Irini P. Chatziralli

Branch retinal vein occlusion: epidemiology, pathogenesis, risk factors, clinical features, diagnosis, and complications. An update of the literature.

Background/Purpose: Retinal vein occlusion is the second most common retinal vascular disorder after diabetic retinopathy and is considered to be an important cause of visual loss. In this review, the purpose is to make an update of the literature about the classification, epidemiology, pathogenesis, risk factors, clinical features, and complications of branch retinal vein occlusion (BRVO). Methods: Eligible articles were identified using a comprehensive literature search of MEDLINE, using the terms “branch retinal vein occlusion,” “pathogenesis,” “epidemiology,” “risk factors,” “clinical features,” “diagnosis,” and “complications.” Additional articles were also selected from reference lists of articles identified by the electronic database search. Results: Classification, epidemiology, pathogenesis, risk factors, clinical features, and complications are analyzed. Conclusions: Branch retinal vein occlusion has an incidence of 0.5% to 1.2%. Several risk factors, such as hypertension, hyperlipidemia, diabetes mellitus, thrombophilia and hypercoagulation, systemic and inflammatory diseases, medications, and ocular conditions, have found to be associated with BRVO. The symptoms depended on the site and severity of the occlusion. The average reduction in visual acuity for ischemic BRVO is 20/50 and for nonischemic BRVO is 20/60. Acute BRVO can be detected by fundoscopy, where flame hemorrhages, dot and blot hemorrhages, cotton wool spots, hard exudates, retinal edema, and dilated tortuous veins can be observed. Chronic BRVO would be more subtle and characterized by the appearance of venous collateral formation and vascular sheathing, in addition to complications previously mentioned. Areas of ischemia can be evaluated using fluorescein angiography. The extent of macular edema and the presence of retinal detachment can be detected by fundoscopic examination or fluorescein angiography, although optical coherence tomography is considered to be the best method. As far as complications, the most common is macular edema, followed by retinal neovascularization, vitreous hemorrhage, or retinal detachment.

Risk factors for intraoperative floppy iris syndrome: a meta-analysis.

PURPOSE To evaluate risk factors (hypertension, diabetes mellitus, and current tamsulosin, alfuzosin, terazosin, or doxazosin use) for intraoperative floppy iris syndrome (IFIS) in patients undergoing phacoemulsification cataract surgery. DESIGN Systematic review and meta-analysis of the literature. PARTICIPANTS Seventeen eligible studies (17 588 eyes) examining the association between IFIS and risk factors. METHODS Pertinent publications were identified through a systematic search of PubMed. All references of relevant reviews and eligible articles were also screened. Language restrictions were not used, and data were extracted from each eligible study by 2 investigators working independently. For medications, 2 separate analyses were performed: an analysis using a dichotomous criterion (use/non-use of the examined agent) and an alternative analysis performing comparisons with patients not receiving any α(1)-blocker. The fixed-effects model (Mantel-Haenszel method) or the random-effects (DerSimonian Laird) model was appropriately used to calculate the pooled odds ratio (OR). Publication bias was appropriately assessed. MAIN OUTCOME MEASURES Pooled OR for the incidence of IFIS. RESULTS The pooled OR for IFIS after tamsulosin use was approximately 40-fold greater (or 16.5 at the alternative analysis) than that after alfuzosin use, that is, the second α(1)-blocker in order of effect size. Alfuzosin and terazosin were also associated with IFIS with comparable ORs; the effect of doxazosin reached formal statistical significance at the alternative analysis. Intraoperative floppy iris syndrome was positively associated with hypertension (pooled OR = 2.2, 95% confidence interval [CI], 1.2-4.2, fixed effects) but not with diabetes mellitus (pooled OR = 1.3, 95% CI, 0.7-2.2, fixed effects). CONCLUSIONS This meta-analysis has highlighted a hierarchy concerning the role of α(1)-blockers in IFIS, indicating an extremely sizeable effect size of tamsulosin; this may entail important physiologic implications. Alfuzosin, terazosin, and doxazosin presented with comparable effect sizes. Hypertension, but not diabetes mellitus, emerged as a risk factor for IFIS.

Structural and Functional Impairment of the Retina and Optic Nerve in Alzheimer’s Disease

PURPOSE The purpose of this study was to evaluate the macular and retinal nerve fiber layer (RNFL) thickness, and the electrical activity of the macula in patients with Alzheimers disease (AD). MATERIAL AND METHODS 30 patients with AD and 30 age and sex matched healthy controls were studied. The thickness and the electrical activity of the macula were evaluated by means of optical coherence tomography (OCT) and multifocal-electroretinogram (mf-ERG). RESULTS Visual acuity, as well as visual fields and colour vision testing of all patients were normal. However, the mean foveal thickness was 148.50 μm (vs. 171.50 μm in the control group, p=0.001) and the RNFL thickness was 104.5 μm in the superior area (vs 123 μm in the control group, p < 0.0001) and 116.5 μm in the inferior area (vs. 138 μm in the control group, p < 0.0001) around the optic nerve. The mean P1 response density amplitude of the foveal area was 146.50 nV/deg2 (vs. 293 nV/deg2 in the control group, p < 0.0001) and the perifoveal area was 56.60 nV/deg2 (vs. 81.50 nv/deg2 in the control group, p < 0.001). CONCLUSION Our study showed that in patients with AD, even without visual failure there was a decrease in macular and RNFL thickness, as well as a decrease of the electrical activity of the macula.

