Comparison of modern high-speed vitrectomy systems and the advantages of using dual-bladed probes.

PURPOSE: This study analyzes the efficiency of different vitrectomy systems and compares single with double-bladed cutters. METHODS: The systems EVA™ (DORC), Constellation® Vision System (ALCON), megaTRON S4HPS (Geuder) and Stellaris® PC (Bausch and Lomb) were used. We chose 20G and 23G probes, since not all systems had switched to a smaller G at the time the study was conducted in 2016. Cut rates were varied in increments of 1000 cuts/min from 500 cpm to the system's maximum and vacuum pressures were varied in increments of 100 mmHg, from 100 to 600 mmHg up to the individual system's maximum. In this study water, egg white, Pluronic®-F127 gel and isolated porcine vitreous were used as models of human vitreous. The vitrectomy efficiency was calculated from the aspirated mass (g) within 30 s. The aperture of the different vitrectomy probes was filmed with a high-speed camera. RESULTS: The area under the curve analysis showed differences in efficiency between vitrectomy systems. For water, a reverse relationship between the aspirated mass and cut rate was shown. By contrast, for most systems aspirated egg white and porcine vitreous showed a non-linear increase or decrease for 4000 cpm and above. For all vitreous surrogates, EVA™'s double-bladed probe aspirated significantly (p < 0.001) more vitreous than its mono-bladed probe. Video recordings showed less vitreous traction for double- in contrast to single-bladed probes. CONCLUSION: We can demonstrate differences in the efficiency of vitrectomy depending on the vitrectomy system used. Double-bladed probes were more efficient and probably safer than single-bladed probes.

Effectiveness of introducing a 20-gauge core biopsy needle with a core trap in EUS-FNA/B for diagnosing pancreatic cancer.

BACKGROUND: Endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNA/B) is a standard method for pathological diagnosis of pancreatic solid lesions. The EchoTip ProCore 20G® (PC20), a 20-gauge biopsy needle with a forward-bevel core trap, has been available in Japan since 2015. METHODS: We compared the efficacy of the PC20 with that of the EchoTip ProCore 22G® (PC22) and Acquire 22G® (AC22) in EUS-FNA/B for diagnosing pancreatic cancer. This retrospective study included 191 patients with pancreatic cancer who underwent EUS-FNA/B using the PC20, PC22, or AC22 at our facility from April 2013 to October 2019. We investigated the patients' clinical characteristics and the diagnostic accuracy and safety of each needle. RESULTS: A sufficient stroke length of puncture was secured in all patients. The maximum length under EUS was shorter with the AC22 (22.1 ± 2.2 mm) than PC20 (30.6 ± 0.7 mm, p < 0.01) and PC22 (30.3 ± 0.8 mm, p < 0.01). The histological accuracy was 96.4% with the PC20 but only 58.8% with the PC22 (adjusted p (p-adj) < 0.0001) and 75.0% with the AC22 (p-adj = 0.06). The diagnostic accuracy of the combination of histology and cytology was 96.4% with the PC20, while it was 72.1% with the PC22 (p-adj < 0.0001) and 91.7% with the AC22 (p-adj > 0.99). One patient (0.9%) in the PC20 group developed mild pancreatitis, but no adverse events occurred with the other needles. CONCLUSIONS: The PC20 showed better diagnostic capability than the PC22. The diagnostic efficacy was similar between the PC20 and AC22. The high histological accuracy of the PC20 could be advantageous for lesions in which histological assessment is critical.

International multi-center study of iatrogenic retinal tears in pars plana vitrectomy.

