Oxidative Stress Mediates Epigenetic Modifications and the Expression of miRNAs and Genes Related to Apoptosis in Diabetic Retinopathy Patients.

Knowledge on the underlying mechanisms and molecular targets for managing the ocular complications of type 2 diabetes mellitus (T2DM) remains incomplete. Diabetic retinopathy (DR) is a major cause of irreversible visual disability worldwide. By using ophthalmological and molecular-genetic approaches, we gathered specific information to build a data network for deciphering the crosslink of oxidative stress (OS) and apoptosis (AP) processes, as well as to identify potential epigenetic modifications related to noncoding RNAs in the eyes of patients with T2DM. A total of 120 participants were recruited, being classified into two groups: individuals with T2MD (T2MDG, n = 67), divided into a group of individuals with (+DR, n = 49) and without (-DR, n = 18) DR, and a control group (CG, n = 53). Analyses of compiled data reflected significantly higher plasma levels of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx) and significantly lower total antioxidant capacity (TAC) in the +DR patients compared with the -DR and the CG groups. Furthermore, the plasma caspase-3 (CAS3), highly involved in apoptosis (AP), showed significantly higher values in the +DR group than in the -DR patients. The microRNAs (miR) hsa-miR 10a-5p and hsa-miR 15b-5p, as well as the genes BCL2L2 and TP53 involved in these pathways, were identified in relation to DR clinical changes. Our data suggest an interaction between OS and the above players in DR pathogenesis. Furthermore, potential miRNA-regulated target genes were identified in relation to DR. In this concern, we may raise new diagnostic and therapeutic challenges that hold the potential to significantly improve managing the diabetic eye.

Enhanced Oxidative Stress and Other Potential Biomarkers for Retinopathy in Type 2 Diabetics: Beneficial Effects of the Nutraceutic Supplements.

We have studied the global risk of retinopathy in a Mediterranean population of type 2 diabetes mellitus (T2DM) patients, according to clinical, biochemical, and lifestyle biomarkers. The effects of the oral supplementation containing antioxidants/omega 3 fatty acids (A/ω3) were also evaluated. Suitable participants were distributed into two main groups: (1) T2DMG (with retinopathy (+DR) or without retinopathy (-DR)) and (2) controls (CG). Participants were randomly assigned (+A/ω3) or not (-A/ω3) to the oral supplementation with a daily pill of Nutrof Omega (R) for 18 months. Data collected including demographics, anthropometrics, characteristics/lifestyle, ophthalmic examination (best corrected visual acuity, ocular fundus photographs, and retinal thickness as assessed by optical coherence tomography), and blood parameters (glucose, glycosylated hemoglobin, triglycerides, malondialdehyde, and total antioxidant capacity) were registered, integrated, and statistically processed by the SPSS 15.0 program. Finally, 208 participants (130 diabetics (68 +DR/62 -DR) and 78 controls) completed the follow-up. Blood analyses confirmed that the T2DMG+DR patients had significantly higher oxidative stress (p < 0.05), inflammatory (p < 0.05), and vascular (p < 0.001) risk markers than the T2DMG-DR and the CG. Furthermore, the A/ω3 oral supplementation positively changed the baseline parameters, presumptively by inducing metabolic activation and ameliorating the ocular health after 18 months of supplementation.

NAVILAS Laser System Focal Laser Treatment for Diabetic Macular Edema - One Year Results of a Case Series.

