Ocular photodynamic therapy for serous macular detachment in the diffuse retinal pigment epitheliopathy variant of idiopathic central serous chorioretinopathy

PURPOSE: To describe the anatomical and functional outcome of verteporfin ocular photodynamic therapy (PDT) in serous retinal detachment caused by the diffuse retinal pigment epitheliopathy form of chronic idiopathic central serous chorioretinopathy. DESIGN: Interventional case report. METHOD: A 48-year-old Caucasian man with unilateral exudative retinal detachment from diffuse retinal pigment epitheliopathy and visual acuity of 20/40 was managed with verteporfin PDT applied sequentially in three separate spots targeting all retinal pigment epithelium leaks identified with intravenous fluorescein angiography (IVFA). Outcome measures included visual acuity, biomicroscopic appearance, and leakage on IVFA.Clinical practice.Subretinal fluid resolved within 2 weeks; visual acuity returned to 20/20 with no recurrence at 6 months of follow-up. There was no leakage on IVFA posttreatment and no obvious toxicity.To our knowledge, this is the first report of PDT causing resolution of macular detachment in diffuse retinal pigment epitheliopathy. Its long-term results with regard to the prognosis of the disease and the recurrence rate remain to be evaluated.     

The effect of intraoperative retinal manipulation on the underlying retinal pigment epithelium: an experimental study

PURPOSE: Retinal pigment epithelial changes described after vitreoretinal surgery may result from localized compression injury caused by intentional or inadvertent contact with vitreoretinal instruments. The authors evaluated these changes resulting from manipulation of the retina without frank retinal injury. METHODS: One eye each of six pigmented rabbits underwent surgery during which the inner retinal surface was touched at several points with a 20-gauge silicone-tipped subretinal fluid cannula without causing a retinal break or subretinal hemorrhage. The rabbits were followed-up with indirect ophthalmoscopy, fundus photography, and fluorescein angiography, and were killed at 1 hour, 1 week, or 2 weeks. Light microscopy was used for histopathologic evaluation. RESULTS: On fluorescein angiography, diffuse leakage noted at the injury sites significantly decreased by the fourth day and almost completely disappeared by the second week. Disruption of photoreceptor outer segments and retinal pigment epithelium in the early specimens, and irregular pigmentation, proliferation, and migration of the retinal pigment epithelium at 1 and 2 weeks were the prominent features on histopathologic examination. CONCLUSIONS: Intraoperative manipulation of the attached retina may cause significant pigment epithelium displacement and proliferation and varying degrees of disorganization of normal retinal architecture in the absence of clinically evident retinal breaks and subretinal hemorrhages.     

Scientific presentation using modern media

When showing slides with so called "Blue Prints", it is often difficult to explain complex graphics despite the help of a Laserpointer. The Notebook and Videoprojector aid modern presentations in the step by step development of complex graphics. The audience's eyes are directly guided towards the projected image; the attention of the audience is more easily won and held through animation and moving pictures. The central messages of a scientific work can be more simply and clearly conveyed. This method also allows an up-dating of the picture contents at short notice, which is not possible with the common slide. Considering these advantages, modern media should be promoted within the framework of conferences, seminars and further education courses despite the need of greater technical and material equipment.     

Toxicity of the photosensitizer NPe6 following intravitreal injection

BACKGROUND AND OBJECTIVE: To determine the retinal toxicity of mono-L-aspartyl chlorin e6 (NPe6) following intravitreal injection. METHODS: Twelve Dutch-belted rabbits divided into 5 experimental groups (n=2 each) were injected intravitreally with 6.25, 12.5, 25, 50, or 100 microg of NPe6; one control group (n=2) was injected with intravitreal normal saline. One eye in each rabbit was sutured shut to test the effect of light exposure. Fundus photography and electroretinograms were performed before treatment and 2 days, 1 week, and 2 weeks after injection. Animals were euthanized and the eyes enucleated for histopathologic analysis. RESULTS: After 1 week, 4 uncovered eyes given 50 and 100 microg had central retinal vein occlusion and varying degrees of retinal hemorrhage. RPE proliferation was seen in the covered eyes given 50 or 100 microg. Electroretinograms revealed absent retinal response at 100 microg and mild toxicity at 50 microg, but no change from normal at doses of < or = 25 microg of NPe6. CONCLUSIONS: Intravitreal doses of < or = 25 microg NPe6 caused little or no apparent toxicity; however, toxicity was significant at doses of 50 microg and 100 microg.     

