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Purpose: Traction exerted on the vitreous base during vitrectomy poses a risk for retinal tears. We aimed to quantify core vitreous traction during vitrectomy using spring return and pneumatic cutters., Methods: Juvenile porcine vitreous was vacuum held in a vitreous bath while traction was measured using precision force gauge during vitrectomy. The parameters included were aspiration rate, cut-rate, cutter size, and machine types., Results: An empirical probabilistic model was developed. The traction was proportional to the aspiration rate but insignificantly dependent on the cut-rate. The traction probability was inversely proportional to the exponential function of the traction (p < 0.05). The traction was < 0.003 N for 99% of the time using either 23- or 25-gauge cutters., Conclusion: The tractions measured were considered similar to the causative forces of an iatrogenic retinal tear during a pars plana vitrectomy. The results provide a safety reference matrix of instrumental parameters during vitrectomy.

Purpose: To determine functional and anatomical outcomes of pars plana vitrectomy for persistent full-thickness macular hole (MH) after intravitreal injection of ocriplasmin., Methods: This is a multicenter retrospective interventional study of 37 eyes of 37 patients who underwent pars plana vitrectomy with internal limiting membrane peeling for persistent MH after ocriplasmin treatment between December 2013 and December 2015 and comparison with 35 eyes of 35 patients who were offered ocriplasmin injection but underwent pars plana vitrectomy alone without pharmacologic vitreolysis before surgery. In addition, 24 matched pairs (MH diameter at baseline ±5 µm) were analyzed. Clinical data such as visual acuity, intraoperative characteristics, and spectral domain optical coherence tomography images were reviewed. Main outcome measures were visual acuity and MH closure rate., Results: After a mean follow-up period of 9 months, postoperative mean visual acuity showed no significant differences between ocriplasmin-treated eyes (logarithm of minimum angle of resolution 0.37 ± 0.26, Snellen 20/47) and eyes without ocriplasmin treatment (logarithm of minimum angle of resolution 0.39 ± 0.25; Snellen 20/49) (P > 0.9). After ocriplasmin injection, mean MH diameter enlarged from 217 ± 102 µm to 384 ± 239 µm (P < 0.001). Matched-pair analysis revealed no difference in gain of visual acuity between the first visit and the last follow-up (P = 0.29). Macular hole closure was observed in similar proportion in ocriplasmin-treated eyes (97%) and vitrectomy-only eyes (94%) (P > 0.5)., Conlcusion: Eyes with persistent MH after ocriplasmin injection showed significant visual improvement after pars plana vitrectomy. Matched-pair analysis revealed no statistical differences in functional and anatomical postoperative results comparing with eyes of similar MH diameter that proceeded directly to surgery without ocriplasmin pretreatment.

Purpose: To evaluate the efficacy of intravitreal dexamethasone implant for the treatment of postoperative persistent cystoid macular edema (CME) following macular pucker surgery., Methods: In this multicenter study, we retrospectively reviewed the data of 37 patients (39 eyes) who had been treated with intravitreal dexamethasone implant (Ozurdex®) for persistent CME following macular pucker surgery. Main outcome measures were change in best-corrected visual acuity (BCVA) and central retinal thickness (CRT)., Results: All eyes underwent spectral domain optical coherence tomography examination within 130 days after implantation. We observed a significant decrease in mean CRT from 519.9 to 392.9 µm (p < 0.0001). By this time, mean BCVA had improved from 0.60 to 0.43 logMAR (p = 0.003). Seventeen eyes (43.6%) required at least 1 repeat injection of dexamethasone. Of these, 8 (47%) eyes received a total number of 3 or more dexamethasone injections., Conclusion: Intravitreal dexamethasone implant injection is an effective treatment option for persistent CME following macular pucker surgery., (© 2017 S. Karger AG, Basel.)

Background: Endophthalmitis is potentially devastating intraocular inflammation following eye trauma or surgery. We describe the visual outcomes and causative pathogens in acute bacterial postoperative and posttraumatic endophthalmitis treated with immediate pars plana vitrectomy (PPV) with Vancomycin dissolved in the infusion fluid., Methods: Clinical records of consecutive 30 patients with postoperative endophthalmitis and 15 patients with posttraumatic endophthalmitis were evaluated. Vancomycin was administered constantly in the infusion fluid at the time of complete PPV. Cultures were prepared from anterior chamber paracentesis. The mean follow-up period was 13 months., Results: The visual acuities were improved in 38 cases (84 %) and remained stable in seven cases (16 %). Median post-PPV visual acuity was 1.0 logMAR in a group with postoperative endophthalmitis and 1.3 logMAR in a group with posttraumatic endophthalmitis (p < 0.05). Twenty cases (44 %) were culture-positive (Staphylococcus, Streptococcus, Enterococcus and Bacillus spp)., Conclusions: Early PPV with Vanomycin in infusion leads to vision improvement in patients with both posttraumatic and postoperative endophthalmitis. In our series of 45 cases culture was positive only in half of the cases.

