Manuel Garcia-Medina

A 5-year follow-up of antioxidant supplementation in type 2 diabetic retinopathy.

Purpose This study was designed to evaluate the effect of antioxidant supplementation on diabetic retinopathy (DR) over a 5-year follow-up period. To our knowledge, this is the first such clinical trial performed. Methods We recruited 105 type 2 diabetic patients with nonproliferative DR. A complete ophthalmic checkup and a plasma determination of oxidative (malonyldialdehyde [MDA]) and antioxidant parameters (total antioxidant status [TAS]) were obtained as the baseline. One part of the cohort was randomly assigned to oral antioxidant supplementation at nutritional doses. The same examinations were performed with 97 diabetic patients who completed the 5-year follow-up period. The best-corrected visual acuity, DR score, MDA, and TAS values were compared at the beginning and the end of the follow-up. Results Best-corrected visual acuity did not change during the follow-up, irrespective of supplementation. However, the retinopathy stage showed a retardation of progression in the subgroup with supplementation, but worsened in the subgroup with no antioxidant supplementation. Furthermore, the antioxidant supplementation group maintained its antioxidant plasma status levels, which was related to decreased oxidative plasma activity. Conclusions Oral antioxidant supplementation could be a useful adjunctive long-term therapy in the treatment of nonproliferative DR.

A two-year follow-up of oral antioxidant supplementation in primary open-angle glaucoma: an open-label, randomized, controlled trial.

To evaluate the effect of oral antioxidant supplementation (OAS) on primary open‐angle glaucoma (POAG) over a 2‐year follow‐up period.

Effect of posterior capsular opacification removal on scanning laser polarimetry measurements

PurposeTo evaluate the effect of posterior capsular opacification (PCO) on retinal nerve fiber layer (RNFL) retardation measurements obtained during scanning laser polarimetry (SLP). We are unaware of previous studies undertaken in this sense.MethodsSLP was performed using GDx variable corneal compensation (VCC) on 28 eyes of 28 non-glaucomatous patients with clinically significant PCO, previous uneventful cataract surgery and no other ocular pathology, both before and after Nd:YAG capsulotomy. Best-corrected visual acuity (BCVA), intraocular pressure (IOP) and SLP examination parameters prior and following PCO removal were compared using the Student t-test and Wilcoxon’s test. Spearman correlations between BCVA and SLP measurements before and after capsulotomy were also performed.ResultsPCO removal was associated with an increase of BCVA (P<0.0001), nerve fiber indicator (NFI) (P<0.0001) and typical scan score (TSS) (P<0.0001). In parallel, significant decreases of all absolute parameters were observed after capsulotomy. IOP, symmetry, superior ratio, inferior ratio and temporal-superior-nasal-inferior-temporal (TSNIT) standard deviation (SD) revealed no changes. Before capsulotomy, marked correlation existed between the BCVA and some SLP measurements such as nasal average (r= −0.703; P<0.0001) or NFI (r= 0.564; P=0.0017). After PCO removal these correlations were no longer found.ConclusionsPCO removal changes SLP measurements. Therefore, new measurements to serve as a baseline for future comparisons should be obtained after Nd:YAG capsulotomy. Furthermore, some SLP measurements were significantly associated with BCVA before capsulotomy, suggesting that this technology may be useful to quantify PCO degree in non-glaucomatous patients.

Central corneal thickness, intraocular pressure, and degree of myopia in an adult myopic population aged 20 to 40 years in southeast Spain: determination and relationships

Objective: To determine the values of, and study the relationships among, central corneal thickness (CCT), intraocular pressure (IOP), and degree of myopia (DM) in an adult myopic population aged 20 to 40 years in Almeria (southeast Spain). To our knowledge this is first study of this kind in this region. Methods: An observational, descriptive, cross-sectional study was done in which a sample of 310 myopic patients (620 eyes) aged 20 to 40 years was selected by gender- and age-stratified sampling, which was proportionally fixed to the size of the population strata for which a 20% prevalence of myopia, 5% epsilon, and a 95% confidence interval were hypothesized. We studied IOP, CCT, and DM and their relationships by calculating the mean, standard deviation, 95% confidence interval for the mean, median, Fisher’s asymmetry coefficient, range (maximum, minimum), and the Brown-Forsythe’s robust test for each variable (IOP, CCT, and DM). Results: In the adult myopic population of Almeria aged 20 to 40 years (mean of 29.8), the mean overall CCT was 550.12 μm. The corneas of men were thicker than those of women (P = 0.014). CCT was stable as no significant differences were seen in the 20- to 40-year-old subjects’ CCT values. The mean overall IOP was 13.60 mmHg. Men had a higher IOP than women (P = 0.002). Subjects over 30 years (13.83) had a higher IOP than those under 30 (13.38) (P = 0.04). The mean overall DM was −4.18 diopters. Men had less myopia than women (P < 0.001). Myopia was stable in the 20- to 40-year-old study population (P = 0.089). A linear relationship was found between CCT and IOP (R2 = 0.152, P ≤ 0.001). CCT influenced the IOP value by 15.2%. However no linear relationship between DM and IOP, or between CCT and DM, was found. Conclusions: CCT was found to be similar to that reported in other studies in different populations. IOP tends to increase after the age of 30 and is not accounted for by alterations in CCT values.

