Advantages and limitations of small gauge vitrectomy

3D nanoprinted catadioptric fiber sensor for dual-axis distance measurement during vitrectomy

Retinal damage is a common intraoperative complication during vitrectomy, caused by a complex interplay between the suction of the vitrectome, the cut- and aspiration rate, and the distance of the instrument to the retina. To control this last factor, we developed two miniaturized fiber-optic distance sensors based on low-coherence interferometry for direct integration into the vitrectome. Both sensors have a diameter of 250 µm, which makes them compatible with a 25G vitrectome. The first sensor measures distance in the lateral direction. The second sensor is capable of simultaneously measuring distance in both the lateral and the axial direction. Axial and lateral directions correspond to the direction of the cutter port of the vitrectome and the direction along the vitrectome's shaft, respectively. In both sensors, a free-form mirror deflects and focuses the beam in the lateral direction. In the dual-axis distance sensor, an additional lens is integrated into the free-form mirror for distance measurement in the axial direction. The beam-shaping micro-optics at the tip of the sensor fibers were fabricated through two-photon polymerization and are selectively gold coated for increased reflectivity of the mirror. Distance measurements were successfully demonstrated in artificial samples and in ex vivo pig eyes with a back-end that uses a current-tuned VCSEL as a swept-source. We experimentally demonstrate that the complete sensor system can attain a S N R max of up to 80 dB. The small dimensions of the developed sensors make them a potential solution for various other medical applications.

Wound healing and postoperative management in paediatric patients following 27-Gauge Transconjunctival Sutureless Vitrectomy for vitreoretinal conditions

The utilization of 27-G TSV, or 27-Gauge Transconjunctival Sutureless Vitrectomy, poses distinct difficulties in the context of paediatric patients, particularly those younger than 14 years old, on account of the dearth of exhaustive documentation concerning the efficacy and results of these operations. Therefore, this retrospective study was to evaluate the safety and efficacy of 27-G TSV in paediatric patients, with emphasis on management of intraoperative and postoperative complications and postoperative wound healing. A total of 54 eyes of 52 paediatric patients who underwent 27-G TSV at Sichuan Provincial People's Hospital were included in the study. The average duration of follow-up was 9.32 ± 3.35 months. The complication with the highest incidence rate was Rhegmatogenous Retinal Detachment (RRD), which was detected in 27.8% cases. Familial Exudative Vitreoretinopathy (FEVR) and Persistent Fetal Vasculature (PFV) each accounted for 16.7% of the cases. Retinopathy of Prematurity (ROP) and Vitreous Haemorrhage (VH) constituted 11.1% and 14.8%, respectively, of the reported cases. Lens injury (1.9%), cannula slippage (7.4%) and wound leakage (5.6%) were intraoperative complications. Iatrogenic retinal detachment occurred at 3.7%. Hypotony (10.8% of patients), vitreous haemorrhage (9.3%), cataract formation (9.3%), ocular hypertension (8.1%) and retinal detachment (5.6%) were postoperative complications. Effective management strategies were executed, such as performing in situ trocar puncture to address cannula slippage and promptly suturing to address wound leakage. 27-G TSV exhibited promise as the therapeutic alternative for range of vitreoretinal disorders in paediatric patients, accompanied by complications that were controllable during and after the procedure. Strict preoperative planning and precise surgical technique are indispensable in order to maximize patient outcomes and guarantee effective wound healing and recovery within this particular demographic.

Clinical Performance Comparison of Ultrahigh-speed Dual Pneumatic Vitrectomy Probes: Is Faster and Smaller Better?

PURPOSE

Various vitrectomy probes are currently being used commercially, and there are ongoing efforts toward developing probes with higher cutting rates and smaller gauges. This study aimed to compare the efficiency and safety of various commercially available small gauge ultrahigh-speed dual pneumatic vitrectomy probes.