PURPOSE: To report one year outcomes of focal Navigated Retina Laser Therapy (NAVILAS) for diabetic macular edema (DME). METHODS: Retrospective cohort series of 7 diabetic patients treated with NAVILAS focal laser. Statistical analysis included descriptive and continuous variables (Best-corrected logMAR Visual Acuity and time-domain optical coherence tomography (OCT) parameters) which were compared using a non-parametric procedure, the Friedman tests for repeated measures. A p-value of less than 0.05 was considered to denote statistical significance. RESULTS: diabetic patients (4 male; 3 female) with an average age of 60.8 years (range 48-85 years) were included. All treated eyes were phakic; patients had an average hemoglobin A1C of 9.1 (range 7.8-11.7) at baseline and 8.0 (range 7.4-8.4) at 12 months. Six of the 7 patients had intravitreal bevacizumab injections prior to focal laser treatment with 1 patient having had more than 1 prior injection (total 3). At 12 months, median logMAR improved from 0.695 (± interquartile range 0.574) to 0.477 (± 0.573, p <0.001). OCT median central foveal thickness decreased from 248 (± 112) to 220 µm (± 41, p <0.001); total macular volume decreased from 7.84 (± 0.8) to 7.44 mm3 (± 0.7, p = 0.117); and largest macular subfield thickness decreased from 354 (± 116) to 289 µm (± 42, p <0.001). All patients were treated without complications. CONCLUSIONS: Focal NAVILAS showed to be safe and effective in treating DME with improvement in visual acuity and macular edema on OCT over 12 months in this case series. In clinical practice, combined treatment with focal laser including NAVILAS and anti-vascular endothelial growth factor may provide long-term improvement in DME.

Ranibizumab for serous macular detachment in branch retinal vein occlusions.

BACKGROUND: The purpose of this study was to compare the efficacy of intravitreal ranibizumab in the treatment of macular edema due to branch retinal vein occlusions (BRVO) with and without serous macular neuroretinal detachment (SMD). METHODS: Forty-nine eyes of 49 patients with macular edema due to branch retinal vein occlusion (22 with SMD and 27 without SMD) were included in this prospective, parallel-group, comparative study. Intravitreal injection of ranibizumab was administered at baseline. Thereafter patients were followed monthly and further injections were performed in the presence of persistence or recurrence of macular thickening. Flattening of the macula was considered success. At the last visit, best-corrected visual acuity (BCVA), and spectral-domain optical coherence tomography (SD-OCT) quantitative parameters (central subfield thickness, cube volume, average cube thickness) were compared between groups. RESULTS: In patients with SMD, BCVA and all the SD-OCT quantitative parameters improved significantly after a mean number of 5.0 ranibizumab intravitreal injections through a median follow-up of 12.5 months (range, 7-34). In patients without SMD, all the variables analyzed improved significantly except for the cube volume, after a mean number of 4.3 ranibizumab intravitreal injections through a median follow-up of 10.4 months (range, 6.5-40.2). The numbers of injections were similar in both groups. The final BCVA was better in patients without SMD at baseline but without significant differences in the SD-OCT parameters between groups. CONCLUSIONS: The presence of SMD may be a baseline predictive factor for ranibizumab treatment outcomes in BRVO patients, with no influence in the number of treatments needed between patients with or without SMD at baseline. Further studies are needed in order to confirm the role of SMD as an independent predicitive factor in cases of BRVO.

Oxidative stress in primary open-angle glaucoma.

PURPOSE: To analyze oxidative stress in primary open-angle glaucoma (POAG). MATERIAL AND METHODS: A case-control study including 90 eyes of 90 patients who needed antiglaucomatous surgery in the course of POAG (glaucoma group, n=50) and from patients who were operated of nonpathologic cataracts (cataract group, n=40). Free radical formation via lipid peroxidation by malondialdehyde-thiobarbituric acid reactive substances (MDA-TBARS) test and total antioxidant status in the aqueous humor samples of both groups were determined. Statistical analyses were carried out in relation to MDA-TBARS and total antioxidant status and their correlations with glaucoma risk factors. RESULTS: Significantly higher MDA-TBARS were detected in the POAG with respect to the comparative group of cataract subjects (P<0.001). Antioxidant activity was significantly lower in the POAG than in the cataract group (P<0.001). CONCLUSIONS: Aqueous humor samples may be used for determining oxidative and antioxidant status in pathologic processes. Glaucomatous eyes had a significant increase in oxidative status and decreased antioxidant activity in the aqueous humor than the cataract eyes. Oxidative stress may play a pathogenical role in the POAG.

Changes in the visual field following laser in situ keratomileusis for myopia.

