Minocycline is cytoprotective in human corneal endothelial cells and induces anti-apoptotic B-cell CLL/lymphoma 2 (Bcl-2) and X-linked inhibitor of apoptosis (XIAP)

Introduction Loss of corneal endothelial cells (CECs) is one major factor limiting transplant clarity and survival after keratoplasty. Amongst other factors, apoptosis due to cellular stress is responsible for these problems. This study investigates the possible anti-apoptotic and cytoprotective effects of minocycline on a human corneal endothelial cell line (HCEC-SV40) cultured under oxidative stress and with transforming growth factor beta (TGF-beta). Methods CECs were treated with 1-150 mM minocycline. Cell viability and the median inhibitory concentration (IC(50)) were evaluated after 48 h and after H(2)O(2) treatment (tetrazolium dye reduction assay and liveedead assay). Expression of B-cell CLL/lymphoma 2 (Bcl-2) and X-linked inhibitor of apoptosis (XIAP) and their mRNA were assessed by reverse transcriptase (RT)-PCR and western blot analysis after treatment with minocycline alone and consecutive incubation with 200 mM H(2)O(2) and TGF-beta 2. A quantitative detection of histone-associated DNA fragmentation by ELISA was performed. Results Minocycline concentrations from 1-50 mM showed no toxic effects on CECs. Pre-treatment with 10-40 mM minocycline led to an increase in viability after H(2)O(2) treatment. In addition, minocycline pretreatment attenuated the increase of histone-associated DNA fragmentation after treatment with H(2)O(2) and TGF-beta 2 significantly. When CECs were treated with minocycline and then consecutively with H(2)O(2) or TGF-beta 2, RT-PCR and western blot analysis yielded an overexpression of Bcl-2 and XIAP. Conclusion In this study minocycline prevented apoptotic cell death in cultured CECs in vitro. Our results suggest that minocycline might offer cytoprotective properties that might help to prevent loss of corneal endothelial cells in vivo

Anatomic Success of Scleral Buckling for Rhegmatogenous Retinal Detachment - A Retrospective Study of 524 Cases

Background/Aim: Our purpose was to investigate the anatomic success of scleral buckling surgery for rhegmatogenous retinal detachment. Material and Methods: A total of 524 consecutive patients were retrospectively analysed. Several parameters including the lens status, number of breaks and extent of retinal detachment, preoperative proliferative vitreoretinopathy and refractive errors were examined. The minimum follow-up was 6 months. The primary success rate was defined as anatomic success being stable over a period of at least 6 months after surgery. The secondary success rate was defined as anatomic success after the second intervention if necessary. Besides an analysis over all patients, the patients were grouped according to the severity of the preoperative situation in simple, medium and severe cases. Results: The overall primary anatomic success rate was 84.7% and the secondary success rate 96.4% after 1 initial scleral buckling surgery and 1 additional surgery in case of persisting retinal detachment, and 19.1% of the patients with an initially attached retina after 1 scleral buckling surgery experienced a redetachment in the postoperative course and were successfully treated in 60/85 cases. In phakic patients (n = 359) the primary success rate was 89.7%, whereas in pseudophakic patients (n = 165) a primary success rate of 73.9% was obtained. The primary success was additionally influenced by the extent of the retinal detachment measured in clock hours (p <0.001), undetected holes (p = 0.004), small (p = 0.037) and no gas tamponade (p = 0.021). In simple, medium and severe cases, phakic patients always achieved better anatomic results (89.9, 89.1 and 90.2%) compared to pseudophakic ones (82.5, 70.3 and 36.4%). Conclusion: Scleral buckling is a very good surgical option in phakic patients irrespective of the preoperative severity and simple cases in pseudophakic patients. Scleral buckling represents a surgical technique worth being trained and performed in the light of favourable results especially in phakic eyes. Copyright (C) 2010 S. Karger AG, Base

Interference microscopy delineates cellular proliferations on flat mounted internal limiting membrane specimens.

Aim: To demonstrate that interference microscopy of flat mounted internal limiting membrane specimens clearly delineates cellular proliferations at the vitreomacular interface. Methods: ILM specimens harvested during vitrectomy were fixed in glutaraldehyde 0.05% and paraformaldehyde 2% for 24 h (pH 7.4). In addition to interference microscopy, immunocytochemistry using antibodies against glial fibrillar acidic protein (GFAP) and neurofilament (NF) was performed. After washing in phosphatebuffered saline 0.1 M, the specimens were flat-mounted on glass slides without sectioning, embedding or any other technique of conventional light microscopy. A cover slide and 49,6-diamidino-2-phenylindole (DAPI) medium were added to stain the cell nuclei. Results: Interference microscopy clearly delineates cellular proliferations at the ILM. DAPI stained the cell nuclei. Areas of cellular proliferation can be easily distinguished from ILM areas without cells. Immunocytochemistry can be performed without changing the protocols used in conventional microscopy. Conclusion: Interference microscopy of flat mounted ILM specimens gives new insights into the distribution of cellular proliferations at the vitreomacular interface and allows for determination of the cell density at the ILM. Given that the entire ILM peeled is seen en face, the techniques described offer a more reliable method to investigate the vitreoretinal interface in terms of cellular distribution compared with conventional microscopy

