Intravitreal 5-Fluorouracil and Heparin to Prevent Proliferative Vitreoretinopathy: Results from a Randomized Clinical Trial.

PURPOSE: Proliferative vitreoretinopathy (PVR) is the major cause for surgical failure after primary rhegmatogenous retinal detachment (RRD). So far, no therapy has been proven to prevent PVR. Promising results for 5-fluorouracil (5-FU) and low-molecular weight heparin (LMWH) in high-risk eyes have been reported previously. The objective of this trial was to examine the effect of adjuvant intravitreal therapy with 5-FU and LMWH compared with placebo on incidence of PVR in high-risk patients with primary RRD. DESIGN: Randomized, double-blind, controlled, multicenter, interventional trial with 1 interim analysis. PARTICIPANTS: Patients with RRD who were considered to be at high risk for PVR were included. Risk of PVR was assessed by noninvasive aqueous flare measurement using laser flare photometry. METHODS: Patients were randomized 1:1 to verum (200 mg/ml 5-FU and 5 IU/ml dalteparin) and placebo (balanced salt solution) intravitreally applied during routine pars plana vitrectomy. MAIN OUTCOME MEASURES: Primary end point was the development of PVR grade CP (full-thickness retinal folds or subretinal strands in clock hours located posterior to equator) 1 or higher within 12 weeks after surgery. For grading, an end point committee assessed fundus photographs. Secondary end points included best-corrected visual acuity and redetachment rate. A group sequential design with 1 interim analysis was applied using the O'Brien and Fleming boundaries. Proliferative vitreoretinopathy grade CP incidence was compared using a Mantel-Haenszel test stratified by surgeon. RESULTS: A total of 325 patients in 13 German trial sites had been randomized (verum, n = 163; placebo, n = 162). In study eyes, mean laser flare was 31 ± 26 pc/ms. No significant difference was found in PVR rate. Primary analysis in the modified intention-to-treat population results were: verum 28% vs. placebo 23% (including not assessable cases as failures); odds ratio [OR], 1.25; 95% confidence interval [CI], 0.76-2.08; P = 0.77. Those in the per-protocol population were: 12% vs. 12%; OR, 1.05; 95% CI, 0.47-2.34; P = 0.47. None of the secondary end points showed any significant difference between treatment groups. During the study period, no relevant safety risks were identified. CONCLUSIONS: Rate of PVR did not differ between adjuvant therapy with 5-FU and LMWH and placebo treatment in eyes with RRD.

Cyclosporine a protects RGC-5 cells from excitotoxic cell death.

PURPOSE: Cyclosporine A (CSA) is a widely used immunosuppressive drug. Furthermore, CSA showed neuroprotective properties in several neurological disorders. However, nearly no data exist regarding CSA and its possible neuroprotective effect on retinal ganglion cells (RGCs). METHODS: RGC-5 cells were stressed with 10 mM glutamate for 24 hours with or without adding varying concentrations of CSA (1, 3, 6, or 9 µg/mL) to the medium. Cell viability and cell density were analyzed by MTS assay and crystal violet staining, respectively. Induction of apoptosis was determined through caspase 3/7 activity and Annexin V+/PI- flow cytometry. RESULTS: The incubation of RGC-5 cells with 10 mM glutamate for 24 hours induced a 3.1-fold and a 3.4-fold decrease in overall cell viability and cell density, respectively, compared with controls. The supplementation of 9 µg/mL CSA to 10 mM glutamate led to a 2.7-fold increase in overall cell viability (P<0.0005) and a 2.5-fold increase in cell density (P<0.0005) compared with RGC-5 cells treated only with 10 mM glutamate. Furthermore, the addition of 9 µg/mL CSA to 10 mM glutamate significantly reduced caspase 3/7 activity by 1.3-fold (P<0.0005) and the amount of Annexin V+/PI- cells by 2.8-fold compared with RGC-5 cells incubated with 10 mM glutamate alone. The neuroprotective effect of CSA dose-dependently decreased with lower concentrations. CONCLUSIONS: CSA can effectively protect RGC-5 cells against glutamate-induced excitotoxicity. Therefore, CSA should be tested in further experiments to evaluate its potential as a neuroprotective substance against RGC disorders.