PURPOSE: To assess the changes of the visual field (VF) caused by transient intraocular pressure (IOP) peaks during laser in situ keratomileusis (LASIK) surgery for myopia using automated perimetry. METHODS: This prospective study involved 94 eyes of 94 patients who underwent a conventional LASIK procedure. A complete eye examination was carried out in which the IOP measurement, and Humphrey 24-2 SITA standard VF were tested prior to LASIK and 6 and 12 months after LASIK. Patients were divided into two subgroups according to their refractive error. VF global indices, Glaucoma Hemifield Test and the number of depressed points deviating at p < 5%, p < 2%, p < 1% and p < 0.5% on the Pattern Deviation probability maps were compared using the analysis of variance. RESULTS: In the low myopia group, there were no significant differences in the analysed variables, except a slight decrease in mean deviation (MD) when comparing results prior to and 6 months following LASIK (p = 0.036; anova) that returned to baseline values at 12 months after surgery. In the moderate and high myopia group, there were no statistically significant differences in any of the variables analysed. No significant correlation was found between the transitory reduction in MD and any of the variables studied. CONCLUSIONS: In patients with low myopia, the VF undergoes a transitory increase in diffuse defects 6 months after surgery, with spontaneous recovery at 12 months after LASIK procedure. Possible explanations for these findings are discussed.

Quantitative anatomical differences in central corneal thickness values determined with scanning-slit corneal topography and noncontact specular microscopy.

PURPOSE: This study was designed to analyze the differences in central corneal thickness values determined with noncontact specular microscopy and scanning-slit corneal topography. The measurements were performed on the same eye. METHODS: We analyzed the central corneal thickness values of 93 patients (n = 93) by means of noncontact specular microscopy (Topcon SP-2000P noncontact specular microscope, Topcon Corp., Tokyo, Japan) and scanning-slit corneal topography (Orbscan Topography System II, Orbscan Inc., Salt Lake City, UT). One experienced physician performed 3 consecutive central corneal thickness measurements with both devices. RESULTS: The central corneal thickness values obtained by means of Orbscan pachymetry were 17 +/- 2.7 (range, 12-24) microm greater. A significant correlation was observed between scanning-slit corneal topography and noncontact specular microscopy (Pearson correlation coefficient, r = 0.976; P < 0.001). CONCLUSIONS: Researchers should know of the existence of this difference between noncontact specular microscopy and Orbscan pachymetry when interpreting central corneal thickness values.

Reduced corneal thickness values in postmenopausal women with dry eye.

PURPOSE: To study and compare the corneal thickness values of postmenopausal women with dry eye and postmenopausal women without dry eye. METHODS: The corneal thickness value of 30 postmenopausal women with dry eye (dry eye group; aged 52 to 55 years) and 32 postmenopausal women without dry eye (normal group; aged 51 to 55 years) was analyzed with the Orbscan Topography System II. Each woman underwent a tear breakup test, the Schirmer test, fluorescein staining of the cornea, and an analysis of the meibomian gland by slit lamp before corneal thickness measurement. The statistical analysis was performed by means of the unpaired Student t test. RESULTS: The mean corneal thickness value was significantly decreased in postmenopausal women with dry eye (P < 0.001 at each corneal location). The central cornea had the thinnest mean values in dry eyes and normal eyes (533.10 +/- 4.74 microm and 547.63 +/- 15.11 microm, respectively), whereas superonasal cornea had thicker mean values in both groups (632.43 +/- 6.11 microm and 648.78 +/- 14.98 microm in dry eye and normal eyes, respectively). CONCLUSIONS: Postmenopausal women with dry eye have lower corneal thickness values than postmenopausal women without dry eye. Special care must be taken with these reduced corneal thickness values when selecting postmenopausal women for surgery involving corneal photoablation.

Anatomic study of the corneal thickness of young emmetropic subjects.