Purpose: To evaluate intraocular pressure (IOP) changes during experimental vitrectomy and the efficacy of Constellation Vision System's IOP control (IOPc) feature in reestablishing baseline pressure., Methods: Using a pressure transducer in freshly enucleated porcine eyes, a broad range of parameters (baseline pressures, aspiration levels, and cut rates) were tested with 23- and 25-gauge probes and IOPc turned ON versus OFF., Results: IOPc turned ON was significantly more effective than IOPc turned OFF in controlling IOP drop and stabilizing pressure during vitrectomy using a wide range of baseline pressures (20-70 mmHg). The 23-gauge system consistently presented a reduced drop from baseline compared with the 25-gauge system. The overall average drop for the 23- and 25-gauge systems was 12.79 mmHg and 21.17 mmHg, respectively. Both gauge sizes reestablished baseline pressure approximately 1.6 seconds after the initial pressure drop generated at the beginning of aspiration. A peak of IOP (overshooting) was observed when the pressure was returning to baseline using both 23- and 25-gauge systems., Conclusion: Using IOPc feature turned ON, 23- and 25-gauge probes were effective in reestablishing and sustaining baseline infusion pressures, although 23-gauge probes showed less IOP fluctuation than did 25-gauge probes.

Purpose: To evaluate the efficacy of the virtual reality training simulator Eyesi to prepare surgeons for performing pars plana vitrectomies and its potential to predict the surgeons' performance., Methods: In a preparation phase, four participating vitreoretinal surgeons performed repeated simulator training with predefined tasks. If a surgeon was assigned to perform a vitrectomy for the management of complex retinal detachment after a surgical break of at least 60 hours it was randomly decided whether a warmup training on the simulator was required (n = 9) or not (n = 12). Performance at the simulator was measured using the built-in scoring metrics. The surgical performance was determined by two blinded observers who analyzed the video-recorded interventions. One of them repeated the analysis to check for intra-observer consistency. The surgical performance of the interventions with and without simulator training was compared. In addition, for the surgeries with simulator training, the simulator performance was compared to the performance in the operating room., Results: Comparing each surgeon's performance with and without warmup trainingshowed a significant effect of warmup training onto the final outcome in the operating room. For the surgeries that were preceeded by the warmup procedure, the performance at the simulator was compared with the operating room performance. We found that there is a significant relation. The governing factor of low scores in the simulator were iatrogenic retinal holes, bleedings and lens damage. Surgeons who caused minor damage in the simulation also performed well in the operating room., Conclusions: Despite the large variation of conditions, the effect of a warmup training as well as a relation between the performance at the simulator and in the operating room was found with statistical significance. Simulator training is able to serve as a warmup to increase the average performance.

Background: Open globe injuries complicated with the presence of an intraocular foreign body constitute a vision threatening condition., Purpose: To present the results of pars plana vitrectomy in patients with intraocular foreign body., Material and Methods: Medical records of 22 patients were analyzed. Retrospective analysis of data included visual acuity, age, gender and type of injury., Results: All patients were men and the mean age was 37 years. All injuries occurred while working with a hammer. All patients were treated with pars plana vitrectomy combined with intraocular foreign body removal and internal limiting membrane peeling. The visual acuities improved in 9 cases (41%), in 13 cases (59%) the deterioration of visual acuity was observed, no eye was enucleated. In 14 eyes pars plana vitrectomy was combined with lens removal, in 14 eyes silicone oil was used as a tamponade., Conclusions: Surgical intervention with pars plana vitrectomy combined with intraocular foreign body removal and cataract extraction may preserve severely traumatized eyes and maintain or even improve vision. ocular trauma, vitrectomy, intraocular foreign body.