Risk factors associated with diabetic retinopathy in patients with diabetes mellitus type 2.

BackgroundDiabetes mellitus (DM) is associated with microvascular complications, such as diabetic retinopathy (DR). DR is one of the main causes of visual loss in individuals aged 20-64 years old. This study aims to investigate the independent associations between the stage of DR and a variety of possible risk factors, including years since DM diagnosis, HbA1c levels, the coexistence of hypertension, age and gender.Findings120 patients were recruited in the Department of Internal Medicine, Veroia General Hospital, Veroia, Greece, and the DR stage was defined by an ophthalmologist. Afterwards, the DR association with the aforementioned factors was examined. Univariate and multivariate analysis (multivariate ordinal logistic regression) was performed. At the univariate analysis, there was a positive association between DR severity and age (Spearmans rho = 0.4869, p < 0.0001), years since DM diagnosis (Spearmans rho = 0.6877, p < 0.0001), HbA1c levels (Spearmans rho = 0.6315, p < 0.0001), history of hypertension (2.47 ± 1.37 vs. 0.50 ± 0.80 for patients without hypertension; p < 0.0001) and male sex (2.56 ± 1.41 vs. 2.05 ± 1.45 for female patients; p = 0.045, MWW). All these factors, except for age, retained their statistical significance at the multivariate ordinal logistic model.ConclusionsYears since DM diagnosis, hypertension, HbA1c levels and male sex are independently associated with severe DR. The effect of age seems to reflect a confounding association.

Perspectives on reticular pseudodrusen in age-related macular degeneration

Drusen have been considered the clinical hallmark of age-related macular degeneration (AMD). Reticular pseudodrusen (RPD), although first described about 25 years ago, have only been recently recognized as an additional clinical phenotype of AMD with distinct characteristics on multimodal imaging and significant impact on visual function. Eyes with RPD are at greater risk of progression to advanced AMD when compared with eyes with drusen only. RPD can also occur in the absence of drusen. Unlike features external to the retinal pigment epithelium that have received most attention in AMD, evidence suggests that RPD are associated with changes internal to the RPE. Therefore, new avenues regarding the pathogenesis of AMD are highlighted by these recent observations. We summarize the current knowledge regarding the histology, imaging, and functional changes in eyes with RPD in AMD and offer concepts of future research for the AMD community to discuss.

Long-term Results Of Intravitreal Ranibizumab, Intravitreal Ranibizumab With Photodynamic Therapy, And Intravitreal Triamcinolone With Photodynamic Therapy For The Treatment Of Retinal Angiomatous Proliferation

Purpose: To compare intravitreal ranibizumab, intravitreal ranibizumab plus photodynamic therapy (PDT), and intravitreal triamcinolone plus PDT in retinal angiomatous proliferation, presenting the results of a 3-year follow-up. Methods: Thirty-seven eyes of 37 patients with retinal angiomatous proliferation were randomized to 1 of the 3 groups. Group 1 (n = 13) received 3 monthly injections of 0.5 mg ranibizumab, Group 2 (n = 13) received 1 session of PDT and 3 monthly injections of ranibizumab, and Group 3 (n = 11) received 1 session of PDT and 1 injection of 4 mg triamcinolone. Retreatment, with the same therapeutic scheme in each group, was considered in case of persistence or recurrence of subretinal/intraretinal fluid. Results: Twelve patients in Groups 1 and 2 and 9 patients in Group 3 completed the 3-year follow-up. A total of 58% of patients in Group 1, 50% in Group 2, and 88.9% in Group 3 had the same or better visual acuity at the end of the follow-up (P = 0.081). Patients in Group 3 exhibited considerable improvement in visual acuity (P = 0.032) and statistically significant decrease in central retinal thickness (P < 0.0001) than the 2 other groups at the end of the follow-up. Also, the patients in Group 3 received on average the lowest number of injections (P < 0.0001). Of note, geographic atrophy mainly at the place of previous retinal angiomatous proliferation lesion was detected in 0% in Group 1, 25% in Group 2, and 55.6% in Group 3 (P = 0.203), while 33.3% of patients in Group 1 developed retinal scar. Conclusion: Treatment with ranibizumab or ranibizumab plus PDT resulted in stabilization of the disease, while treatment with IVT plus PDT achieved better results in terms of functional and anatomical features compared with the other groups.