PURPOSE: To study the corneal thickness of young emmetropic subjects. METHODS: One thousand eyes of 1000 young healthy emmetropic subjects were analyzed with the Orbscan Topography System II (Orbscan, Inc, Salt Lake City, UT) from January 2001 to May 2003. The age of the subjects ranged from 20 to 30 years old (mean +/- SD = 27.12 +/- 2.86). The mean of 5 consecutive measurements of the corneal thickness in the center of the cornea and at temporal, superotemporal, inferotemporal, nasal, inferonasal, and superonasal cornea were recorded. RESULTS: The corneal thickness at the following areas ranged as follows: 518 to 589 microm center; 603 to 678 microm nasal; 620 to 689 microm superonasal; 600 to 669 microm inferonasal; 571 to 639 microm temporal; 601 to 669 microm superotemporal; and 572 to 647 microm inferotemporal. In each individual the difference between the central thickness and the maximum paracentral thickness ranged from 85 to 107 microm (mean +/- SD, 99.21 +/- 3.80). The difference between the central thickness and the minimum paracentral thickness ranged from 36 to 59 microm (48.97 +/- 4.23 microm). The difference between the minimum paracentral corneal thickness and the maximum paracentral corneal thickness ranged from 37 to 58 microm (50.24 +/- 4.30). The tonometry was statistically correlated with the corneal thickness (P < 0.05 at each corneal location analyzed). CONCLUSIONS: In emmetropic corneas the difference between the minimum paracentral thickness and the maximum paracentral thickness was similar to the difference between the central thickness and the minimum paracentral thickness.

Goldmann tonometry after hyperopic laser in situ keratomileusis: comparison between retreated and nonretreated patients.

PURPOSE: To identify differences in applanation tonometry between retreated and nonretreated eyes (primary LASIK eyes) 6 months after hyperopic laser in situ keratomileusis. METHODS: In a prospective study 100 eyes (100 patients) underwent conventional hyperopic laser in situ keratomileusis under a 160-microm flap. Central Goldmann applanation tonometry was determined before and 6 months after surgery in 78 (78%) primary LASIK eyes and before surgery and 6 months after the retreatment date in 22 (22%) retreated eyes. RESULTS: Preoperative mean tonometry was 14.96 +/- 1.96 mm Hg and 15.30 +/- 1.95 mm Hg in primary LASIK and retreated eyes, respectively. Six months after surgery it was 12.99 +/- 2.03 mm Hg (P < 0.001) and 12.67 +/- 2.20 mm Hg (P < 0.001), respectively. No significant differences in mean tonometry were found between retreated and primary LASIK eyes 6 months after surgery (P = 0.537). Decreased tonometric values were found in 20 retreated eyes (90.91%) and in 62 primary LASIK eyes (79.48%). Increased tonometric values higher than 1 mm Hg were found in 3 primary LASIK eyes (3.84%), but no retreated eyes showed increased values 6 months after surgery. Two retreated eyes (9.09%) and 10 primary LASIK eyes (79.49%) presented the same tonometric values before surgery and at the end of the study. CONCLUSIONS: After hyperopic laser in situ keratomileusis there was no significant difference in Goldmann applanation tonometry between retreated and primary LASIK eyes.

Inter-observer variability of central corneal thickness measurements using non-contact specular microscopy after laser in situ keratomileusis.

BACKGROUND: The aim of this study was to investigate the inter-observer variability of central corneal thickness measurements carried out with a non-contact specular microscope in patients who had undergone myopic laser in situ keratomileusis. METHODS: Twenty-six eyes of 26 subjects who had undergone myopic laser in situ keratomileusis were studied with the Topcon SP-2000P non-contact specular microscope (Topcon Corp, Tokyo, Japan). The mean of three consecutive measurements of the central corneal thickness was recorded by two investigators prior to and one month after myopic laser in situ keratomileusis. Results obtained by each of the two physicians were compared. RESULTS: Prior to surgery the mean central corneal thickness was 536.2 +/- 22.2 microm for physician 1 and 536.3 +/- 22.2 microm for physician 2 (p = 0.980). The pre-operative 95 per cent confidence interval was 522.7 to 544.2 microm (physician 1) and 523.1 to 544.1 microm (physician 2). The mean central corneal thickness was 485.8 +/- 29.3 microm for physician 1 and 485.6 +/- 28.0 micro m for physician 2 one month after laser in situ keratomileusis (p = 0.977). The post-operative 95 per cent confidence intervals were 470.1 to 496.2 microm and 470.3 to 495.4 microm for physicians 1 and 2, respectively. CONCLUSION: Central corneal thickness measurements can be carried out by different clinicians after laser in situ keratomileusis with non-contact specular pachymetry, without there being any significant differences among them.