Purpose: To investigate the clinical efficacy and safety of an additional core vitrectomy to the standard therapy in patients with exudative age-related macular degeneration (ARMD)., Methods: In this prospective, controlled, single-centre study, 50 eyes of 50 patients (mean age: 74.1 ± 7.1; median 74 (69/78)) with ARMD were enrolled and randomized 1:1 to group 1 - core vitrectomy additional to three times injections of ranibizumab (3x Rbz) and Group 2 - 3x Rbz (control). 1 16 of 25 eyes in Group 1(64%) and 12 of 25 (48%) in Group 2 had a posterior vitreous detachment (PVD) prior to start of the study. Changes in best-corrected visual acuity (BCVA) using ETDRS charts, central macular thickness and macular volume (OCT) as well as the rate of reinjection with an OCT-based pro renata (PRN) protocol were monitored prospectively over 48 weeks. Forty-seven eyes completed follow-up at week 48., Results: In Group 1, 4 of 24 lost 1 line of BCVA (16.7%) and 3 of 24 lost 2 lines (12.5%), whereas 17 of 24 gained more than 1 line (70.8%) and improved in average by 9.8 letters. In Group 2, 3 of 23 remained stable and 20 of 23 gained more than or exactly 1 line (78.3%), resulting in 14.3 letters, with no loss of lines. Central macular thickness decreased by 85.58 μm (28.8%) in Group 1 and by 121.43 μm (32.68%) in Group 2 compared with baseline. In Group 1, four patients received three additional and two patients, two additional Rbz injections. In Group 2, three patients received three additional, three patients two and 12 patients one additional Rbz injections. This yielded in an average injection rate of 3.66 in Group 1 and 4.17 in Group 2 over 48 weeks. Posterior vitreous detachment (PVD) was identified in Group 1 in 16 of 24 (66.7%) and in Group 2 in 12 of 23 (52.2%) patients at baseline. At week 48, 6 of 8 (75%) of the patients in Group 1 with initial attached vitreous showed a vitreal detachment, whereas only 1 of 11 (9%) in Group 2 had a new occurred detachment of the vitreous. No systemic or ocular adverse events were noticed., Conclusion: An initial core vitrectomy combined with a conventional ranibizumab injection regimen for exudative AMD patients was safe and lead to similar functional results with less intravitreal ranibizumab injections over 48 weeks., (© 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Objective: To describe the procedure of pars plana vitrectomy (PPV) using an instrument designed for microincision vitrectomy., Methods: In this retrospective, noncomparative, interventional case series, 6 different surgeons performed 4509 PPV procedures from August 1, 2005, through May 31, 2010, with 1-port vitrectomy using a miniaturized multifunction probe (the Intrector)., Results: Complications were reported in 20 eyes (0.44%). Culture-positive endophthalmitis occurred in 2 eyes (0.04%), sterile endophthalmitis occurred in 6 eyes (0.13%), intraoperative or postoperative retinal detachment occurred in 4 eyes (0.09%), and vitreous hemorrhage occurred in 8 eyes (0.18%). None of the 20 eyes with complications of 4509 total eyes had worse visual outcomes than preoperative visual acuity., Conclusion: One-port vitrectomy using the Intrector is a procedure that can be used efficiently for selected cases that do not require membrane peeling.

Aim: To investigate the efficacy of a combined intravitreal therapy with prior photodynamic therapy (PDT) in patients with wet age-related macular degeneration., Methods: Fifty-two patients (mean age: 72.7 years) with predominantly classic choroidal neovascularization received low-fluence PDT (42 J/cm2 for 72 s), followed 24 h later by a 0.4-ml core pars plana vitrectomy with intravitreal injection of dexamethasone (0.8 mg) and bevacizumab (1.25 mg). The best-corrected visual acuity (BCVA; 6 m Snellen), central macular thickness (optical coherence tomography), intraocular pressure and the need for retreatment were assessed., Results: BCVA changed significantly (vs. baseline) at 3 months (+0.11), 9 months (+0.19) and 14 months (+0.16). At the end of the follow-up period, BCVA had improved by > 0.1 in the majority of the patients (72.9%), and the mean central retinal thickness had decreased by -44.3% (-211 μm). The retreatment rate was 25%. No increase in intraocular pressure or other adverse event was reported., Conclusions: The pharmacological effects of the drugs, the low-fluence PDT, and the physiological effects of the therapy may have contributed to the sustainability of the therapeutic benefits., (Copyright © 2011 S. Karger AG, Basel.)