The influence of posterior capsular opacification removal on anterior segment birefringence parameters as measured by scanning laser polarimetry

Purpose:  To determine the effect of posterior capsular opacification (PCO) removal on anterior segment birefringence (ASB) and its influence on peripapillary retinal nerve fibre layer (RNFL) retardation measurements obtained by means of scanning laser polarimetry.

Comparison of global indices and test duration between two visual field analyzers: Octopus 300 and Topcon SBP-3000.

PurposeTo compare the global indices and test duration as measured by Octopus 300 and Topcon SBP-3000 perimeters. To our knowledge, this is the first study performed in this way.MethodsEighty eyes of 40 glaucomatous and ocular hypertensive patients with previous perimetric experience had visual field tests with Octopus 300 (TOP strategy) and TOPCON SBP-3000. All pairs of tests were performed randomly on separate days, but within 1 month of each other. Taking into account reliability factors of both perimetric examinations, 54 eyes of thirty patients were eligible. Only one eye from each patient was considered. Mean sensitivity (MS), mean defect (MD), loss of variance (sLV-Octopus- and LV -Topcon-) and test duration times were considered.ResultsA significant difference was found between the global indices and duration times of the Octopus and the Topcon perimeters (p < 0.05; Wilcoxon test). Moderate degrees of correlation were obtained for MS (Spearman´s rho = 0.635; p < 0.001) and MD (Spearman´s rho = 0.592; p = 0.001) measurements. There was no correlation between sLV and LV (Spearman´s rho = 0.181; p = 0.337). Agreements between pairs of global indices were low as measured by concordance correlation coefficient.ConclusionGlobal indices measured by the Octopus and Topcon perimeters are significantly different, so direct comparison of the measured values is not reliable. Because of the poor association and agreement between values obtained by these two perimeters, indirect comparison is also inadvisable.

Herpetic Blepharitis and Inhaled Budesonide

Dear Editor: Inhaled corticosteroids (ICS) are recommended as first-line agents for the management of persistent asthma and are also widely used for chronic obstructive pulmonary disease (COPD). We describe a periocular and ocular herpetic infection in a patient treated with ICS. A 63-year-old man was hospitalized for an exacerbation of COPD. He was a smoker of 40 cigarettes per day for more than 30 years. His medical and ocular histories were otherwise noncontributory. Physical examination revealed a temperature of 38°C and diffuse expiratory rhonchi. Laboratory tests were within normal limits except for leukocytosis with neutrophilia. Chest X-ray showed a bilateral basal interstitial pattern with no evidence of inflammatory infiltrate. Sputum and blood cultures, human immunodeficiency virus (HIV), and tuberculin skin tests were negative. Treatment was initiated with intravenous levofloxacin (500 mg daily), oxygen supplementation and inhaled ipratropium (500 g), salbutamol (2500 g), and budesonide (500 g) every 6 hours delivered by a nebulizer with facemask (Fig 1A, available at http://aaojournal. org). Five days later, he developed multiple periocular skin ulcers and intermarginal erosions bilaterally (Figs 1B, 2A, and 2C, available at http://aaojournal.org). Regional preauricular lymph nodes were enlarged. Best-corrected visual acuity (BCVA) was 20/30 in both eyes. Bulbar conjunctiva displayed moderate hyperemia and the tarsal portion showed follicular swelling. Both corneas showed epithelial keratitis (Figs 2B and 2D, available at http://aaojournal. org). There was no anterior-chamber reaction or sign of stromal or endothelial involvement. Fundus examination revealed no abnormalities. The patient could not recall any previous herpes infections anywhere. The probable diagnosis of an erosive-ulcerative herpes simplex blepharitis with herpetic keratoconjunctivitis was postulated. Scrapings were obtained from skin ulcers, intermarginal erosions, and conjunctiva and sent for viral culture. Budenoside was withdrawn as respiratory insufficiency had improved. Local application of topical acyclovir ointment 3% (5 times a day) and erythromycin ointment 0.5% (3 times a day) was initiated. Herpes simplex type I was isolated from viral cultures of scrapings and confirmed by immunofluorescence. The corneal lesions disappeared and BCVA improved to 20/20 bilaterally by day 7 of treatment while conjunctivitis, intermarginal erosions, and skin ulcers healed by the day 14 (Figs 1B-D, available at http://aaojournal.org). Aerosolized medications maximize clinical benefit by targeting the airways and minimize side effects by reducing systemic exposure. These medications delivered with a facemask may inadvertently deposit on the skin of the face and in the eyes causing cutaneous and ocular side effects. Inhaled corticosteroids have been associated with an in-