Caucasian emmetropic aged subjects have reduced corneal thickness values: emmetropia, CCT and age.

We aimed to analyze the possible changes in corneal thickness values according to age in emmetropic subjects. The central corneal thickness values of 100 emmetropic subjects (n = 100) were analyzed with the DGH 2000 AP ultrasonic pachymeter (DGH Technology, Inc., San Diego, CA, USA) by one experienced physician. The mean age of the subjects was 40.6 +/- 12.1 years old (range, 21-64). Analysis of the central corneal thickness (CCT) values by age subgroups indicated that subjects aged between 20 and 30 years had the higher CCT values. Differences in CCT values between the age groups were significant (p < 0.001; 1-way ANOVA test). A significant correlation between CCT values and age was found (r = -0.974; p < 0.001). In sum, it seems that there is a decrease in CCT values with age in emmetropic subjects.

Intraocular pressure in myopic patients after Worst-Fechner anterior chamber phakic intraocular lens implantation.

PURPOSE: To assess intraocular pressure measured with a Goldmann tonometer over a period of 1 year after implantation of a Worst-Fechner anterior chamber phakic intraocular lens to correct myopia of -7.00 D or more. METHODS: We performed a prospective, non-masked study of 100 patients (100 myopic eyes) who had a Worst-Fechner phakic intraocular lens implanted to correct myopia of -7.00 D or greater. Central corneal Goldmann tonometry was performed before surgery and 1, 3, 6, and 12 months after surgery. The influence of different variables was assessed. RESULTS: IOP showed a significant increase of a mean 2.1 mmHg at 3 months after surgery (P=.001). There was not a statistically significant difference between IOP before surgery and 6 months after PIOL implantation (P=.244) or 1 year after surgery (P=.845). In one eye, the lens was explanted 11 months after surgery because of the presence of ocular hypertension. No variables studied showed a statistically significant difference from before to after surgery. CONCLUSIONS: Worst-Fechner anterior chamber phakic intraocular lens implantation led to a slight transitory increase of intraocular pressure during the first 3 months after surgery, but returned to preoperative levels by 6 months after implantation.

Assessment of applanation tonometry after hyperopic laser in situ keratomileusis.

PURPOSE: To determine the reliability and identify pitfalls in intraocular pressure measurement by Goldmann applanation tonometry after hyperopic laser in situ keratomileusis (LASIK). METHODS: Prospective non-masked case series at University of Valencia, Faculty of Medicine and Rahhal Ophthalmology Clinic, Valencia, Spain. One hundred three patients (103 eyes) treated with hyperopic LASIK were evaluated. The main treatment was hyperopic LASIK using a microkeratome Chiron Hansatome (Chiron Vision Corp, Claremont, CA) and the excimer laser Chiron Technolas 217-C LASIK (Chiron Technolas GmbH, Dornack; Germany). Central Goldmann applanation tonometric readings before surgery and 1, 3, and 6 months after surgery were analyzed. RESULTS: After hyperopic LASIK, a significant decrease in intraocular pressure was observed in the postoperative controls. In the low hyperopia patients (range: 1.00-3.00 D) a decrease of 2.43 mmHg was observed at the 6-month follow-up (p < 0.001). In the moderate hyperopia group (range: 3.25-6.00 D) a decrease of 2.05 mmHg was observed at the 6-month follow-up (p < 0.001). There were no significant differences between low and moderate hyperopia (p = 0.812). There was no statistically significant correlation between the magnitude of decrease in tonometry and gender, age, treated spherical equivalent, pachymetry, and anterior chamber depth (ACD). CONCLUSIONS: This clinical study displays that postoperative tonometry after hyperopic LASIK was significantly lower than the preoperative, hence modifying the reliability of Goldmann tonometry, and causing an intraocular pressure underestimation. A correcting factor should be applied when using applanation tonometry to measure postoperative intraocular pressure in patients who have undergone hyperopic LASIK.