Purpose: To stimulate the discussion about 'mini-gauge' pars plana vitrectomy., Methods: Gradient index high-resolution endoscopy to analyze the 23- or 25-gauge access into the vitreous cavity. A total number of 66 pars plana interventions (almost 200 cannulas) were performed and recorded with the gradient index solid rod endoscope as well as through the microscope., Results: Five main 'inside-out' observations were made through the endoscope. Some very slight rotating movement of the trocar was required to achieve a safe cannula implantation. Rotating the cannula too much could result in some unwanted side effects. The major amount of vitreous incarceration occurs during the implantation of cannulas. Incarcerated vitreous causes significant anterior-posterior vitreous traction. Intraocular cleaning of the port with the suction cutter releases the anterior-posterior traction without increasing the postoperative rate and degree of hypotony. Side effects like bleeding of the wound are likely to occur due to any sort of manipulation to the outside of the sclerotomy (i.e. cotton tips) other than the essential replacement of the conjunctiva., Discussion: Surgeons who are considering the conversion to mini-gauge pars plana vitrectomy systems may be aided by endoscopic observations., ((c) 2007 S. Karger AG, Basel.)

Purpose: To study the functional and morphological results of the inverted internal limiting membrane (ILM) flap technique for the treatment of idiopathic macular holes (MHs) sized ≤ 250 µm, > 250 and ≤ 400 µm, and > 400 µm. Methods: Retrospective, nonrandomized interventional study of 65 eyes with primary idiopathic MHs who underwent pars plana vitrectomy (PPV) with the inverted ILM flap technique. Closure rate, best-corrected visual acuity (BCVA), and integrity of external limiting membrane (ELM) and ellipsoid zone (EZ) were analyzed by optical coherence tomography (OCT). Results: Total closure rate was 96.9% with 100% in the ≤ 250 µm group, 100% in the > 250 and ≤ 400 µm group, and 91.7% in the > 400 µm group. Mean BCVA significantly improved after treatment: from 0.7 to 0.3 LogMAR in the ≤ 250 µm group (n = 15, p < 0.001), from 0.9 to 0.4 LogMAR in the > 250 and ≤ 400 µm group (n = 26, p < 0.001), and from 1.0 to 0.5 LogMAR in the > 400 µm group (n = 24, p < 0.001). A total of 16 patients had follow-up over 14 months: BCVA increased from 0.9 LogMAR preoperatively to 0.4 after 1 month (p < 0.00001) and to 0.3 LogMAR after 14 months (p = 0.03). A recovered ELM could be observed in 56.3% after 1 month and in 87.5% after 14 months. A recovered EZ could be observed in 18.8% after 1 month and in 68.8% after 14 months. Conclusion: The study demonstrates a high closure rate with corresponding restitution of outer retinal layers. In addition to its importance for the treatment of MHs > 400 µm, the inverted ILM flap technique also appears to be effective and safe for the treatment of MHs < 400 µm. Trial registration: WHO: DRKS00021241 [ABSTRACT FROM AUTHOR]

Purpose: Traction exerted on the vitreous base during vitrectomy poses a risk for retinal tears. We aimed to quantify core vitreous traction during vitrectomy using spring return and pneumatic cutters. Methods: Juvenile porcine vitreous was vacuum held in a vitreous bath while traction was measured using precision force gauge during vitrectomy. The parameters included were aspiration rate, cut-rate, cutter size, and machine types. Results: An empirical probabilistic model was developed. The traction was proportional to the aspiration rate but insignificantly dependent on the cut-rate. The traction probability was inversely proportional to the exponential function of the traction (p < 0.05). The traction was < 0.003 N for 99% of the time using either 23- or 25-gauge cutters. Conclusion: The tractions measured were considered similar to the causative forces of an iatrogenic retinal tear during a pars plana vitrectomy. The results provide a safety reference matrix of instrumental parameters during vitrectomy. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the safety and effectiveness of the Intrector® for treating postoperative endophthalmitis. Materials and methods: In a retrospective multicenter study, patients who received a single port 23-gauge core pars plana vitrectomy and isovolumetric injection of vancomycin, ceftazidime, and dexamethasone/amphotericin B using the Intrector® for postoperative endophthalmitis of intermediate severity (grade II or III vitreous inflammation and best-corrected visual acuity between hand movements and 0.3 logMAR [logarithm of the minimum angle of resolution]) were evaluated. Improvement in visual acuity, resolution of intraocular inflammation, the need for additional surgical procedures, and the development of complications were evaluated at a 1-month follow-up examination. Results: Fifteen patients (mean age 55.6±7.2 years) underwent treatment with the Intrector®. The mean vitreous volume aspirated was 0.78±0.22 mL. The vitreous samples indicated positive microorganism culture results in six of the 15 cases, but the samples were positive when analyzed by real-time polymerase chain reaction in all cases (15/15). The mean best-corrected visual acuity improved significantly (P=0.01) from 0.88±0.29 (logMAR) to 0.32±0.28. Each patient demonstrated at least three lines of visual improvement. No additional medical or surgical interventions were required, and the complete resolution of intraocular inflammation was noted in all patients at the 1-month follow-up examination. No procedure-related complications were observed. Conclusion: The Intrector® may be a safe and effective treatment option for infectious postoperative endophthalmitis. Larger studies comparing the outcomes of the Intrector® to the traditional treatments for postoperative endophthalmitis need to be conducted before its role in the treatment of postoperative endophthalmitis can be properly defined. [ABSTRACT FROM AUTHOR]