Diabetic Retinopathy and Oxidative Stress

Abstract Diabetic retinopathy (DR) is the leading cause of acquired blindness in working age adults worldwide. Biochemical changes in DR contribute to both the microscopic structural and functional changes in the retina. All these alterations result in macroscopic retinal damage that can be assessed by funduscopy. The overproduction of reactive oxygen species (ROS) in the mitochondria is considered a causal link between elevated glucose and biochemical abnormalities in the pathophysiology of DR. Moreover, oxidatively induced pathways also seem to provide positive feedback to ROS production, resulting in a vicious cycle. ROS can directly damage lipids, proteins and DNA, leading to cell death. To make the situation worse, antioxidant defenses are also impaired in diabetes. Otherwise, ROS are involved in the production of inflammatory cytokines and growth factors such as interleukins or vascular endothelial growth factor (VEGF). In addition, ROS not only contribute to the development of DR, but also play a role in its progression when the hyperglycemic insult is controlled. This phenomenon is called metabolic memory.

Antioxidant Supplements and Diabetic Retinopathy

Abstract Conventional treatments for diabetic retinopathy (DR) includes glycemic control, laser photocoagulation, vitrectomy, intravitreal triamcinolone, and intravitreal anti-vascular endothelial growth factor agents. However these strategies have not proved capable of halting the progression of this disease in all cases. The mechanisms leading to DR are not fully understood, but there is a growing body of evidence showing that oxidative stress plays a pivotal role in the development of this diabetic complication. In fact it has been proposed that oxidative stress is the initial and maintaining event that triggers and provides feedback to the other pathophysiological pathways related to DR. The experimental data discussed in this review show that different antioxidant agents may prevent various biochemical and structural alterations in retinal cells cultured under hyperglycemic conditions, and also in experimental diabetic animals. Although the results of human trials are somewhat variable, some clinical studies have provided promising results.

Re: Effects of posterior capsular opacification on the evaluation of retinal nerve fiber layer as measured by Stratus optical coherence tomography. 47(2)

We read with interest the article by Kara et al. The authors investigated the effect that posterior capsule opacification (PCO) has on the results of retinal nerve fiber layer (RNFL) thickness as measured by means of optical coherence tomography (OCT) (Carl Zeiss Meditec, Dublin, Calif.). They concluded that RNFL thickness is affected by PCO. The authors also stated that the effect of PCO on the evaluation of RNFL by Stratus OCT has not been studied so far. However, our group has previously performed this kind of study. We also obtained a significant increase of signal strength (SS), but we did not find changes in the RNFL thicknesses after capsulotomy. In a similar study conducted by our group, when dealing with macular thickness parameters no significant differences were found between mean preand postcapsulotomy results, and an association was obtained between visual acuity and SS before membranotomy. The methods used by Kara et al. and our group were similar. Nevertheless, some questions are raised that may help us to understand the apparently surprising differences in the results. According to the OCT manual, a single examination is not reliable when the SS is lower than 5 and there are tomographic messages. Thus, examinations with these features were excluded in our above-mentioned studies of the statistical comparison of thickness parameters. Kara et al. adopted a different but interesting approach: they divided the eyes into groups according to the value of each SS obtained, including unreliable examinations (SS 5) and reliable examinations (SS 5), and they performed the comparison of thicknesses in each group independently.