Low-dose transscleral diode laser cyclophotocoagulation (TSCPC) as a potential single treatment for primary open-angle glaucoma (POAG) in Malawi?

PURPOSE: To investigate if low-dose 810 nm transscleral cyclophotocoagulation (TSCPC) can be used as single treatment in Malawian glaucoma patients. METHODS: Forty-seven eyes of 28 patients with primary open-angle and pseudoexfoliation glaucoma were treated with TSCPC using 12 spots with 900 mW, 2,000 ms (1.8 J per spot); six spots in the upper half, six in the lower by sparing the 3 and 9 o'clock positions ±20°. Intraocular pressure (IOP) and uncorrected visual acuity (UVA) were measured by an independent examiner preoperatively, on the first postoperative day, after 2 weeks, and after 3 months. RESULTS: Twenty-four (86%) and 18 (64%) of 28 patients (31 of 47 eyes; 66%) completed follow-up at 2 weeks and at 3 months respectively. After a single treatment session, IOP decreased by at least 25 % in 88% (21 of 24) after 2 weeks, and in 50% (nine of 18) of patients after 3 months. Mean IOP was 38.5 mmHg before TSCPC, 23.5 mmHg (p < 0.001) after 1 day, 24.5 mmHg (p < 0.001) after 2 weeks, and 35.6 mmHg (p = 0.37) after 3 months. In three patients, however, IOP increased after 3 months to levels significantly higher than before TSCPC. CONCLUSION: Low-dose TSCPC caused a significant IOP lowering for up to 2 weeks (15 mmHg less from baseline) in most patients. After 3 months, this effect was stable in 50% of patients; in the other half, IOP nearly returned back to baseline.

Comparing the effects of two different irrigation solutions on an isolated perfused vertebrate retina.

PURPOSE: To compare the effect of a taurine-containing intraocular irrigation solution (PuriProtect TM) to a standard irrigation solution (BSS TM) we evaluated the retinal function using an electroretinogram (ERG) and analyzed the survival of retinal ganglion cells on isolated whole mount retinas. MATERIALS AND METHODS: During ERG recordings, each irrigation solution was superfused for 45 min with the relevant irrigation solution. To investigate the effects on photoreceptor function, 1 m M asparate was added to obtain a-waves.The recovery of the a- and b-wave was monitored after superfusing the retinas with standard medium again. To evaluate the percentage of dead ganglion cells, retinas were stored for 24 h at 4°C in darkness and after staining the retinas with ethidium homodimer-1 the retinas were analyzed using fluorescence microscopy. RESULTS: The application of standard medium supplemented with 2 m M taurine resulted in a significant increase of the b-wave amplitude compared to standard medium alone. The a-wave amplitudes showed no significant changes under taurine supplementation. Compared to standard medium BSS showed no significant decrease in b-wave amplitudes, but a significant decrease ina-wave amplitudes. In contrast to BSS there were no significant changes in the a- or b-wave amplitudes detectable after the application of PuriProtect. At the end of the washout period no significant changes in a- or b-wave amplitudes were recorded for any tested irrigation solution. Retinas stored for 24 h in PuriProtect or in standard medium with taurine had a statistically significant smaller amount of dead cells than retinas stored in standard medium without taurine supplementation. CONCLUSIONS: BSS does not seem to be an ideal irrigation solution, because it compromises the a-wave in the ERG. In contrast to BSS, PuriProtect showed no significant impact on the ERG and showed a better long-term effect on ganglion cell survival. Taurine supplementation,therefore, seems to be neuroprotective and its supplementation to an intraocular irrigation solution favorable for the retina.

Neuroprotective effects of a taurine-containing irrigation solution for vitrectomy.