METHODS

We retrospectively analyzed the medical records of patients and recorded intraoperative videos while they underwent microincision three-port vitrectomy surgery for idiopathic epiretinal membrane at Soonchunhyang University Seoul Hospital. The patients were categorized into four groups based on the vitrectomy probe used during surgery: 23-7500 (UltraVit 23-gauge 7,500 cuts per minute [CPM]), 23-7500 (UltraVit 25-gauge 7,500 CPM), 25-10K (Advanced UltraVit 25-gauge 10,000 CPM), and 27-10K (Advanced UltraVit 27-gauge 10,000 CPM).

RESULTS

In total, 82 eyes from 82 patients were included in this work, with 16, 11, 26, and 29 eyes in groups 23-7500, 25-7500, 25-10K, and 27-10K, respectively. The corresponding vitrectomy times were 295.56 ± 53.55, 293.09 ± 50.28, 299.92 ± 59.42, and 349.38 ± 67.23 seconds, respectively. There was a significant difference in the vitrectomy time between the groups (p = 0.004). The mean number of sutures was 3, 3, 2.96, and 0.83, respectively. In the 23-7500 group, there was one case of iatrogenic retinal break, while in the 27-10K group, there was one case of postoperative hypotony.

CONCLUSIONS

Although advancements have been made in the 27-gauge vitrectomy probe, it still takes more vitrectomy time than it does when using the 23- and 25-gauge probes. However, the delay was within an average of 1 minute, and considering the significantly reduced need for sutures, there is a substantial benefit in terms of postoperative discomfort. Therefore, when choosing a probe for epiretinal membrane surgery among the four options, it is reasonable to select the 27-gauge probe according to the surgeon's preference.

Twenty-seven-gauge vitrectomy: a consecutive, single-centre case series with exclusive use over a 4-year period

BACKGROUND

To assess the safety and effectiveness of the exclusive use of 27-gauge instruments for all vitreoretinal diseases requiring vitrectomy.

METHODS

In this retrospective study, 1020 consecutive surgeries were performed on 958 eyes of 848 patients using 27-gauge instruments from March 2017 to June 2021. Patients with a minimum follow-up of 3 months were included. Surgical case-mix, best-corrected visual acuity (BCVA), intraocular pressure (IOP), intra- and post-operative complications, and surgery times were recorded.

RESULTS

The study patients were followed up for averagely 11 months. Of the 1020 vitrectomies, 958 were primary procedures. Of the 148 retinal detachment (RD) cases, 138 (93%) required a single vitrectomy. Primary macular hole closure was achieved in 143 of 145 (99%) cases. The average surgical times were 55 and 38 min for RD surgeries and for all other indications, respectively. BCVA improved significantly at the final visit (20/49) compared with the pre-operative visit (20/78) (p < 0.01). IOP was similar at the pre-operative (14.8mmHg) and final (14.3mmHg) visits. Complications recorded include transient hypotony in 39 eyes, iatrogenic retinal breaks in 2 eyes, and a vitreous bleed in 1 other eye.

CONCLUSION

This study revealed that 27-gauge vitrectomy instruments can be used for a wide range of indications, with exclusive use in certain settings. The outcomes were similar to other gauges, including for rhegmatogenous retinal detachment, with minimal complications.

An Evaluation of the Repeatability of Visual Function Following Surgical Repair of Macula-Off Rhegmatogenous Retinal Detachment

Purpose

To evaluate the reliability and reproducibility of visual function assessments for patients with macula-off rhegmatogenous retinal detachment (RRD).

Methods

This prospective study included patients with unilateral macula-off RRD of <10-day duration successfully treated with a single, uncomplicated surgery at least 1 year following repair. Visual function assessments were performed at time of enrollment and 1 month later. Testing included Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA), low-luminance visual acuity (LLVA), low-contrast visual acuity (VA) 2.5% and 5%, contrast sensitivity assessment with Mars and Gabor patches, reading speed (acuity, speed, and critical print size), color vision testing (protan, deutan, and tritan), and microperimetry. Spectral-domain ocular coherence tomography (SD-OCT) was performed. Paired t-statistics were used to compare values between visits and between the study and fellow eyes.