AIM: To study and compare the effect of different surgical settings on the development of iatrogenic retinal tears (IRT) in conventional (20-gauge) and microincisional vitrectomy. METHODS: An international retrospective comparative study of 394 patients who had simple vitrectomy at three tertiary centers. Surgeries were performed by four retina surgeons using different viewing systems. Two groups of eyes were compared: microincisional vitrectomy (327 eyes) and conventional (67 eyes) vitrectomy. An iatrogenic tear was defined as the occurrence of one or more peripheral retinal tears during surgery or at any visit in the first 6wk postoperatively. RESULTS: Mean age was 67±12y and 55% were female. Iatrogenic tears occurred in 11/394 (2.8%) of eyes. The rate of tears was similar among different surgeons and viewing systems (P=0.93 and P=0.76, respectively). Surgical indication, preexisting pseudophakia/aphakia, induction of posterior vitreous detachment (PVD) during surgery, and the use triamcinolone acetonide didn't significantly affect the rate of tears (P>0.1 for all factors). A higher rate of tears was found in the conventional group compared to the microincisional group (respectively, 7.5%, 1.8%, P=0.02). CONCLUSION: The rate of IRT in vitrectomy is not significantly affected by surgical indication, preexisting PVD or pseudophakia, or use of triamcinolone or different viewing systems but is significantly higher in conventional vitrectomy. Microincisional platforms improve the safety of vitrectomy regardless of the viewing system used.

A Randomized Controlled Clinical Trial Comparing 20 Gauge and 23 Gauge Vitrectomy for Patients with Macular Hole or Macular Pucker.

INTRODUCTION: To compare the transconjunctival sutureless 23 gauge (G) pars plana vitrectomy (PPV) with 20 G PPV regarding inflammation, safety, visual outcome and patient comfort. METHODS: We included 103 patients with symptomatic macular hole or macular pucker, scheduled for vitrectomy in this prospective, randomized, controlled, mono-center clinical trial. Patients were randomized 1:1 to either 20G PPV (n = 51) or 23G PPV (n = 52). All eyes underwent standard 20G or 23G PPV with membrane peeling. Primary outcome measure was change in aqueous humor flare 3 weeks after surgery compared with baseline. Secondary outcome measures were flare values 2 days and 26 weeks after surgery, subjective discomforts measured with a visual analog scale, best-corrected visual acuity, duration of surgery, intraocular pressure (IOP) and adverse events. RESULTS: There was no significant difference in change of flare 3 weeks after PPV [- 1.7, 95% CI (- 6.3 to 2.9), p = 0.466]. Both groups showed a significant increase in flare 2 days after surgery (20G: p < 0.001, 23G: p = 0.002), but only the 20G group after 3 weeks (p = 0.011). The gain in visual acuity after 3 weeks was higher after 23G PPV (4.2 95% CI (0.4-8.0, p = 0.029), but without a difference after 6 months. The duration of surgery was shorter in the 23G group (p < 0.001). Patient comfort 3 weeks after surgery was greater after 23G PPV (foreign body sensation p = 0.002; itching: p = 0.021). However, the rate of complications did not differ between the groups. CONCLUSION: The primary aim, showing the superiority of the 23G group regarding the change of flare value from baseline to 3 weeks after surgery, was not met, but the level of inflammation decreased faster after 23G PPV. Clear advantages of the 23G PPV were a lower risk of postoperative IOP elevation, a shorter surgery time, faster visual recovery and greater patient comfort in the early postoperative phase. CLINICAL TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT01969929.

Removal of silicone oil droplets adhering to the posterior surface of an intraocular lens (IOL).

PURPOSE: We report a rare case of silicone oil droplets adhering to the posterior surface of an intraocular lens (IOL) after removal of silicone oil for a patient with retinal reattachment, who had a history of pseudophakic rhegmatogenous retinal detachment. CASE REPORT: A 45-year-old male with a history of cataract surgeries of both eyes developed pseudophakic retinal detachment in his left eye. He received surgeries of scleral buckle and standard 3-port pars plana vitrectomy with silicon oil tamponade. With retinal attachment for 7 months, he underwent removal of silicone oil in the left eye. However, a big silicone oil droplet was found on the posterior surface of the IOL with complaints of distorted micropsia and poor vision, a month later. Pars plana vitrectomy using a 20-gauge vitreous cutter, which was supposed to have a higher cleaning capability compared with a smaller size device, was performed to aspirate the main part of the big oil droplet. The residual dispersed smaller droplets at the center of the visual axis were swept peripherally using a 27-gauge bending tip cannula. Fortunately, the patient regained his vision of 20/20 without distortion and micropsia in his left eye. CONCLUSION: This was a rare case where silicone oil droplets were found adhering to the posterior surface of an IOL after removing silicone oil a month later. We used a 20-gauge vitrectomy system to remove large oil droplets and swept smaller ones off the visual axis to improve the vision and visual quality.

