Mojca Urbančič

Efficacy of 12-month treatment of neovascular age-related macular degeneration with intravitreal bevacizumab based on individually determined injection strategies after three consecutive monthly injections.

Purpose:  To report the results of intravitreal treatment with bevacizumab in neovascular age‐related macular degeneration (AMD) after a loading dose (LD) of three monthly injections followed by an optical coherence tomography (OCT)‐guided strategy, based on best‐corrected visual acuity (VA) and number of injections required over 1 year.

A Flow Cytometric Analysis of Vitreous Inflammatory Cells in Patients with Proliferative Diabetic Retinopathy

The purpose of this study was to investigate inflammatory cells in vitreous from patients with proliferative diabetic retinopathy (PDR) using flow cytometric analysis. Twenty-eight patients with PDR requiring vitrectomy because of macular traction or tractional retinal detachment were enrolled in the study (n = 28), and 6 patients with macular hole (MH) formed the control group. Samples of vitreous and peripheral venous blood were obtained at the beginning of vitrectomy. T lymphocytes were found in vitreous from patients with PDR, and CD4/CD8 ratio was higher in vitreous (median 4.3) compared to blood (median 1.9; P = 0.003). No B lymphocytes were detected in vitreous. The percentage of histiocytes/macrophages was significantly higher in vitreous (median 62.1) in comparison with blood (median 5.5; P < 0.0001). No lymphocytes were detected in vitreous of the control group. There were more T lymphocytes in vitreous from patients with active PDR. No association between cells in the vitreous and visual acuity improvement after surgery was found. In conclusion, T lymphocytes are found in vitreous from patients with PDR and reflect the activity of PDR but do not seem to predict visual prognosis. Higher CD4/CD8 ratio in vitreous compared to blood from patients with PDR is consistent with local inflammatory response in PDR.

Epiretinal membrane inflammatory cell density might reflect the activity of proliferative diabetic retinopathy.

PURPOSE Diabetic retinopathy (DR) has features of chronic low-grade inflammation. The purpose of our study was to investigate whether the presence of inflammatory cells in fibrovascular membranes (FVMs) from patients with proliferative diabetic retinopathy (PDR) is associated with the activity of PDR and visual acuity improvement after vitreoretinal surgery. METHODS Forty FVMs from 40 patients with PDR were obtained during vitrectomy, prepared by using the agar sandwich method, and examined using light microscope and immunohistochemistry methods to define the presence and density of inflammatory cells: CD45+ cells (leukocytes), CD4+ cells (T helper lymphocytes), CD8+ cells (T cytotoxic lymphocytes), CD19+ cells (B lymphocytes), and CD14+ cells (monocytes/macrophages). For each FVM, the inflammatory cell density defined as numerical areal density was calculated. The number of vessels was defined as the volume density of vessels. RESULTS Among 40 patients with PDR, 33 patients had active PDR and 7 quiescent PDR. Significant differences in cell densities for CD4+, CD8+, and CD19+ cells were observed between patients with active and quiescent PDR. B lymphocytes were present in membranes of active PDR only. No correlation was observed between numerical areal density of inflammatory cells and the volume density of vessels. No association was found between visual acuity improvement after surgery and cell densities. CONCLUSIONS Lymphocyte infiltration of FVMs might be associated with the activity of retinopathy but not with visual acuity improvement after surgery.

Functional and molecular characterization of ex vivo cultured epiretinal membrane cells from human proliferative diabetic retinopathy.

Characterization of the cell surface marker phenotype of ex vivo cultured cells growing out of human fibrovascular epiretinal membranes (fvERMs) from proliferative diabetic retinopathy (PDR) can give insight into their function in immunity, angiogenesis, and retinal detachment. FvERMs from uneventful vitrectomies due to PDR were cultured adherently ex vivo. Surface marker analysis, release of immunity- and angiogenesis-pathway-related factors upon TNFα activation and measurement of the intracellular calcium dynamics upon mechano-stimulation using fluorescent dye Fura-2 were all performed. FvERMs formed proliferating cell monolayers when cultured ex vivo, which were negative for endothelial cell markers (CD31, VEGFR2), partially positive for hematopoietic- (CD34, CD47) and mesenchymal stem cell markers (CD73, CD90/Thy-1, and PDGFRβ), and negative for CD105. CD146/MCAM and CD166/ALCAM, previously unreported in cells from fvERMs, were also expressed. Secretion of 11 angiogenesis-related factors (DPPIV/CD26, EG-VEGF/PK1, ET-1, IGFBP-2 and 3, IL-8/CXCL8, MCP-1/CCL2, MMP-9, PTX3/TSG-14, Serpin E1/PAI-1, Serpin F1/PEDF, TIMP-1, and TSP-1) were detected upon TNFα activation of fvERM cells. Mechano-stimulation of these cells induced intracellular calcium propagation representing functional viability and role of these cells in tractional retinal detachment, thus serving as a model for studying tractional forces present in fvERMs in PDR ex vivo.