Results

Fourteen patients (9 male, 5 female) with a mean age of 69 years at time of surgery were evaluated. Correlation coefficients across the two visits were highest for ETDRS BCVA (0.97), tritan color vision testing (0.96), and low-contrast VA 5% (0.96), while the average t-statistic was largest for low-luminance deficit (4.2), ETDRS BCVA (4.1), and reading speed critical print size (3.7). ETDRS BCVA did not correlate with SD-OCT findings.

Conclusions

ETDRS BCVA can be considered a highly reliable and reproducible outcome measure. LLVA, protan color discrimination, contrast sensitivity, and reading speed may be useful secondary outcome measures.

Translational Relevance

This study provides guidance on the selection of visual function outcome measures for clinical trials of patients with macula-off RRD.

A Systematic Review and Meta-Analysis of Clinical Outcomes of Small Gauge Vitrectomy with or without Intravitreal Anti-Vascular Endothelial Growth Factor Agents Pretreatment for Proliferative Diabetic Retinopathy

BACKGROUND

Proliferative diabetic retinopathy (PDR) is a common visual threatening ocular disease, patients with nonclearing vitreous hemorrhage (VH), tractional retinal detachment (RD), or extensive fibrovascular proliferation are always in need for surgical treatment. Although several studies reported better surgical outcome in patients underwent surgery after anti-VEGF injection, the effect of anti-VEGF pretreatment for small gauge vitrectomy in PDR patients remains to be elucidated.

OBJECTIVES

The objective of the study was to evaluate the benefits of preoperative anti-VEGF treatment in small gauge vitrectomy for PDR patients.

METHODS

A comprehensive literature search in PubMed, Embase, and the Cochrane Central Register of Controlled Trials was performed to identify relevant studies. Meta-analyses were performed for intraoperative (including intraoperative bleeding, endodiathermy, iatrogenic retinal breaks, surgical time, etc.) and postoperative outcome parameters (including best-corrected visual acuity (BCVA), postoperative VH, postoperative RD, etc.).

RESULTS

Ten randomized controlled trials were identified and used for comparing small gauge vitrectomy alone (344 eyes, control group) and small gauge vitrectomy with preoperative anti-VEGF injection (355 eyes). The intraoperative findings showed that the surgical time, the incidence of clinically significant intraoperative bleeding, iatrogenic retinal breaks, silicone oil tamponade, and the frequency of endodiathermy were significantly less in the anti-VEGF pre-treated group than in the vitrectomy alone group (p < 0.01). The postoperative findings showed that the incidences of early postoperative VH, postoperative RD were significantly less in the anti-VEGF pre-treated group than in the control group (p < 0.05). The pooled result of postoperative rubeosis iridis/neovascular glaucoma was borderline (p = 0.072) between cases and controls, while no statistically significant differences in BCVA at last follow-up and incidences of late postoperative VH were found between these two groups (p > 0.05).

CONCLUSIONS

Anti-VEGF injection prior to small gauge vitrectomy in PDR patients might facilitate easier surgical procedure and reduce intra- and postoperative complications. Further studies are needed to verify our findings and evaluate the optimal interval and dosage for preoperative anti-VEGF injection.

Outcomes and complications of primary rhegmatogenous retinal detachment repair with pars plana vitrectomy in young adults

BACKGROUND

Scleral buckling has been the standard for rhegmatogenous retinal detachment repair in young patients given the typical lack of posterior vitreous detachment, phakic status, and lower risk of proliferative vitreoretinopathy. In older patients, pars plana vitrectomy alone is typically used for rhegmatogenous retinal detachment repair. We report the outcomes and complications of pars plana vitrectomy for rhegmatogenous retinal detachment in young eyes.

METHODS

Retrospective, single-center cohort study. Medical records of patients between 15 to 45 years of age undergoing primary pars plana vitrectomy for rhegmatogenous retinal detachment repair between 2010 and 2020 were carefully reviewed. All analyses were performed using the Kruskal-Wallis tests for numeric covariates between age groups.