Schirmer test changes after 20 gauge and 23 gauge pars plana vitrectomy.

Objective: To evaluate the short-term changes in Schirmer I test (ST) after pars plana vitrectomy and to compare the results between 23 gauge and 20 gauge vitrectomy surgeries. Methods: 42 patients who underwent pars plana vitrectomy for posterior segment diseases were included in this prospective, non-randomized, comparative study. The choice of sclerotomy gauge was at the surgeons' discretion. ST values were recorded before and at 1 and 3 months after vitrectomy. Results: 20 patients in 23 gauge and 22 patients in 20-gauge group with a mean age of 59.9 ± 13.5 years were included. The mean preoperative ST values decreased significantly in both groups at 1 and 3 months after surgery (all P < 0.01). The ST values in the fellow eyes were the same, at baseline and during the follow up (P > 0.05). At 3 months visit, 15 eyes (35.7%) had abnormal ST measurements. There was no statistically significant difference in the changes in the ST measurements between the two groups at one month (P = 0.7), however, 3 months after surgery, the mean decrease in the ST measurements was significantly higher in the 20 gauge group (P = 0.03). At 3 months, 4 eyes in the 23 gauge group (20%) and 11 eyes in the 20 gauge group (50%) had abnormal ST measurements (P = 0.05). Conclusions: Although both 20 and 23-gauge vitrectomy decrease the ST measurements postoperatively, the value is less affected by the 23-gauge vitrectomy.

Endophthalmitis after small-gauge vitrectomy: a retrospective case series from Sweden.

PURPOSE: To investigate the anatomical and functional outcomes of acute-onset endophthalmitis after small-gauge vitrectomy. METHODS: Retrospective case series of patients who underwent 23- or 25-gauge vitrectomy at four centres in Sweden between 2008 and 2012. Postvitrectomy endophthalmitis was identified through the search of the journal records of each institution, and the diagnosis was based on clinical criteria regardless of culture results. RESULTS: Twenty-four patients (24 eyes) were included. The incidence of endophthalmitis following small-gauge vitrectomy was 0.14%. Indications for small-gauge vitrectomy enclosed epiretinal membrane (n = 13), retinal detachment (n = 5) and others (n = 6). Surgical technique included 23- and 25-gauge vitrectomy (23:1). Four eyes had sutured sclerotomies, and two had postoperative hypotony <7 mmHg. Days to endophthalmitis presentation varied between 1 and 21 (mean 6 ± 6). Treatment methods included the following: tap and antibiotic injection (n = 7), tap, antibiotic injection with subsequent vitrectomy (n = 2) and prompt vitrectomy with antibiotics (n = 15). Sixteen eyes (66.7%) were culture positive, whereas the other eight cases were culture negative. Anatomical results included evisceration (n = 1), phthisis (n = 1), and globe intact (n = 22). Presenting best corrected visual acuity (BCVA) were hand motion (n = 14), light perception (n = 7), counting fingers (n = 2), and no data (n = 1). Functionally 19 eyes (79%) had Snellen VA ≥0.1; 11 eyes (46%) had VA ≥0.5 Mean logMar BCVA preoperatively and at the last follow-up were 2.07 ± 0.6 and 0.79 ± 0.99, respectively. CONCLUSIONS: In spite of good anatomical and functional results, this study showed higher rate of endophthalmitis than the latest reports suggesting that small-gauge vitrectomy has reached the safety level of standard 20-gauge vitrectomy when infectious endophthalmitis is concerned.

Corneal approach 20 Guage vitrectomy system for the management of congenital cataract.