Floating Vitreous Cyst: Two Clinical Cases

Purpose: To report two cases of solitary unilateral vitreous cyst. Methods: A complete ocular examination, fundus photography, B-scan ultrasound and spectral-domain optical coherence tomography were performed in both patients. Results: The first patient (a 39-year-old man) presented with transient blurred vision in the right eye. The second patient (a 78-year-old man) reported transient blurred vision in the right eye when changing head position. He was referred to the Eye Hospital because of vitreomacular traction in the other eye. After examination, a diagnosis of vitreous cyst was made in both cases. Conclusions: Vitreous cysts are rare clinical findings. They can occur in normal eyes or in eyes with certain ocular pathologies. When a cyst floats into the visual axis area, it can disturb visual function; therefore, patients usually report transient blurring of vision. A prompt clinical examination is necessary for differentiating this rare condition.

Visual Acuity, Retinal Sensitivity, and Macular Thickness Changes in Diabetic Patients without Diabetic Retinopathy after Cataract Surgery

Aim. Functional and morphological macular study after cataract surgery in a group of diabetics without diabetic retinopathy compared to nondiabetics to evaluate the effect of surgical oxidative stress on diabetic retina. Methods. Prospective, comparative study. Preoperative eye exam, best corrected visual acuity (BCVA) measured by ETDRS letters, and optical coherence tomography (OCT) were followed by standard cataract surgery. The follow-up visits at 1, 3, and 6 months postoperatively included BCVA, OCT, and microperimetry, to analyze changes within and between the groups. Results. The BCVA improved significantly in diabetics and controls: 64.2 to 81.0 and 61.9 to 82.1 ETDRS at 6 months, respectively. The central macula at OCT significantly thickened in both groups, while the central 5 fields, corresponding to the microperimetry area, subclinically thickened from 284.20 to 291.18 μm at 6 months only in diabetics (p = 0.026). A matching slight decrease in the microperimetry sensitivity from 1 to 6 months was found also only in diabetics, with mean average difference −0.75 dB (p = 0.04). Conclusion. Underlying diabetes does not influence the surgical outcome in diabetics without diabetic retinopathy. However, slight thickening of wider macula and corresponding decrease in retinal sensitivity observed in diabetics 6 months postoperatively might influence visual function on long term.

Improvements in visual acuity within one year following intravitreal bevacizumab in neovascular age-related macular degeneration

Purpose To evaluate the effects of intravitreal treatment with bevacizumab on vision and anatomic outcome in patients with neovascular AMD. Methods Retrospective review of 153 eyes that received three or more intravitreal injections of bevacizumab (1.25 mg) for neovascular AMD over a one-year period. Patients underwent ophthalmological examinations, measurements of the best-corrected visual acuity (VA), fluorescein angiography and optical coherence tomography, at baseline and at monthly follow-up visits. Repeated injections were given in the presence of persistent leakage or retinal oedema. We analyzed the data obtained at three time intervals: 1 month (first evaluation) after the third injection, 6 months (second evaluation), and one year (third evaluation) after the onset of treatment. Changes from baseline in VA, central retinal thickness (CRT), and total macular volume (TMV) were analyzed using paired t-tests. Results Mean baseline VA improved from 50.5 to 57.6 letters (P < 0.0001, N = 153) at first evaluation, 58.3 letters (P < 0.0001, N = 119) at second evaluation, and 59.5 letters (P = 0.002, N = 48) at third evaluation. Baseline mean CRT (344.6 μm) and baseline mean TMV (8.6 mm3) decreased at the first evaluation, to 219.0 μm (P < 0.0001) and 7.2 mm3 (P < 0.0001), respectively. No systemic or serious ocular side effects were noted. Conclusion Intravitreal bevacizumab is an effective treatment for neovascular AMD, resulting in significant functional and anatomical improvement seen up to one year. After one year, VA in 27% of patients was improved by 15 letters or more, was maintained stable in 67% of patients, and was worsened by 15 letters or more in 6% of patients.

COMPARISON OF FAST STRATEGIES WITH NORMAL THRESHOLD STRATEGY USING OCTOPUS PROGRAMME M2 IN CENTRAL FIELD DEFECTS

Background. Fast test strategies are relatively new methods for assessing differential light sensitivity threshold in computer assisted perimetry. The purpose of our study was to compare and evaluate the accuracy of normal threshold strategy, dynamic strategy and TOP (Tendency Oriented Perimetry) strategy by testing central visual field with programme Octopus M2, which has the greatest concentration of test points (81 test points in the central 10 degrees area). A similar comparative study with programme Octopus M2 has not been done yet. Methods. 30 normal eyes and 30 eyes with central field defects of different degrees and etiology were tested. The testing was performed with Octopus 101 perimeter in standard conditions. The programme M2 was used. Each eye was tested three times – once with normal, once with dynamic and once with TOP strategy. Each subject had at least 20 minutes of break between each testing. The sequence of the strategies was equally alternated for all three strategies. Differences between strategies were statistically evaluated regarding examination time, parameters MS (Mean Sensitivity), MD (Mean Defect) and LV (Loss Variance), the extent and depth of a field defect, sensitivity and specificity. Results. Fast strategies significantly reduce examination time. There were no statistically significant differences in any of the observed parameters in the group of eyes with field defects. There were statistically significant differences in MS and MD in the group of normal eyes (p < 0.01), but these differences were not clinically important. All three strategies are well comparable regarding sensitivity and specificity. Conclusions. Fast test strategies (especially TOP strategy) represent a good alternative to normal threshold strategy. Better efficiency of fast strategies justifies their greater clinical application.