A simple method for in vivo labelling of infiltrating leukocytes in the mouse retina using indocyanine green dye

We have developed a method to label and image myeloid cells infiltrating the mouse retina and choroid in vivo, using a single depot injection of indocyanine green dye (ICG). This was demonstrated using the following ocular models of inflammation and angiogenesis: endotoxin-induced uveitis, experimental autoimmune uveoretinitis and laser-induced choroidal neovascularization model. A near-infrared scanning ophthalmoscope was used for in vivo imaging of the eye, and flow cytometry was used on blood and spleen to assess the number and phenotype of labelled cells. ICG was administered 72 h before the induction of inflammation to ensure clearance from the systemic circulation. We found that in vivo intravenous administration failed to label any leukocytes, whereas depot injection, either intraperitoneal or subcutaneous, was successful in labelling leukocytes infiltrating into the retina. Progression of inflammation in the retina could be traced over a period of 14 days following a single depot injection of ICG. Additionally, bright-field microscopy, spectrophotometry and flow cytometric analysis suggest that the predominant population of cells stained by ICG are circulating myeloid cells. The translation of this approach into clinical practice would enable visualization of immune cells in situ. This will not only provide a greater understanding of pathogenesis, monitoring and assessment of therapy in many human ocular diseases but might also open the ability to image immunity live for neurodegenerative disorders, cardiovascular disease and systemic immune-mediated disorders

Incidence of submacular haemorrhage (SMH) in Scotland : a Scottish Ophthalmic Surveillance Unit (SOSU) study

PURPOSE: Submacular haemorrhage (SMH) is a cause of severe visual loss in neovascular age-related macular degeneration (nAMD). The incidence is uncertain and furthermore there is no widely used classification system nor agreed best practice. The aim of this national surveillance study was to identify the incidence, presenting features and clinical course of new fovea-involving submacular haemorrhage associated with nAMD. METHODS: A questionnaire was sent monthly to every ophthalmic specialist in Scotland over a 12-month period asking them to report all newly presenting patients with acute SMH secondary to nAMD of at least two disc diameters (DDs) in greatest linear diameter. A follow-up questionnaire was sent 6 months after initial presentation. Cases related to other causes were excluded. RESULTS: Twenty-nine cases were reported giving an incidence of 5.4 per million per annum (range 2-15). The mean age was 83 years (range 66-96) and females accounted for 17/29 (59%). Fifteen of the 29 cases (52%) had a past history of AMD, of which 7 had nAMD. Nineteen of the 29 cases (66%) presented within 7 days of onset and the majority had SMH of < 11 DD (20/29, 69%). Treatment options comprised the following: observation (n = 6, 21%), anti-VEGF alone (n = 6, 21%) or vitrectomy with co-application of tissue plasminogen activator (TPA), anti-VEGF and gas (n = 17, 58%). The vitrectomy group experienced the greatest change in vision from logMAR 1.89-1.50 (p = 0.374). Four of 20 (20%) cases with 6 months follow-up suffered a re-bleed at a mean time of 96 days. CONCLUSIONS: The incidence, clinical features and course of a consecutive national cohort of patients with SMH secondary to nAMD are presented

Vision 20/20: Molecular-guided surgical oncology based upon tumor metabolism or immunologic phenotype: Technological pathways for point of care imaging and intervention

Surgical guidance with fluorescence has been demonstrated in individual clinical trials for decades, but the scientific and commercial conditions exist today for a dramatic increase in clinical value. In the past decade, increased use of indocyanine green based visualization of vascular flow, biliary function, and tissue perfusion has spawned a robust growth in commercial systems that have near-infrared emission imaging and video display capabilities. This recent history combined with major preclinical innovations in fluorescent-labeled molecular probes, has the potential for a shift in surgical practice toward resection guidance based upon molecular information in addition to conventional visual and palpable cues. Most surgical subspecialties already have treatment management decisions partially based upon the immunohistochemical phenotype of the cancer, as assessed from molecular pathology of the biopsy tissue. This phenotyping can inform the surgical resection process by spatial mapping of these features. Further integration of the diagnostic and therapeutic value of tumor metabolism sensing molecules or immune binding agents directly into the surgical process can help this field mature. Maximal value to the patient would come from identifying the spatial patterns of molecular expression in vivo that are well known to exist. However, as each molecular agent is advanced into trials, the performance of the imaging system can have a critical impact on the success. For example, use of pre-existing commercial imaging systems are not well suited to image receptor targeted fluorophores because of the lower concentrations expected, requiring orders of magnitude more sensitivity. Additionally the imaging system needs the appropriate dynamic range and image processing features to view molecular probes or therapeutics that may have nonspecific uptake or pharmacokinetic issues which lead to limitations in contrast. Imaging systems need to be chosen based upon objective performance criteria, and issues around calibration, validation, and interpretation need to be established before a clinical trial starts. Finally, as early phase trials become more established, the costs associated with failures can be crippling to the field, and so judicious use of phase 0 trials with microdose levels of agents is one viable paradigm to help the field advance, but this places high sensitivity requirements on the imaging systems used. Molecular-guided surgery has truly transformative potential, and several key challenges are outlined here with the goal of seeing efficient advancement with ideal choices. The focus of this vision 20/20 paper is on the technological aspects that are needed to be paired with these agents

Acute Macular Neuroretinopathy following Oral Intake of Adrenergic Flu Treatments

Purpose: The purpose of this study was to report a case series of patients with acute macular neureretinopathy in which patients concomitantly used ephedrine or pseudo-ephedrine. Methods: This is a retrospective case review. Results: Two patients with retinal findings consistent with acute macular neuroretinopathy are presented. Conclusion: Acute macular neuroretinopathy should be considered in any young patient with unexplained loss of vision and exposed to direct or indirect adrenergic stimulation

Uveal effusion syndrome

The terms uveal effusion, choroidal effusion, ciliochoroidal effusion, ciliochoroidal detachment, and choroidal detachment have been used interchangeably in the literature. These labels all describe an abnormal collection of fluid that expands the suprachoroidal space, producing internal elevation of the choroidal. There are various inflammatory and hydrostatic conditions that can cause uveal effusion, but in some cases no obvious cause exists. In this setting, patients are thought to have a distinct, primary abnormality of the choroid or sclera, called uveal effusion syndrome (UES). UES may be idiopathic, or associated with hypermetropia, and should be considered a diagnosis of exclusion. Histological studies show amorphous glycosaminoglycan-like material filling the interfibrillary spaces of excised scleral tissue, with disruption of collagen fibers. In some patients there may be reduced macromolecular diffusion that interferes with the normal transscleral egress of albumin out of the eye, perhaps causing choroidal fluid retention due to altered osmotic forces. An alternative, and perhaps complementary hypothesis, is that swollen sclera compresses the transscleral vessels with resulting fluid retention. Patients with UES are most typically middle-aged men who have a relapsing remitting clinical course. There is often co-existing, shifting subretinal fluid that may involve the macula. Chronic disease may lead to secondary retinal pigment epithelial (leopard spot) changes and permanently reduced visual acuity. Treatment with systemic steroids does not appear to be effective. Surgical decompression of the vortex veins as they pass through the sclera has been described, but the most common treatment is full-thickness sclerectomies to provide an exit for choroidal fluid. The largest case series suggests that this produces an anatomic improvement in approximately 83% of treated eyes after a single procedure and in about 96% after one or two procedures. Final visual acuity improves by two or more lines in 56% of the eyes, is stable in 35%, and worsens in 9%. Although extremely rare, UES is a serious condition that is difficult to treat and can lead to severe and permanent visual loss in both eyes