RESULTS

Eyes were stratified by age: 15-24 (group 1, n = 10), 25-34 (group 2, n = 14), and 35-45 (group 3, n = 38). The average number of surgeries were 1.9, 1.4, and 1.1 in groups 1, 2, and 3, respectively (p = 0.004). Single surgery success rates were 50%, 64%, and 92% in groups 1, 2 and 3, respectively (p = 0.005). Final reattachment rates were 80%, 93%, 100% in groups 1, 2, and 3, respectively (p = 0.568). Proliferative vitreoretinopathy developed in 50%, 7%, and 8% of eyes in groups 1, 2, and 3, respectively (p < 0.001).

CONCLUSION

While the final reattachment rates were excellent in all groups, the higher rates of proliferative vitreoretinopathy and lower single surgery success rate in younger patients may suggest that primary pars plana vitrectomy may not be the optimal repair method in these age groups.

Outcomes and Complications of Pars Plana Vitrectomy for Tractional Retinal Detachment in People With Diabetes: A Systematic Review and Meta-analysis

Importance

Tractional retinal detachment (TRD) occurs in approximately 5% of people with proliferative diabetic retinopathy and poses a threat to vision. Pars plana vitrectomy (PPV) is the treatment of choice for TRD.

Objective

To determine anatomic and functional outcomes of PPV for the treatment of TRD in people with diabetes (dTRD).

Data Sources

MEDLINE and Embase were searched systematically from January 1, 2000, to February 20, 2022. In addition, a reference list of eligible studies were screened.

Study Selection

Eligible studies were those published in English, those reporting outcomes of PPV for dTRD, and those that included more than 25 eyes and with a minimum follow-up of 3 months.

Data Extraction and Synthesis

Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines for data extraction/synthesis were followed, and the National Institute for Health quality assessment tool was used to assess risk of bias. Study eligibility was determined independently by 2 reviewers; data extraction was conducted by 1 reviewer and entries checked for accuracy by another. Data were pooled using a random-effects model.

Main Outcomes and Measures

Main outcomes included rate of failure of retinal reattachment following 1 surgery and final visual acuity (VA). The association of baseline patient characteristics and surgical maneuvers with postoperative surgical outcomes was investigated.

Results

Of the 406 studies identified, 38 (3839 eyes) were eligible and included for analysis. Patients had a median (IQR) age of 52.2 (49.6-55.7) years. In the studies reporting patient sex (31 of 38 studies), 1441 were female individuals (50.1%). The overall failure rate of retinal reattachment after 1 surgery was 5.9% (95% CI, 1.4%-8.3%), and the mean final VA was 0.94 (95% CI, 0.82-1.05) logMAR (approximate Snellen equivalent, 6/53; 95% CI, 6/39-6/71). People with higher preoperative VA achieved higher postoperative vision (0.66 logMAR worse final vision; 95% CI, 0.39-0.84 per 1.0 logMAR worse at baseline; P <.001). On multivariable analysis, no other patient characteristics or surgical variables had a statistically significant association with outcomes.

Conclusions and Relevance

Results of this systematic review and meta-analysis suggest that PPV was an effective strategy to achieve retinal reattachment in people with dTRD. Given that higher preoperative VA was the only factor associated with higher postoperative vision, early intervention should be considered and discussed in detail with patients. Overall, final postoperative VA remains low, and patients should be counseled on the guarded prognosis of dTRD.

Rhegmatogenous retinal detachment surgery: A review

Rhegmatogenous retinal detachment (RRD) is a serious surgical condition with significant ocular morbidity if not managed properly. Once untreatable, approaches to the repair of RRD have greatly evolved over the years, leading to outstanding primary surgical success rates. The management of RRD is often a topic of great debate. Scleral buckling, vitrectomy and pneumatic retinopexy have been used successfully for the treatment of RRD. Several factors may affect surgical success and dictate a surgeon's preference for the technique employed. In this review, we provide an overview and supporting literature on the options for RRD repair and their respective preoperative and postoperative considerations in order to guide surgical management.

