Recovery of hydrothermal vent communities in response to an induced disturbance at the Lucky Strike vent field (Mid-Atlantic Ridge).

So far, the natural recovery of vent communities at large scales has only been evaluated at fast spreading centers, by monitoring faunal recolonisation after volcanic eruptions. However, at slow spreading ridges, opportunities to observe natural disturbances are rare, the overall hydrothermal system being more stable. In this study, we implemented a novel experimental approach by inducing a small-scale disturbance to assess the recovery potential of vent communities along the slow-spreading northern Mid-Atlantic Ridge (nMAR). We followed the recovery patterns of thirteen Bathymodiolus azoricus mussel assemblages colonising an active vent edifice at the Lucky Strike vent field, in relation to environmental conditions and assessed the role of biotic interactions in recolonisation dynamics. Within 2 years after the disturbance, almost all taxonomic richness had recovered, with the exception of a few low occurrence species. However, we observed only a partial recovery of faunal densities and a major change in faunal composition characterised by an increase in abundance of gastropod species, which are hypothesised to be the pioneer colonists of these habitats. Although not significant, our results suggest a potential role of mobile predators in early-colonisation stages. A model of post-disturbance succession for nMAR vent communities from habitat opening to climax assemblages is proposed, also highlighting numerous knowledge gaps. This type of experimental approach, combined with dispersal and connectivity analyses, will contribute to fully assess the resilience of active vent communities after a major disturbance, especially along slow spreading centers targeted for seafloor massive sulphide extraction.

Rhegmatogenous retinal detachment treatment guidelines.

This paper outlines general guidelines following the initial diagnosis of rhegmatogenous retinal detachment. These include preoperative evaluation, treatment, possible intra- and post-operative complications, retinal re-detachment, and all therapeutic options available for each case. Treatment of the traumatic retinal detachment is also described, due to its importance and peculiarities. Treatment or prophylactic guidelines are suggested for the different types of retinal detachment described. These are based on both the experience of the ophthalmologists that have participated in preparing the guidelines, and also on evidence-based grading linked to bibliographical sources. However, these guidelines should not be interpreted as being mandatory. Given that there is a wide spectrum of options for treatment of retinal detachment, the surgeons' experience with one or other surgical technique will be of utmost importance in obtaining the best surgical result. As guidelines, they are intended as an additional aid to the surgeon during the decision-making process, with the expectation that the final choice will still be left to the surgeon's judgment and past experience.

Retinal angiomatous proliferation.

Retinal angiomatous proliferation (RAP) is a distinct form of choroidal neovascularization which may complicate a wet age related macular degeneration (AMD). This exudative-AMD has a peculiar clinical history and prognosis. RAP accounts from 8% to 22% of newly diagnosed cases among patients previously diagnosed as exudative AMD, and up to 25% of the occult or minimally classic CNV. The disease is more prevalent in women (90% of cases) and in elderly patients (around 75 years), and is characterized by a very poor prognosis. The neovascular process, whose retinal or choroidal origin is still object of discussion, often hesitates in the formation of a disciform scar, that evolves into a severe loss of central vision. Treatment for RAP is not yet well established; herein are described the most used therapeutic strategies, starting from laser photocoagulation until the nearest anti VEGF. The opportunity of combination among various treatments to obtain a better effectiveness and a lower frequency of recurrence is also discussed.

Can a preoperative bevacizumab injection prevent recurrent postvitrectomy diabetic vitreous haemorrhage?

AIMS: To evaluate the recurrence rate of vitreous haemorrhage (VH) in patients treated with one intravitreal bevacizumab (IVB) injection (2.5 mg/0.1 ml) before planned pars plana vitrectomy for treatment of diabetic non-clearing VH. METHODS: Prospective pilot study of 32 eyes of 31 consecutive diabetic patients who underwent IVB injection within 1 week before surgery for persistent VH in the presence of active proliferative diabetic retinopathy. Three masked retinal specialists graded the amount of VH from grade 0 to grade 3 with slit-lamp biomicroscopy. Main outcome measures were the rate of recurrence of the VH, improvement in visual acuity, incidence of cataract formation, and postoperative complications through a follow-up of 6 months. RESULTS: The percentage of severe recurrent VH with no fundus details (grade 3) was 3% at 1 week follow-up and 3, 6, and 6% respectively at 1-, 3-, and 6-month follow-up. The mean best-corrected visual acuity (BCVA) improved from 1.6 (1/60) to 0.40 (6/15) logMAR (P=0.02) in 29 out of 32 eyes (91%). In all, 12 out of 22 (54%) phakic eyes developed cataract during the follow-up period, and 10 (31%) of them underwent cataract surgery. CONCLUSIONS: Our study suggests that IVB injection few days before planned surgery seems to be efficacious and safe as an adjuvant treatment to prevent rebleeding in eyes undergoing pars plana vitrectomy for treatment of diabetic vitreous haemorrhage. IVB facilitates the surgery and reduces the need for extensive delamination and segmentation, decreasing the possibility of significant early active postoperative VH.

Primary vitrectomy with Densiron-68 for rhegmatogenous retinal detachment.

BACKGROUND: To report a retrospective non-comparative interventional study on the effectiveness and ocular tolerance of a heavy silicone oil tamponade (HSO, Densiron-68) for primary inferior rhegmatogenous retinal detachment (RRD). METHODS: Forty-one eyes of 41 consecutive patients were recruited between January 2004 and August 2006. Primary vitrectomy with Densiron-68, a heavy silicone oil, was used in all cases. Inclusion criteria were primary RRD with at least one retinal break between 4 and 8 clock hours. The study protocol consisted of a minimum of eight clinic visits: baseline, surgery, 1 week, 1 month and 3 months after the initial surgery; removal of oil and 1 week, 1 month and 3 months postoperatively. The primary endpoint was anatomical re-attachment of the retina. Cases were judged successful when there was reattachment of the retina in the absence of any tamponade agent. The secondary endpoint was to record the visual function and any complications arising from the surgery. Out of 41 patients initially included in the study, 33 completed all follow-up visits. RESULTS: Anatomical success was achieved in 91% of cases (30 out of 33) with one retinal operation, and rose to 94% (31 out of 33) with additional surgery. Mean visual acuity improved from logMAR 1.19 (SD 0.9) to 0.5 (SD 0.51, p = 0.001). No significant ocular hypertension, clinically significant emulsification of the tamponade or inflammation developed during follow-up. CONCLUSION: With Densiron-68, high anatomical and functional success rates can be achieved with primary vitrectomy for RRD and predominantly inferior pathology.