were included. Maximum keratometry (Kmax), thinnest pachymetry, minimum radius of curvature back (Rminback), asphericity back, posterior elevation and corneal densitometry, back corneal higher order aberrations (HOAs), back surface deviation (Db), final D, posterior radius of curvature (PRC) and 'B' unit values were recorded at baseline and at the 12, 24, 36 months follow-up. Data were analyzed with repeated measures ANOVA and paired t-tests. RESULTS: Kmax and thinnest pachymetry were significantly changed in the cross-linked and progressive uncross-linked groups. Rminback, asphericity back, and HOAs did not change in either group. Total posterior corneal densitometry improved; posterior elevation, Db and B unit worsened in the cross-linked group and did not change in the uncross-linked groups. PRC and final D worsened in the cross-linked and progressive uncross-linked groups, and did not change in the non-progressive group. CONCLUSION: Despite a decreased Kmax, the posterior corneal surface parameters, posterior elevation values were determined to have significantly worsened in the cross-linked group and this increase was higher than in progressive uncross-linked eyes.

Differential effects of adenylyl cyclase-protein kinase A cascade on shear-induced changes of sickle cell deformability.

BACKGROUND: Erythrocyte deformability is impaired in sickle cell disease (SCD). The regulation of cytoskeletal protein organization plays a key role in erythrocyte deformability. The activation of adenylyl cyclase (AC)/cAMP/Protein kinase A (PKA) signaling pathway was associated with increased deformability in healthy erythrocytes, however the role of this pathway in SCD is unknown. OBJECTIVE: We evaluated mechanical responses of sickle red blood cells under physiological levels of shear stress and the possible link between their deformability and AC/cAMP/PKA signaling pathway. METHODS: The shearing of sickle red blood cells at physiological level (5 Pa) and the measurement of deformability were performed by a laser assisted optical rotational cell analyzer (LORRCA). RESULTS: Red blood cell deformability increased of 2.5-6.5% by blocking the activity of phosphodiesterase with Pentoxifylline (10µM) (p < 0.05). The inhibition of AC with SQ22536 (100µM) produced more significant rise in deformability (+4.8-12%, p < 0.01). No significant change was observed by the inhibition of PKA with H89 (10µM). CONCLUSION: Pentoxifylline and SQ22536 increased the deformability of sickle red blood cells under fluid shear stress. Modulation of the AC/cAMP/PKA pathway could have the potential to be an effective therapeutic approach for SCD through shear-induced improvements of RBC deformability.

Association between Oxidative Stress, Genetic Factors, and Clinical Severity in Children with Sickle Cell Anemia.

OBJECTIVES: To investigate the associations between several sickle cell disease genetic modifiers (beta-globin haplotypes, alpha-thalassemia, and glucose-6-phosphate dehydrogenase deficiency) and the level of oxidative stress and to evaluate the association between oxidative stress and the rates of vaso-occlusive events. STUDY DESIGN: Steady-state oxidative and nitrosative stress markers, biological variables, genetic modulators, and vaso-occlusive crisis events requiring emergency admissions were measured during a 2-year period in 62 children with sickle cell anemia (58 SS and 4 Sß0). Twelve ethnic-matched children without sickle cell anemia also participated as healthy controls (AA) for oxidative and nitrosative stress level measurement. RESULTS: Oxidative and nitrosative stress were greater in patients with sickle cell anemia compared with control patients, but the rate of vaso-occlusive crisis events in sickle cell anemia was not associated with the level of oxidative stress. The presence of alpha-thalassemia, but not glucose-6-phosphate dehydrogenase deficiency or beta-globin haplotype, modulated the level of oxidative stress in children with sickle cell anemia. CONCLUSION: Mild hemolysis in children with alpha-thalassemia may limit oxidative stress and could explain the protective role of alpha-thalassemia in hemolysis-related sickle cell complications.