Self-Healing Injectable Hydrogels for Tissue Regeneration

Biomaterials with the ability to self-heal and recover their structural integrity offer many advantages for applications in biomedicine. The past decade has witnessed the rapid emergence of a new class of self-healing biomaterials commonly termed injectable, or printable in the context of 3D printing. These self-healing injectable biomaterials, mostly hydrogels and other soft condensed matter based on reversible chemistry, are able to temporarily fluidize under shear stress and subsequently recover their original mechanical properties. Self-healing injectable hydrogels offer distinct advantages compared to traditional biomaterials. Most notably, they can be administered in a locally targeted and minimally invasive manner through a narrow syringe without the need for invasive surgery. Their moldability allows for a patient-specific intervention and shows great prospects for personalized medicine. Injected hydrogels can facilitate tissue regeneration in multiple ways owing to their viscoelastic and diffusive nature, ranging from simple mechanical support, spatiotemporally controlled delivery of cells or therapeutics, to local recruitment and modulation of host cells to promote tissue regeneration. Consequently, self-healing injectable hydrogels have been at the forefront of many cutting-edge tissue regeneration strategies. This study provides a critical review of the current state of self-healing injectable hydrogels for tissue regeneration. As key challenges toward further maturation of this exciting research field, we identify (i) the trade-off between the self-healing and injectability of hydrogels vs their physical stability, (ii) the lack of consensus on rheological characterization and quantitative benchmarks for self-healing injectable hydrogels, particularly regarding the capillary flow in syringes, and (iii) practical limitations regarding translation toward therapeutically effective formulations for regeneration of specific tissues. Hence, here we (i) review chemical and physical design strategies for self-healing injectable hydrogels, (ii) provide a practical guide for their rheological analysis, and (iii) showcase their applicability for regeneration of various tissues and 3D printing of complex tissues and organoids.

Success of iOCT in surgical management of ERM peeling

PURPOSE

Epiretinal membranes (ERM) are a disorder leading to progressive vision loss and metamorphopsia. The ERM is treated through a pars-plana vitrectomy (PPV) with membrane peeling. The aim of this study was to define the success of intraoperative optical coherence tomography (iOCT) in ERM surgery to standard surgical visualization techniques and enhance our current approach to clinical practice.

METHODS

This study included 56 eyes of 54 patients who underwent surgical intervention for management of idiopathic ERM. Patients were recruited between February 2018 and March 2020 at "Francesco Miulli" Hospital ophthalmology department in Acquaviva delle Fonti, Bari, Italy.

RESULTS

in 28 eyes, ERM peeling was performed without staining and without iOCT; 25% of these eyes peeling ERM (n   =   7) was performed easily, while 75% of eyes peeling ERM (n   =   21) was not possible without staining and was necessary staining with Brillant Blu G.In 28 eyes ERM peeling were performed with iOCT; in 92.5% of these eyes (n   =   26) ERM peeling was easily done without staining, while in 7.5% of this group of eyes (n   =   2) ERM peeling was not possible without staining.

CONCLUSIONS

Our study shows how iOCT has successfully assisted the surgeon to complete peeling in most of the cases treated without the use of a chromovitrectomy dye; in flat ERM was more difficult and iOCT failed to visualize the inner limiting membrane (ILM).

Intraocular Lens Fixation Technique Without Corneal Incision in Minimally Invasive Vitrectomized Eyes

INTRODUCTION

To introduce a modified technique for primary/secondary intraocular lens (IOL) fixation without corneal incision in vitrectomized eyes.

METHODS

Consecutive case series who had undergone previous or concomitant pars plana vitrectomy (PPV) to have primary/secondary IOL fixation were prospectively included. A self-sealing scleral incision was made underneath the superior scleral flap, through which the IOL was inserted into the anterior chamber. The suture tied with the IOL passed through the sclera to fix the IOL in the ciliary sulcus. Patients were followed up for at least 3 months. Main outcomes were best corrected visual acuity (BCVA), intraocular pressure (IOP), surgically induced astigmatism (SIA), and intraoperative and postoperative complications.

RESULTS

A total of 31 patients were included in the study. The mean follow-up time was 5.35 ± 4.14 months. The BCVA (log MAR unit) improved from 0.97 ± 0.58 preoperative to 0.42 ± 0.36 postoperative (P < 0.001). Mean IOP remained unchanged (preoperative IOP 14.03 ± 2.90 mmHg, postoperative IOP 13.26 ± 3.46 mmHg, P = 0.130). The mean SIA was 0.91 ± 0.76 diopters. No obvious intraoperative and postoperative complications were observed.

