Feeding Behavioural Studies with Freshwater Gammarus spp.: The Importance of a Standardised Methodology.

Freshwater Gammarids are common leaf-shredding detritivores, and they usually feed on naturally conditioned organic material, in other words leaf litter that is characterised by an increased palatability, due to the action and presence of microorganisms (Chaumot et al. 2015; Cummins 1974: Maltby et al. 2002). Gammarus spp. are biologically omnivorous organisms, so they are involved in shredding leaf litter and are also prone to cannibalism, predation behaviour (Kelly et al. 2002) and coprophagy when juveniles (McCahon and Pascoe 1988). Gammarus spp. is a keystone species (Woodward et al. 2008), and it plays an important role in the decomposition of organic matter (Alonso et al. 2009; Bundschuh et al. 2013) and is also a noteworthy prey for fish and birds (Andrén and Eriksson Wiklund 2013; Blarer and Burkhardt-Holm 2016). Gammarids are considered to be fairly sensitive to different contaminants (Ashauer et al. 2010; Bloor et al. 2005; Felten et al. 2008a; Lahive et al. 2015; Kunz et al. 2010); in fact Amphipods have been reported to be one of the most sensitive orders to metals and organic compounds (Wogram and Liess 2001), which makes them representative test organisms for ecotoxicological studies and valid sentinel species for assessing water quality status (Garcia-Galan et al. 2017).

Microplastics, microfibres and nanoplastics cause variable sub-lethal responses in mussels (Mytilus spp.).

We compare the toxicity of microplastics, microfibres and nanoplastics on mussels. Mussels (Mytilus spp.) were exposed to 500 ng mL-1 of 20 µm polystyrene microplastics, 10 × 30 µm polyamide microfibres or 50 nm polystyrene nanoplastics for 24 h or 7 days. Biomarkers of immune response, oxidative stress response, lysosomal destabilisation and genotoxic damage were measured in haemolymph, digestive gland and gills. Microplastics and microfibres were observed in the digestive glands, with significantly higher plastic concentrations after 7-days exposure (ANOVA, P < 0.05). Nanoplastics had a significant effect on hyalinocyte-granulocyte ratios (ANOVA, P < 0.05), indicative of a heightened immune response. SOD activity was significantly increased followed 24 h exposure to plastics (two-way ANOVA, P < 0.05), but returned to normal levels after 7-days exposure. No evidence of lysosomal destabilisation or genotoxic damage was observed from any form of plastic. The study highlights how particle size is a key factor in plastic particulate toxicity.

Evaluation of Bleb Morphology and Reduction in IOP and Glaucoma Medication following Implantation of a Novel Gel Stent.

OBJECTIVE: To evaluate the efficacy and safety of the Xen Gel Stent and provide a macro- and microscopic analyses of bleb morphology. METHODS: A prospective 12-month study on patients with primary open-angle glaucoma. Patients underwent implantation of the XEN Gel Stent (Allergan INC, Dublin, Ireland) either alone or combined with a cataract surgery. Biomicroscopy, in vivo confocal microscopy (IVCM), and anterior segment-optical coherence tomography (AS-OCT) were used to assess bleb morphology. Safety parameters were adverse events, best corrected visual acuity, visual field, and corneal endothelial cell loss. A postoperative IOP ≤ 18 mmHg without or on medications was respectively defined as complete and qualified success while an IOP ≥ 18 mmHg was defined as failure. RESULTS: Twelve eyes of 11 patients were evaluated. At one year, 5 out of 10 patients available achieved a complete success while five were qualified success. AS-OCT showed that bleb wall reflectivity was significantly higher in the failure group; IVCM revealed that stromal density was significantly lower in the success group. No safety issues were recorded. CONCLUSION: Implantation of the XEN Gel Stent appears to be a safe and effective procedure. AS-OCT and IVCM may be helpful in bleb assessment.

Hydrus microstent compared to selective laser trabeculoplasty in primary open angle glaucoma: one year results.