OBJECTIVE: To evaluate the efficacy and complications of 20 gauge vitrectomy via corneal approach for the management of congenital cataract. METHOD: We performed anterior capsular vitreorhexis, lens matter aspiration (LMA), primary posterior vitrectorhexis and anterior vitrectomy via corneal approach using 20 gauge vitrectomy system in children younger than two years of age with congenital cataract between January 2014 to December 2014. The intra and postoperative complications were observed. RESULTS: Twenty nine eyes of 21 children were included in this study. Congenital cataract surgery using 20 gauge vitrectomy system via corneal approach did not reveal any intra operative complication. Post operatively all children were able to freely open their operated eyes. Conjunctival congestion at the incision site in four eyes and mild anterior chamber reaction in 8 eyes were seen on 1(st) daywhich resolved at one week follow up. Other major post operative complications such as inflammatory membrane, irregular pupil, posterior/anterior syneache and opacification of visual axis were not seen during follow up period. CONCLUSION: The 20-gauge vitrectomy system via corneal approach is easy to perform, is less time consuming, safe and effective for the management of congenital cataract in younger children.

Vitreous flow rates through dual pneumatic cutters: effects of duty cycle and cut rate.

PURPOSE: We aimed to investigate effects of instrument settings on porcine vitreous flow rates through dual pneumatic high-speed vitrectomy probes. METHODS: The CONSTELLATION(®) Vision System was tested with 250, 450, and 650 mmHg of vacuum using six ULTRAVIT(®) vitrectomy probes of each diameter (25+(®), 25, 23, and 20 gauge) operated from 500 cuts per minute (cpm) up to 5,000 cpm. Duty cycle modes tested included biased open, 50/50, and biased closed. Flow rates were calculated by assessing the change in weight of porcine eyes during vitreous aspiration. Volumetric flow rate was measured with a computer-connected electronic scale. RESULTS: At lower cut rates, the biased open mode produced higher flow than did the 50/50 mode, which produced higher flow than did the biased closed mode. In the biased closed and 50/50 modes, vitreous flow rates tended to increase with increasing cut rate. Vitreous flow rates in the biased open duty cycle mode remained relatively constant across cut rates. CONCLUSION: Vitreous flow rates through dual pneumatic vitrectomy probes could be manipulated by changing the duty cycle modes on the vitrectomy system. Differences in duty cycle behavior suggest that high-speed cut rates of 5,000 cpm may optimize vitreous aspiration.

25-gauge transconjunctival diagnostic vitrectomy in suspected cases of intraocular lymphoma: a case series and review of the literature.

AIM: To report the cytology results of 25-gauge transconjunctival (25G-TSV) diagnostic vitrectomy in cases suspicious for intraocular lymphoma (IOL), and compare the results to those reported in the literature. METHODS: Clinical and cytopathological records of 18 vitreous biopsy specimens obtained via 25G-TSV diagnostic vitrectomy in 12 patients suspicious for IOL were reviewed retrospectively. A review of the literature in regards to the diagnostic yields of vitreous specimens obtained via 25-gauge and 20-gauge diagnostic vitrectomy in suspected cases of IOL was performed. RESULTS: Eighteen eyes from 12 patients with clinical suspicion of IOL underwent diagnostic 25G-TSV. The cytopathological investigations demonstrated IOL in 15 eyes (83.3%). Vitreous analysis was non-diagnostic in 3 eyes (16.7%). CONCLUSION: Twenty-five-gauge diagnostic vitrectomy yields adequate sample for cytological evaluation of the vitreous in cases suspicious for IOL. The diagnostic results of the 25G-TSV in the current study are superior to those reported for 20-gauge vitrectomy but equivalent to those reported for 25G-TSV in the published literature.

Different techniques of transconjunctival cannulated vitrectomy versus conventional non-cannulated vitrectomy in various vitreoretinal disorders.

