Objective We tested the effect of two phosphodiesterase type-5 (PDE5) inhibitors, sildenafil and tadalafil, on ophthalmic artery (OA) blood flow velocity and investigated the presence of the PDE5 enzyme on human retinal tissue in comparison with the PDE6 enzyme localization. Methods Using Colour Doppler ultrasonography (CDU) we investigated, in 30 healthy young subjects (27.8 years of age; range, 24.3-33.7 years), the effects of a single oral dose of sildenafil (100 mg), tadalafil (20 mg), and placebo on OA blood flow velocity. Western blot for PDE6 and PDE5 protein expression was performed on frozen samples of human retina, testis, sperm, skin, and corpus cavernosum. Immunohistochemistry was performed on two ocular globes from dead donors. Results CDU showed a relationship between the administration of PDE5 inhibitors and OA blood flow velocity modifications in a timedependent manner. Western blot and immunohistochemical analysis showed PDE6 and PDE5 presence in human retinal tissue and gave a map of its distribution. Conclusion We demonstrated that (a) tadalafil and sildenafil are able to modify the OA flux in a time-dependent manner; (b) the PDE5 enzyme is expressed on retinal and choroid vasculature (smooth muscle and endothelial cells), on ganglion and bipolar cells; (c) human retinal tissues express the PDE6 enzyme in the rod and cone photoreceptors; (d) visual side effects after PDE5 inhibitors administration may be linked to a specific effect on the PDE5 enzyme; and (e) the PDE5 enzyme may have a physiologic role on ganglion and bipolar cells that need to be further investigated.

Purpose To compare the effectiveness and safety of excimer laser trabeculotomy (ELT) ab interno vs selective laser trabeculoplasty (SLT) over 24 months of follow-up in patients with primary open-angle glaucoma (POAG) refractory to medical therapy. Patients and methods This prospective, randomized study included 30 consecutive eyes assigned randomly to either ELT or SLT group. ELT was carried out using a XeCl Excimer Laser with an emission wavelength of 308 nm. Eight spots were equally distributed at a distance of 500 lm from one another over the anterior trabeculum. The SLT patients were treated with a frequencydoubled q-switched neodymium : yytriumaluminum-garnet laser (wavelength 532 nm). Approximately 50 adjacent, but not overlapping, laser spots were distributed over 1801 of the trabecular meshwork, using an energy level ranging from 0.7 to 1.0 mJ per pulse. The main outcome measure was intraocular pressure (IOP) lowering after ELT and SLT. Success was defined as X20% reduction in IOP without further glaucoma intervention. Results At 24 months, complete success rates were 53.3% for the ELT group and 40% for the SLT group (P ¼ 0.35, Fisher's exact test); qualified success rates were 33.3% for the ELT and 26.6% for the SLT group (P ¼ 0.5, Fisher's exact test).Mean IOP decreased from 25.0 ± 1.9 to 17.6 ± 2.2 mmHg (À29.6%; Po0.0001) in the ELT group and from 23.9 ± 0.9 to 19.1 ± 1.8 mmHg (À21%;Po0.0001) in the SLT group.Conclusions Both ELT and SLT proved to be effective techniques in the treatment of POAG refractory to medical therapy.

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Purpose To evaluate the effects of carbomer sodium hyaluronate trehalose (CHT) and sodium hyaluronate eye drops on tear film stability and ocular discomfort after cataract surgery. Setting Santa Maria della Misericordia Hospital, Rovigo, Italy. Design Prospective randomized case-control study. Patients and methods This study enrolled sixty patients scheduled for unilateral cataract surgery. After phacoemulsification, subjects received carbomer sodium hyaluronate trehalose (trehalose group) or sodium hyaluronate tears (HG group) substitute and were assessed through objective (break up time, corneal and conjunctival staining) and subjective (OSDI questionnaire) clinical evaluations after a two times a day topical administration. Outcome measures were collected preoperatively (baseline), one week (day 7) and 1 month (day 30) after surgery. Finally, each patient was asked to give his personal treatment satisfaction score. Results Trehalose group showed a steeper break up time (BUT) increase compared to patient treated with hyaluronic acid ( P <0.001). OSDI questionnaire presented a opposite trend, trehalose patients evidenced a significantly major improvement ( P <0.001), and in seven days mean values reduced by more than three times. Fluorescein staining reduction was documented with both treatments, although there was no statistically significant difference between groups. Finally CHT resulted in a significantly greater global satisfaction score ( P <0.001). Conclusions CHT was effective and well tolerated in reducing dry eye disease symptoms and improving the clinical outcome after cataract surgery. On some parameters (BUT, OSDI), this new formulation was more effective than commonly used sodium hyaluronate in treating ocular irritation and tear film alterations.

Purpose: To evaluate the safety, effectiveness, and the best parameters setup of hypersonic vitrectomy.Methods: A prospective, multicentric, interventional study on 50 eyes that had undergone hypersonic vitrectomy because of various vitreoretinal diseases. We primarily assessed the effectiveness of vitreous removal, intraoperative complications, and surgical setup. Secondarily, we evaluated single-surgery anatomical success and postoperative best-corrected visual acuity.Results: Intraoperative complications occurred in 5 eyes (10%), whereas technical problems were detected in 23 eyes (46%), resulting in conversion to guillotine vitrectomy in 15 cases. The most common finding related to the technical problems was an inadequate vitreous liquefaction with the formation of vitreous strands and consequent inadequate vitreous outflow, sometimes complicated by vitreous incarceration in the vitrectomy probe. The best settings were considered a stroke of 60 mm and vacuum of 40 mmHg for both core and peripheral vitrectomy. At 3-month follow-up, primary anatomical success was achieved in 49 eyes (98%) and the mean best-corrected visual acuity overall improved. Conclusion:The availability of hypersonic vitrectomy in the current surgical practice opens a new era in vitreoretinal surgery. Despite the potential advantages in fluidics, the performance of hypersonic vitrectomy system needs to be further optimized, mainly for the occurrence of inadequate vitreous liquefaction and vitreous strands formation.