Fluorescein angiography compared to three-dimensional measurements by the retinal thickness analyzer in classic choroidal neovascularization

Purpose: To compare and correlate imaging of classic subfoveal choroidal neovascularization (CNV) with noninvasive 3-dimensional imaging by the retinal thickness analyzer (RTA) to conventional fluorescein angiography (FA). Methods: A total of 29 eyes of 29 consecutive patients with predominantly classic CNV eligible for photodynamic therapy underwent FA and RTA imaging. The FA dimensions of the CNV were measured independently by two graders. With the RTA, masked to FA the size of the CNV itself as imaged in 3-dimensional reconstruction, the size of significantly thickened retina overlying the CNV and the maximum retinal thickness were measured. Results: The mean diameter of the CNV determined from 3-dimensional RTA reconstructions showed an excellent correlation with measurements from FA (r = 0.91, p < 0.001). The area of retinal thickening was by a mean of 0.7 mm in diameter larger and correlated moderately well with the size of the CNV on FA (r = 0.65, p < 0.001). In contrast, there was no correlation between the absolute retinal thickness and the CNV size on FA. Conclusions: Noninvasive quantitative mapping of predominantly classic CNV by RTA is feasible and also allows 3-dimensional measurement of the lesion itself. The results correlate well with FA assessment but visualize different properties of the disease. Copyright (c) 2007 S. Karger AG, Basel

Alpha-Lipoic Acid for the Prevention of Diabetic Macular Edema

Introduction: To evaluate the effect of alpha-lipoic acid (ALA) on the occurrence of diabetic macular edema. Methods: Randomized, double-blind, placebo-controlled, multicenter, multinational study. Patients were randomized to the treatment group with 600 mg ALA per day or the placebo group. Every 6 months stereo fundus photographs, HbA1c levels, and an ophthalmological examination were documented. The primary endpoint was the occurrence of clinically significant macular edema (CSME) within a follow-up period of 2 years. Results: We randomized 235 patients with type II diabetes mellitus into the treatment group (mean age 58.0 years) and 232 into the placebo group (mean age 57.9 years). Mean HbA1c level was 8.1, with no significant differences between the treatment (mean 8.2, SD +/- 1.35) and placebo groups (mean 8.1, SD +/- 1.29). HbA1c values remained constant over time. In the treatment and placebo groups, 84 and 86 patients (35.7 and 37.1%) had insulin-dependent diabetes mellitus (IDDM) with a median duration of diabetes of 9.3 versus 9.0 years in the placebo group. Visual acuity remained unchanged during the entire trial. Concerning the primary endpoint, the study provided a negative result, i.e. 26/235 patients in the treatment group and 30/232 patients in the placebo group developed CSME. Confirmatory intention-to-treat analysis of the primary endpoint revealed no statistically significant difference between groups (log-rank test, p = 0.7108, HR = 0.9057 with CI = 0.5355-1.5317). Median follow-up was identical (2.00 years). Conclusions: A daily dosage of 600 mg ALA does not prevent the occurrence of CSME in IDDM patients. Copyright (C) 2011 S. Karger AG, Base

Staining and peeling of the internal limiting membrane using a fluorescent dye (Rhodamine 6 G)

Aim: To assess whether low concentrations of a fluorescent dye such as Rhodamine 6G would help the unaided human eye visualise the vitreous and the internal limiting membrane (ILM) under standard halogen illumination.Material/methods: The UV/Vis absorption (E) and fluorescence (I) spectra of Rhodamine 6G in water were measured and compared with Indocyanine Green (ICG). Surgery was performed in two rhesus monkeys and consisted of standard pars plana vitrectomy with halogen light source used for illumination. Rhodamine 6G was diluted in balanced salt solution (BSS). A few drops of the dye in a concentration of 0.1% (307 mOsm) were applied over the posterior pole in the air-filled globe and washed out by irrigation after 1 min. Immediately after surgery, the globes were enucleated, fixated and prepared for histological evaluation.Results: In contrast to ICG, both the maximum of the absorption and emission of Rhodamin 6G are very much within the spectral sensitivity of the human eye. The Rhodamine 6G--BSS itself appears red in colour. Using a dye concentration of 0.1%, there was no visible red-staining of the ILM as such. As the dye was irrigated out with BSS, a marked green fluorescence of the fluid within the vitreous cavity was noted. With halogen illumination through a standard 20-gauge light pipe, the dye provided a sufficient green fluorescence to identify and safely remove the ILM and to clearly differentiate areas of peeled from non-peeled ILM. During light microscopy, eyes revealed a peeled ILM demarcation with no signs of acute retinal toxicity.Conclusion: The findings indicate that a fluorescent dye can be used for ILM peeling. Assuming that the fluorophore provides a high enough fluorescence quantum yield after adsorption to the ILM, much lower dye concentrations could be used compared with absorbent dyes, thereby minimising toxic effects