CONCLUSION

This method has favorable postoperative visual recovery and IOP control. This modified method could be taken into account as an option by surgeons in vitreoretinal surgery.

Indications for surgical management of retained lens fragments

PURPOSE OF REVIEW

Retained lens fragments are a relatively rare occurrence after cataract surgery. While no definite guidelines for the surgical management or timing of surgery of this complication exist, surgery is indicated for patients with large lens fragments, persistent inflammation, secondary glaucoma, corneal edema, retinal tears or detachments, and associated endophthalmitis. The aim of this review is to summarize the current surgical management of retained lens material.

RECENT FINDINGS

The Intelligent Research in Sight registry database of 2.26 million patients who underwent cataract surgery in the US indicated that 0.18% (1 in 563) had secondary removal of retained lens fragments in the anterior chamber in the operating room within 1 year of the original cataract surgery. The risk of returning to the operating room for retained lens material removal was greater among men, smokers, patients with Medicaid or military insurance, and those who had complex cataract surgery. Medical management with topical corticosteroids or observation may be considered for small lens fragments, but surgical removal remains the mainstay of the treatment for large lens fragments.

SUMMARY

Retained lens fragments following cataract surgery may result in various vision-threatening complications. Understanding the risk factors, diagnosis, and surgical management of retained lens fragments are critical to preserving good visual outcomes. Vitrectomy is effective in patients with posterior nuclear fragments, retinal detachment, endophthalmitis, or uncontrolled glaucoma not responding to medical management. The best timing for surgery for retained lens fragments should be further investigated in a prospective study.

Pars plana vitrectomy in uveitis in the era of microincision vitreous surgery

Pars plana vitrectomy (PPV) in uveitis is indicated for various diagnostic and therapeutic indications. With the advent of microincision vitreous surgery (MIVS), the use of PPV in uveitis has increased with a wider spectrum of indications due to shorter surgical time, less patient discomfort, less conjunctival scarring, and a decreased rate of complications as compared to standard 20G vitrectomy. Because of faster post-operative recovery in terms of visual improvement and reduction of inflammation, and reduced duration of systemic corticosteroids, MIVS has gained popularity in uveitis as an adjunctive therapy to the standard of care medical therapy. The safety and efficacy of MIVS is related to the emerging vitrectomy techniques with better and newer cutters, illuminating probes, and accessory instruments. Because of the instrumentation and fluidics of MIVS, PPV is emerging as a safe and useful alternative for diagnostic challenges in uveitis, aiding in earlier diagnosis and better outcome of inflammatory disease, even in the presence of severe and active inflammation, which was once considered a relative contraindication for performing vitreous surgery. However, for surgical interventions for therapeutic indications and complications of uveitis, it is advisable to achieve an optimum control of inflammation for best results. The increasing reports of the use of MIVS in uveitis have led to its wider acceptance among clinicians practicing uveitis.

Surgical repair of primary non-complex rhegmatogenous retinal detachment in the modern era of small-gauge vitrectomy

OBJECTIVE

To report anatomic and visual outcomes of pars plana vitrectomy (PPV), as well as scleral buckling (SB) and PPV/SB as surgical treatments for the management of primary, non-complex rhegmatogenous retinal detachment (RRD).

METHODS AND ANALYSIS

Data from 751 eyes that underwent PPV, SB or combined PPV/SB as a surgical treatment for primary non-complex RRD with at least 3 months of follow-up were analysed to determine rates of single surgery anatomic success (SSAS) and final anatomic success (FAS). Patients or the public were not involved in the design, conduct or reporting of this research.

RESULTS

PPV accounted for 89.0% (n=668), PPV/SB for 6.8% (n=51) and SB for 4.2% (n=32) cases. Overall SSAS (91.2% PPV, 84.3% PPV/SB, 93.8% SB; p=0.267) and FAS (96.7% PPV, 94.1% PPV/SB and 100.0% SB; p=0.221) were reported for the three surgical groups. SSAS and FAS were similar for lens status, macular detachment status and the presence or absence of inferior retinal breaks for each of the PPV, PPV/SB and SB groups.