PURPOSE: To evaluate the safety and efficacy of different methods of transconjunctival cannulated vitrectomy versus conventional non-cannulated vitrectomy in various vitreoretinal disorders. METHODS: A prospective randomized study was done from August 2009 to February 2011. The study included 129 eyes of 122 patients, randomly divided into four groups. Group 1 comprised 34 eyes operated on using transconjunctival 20-gauge cannula Claes system. Group 2 comprised 32 eyes operated on using transconjunctival cannulated 23 gauge system. Group 3 comprised 27 eyes operated on using combined 20-gauge non-cannulated and 23-gauge transconjunctival cannulated system. Group 4 comprised 36 eyes operated on using conventional non-cannulated 20-gauge system. RESULTS: The four groups were demographically similar. Anatomical outcome was achieved in all cases. Vision was improved in 29 eyes (85.3%) in group 1, 23 eyes (71.9%) in group 2, 19 eyes (70.4%) in group 3, and 26 eyes (72.2%) in group 4. There was no statistical difference between the four groups 1-day postoperative (P=0.405) and 1-week postoperative intraocular pressure (P=0.254). The number of sutureless sclerotomies was 68 (66.6%) in group 1, 78 (81.3%) in group 2, 50 (61.8%) in group 3, and 0 in group 4. Hypotony occurred in one eye (2.9%) in group 1, three eyes (9.4%) in group 2, two eyes (7.4%) in group 3, and no eyes in group 4. Operative endophthalmitis did not occur in any one of the four groups. CONCLUSION: Final anatomical and functional outcomes were not related to the type of sclerotomy used (cannulated or non-cannulated), the gauge used (20 or 23), the route (transconjunctival or transscleral), or type of suture used. The advantages of small-gauge transconjunctival vitrectomy were patient comfort, early ambulation, and preservation of the conjunctiva. This should be weighed against the cost of this cannula system.

Hybrid microincision vitrectomy surgery combined with 20-gauge silicone cannulas for use with 20-gauge horizontal scissors in diabetic tractional retinal detachment.

PURPOSE: To verify the utility and preliminary safety of a 20-gauge silicone cannula for use with 20-gauge horizontal scissors delamination during microincision vitrectomy surgery (MIVS). METHODS: Thirty-eight eyes in 35 consecutive patients with diabetic tractional retinal detachment, who underwent MIVS between April 2010 and March 2012 and were followed for 3-24 months, were retrospectively assessed using a chart review. Twenty-gauge scissors delamination through a silicone cannula, with an additional 20-gauge port as a hybrid, was primarily selected when treating thick and rigid fibrovascular membranes, including fluctuating vessels over the detached retina near the macula. The main outcome measures included the proportion of patients treated with this hybrid method, the postoperative visual acuity, and the incidence of complications. RESULTS: Compared with the 26 eyes treated with MIVS only, 12 eyes (32%) required a hybrid technique with the use of 20-gauge instruments through a silicone cannula in addition to MIVS. Two patients underwent additional surgery. Temporary silicone oil tamponade was performed in one case of retinotomy and one case of schizophrenia. The mean visual acuity (logarithm of the minimum angle of resolution [logMAR]) improved from 1.43 ± 0.85 to 0.72 ± 0.47 at the last follow-up visit. No patients exhibited worsening of their visual acuity postoperatively. No sclerotomy-related complications were recorded during the intraoperative or postoperative periods. CONCLUSION: Hybrid MIVS combined with a 20-gauge silicone cannula for use with 20-gauge horizontal scissors in diabetic tractional retinal detachment eyes is useful and safe due to the reduced risk of sclerotomy-related retinal breaks. This procedure is a reasonable option when performing complex surgery for diabetic vitrectomy.

Outcome of 20-gauge transconjunctival cannulated sutureless vitrectomy using silicone oil or air tamponade.

BACKGROUND: The purpose of this study was to assess the outcome of pars plana vitrectomy using a 20-gauge transconjunctival cannulated sutureless system with air or silicone oil tamponade in cases of retinal detachment of different etiologies. METHODS: A prospective study was performed in 60 eyes from consecutive 60 patients who underwent 20-gauge transconjunctival cannulated sutureless vitrectomy (30 eyes with air tamponade and 30 eyes with silicone oil tamponade), with the inclusion of a further 30 patients who underwent conventional 20-gauge vitrectomy and served as a control group. The main outcome measures were intraocular pressure, wound leakage, and comfort score. RESULTS: Preoperative intraocular pressure increased from 17.67 ± 5.6 mmHg preoperatively to 18.78 ± 6.1 mmHg on the first postoperative day in group A and decreased from 16.97 ± 4.9 mmHg to 15.88 ± 5.3 mmHg in group B. These changes were not statistically significant (P > 0.05). The comfort score ranged from 1 to 5 (1 = very bad, 2 = bad, 3 = good, 4 = very good, and 5 = excellent), with a mean of 4.4 ± 0.94 in group A and 4.35 ± 0.99 in group B on the first postoperative day, and no significant difference in scores between the groups at any follow-up visit. There was intraoperative wound leakage in two cases (6.7%) in group A which required suturing and one case (3.3%) in group B, but the difference was not statistically significant (P > 0.05). There was no wound leakage at follow-up in either group. No cases of hypotony, endophthalmitis, or unsealed sclerotomies were noted. CONCLUSION: Pars plana vitrectomy using a 20-gauge transconjunctival cannulated sutureless system combines the advantages of smaller-gauge vitrectomy systems with the economic advantage of not needing to purchase any additional handheld instruments. It can be used with both air and silicone oil tamponade in most cases of retinal detachment.