The recent approval by the US Food and Drug Administration of ocriplasmin for the treatment of symptomatic vitreomacular adhesion (VMA), often associated with vitreomacular traction (VMT) and macular hole (MH), has brought new attention to the field of pharmacologic vitreolysis. The need for an enzyme to split the vitreomacular interface, which is formed by a strong adhesive interaction between the posterior vitreous cortex and the internal limiting membrane, historically stems from pediatric eye surgery. This review summarizes the different anatomic classifications of posterior vitreous detachment or anomalous posterior vitreous detachment and puts these in the context of clinical pathologies commonly observed in clinical practice of the vitreoretinal specialist, such as MH, VMT, age-related macular degeneration, and diabetic macular edema. We revisit the outcome of the Phase II studies that indicated ocriplasmin was a safe and effective treatment for selected cases of symptomatic VMA and MH. Release of VMA at day 28 was achieved by 26.5% of patients in the ocriplasmin group versus 10.1% in the placebo group (P<0.001). Interestingly, for MHs, the numbers were more remarkable. Predictive factors for successful ocriplasmin treatment were identified for VMT (VMA diameter smaller than 1,500 μm) and MH (smaller than 250 μm). In comparison with the highly predictable outcome after vitrectomy, the general success rate of ocriplasmin not under clinical trial conditions has not fully met expectations and needs to be proven in real-world clinical settings. The ocriplasmin data will be compared in the future with observational data on spontaneous VMA release, will help retina specialists make more accurate predictions, and will improve outcome rates. [ABSTRACT FROM AUTHOR]

. Purpose: To compare cytokines in undiluted vitreous of treatment-naïve patients with macular oedema without vitreomacular traction secondary to branch (BRVO), central (CRVO) and hemi-central (H-CRVO) retinal vein occlusion. Methods: Ninety-four patients (median age 72 years, 42 men) underwent an intravitreal combination therapy, including a single-site 23-gauge core vitrectomy and the application of bevacizumab and dexamethasone due to vision-decreasing macular oedema. Among these were 43 patients with BRVO, 35 with CRVO and 16 patients with hemi-CRVO, which were distributed in a fresh or old retinal vein occlusion type (seven or more months after onset). Undiluted vitreous samples were analysed for interleukin 6 (IL-6), monocyte chemoattractant protein-1 (MCP-1) and vascular endothelial growth factor (VEGF-A) with cytometric BEAD assay. Vitreous samples from patients with idiopathic epiretinal membrane served as controls ( n = 14). Results: The mean cytokine values were highest in the CRVO group with IL-6 = 64.7 pg/ml (SD ± 115.8), MCP-1 = 1015.8 pg/ml (±970.1) and VEGF-A = 278.4 pg/ml (±512.8), followed by the H-CRVO group with IL-6 = 59.9 pg/ml (SD ± 97.5), MCP-1 = 938.8 pg/ml (±561.1) and VEGF-A = 211.5 pg/ml (±232.4). The BRVO group had IL-6 = 23.2 pg/ml (SD ± 48.8), MCP-1 = 602.6 pg/ml (±490.3) and VEGF-A = 161.8 pg/ml (±314.4). The values of MCP-1 and VEGF-A were significantly different for CRVO or H-CRVO versus BRVO. All values were significantly higher than in the control samples, which had 6.2 ± 3.4 pg/ml (IL-6), 253 ± 74 pg/ml (MCP-1) and 7 ± 4.9 pg/ml (VEGF-A). Within the old RVO type, only MCP-1 was significantly different for CRVO or H-CRVO versus BRVO. Conclusions: Both inflammatory markers and VEGF-A were higher in CRVO and H-CRVO than in BRVO undiluted vitreous samples. It seems that monocyte recruitment to the vessel wall, which might underlie the importance of eosinophils in tissue remodelling after RVO, is of special interest owing to the significant difference in MCP-1 in the older RVO types. [ABSTRACT FROM AUTHOR]