Sequential epiretinal membrane removal with internal limiting membrane peeling in brilliant blue G-assisted macular surgery

Purpose To assess the selectivity of brilliant blue G (BBG) staining by analysing the morphological components of unstained and stained tissue obtained during epiretinal membrane (ERM) removal with internal limiting membrane (ILM) peeling in BBG-assisted macular surgery. Methods Twenty-six surgical specimens were removed from 13 eyes with epiretinal gliosis during vitrectomy using BBG for ERM and ILM peeling. We included eyes with idiopathic macular pucker, idiopathic macular hole and vitreomacular traction syndrome. The dye was injected into the fluid-filled globe. Unstained and stained epiretinal tissue was harvested consecutively and placed into separate containers. All specimens were processed for conventional transmission electron microscopy. Results The first surgical specimen of all eyes showed no intraoperative staining with BBG and corresponded to masses of cells and collagen. The second surgical specimen demonstrated good staining characteristics and corresponded to the ILM in all patients included. In seven eyes, the ILM specimens were seen with minor cell proliferations such as single cells or a monolayer of cells. Myofibroblasts, fibroblasts and astrocytes were present. In five cases, native vitreous collagen fibrils were found at the ILM. In six of the eyes, ILM specimens were blank. Conclusion Our clinicopathological correlation underlines the selective staining properties of BBG. The residual ILM is selectively stained by BBG even when a small amount of cells and collagen adheres to its vitreal side. To reduce the retinal exposure to the dye, the surgeon might choose to remove the ERM without using the dye, followed by a BBG injection to identify residual ILM

Comparison of Intravitreal Bevacizumab Upload Followed by a Dexamethasone Implant versus Dexamethasone Implant Monotherapy for Retinal Vein Occlusion with Macular Edema

Purpose: To compare the efficacy and safety of three intravitreal bevacizumab upload injections followed by a dexamethasone implant versus dexamethasone implant monotherapy in eyes with macular edema due to retinal vein occlusion. Methods: Sixty-four eyes of 64 patients were included in this prospective, consecutive, nonrandomized case series: group 1 consisted of 38 patients (22 with central retinal vein occlusion, CRVO, 16 with branch retinal vein occlusion, BRVO) treated using a dexamethasone implant (Ozurdex) alone; group 2 consisted of 26 patients (14 CRVO, 12 BRVO) treated with three consecutive intravitreal bevacizumab injections at monthly intervals followed by a dexamethasone implant. In case of recurrence, both cohorts received further dexamethasone implants. Preoperatively and monthly best corrected visual acuity (BCVA, ETDRS), central retinal thickness (Spectralis-OCT), intraocular pressure, and wide-angle fundus photodocumentation (Optomap) were performed. The primary clinical endpoint was BCVA at 6 months after initiation of therapy. Secondary endpoints were central retinal thickness and safety of the therapy applied. Results: In group 1, an increase in BCVA of 2.5 (+/- 1.6) letters in the CRVO and of 13.0 (+/- 3.2) letters in BRVO patients was seen after 6 months, in group 2 of 5.9 (+/- 0.4) letters (CRVO) and 3.8 (+/- 2.4) letters (BRVO), which was not statistically significant. When comparing the two treatment groups with respect to the type of vein occlusion, there was a significant advantage for BRVO patients for the dexamethasone implant monotherapy (BRVO patients in group 1, p = 0.005). Central retinal thickness showed a significant reduction after 6 months only in patients of group 1, both for CRVO (p = 0.01) and BRVO (p = 0.003). First recurrence after the first dexamethasone implant injection occurred after 3.8 months (mean) in CRVO and 3.5 months in BRVO patients (group 1), versus 3.2 and 3.7 months, respectively, in group 2. In group 1, 63.6% with CRVO and 50% with BRVO showed an increased intraocular pressure after treatment; in group 2, 57.1% with CRVO and 50.0% with BRVO, respectively. Conclusion: In CRVO, there was no difference between the two treatment strategies investigated. However, in BRVO, dexamethasone implant monotherapy was associated with better functional outcome. Copyright (C) 2012 S. Karger AG, Base