Solvoplex: a new type of synthetic vector for intrapulmonary gene delivery

A novel type of synthetic vector, termed solvoplex, is described that can greatly enhance gene expression in lung after intrapulmonary delivery. Solvoplexes consist of plasmid DNA and organic solvents. Several organic solvents were analyzed, and luciferase reporter gene expression was observed after intrapulmonary delivery of solvoplexes containing DPSO (di-n-propylsulfoxide), TMU (tetramethylurea), or BMSO (butylmethylsulfoxide). Expression levels correlated with the amount of solvent used at constant DNA amounts. Highest expression was obtained in the lung after intratracheal injection with 15% DPSO resulting in an increase up to 440-fold compared with DNA alone. DPSO-solvoplexes (15%) gave higher reporter gene expression than polyplexes (ExGen 500) or lipoplexes (DOTAP-cholesterol or DOTAP-DOPE). Solvoplex-mediated gene expression did not depend on the delivery mode, and was observed in both mice and rats. Readministration of DPSO-solvoplexes was possible. A second injection after 4 weeks resulted in expression levels similar to the first administration. Histological analyses using lacZ and GFP reporter genes demonstrated gene expression in the lung airway epithelium after intratracheal and microspray delivery. When luciferase expression levels in lung homogenates were compared with adenovirus vectors, DPSO-solvoplexes were 4- or 100-fold less efficient, depending on the promoter used in the viral vector. A quantitative histological comparison between solvoplexes and adenovirus vectors in the best expressing regions revealed that solvoplexes yielded about 2% LacZ-positive cells in the lung airway epithelium, and adenovirus vectors about 20%. Using the microsprayer system, we demonstrated that DNA remained intact in solvoplexes on spraying and that reporter gene expression was observed in mice after intrapulmonary delivery of a solvoplex spray. DNA in DPSO-solvoplexes remained stable and functional after prolonged storage at room temperature.     

An Unusually Frequent β-Thalassemia Mutation in an Iranian Province

Iran, a country located on the “thalassemia belt”, is an area with an unusually high prevalence of β-thalassemia (thal). The gene frequency of thalassemia shows great variation within Iran from one area to another. The purpose of this study was to determine the spectrum of β-thal mutations in Sistan-Baluchestan (S-B), a southeastern province of Iran which has a high mutation frequency of about 10%, and to compare this with neighboring provinces and countries. A total of 400 carriers (200 pre-marriage young couples selected at centers conducting prenatal diagnosis programs) with an established diagnosis of β-thal minor, were enrolled into the study. Mutations in the β-globin gene were detected using amplification refractory mutation system (ARMS) and restriction fraction length polymorphism (RFLP). Three hundred and sixty mutant chromosomes (13 different mutations) were detected with the two most common mutations accounting for about 80% of all detected β-thal alleles in this region. The most common mutation by far was IVS-I-5 (G>C) (72.3%), followed by frameshift codons (FSC) 8/9 (+G) (5.8%) and codon 44 (?C) (2.5%). In conclusion, IVS-I-5 and FSC 8/9 (+G) account for about 80% of all mutations in S-B. Sistan-Baluchestan may be regarded as the ‘hot zone’ for the IVS-I-5 mutation.     

Intraoperative complications of perfluoroperhydrophenanthrene: subretinal perfluorocarbon, retinal slippage and residual perfluorocarbon. Vitreon Study Group.

BACKGROUND: An earlier analysis of postoperative complications of the perfluorocarbon liquid perfluoroperhydrophenanthrene (Vitreon) showed a low overall rate of posterior segment complications. A study was conducted to determine the incidence of specific intraoperative complications in a wide variety of vitreoretinal procedures performed by many different surgeons using Vitreon. METHODS: The records of consecutive patients enrolled in the Vitreon Collaborative Study were reviewed to determine the incidence of subretinal Vitreon, retinal slippage and residual Vitreon. A total of 1867 vitreoretinal procedures performed between Nov. 16, 1989, and Dec. 14, 1994, at 35 participating centres were studied. Vitreon was used as a surgical tool at the surgeon's discretion after informed consent was obtained. The incidence of intraoperative complications was determined, and preoperative, intraoperative and postoperative characteristics were tabulated. RESULTS: Subretinal Vitreon was observed in 24 patients (1.3%), retinal slippage in 20 patients (1.1%) (15 [6.9%] of the 216 patients with giant retinal tears) and residual Vitreon in 68 patients (3.6%). INTERPRETATION: Vitreon can be used as a surgical tool in a wide variety of vitreoretinal procedures with a low incidence of intraoperative complications.     

Tissue plasminogen activator in the treatment of experimental retinal vein occlusion

The thrombolytic effect of recombinant tissue plasminogen activator was studied in 28 randomly selected rabbit eyes to lyse photochemically induced retinal vein occlusion. Occlusion was confirmed histologically and assessed by fluorescein angiography. Sixteen eyes were treated with recombinant tissue plasminogen activator given intravenously and 12 control eyes were given similar volumes of normal saline solution. Fluorescein angiography was performed before and at various intervals after treatment. Four hours after treatment, the retinal vein was patent in 16 eyes (100%) treated with recombinant tissue plasminogen activator, as opposed to one eye (8.3%) treated with normal saline. The results indicate that tissue plasminogen activator is effective in lysing experimentally induced retinal vein thrombi.