BACKGROUND: To compare the reduction of intraocular pressure (IOP) and glaucoma medications following selective laser trabeculoplasty (SLT) versus stand-alone placement of the Hydrus microstent, a microinvasive glaucoma surgery device. DESIGN: Prospective interventional case-series. University practice. PARTICIPANTS: Fifty six eyes (56 patients) with uncontrolled primary open-angle glaucoma. METHODS: Patients received either SLT (n = 25) or Hydrus implantation (n = 31) in two centres. Patients were evaluated at baseline and 1, 7 days, 1, 3, 6 and 12 months after surgery. MAIN OUTCOME MEASURES: Intraocular pressure and number of glaucoma medications variations inter-groups and intra-groups. RESULTS: There were no significant differences at baseline between groups, but the mean deviation was worse in the Hydrus group (-8.43 ± 6.84 dB, confidence limits (CL)-2.8/-3.3 vs.-3.04 ± 0.65 dB, CL-6/-10.8; P < 0.001). After 12 months, there was a significant decrease in IOP and medications in the Hydrus group compared with baseline values. In the SLT group, only the decrease in IOP was significant. There was 3-fold greater reduction in medication use in the Hydrus group compared with SLT (-1.4 ± 0.97 vs.-0.5 ± 1.05, P = 0.001). 47% of patients were medication free at 12 months in the Hydrus group (4% in the SLT group). No complications were recorded in the SLT group. In the Hydrus group, three patients experienced a temporary reduction of visual acuity post-operatively, and two patients had post-operative IOP spikes that resolved within one week. CONCLUSIONS: Both SLT and Hydrus implantation reduced IOP without serious adverse events. Hydrus implantation led to a significant and further reduction in medication dependence at 12 months.

A Comparison of Endothelial Cell Loss in Combined Cataract and MIGS (Hydrus) Procedure to Phacoemulsification Alone: 6-Month Results.

Purpose. To compare the corneal endothelial cell loss after phacoemulsification, alone or combined with microinvasive glaucoma surgery (MIGS), in nonglaucomatous versus primary open angle glaucoma (POAG) eyes affected by age-related cataract. Methods. 62 eyes of 62 patients were divided into group 1 (n = 25, affected by age-related cataract) and group 2 (n = 37, affected by age-related cataract and POAG). All patients underwent cataract surgery. Group 2 was divided into subgroups A (n = 19, cataract surgery alone) and B (n = 18, cataract surgery and MIGS). Prior to and 6 months after surgery the patients' endothelium was studied. Main outcomes were CD (cell density), SD (standard deviation), CV (coefficient of variation), and 6A (hexagonality coefficient) variations after surgeries. Results. There were no significant differences among the groups concerning preoperative endothelial parameters. The differences in CD before and after surgery were significant in all groups: 9.1% in group 1, 17.24% in group 2A, and 11.71% in group 2B. All endothelial parameters did not significantly change after surgery. Conclusions. Phacoemulsification determined a loss of endothelial cells in all groups. After surgery the change in endothelial parameters after MIGS was comparable to the ones of patients who underwent cataract surgery alone.

Micro-Bypass Implantation for Primary Open-Angle Glaucoma Combined with Phacoemulsification: 4-Year Follow-Up.

Purpose. To report the long-term follow-up results in patients with cataract and primary open-angle glaucoma (POAG) randomly assigned to cataract surgery combined with micro-bypass stent implantation or phacoemulsification alone. Methods. 36 subjects with cataract and POAG were randomized in a 1 : 2 ratio to either iStent implantation and cataract surgery (combined group) or cataract surgery alone (control group). 24 subjects agreed to be evaluated again 48 months after surgery. Patients returned one month later for unmedicated washout assessment. Results. At the long-term follow-up visit we reported a mean IOP of 15,9 ± 2,3 mmHg in the iStent group and 17 ± 2,5 mmHg in the control group (p = NS). After washout, a 14,2% between group difference in favour of the combined group was statistically significant (p = 0,02) for mean IOP reduction. A significant reduction in the mean number of medications was observed in both groups compared to baseline values (p = 0,005 in the combined group and p = 0,01 in the control group). Conclusion. Patients in the combined group maintained low IOP levels after long-term follow-up. Cataract surgery alone showed a loss of efficacy in controlling IOP over time. Both treatments reduced the number of ocular hypotensive medications prescribed. This trial is registered with: NCT00847158.

Managing Drawbacks in Unconventional Successful Glaucoma Surgery: A Case Report of Stent Exposure.

Traditional options in managing failed trabeculectomy (bleb needling, revision, additional incisional surgery and tube surgery) have a relatively high failure and complication rate. The use of microinvasive glaucoma surgery (MIGS) has generally been reserved to mild to moderate glaucoma cases, proving good safety profiles but significant limitations in terms of efficacy. We describe a patient who underwent MIGS (XEN Aquesys subconjunctival shunt implantation) after a prior failed trabeculectomy. After the surgery, the IOP was well controlled but as the stent was close to an area of scarred conjunctiva of the previous trabeculectomy, it became partially exposed. As a complete success was achieved, we decided to remove the conjunctiva over the exposed area and replace it by an amniotic membrane transplantation and a conjunctiva autograft. Six months after surgery, the unmedicated IOP is still well controlled with complete visual acuity recovery.