Polymorphism Analysis of VSX1 and SOD1 Genes in Greek Patients with Keratoconus

Abstract Background: A number of mutations in the VSX1 and SOD1 genes have been reported to be associated with keratoconus (KC), however the results from different studies are controversial. In this study, we conducted the genotyping of common polymorphisms [VSX1: D144E, H244R, R166W, G160D; SOD1: intronic 7-base deletion (c.169 + 50delTAAACAG)], in a case–control sample panel of the Greek population. Materials and methods: A case–control panel, with 33 KC patients and 78 healthy controls, were surveyed. DNA from each individual was tested for the VSX1: D144E, H244R, R166W, G160D and SOD1: intronic 7-base deletion (c.169 + 50delTAAACAG) polymorphisms by direct sequencing. Results: We observed no polymorphisms of the VSX1 gene in the case–control panel. Concerning the SOD1 intronic 7-base deletion (c.169 + 50delTAAACAG), our findings suggest that heterozygous carriers are over-represented among KC cases compared to healthy controls (p = 0.002). Conclusions: We cannot confirm the previously reported association of the polymorphism in the VSX1 gene with KC. Our results suggest a possible causative role of SOD1 in the pathogenesis of KC. Further studies are required to identify other important genetic factors involved in the pathogenesis and progression of KC.

Cross Talk between Lipid Metabolism and Inflammatory Markers in Patients with Diabetic Retinopathy

Purpose. The purpose of this study was to examine the relationship between metabolic and inflammatory markers in patients with diabetic retinopathy (DR). Methods. 208 adult patients with type 2 diabetes participated in this study and were categorized into (1) mild nonproliferative diabetic retinopathy (NPDR) without clinically significant macular edema (CSME), (2) NPDR with CSME, (3) proliferative diabetic retinopathy (PDR) without CSME, and (4) PDR with CSME. Variable serum metabolic markers were assessed using immunoassays. Multinomial logistic regression analysis was performed. Results. Diabetes duration and hypertension are the most significant risk factors for DR. Serum Apo-B and Apo-B/Apo-A ratio were the most significant metabolic risk factors for PDR and CSME. For every 0.1 g/L increase in Apo-B concentration, the risk of PDR and CSME increased by about 1.20 times. We also found that 10 pg/mL increase in serum TNF-α was associated with approximately 2-fold risk of PDR/CSME while an increase by 100 pg/mL in serum VEGF concentration correlated with CSME. Conclusions. In conclusion, it seems that there is a link between metabolic and inflammatory markers. Apo-B/Apo-A ratio should be evaluated as a reliable risk factor for PDR and CSME, while the role of increased systemic TNF-α and VEGF should be explored in CSME.

Viscoat versus Visthesia during phacoemulsification cataract surgery: corneal and foveal changes

BackgroundOphthalmic viscosurgical devices (OVDs) are widely used in phacoemulsification cataract surgery to maintain adequate intraocular space, stabilize ocular tissue during the operation and decrease the possible damage of the corneal endothelium. Our study has the purpose to compare the corneal and foveal changes of Viscoat and Visthesia in patients undergoing uneventful phacoemulsification cataract surgery.MethodsParticipants in our study were 77 consecutive patients, who were randomized into two groups based on type of OVD used during phacoemulsification: Viscoat or Visthesia. All patients underwent a complete ophthalmological examination i.e., measurement of best corrected visual acuity (BCVA) by means of Snellen charts, intraocular pressure examination by Goldmann tonometry, slit lamp examination, fundus examination, optical coherence tomography, specular microscopy and ultrasound pachymetry preoperatively and at three time points postoperatively (day 3, 15, 28 postoperatively). The differences in baseline characteristics, as well as in outcomes between the two groups were compared by Mann-Whitney-Wilcoxon test and Students t-test, as appropriate.ResultsIntraoperatively, there was no statistically significant difference in the duration of the ultrasound application between the two groups, while Viscoat group needed more time for the operation performance. It is also worthy to mention that Visthesia group exhibited less intense pain than patients in Viscoat group. Postoperatively, there was a statistically significant difference in central corneal thickness, endothelial cell count and macular thickness between the two groups, but BCVA (logMAR) did not differ between the two groups.ConclusionsOur study suggests that Viscoat is more safe and protective for the corneal endothelium during uneventful phacoemulsification cataract surgery, while Visthesia is in superior position regarding intraoperative pain. Patients of both groups acquired excellent visual acuity postoperative. Finally, this is the first study comparing OVDs in terms of macular thickness, finding that Visthesia cause a greater increase in macular thickness postoperatively than Viscoat, although it reaches normal ranges in both groups.

Evaluation of retinal nerve fibre layer thickness and visual evoked potentials in optic neuritis associated with multiple sclerosis

Background:  The aim was to compare the retinal nerve fibre layer (RNFL) thickness and visual evoked potentials (VEP) among eyes with multiple sclerosis (MS)‐associated optic neuritis, unaffected eyes of the same patients and eyes of disease‐free controls. Changes in RNFL thickness, visual acuity (VA) and VEP over time are evaluated in MS‐associated optic neuritis.