CONCLUSIONS

In this large, single institution, retrospective case series, we report surgical outcomes for patients with primary non-complex RRD managed with PPV, SB or PPV/SB in the modern era of small-gauge vitrectomy. We demonstrate that primary PPV without adjunct SB provides excellent anatomic and visual outcomes irrespective of lens status, macular involvement or pathology location.

Effect of prophylactic laser during small-gauge vitrectomy for epiretinal membranes

PURPOSE

To determine the rate of post-operative retinal detachment after elective pars plana vitrectomy for epiretinal membrane, and to test for the mitigating effect of prophylactic endolaser.

METHODS

We identified 459 eyes of 411 patients undergoing vitrectomy for epiretinal membrane at Vanderbilt University Medical Center between January 2010 and May 2017. Patients who underwent concurrent endolaser without any identified retinal break were included in the exposure cohort. Patients who underwent no prophylactic retinopexy or ablation were included in the unexposed cohort. Exposure data, demographic data, and outcome data were tabulated for comparison.

RESULTS

The final analysis included 343 eyes of 343 patients. Approximately 7% of eyes undergoing ERM surgery were found to have a full-thickness retinal break which was not seen preoperatively. The overall rate of postoperative RD was 2.04%. Postoperative retinal detachment occurred in 0 of the 34 eyes exposed to prophylactic laser, and in 7 of the 309 control eyes. Odds ratio was found to be 0.60 (p = 0.598 (95%CI 0.0327-10.7), p = 0.72), indicated the results were not statistically significant.

DISCUSSION

Looking at patients undergoing routine vitrectomy surgery for epiretinal membrane, no retinal detachments occurred in the group receiving prophylactic treatment, though this association did not reach statistical significance. With modern surgical techniques, post-operative retinal detachment remains relatively rare after vitrectomy for ERM though a thorough intraoperative exam is critical to identify occult retinal breaks.

Outcomes of Pars Plana Vitrectomy Alone versus Combined Scleral Buckling plus Pars Plana Vitrectomy for Primary Retinal Detachment

PURPOSE

We compared the outcomes of primary uncomplicated rhegmatogenous retinal detachment (RRD) repair using pars plana vitrectomy (PPV) alone versus combined scleral buckling plus PPV (SB+PPV).

DESIGN

Retrospective, observational study.

PARTICIPANTS

Patients with primary RRD who underwent PPV or SB+PPV from June 1, 2014, through December 31, 2017.

METHODS

We performed a single-institution, retrospective, observational study of 488 consecutive patients with primary RRD repaired via PPV alone or SB+PPV and gas tamponade. We excluded patients younger than 18 years and those with advanced proliferative vitreoretinopathy, giant retinal tear, trauma, or secondary forms of RRD. We performed logistic regression and Cox proportional hazard regression analyses to identify potential risk factors associated with a retinal redetachment.

MAIN OUTCOME MEASURES

Single-operation anatomic success (SOAS), defined as adequate retinal reattachment achieved with only 1 procedure.

RESULTS

The mean follow-up interval was 14.3 months. Single-operation anatomic success and final anatomic success were achieved in 425 eyes (87.1%) and 487 eyes (99.8%), respectively. Single-operation anatomic success was achieved in 90 of 111 eyes (81.1%) with PPV alone compared with 345 of 374 eyes (92.2%) with SB+PPV (P = 0.0010). Scleral buckling plus PPV showed greater SOAS than PPV alone in phakic eyes (P < 0.0001), but not in eyes with a posterior chamber intraocular lens (PCIOL). Retinal redetachments occurred on average at 1.5 and 9 months after the initial surgery. Significant best-corrected visual acuity improvement was associated with SOAS (P < 0.0001).

