Autoimmune and autoinflammatory mechanisms in uveitis

The eye, as currently viewed, is neither immunologically ignorant nor sequestered from the systemic environment. The eye utilises distinct immunoregulatory mechanisms to preserve tissue and cellular function in the face of immune-mediated insult; clinically, inflammation following such an insult is termed uveitis. The intra-ocular inflammation in uveitis may be clinically obvious as a result of infection (e.g. toxoplasma, herpes), but in the main infection, if any, remains covert. We now recognise that healthy tissues including the retina have regulatory mechanisms imparted by control of myeloid cells through receptors (e.g. CD200R) and soluble inhibitory factors (e.g. alpha-MSH), regulation of the blood retinal barrier, and active immune surveillance. Once homoeostasis has been disrupted and inflammation ensues, the mechanisms to regulate inflammation, including T cell apoptosis, generation of Treg cells, and myeloid cell suppression in situ, are less successful. Why inflammation becomes persistent remains unknown, but extrapolating from animal models, possibilities include differential trafficking of T cells from the retina, residency of CD8(+) T cells, and alterations of myeloid cell phenotype and function. Translating lessons learned from animal models to humans has been helped by system biology approaches and informatics, which suggest that diseased animals and people share similar changes in T cell phenotypes and monocyte function to date. Together the data infer a possible cryptic infectious drive in uveitis that unlocks and drives persistent autoimmune responses, or promotes further innate immune responses. Thus there may be many mechanisms in common with those observed in autoinflammatory disorders

Evaluation of 3D heads-up vitrectomy: outcomes of psychometric skills testing and surgeon satisfaction

OBJECTIVES: To evaluate the use of a three-dimensional heads-up microscope (3DM) during 25-gauge pars plana vitrectomy (PPV) compared with a traditional ophthalmic microscope (TM) in terms of efficacy, safety, and teaching and learning satisfaction. METHODS: Prospective comparative interventional study. Fifty eyes affected by one of the following diseases: rhegmatogenous or tractional retinal detachment, epiretinal membrane, full-thickness macular hole, vitreous hemorrhage, or dropped lens. The 50 eyes were randomly assigned to one of two groups: group A (25 eyes) underwent 25-gauge PPV with 3DM, and group B (25 eyes) underwent 25-gauge PPV with TM. The main outcome measures were the duration of the operation, intraoperative complications, and surgeon and observer satisfaction. A questionnaire was used to assess surgeon satisfaction according to the following parameters: comfort, visibility, image quality, depth perception, simplicity of use, maneuverability, and teaching. A questionnaire to assess observer satisfaction was completed by 20 observers (surgical residents or ophthalmic surgeons). RESULTS: The degree of satisfaction was higher using 3DM for both surgeons and observers (P < 0.001). The average duration of the operation did not differ significantly between the two methods. No major complications occurred for either method. CONCLUSIONS: PPV with 3DM is more comfortable for the surgeon and poses no substantially greater risk of complications for the patient. The high-definition screen delivers excellent depth perception and better screen parameter control, which results in high-quality surgical performance. 3DM surgery helps to significantly improve teaching and learning intra-operative surgical procedure