BACKGROUND: During pars plana vitrectomy, the retina is exposed to several iatrogenic risk factors, including excitotoxicity. A taurine-containing irrigation solution for pars plana vitrectomy (PURI PROTECT) has been developed and is claimed to have neuroprotective properties. METHODS: Retinal ganglion cells (RGC-5) and retinal whole mounts were incubated in standard irrigation solution (SIS) and SIS supplemented with 3 mM taurine (SIS-taurine). Excitotoxicity was induced by the addition of 8, 10, and 12 mM or 250 µM glutamate. Cell viability and cell survival were assessed by the MTT test and Annexin-V/propidium iodide flow cytometry. Whole mounts were stained with the Live/Dead staining assay. Pars plana vitrectomy with SIS or SIS-taurine was performed in rabbits. Animals were followed-up by electroretinography. RESULTS: RGC-5 incubated in SIS-taurine showed a 4.3-fold (P < 0.0005) better overall cell viability and an up to 8.5-fold (P < 0.05) increased cell survival under excitotoxic conditions compared with that incubated in SIS. Whole mounts incubated in SIS-taurine showed a 1.7-fold (P < 0.0005) and 1.6-fold (P < 0.0005) better cell survival under excitotoxic and nonexcitotoxic conditions, respectively. In the immediate postoperative period, b-wave amplitudes were significantly better in animals operated with SIS-taurine compared with control (P < 0.01). CONCLUSION: A taurine-containing irrigation solution may protect retinal ganglion cells against excitotoxicity.

Circulating melanoma cells in peripheral blood of patients with uveal melanoma before and after different therapies and association with prognostic parameters: a pilot study.

PURPOSE: To evaluate whether tumour therapy for malignant uveal melanoma leads to a shedding of melanoma cells into the systemic circulation. METHODS: Ninety-four peripheral blood samples from 81 patients with malignant uveal melanoma were collected before and after different tumour therapies and the number of circulating melanoma cells (CMCs) was investigated (seven patients with enucleation, 49 patients with stereotactic radiotherapy, 19 patients with endoresection of the tumour, 15 patients with ruthenium-brachytherapy and four patients with transpupillary thermotherapy). A cellular approach was used to detect CMCs through an immunocytological assay with tumour cell enrichment by immunomagnetic cell sorting. The number of CMCs was analysed further according to specific patient characteristics, tumour parameters and the development of metastasis. RESULTS: There was no significant difference between the number of CMCs before and after the different therapies (p = 0.78). There was also no significant association between established prognostic parameters of primary uveal melanoma and the detection of CMCs (all p >0.05). The number of CMCs was not related to the development of metastasis in a short median follow-up time of 16 months (p > 0.05). CONCLUSION: No changes in CMC values were observed before and after different tumour therapies. In the majority of cases therapy does not lead to a shedding of detectable melanoma cells into the systemic circulation.

The distribution, release kinetics, and biocompatibility of triamcinolone injected and dispersed in silicone oil.

PURPOSE: Triamcinolone acetonide (TA) has been proposed as an adjuvant to pars plana vitrectomy with silicone oil for the surgical treatment of proliferative vitreoretinopathy and proliferative diabetic retinopathy. However, to date no data about the distribution and pharmacokinetics of lipophilic TA injected into silicone oil have been reported. METHODS: An artificial vitreous space chamber was filled with silicone oil. TA was either injected or dispersed into silicone oil. TA release using a continuous flow model was measured spectrophotometrically. To determine the antiproliferative or cytotoxic effect of the released TA, monolayer cultures of retinal pigment epithelial cells (ARPE19) and retinal ganglion cells (RGC5) were used. Bromodeoxyuridine incorporation, MTT assay, and scanning electron microscopy were performed. RESULTS: Injected TA sank slowly through the silicone oil and started to sediment below the silicone oil bubble shortly after injection. After the simulated intravitreal injection, no TA could be retrieved from the silicone oil bubble. In contrast, when a suspension of silicone oil and TA was prepared before injection, stable noncytotoxic amounts of TA (25 microg/mL) could be retrieved for up to 90 days. After mere injection (without previous suspension in silicone oil), the sedimented TA crystals showed a pronounced cytotoxic effect. CONCLUSIONS: Intravitreally injected TA does not mix with silicone oil. TA crystals that sediment at the lower border of a silicone oil bubble may be harmful to retinal cells. A suspension of TA in silicone oil may exhibit safer extended release over several days.