Iatrogenic retinal breaks during 20-gauge vitrectomy for proliferative diabetic retinopathy.

BACKGROUND: We classified iatrogenic retinal break formation during 20-gauge pars plana vitrectomy for proliferative diabetic retinopathy into three types according to the mechanism of development, and evaluated the association of each type with postoperative complications. This is the largest series of such patients published to date. METHODS: This was a retrospective comparative study of 760 eyes from 609 cases who underwent primary 20-gauge vitrectomy for proliferative diabetic retinopathy and were followed-up for at least 6 months after surgery. Postoperatively, the eyes were classified as having vitreous hemorrhage only (group 1), fibrovascular membrane without traction retinal detachment (group 2), or fibrovascular membrane with traction retinal detachment (group 3). RESULTS: The overall incidence of iatrogenic retinal breaks was 29%. Fibrovascular membrane dissection was associated with retinal break formation in 50 of the eyes in group 3, an incidence which was significantly higher than that in group 2 (P < 0.001). Posterior vitreous detachment creation and peripheral vitreous shaving were associated with retinal break formation in 8% of eyes overall, and oral dialysis occurred in 2%. Postoperatively, vitreous hemorrhage requiring washout, neovascular glaucoma, recurrent retinal detachments, and fibrovascular proliferation at the sclerotomy sites occurred in 4%, 4%, 3%, and 1%, respectively, of all eyes. Outcomes of eyes with these postoperative complications, other than vitreous hemorrhage, were poor. Multiple regression analysis revealed retinal break formation during fibrovascular membrane dissection to be significantly related to postoperative vitreous hemorrhage (P = 0.019), recurrent retinal detachments (P < 0.001), and neovascular glaucoma (P = 0.048). Oral dialysis was also significantly related to postoperative vitreous hemorrhage (P = 0.001). CONCLUSION: Iatrogenic retinal break formation during fibrovascular membrane dissection was more likely to be the cause of poor outcomes than peripheral retinal breaks or oral dialysis.

Differences between the combination of the 25-gauge vitrectomy with phacoemulsification versus 20-gauge vitrectomy and phacofragmentation.

INTRODUCTION: In the present study we determine the differences observed between 25-gauge-vitrectomy combined with phacoemulsification, and the 20-gauge-vitrectomy combined with pars plana phacofragmentation. METHODS: A prospective study of a sample of 987 eyes of 661 patients randomly divided into two groups. 25-gauge-vitrectomy plus phacoemulsification included 486 eyes, and 20-gauge-vitrectomy plus phacofragmentation 501 eyes. We evaluated the differences at the time of the surgery, the intra-and postoperative complications, and the variations in intraocular pressure. RESULTS: The final visual outcome was similar in both groups. The most important differences between groups were: surgical time was faster in group 1 than in group 2, (mean time: 35.16 +/- 3.49, 44.74 +/- 5.30 minutes). Intraoperative complications were more numerous in group 1. In group 1, postoperative low levels of intraocular pressure are present in all patients with 2.77% of patients with hypotension (<8 mmHg), and three choroidal effusion. In group 2, intraocular lens decentration and retinal detachment are more frequent (2.38% and 1.39%, respectively). CONCLUSIONS: In the present study, both techniques have a similar number of complications and have a similar postoperative outcome, and are valid for the management of the pathologies selected.