CONCLUSIONS

Scleral buckling plus PPV resulted in greater SOAS outcomes than PPV alone for primary RRD repair. Phakic eyes achieved greater surgical success with SB+PPV, whereas eyes with a PCIOL achieved similar results with both methods. Most retinal redetachments occurred within the initial postoperative 3-month period. Single-operation anatomic success was associated with statistically significant visual improvement.

Long-term outcomes of vitrectomy for proliferative diabetic retinopathy

PURPOSE

To investigate the long-term outcomes of patients who underwent vitrectomy for proliferative diabetic retinopathy.

METHODS

Cumulative incidences were calculated for low vision (<0.3), re-vitrectomy in the study eye and fellow eye vitrectomy. To identify potential prognostic factors that associate with these outcomes, we used multivariable Cox regression models.

RESULTS

In a total of 217 patients, we found 1-, 5- and 10-year cumulative incidences of low vision in the study eye of 24%, 31% and 39%, respectively. For both eyes, these rates were, respectively, 10%, 14% and 14%. Low vision in both eyes was associated with higher age and worse contralateral visual acuity. The 1-, 5- and 10-year cumulative incidences for re-vitrectomy in the study eye were 16%, 27% and 27%, respectively, and for a vitrectomy in the fellow eye 24%, 40% and 54%, respectively. Re-vitrectomy of the study eye was associated with worse contralateral visual acuity, while vitrectomy of the fellow eye was associated with shorter diabetes duration, worse contralateral visual acuity, higher HbA1c level and worse diabetic retinopathy severity stage of the fellow eye.

CONCLUSION

Functional visual acuity in at least one eye was achieved or preserved in most patients. After 10 years, about a quarter of all patients underwent a re-vitrectomy, while more than half of the patients needed a vitrectomy of the fellow eye. Knowledge of these long-term outcomes is essential when counselling patients for a vitrectomy.

Comparison of Characteristics and Clinical Outcomes in 27-Gauge versus 23-Gauge Vitrectomy Surgery

Purpose

To compare characteristics, clinical outcomes and complication profiles of a cohort of patients undergoing 27-gauge versus 23-gauge vitrectomy surgery at a tertiary medical center in the Middle East.

Methods

This is a retrospective comparative study of indication-matched patients undergoing 27-gauge versus 23-gauge pars plana vitrectomy for a set of predetermined diagnoses. Data including indications for surgery, clinical exams, visual outcomes, and complications were documented and analyzed.

Results

A total of 22 patients who had 27-gauge pars plana vitrectomy were compared with 44 patients who had 23-gauge surgery for matched indications by a single retina surgeon. Mean follow-up was 14 months after surgery. Indications included macular pucker, macular hole, and vitreous hemorrhage. Both the rate of hypotony at postoperative day 1 and the need for sclerotomy stitching at the end of surgery were significantly more frequent in 23-gauge compared to 27-gauge cases (25% in 23-gauge compared to 0% in 27-gauge (p=0.012) and 18% in the 23-gauge compared to 0% in the 27-gauge (p=0.045), respectively). The mean duration of surgery was similar among groups (35 mins in the 27-gauge group versus 39 mins in the 23-gauge group (p=0.116)), and all eyes achieved anatomic success. In the 27-gauge group, best-corrected visual acuity improved from a mean of 20/90 at baseline to a mean of 20/40 at 1 month (p=0.005) and in the 23-gauge group from a mean of 20/95 to 20/50 (p=0.001) with no statistical difference between the groups.

Conclusion

In this cohort of patients undergoing vitrectomy at a tertiary eye center, the rate of hypotony and the need for sclerotomy suturing were significantly less in the 27-gauge group versus the 23-gauge group. Surgical outcomes were similar in both study groups. The use of the novel 27-gauge instrument system is useful in selected vitreoretinal diseases and appears comparable to the widely used 23-gauge system.

A relatively higher intraocular pressure set at the end of vitrectomy is associated with a more stable and rapid visual recovery for patients with vitreous haemorrhage

PURPOSE

To compare structural and functional improvements in patients with vitreous haemorrhage (VH) with different IOPs re-established at the end of pars plana vitrectomy (PPV).

METHODS

It is a prospective, randomized, comparative, interventional study. Ninety-five patients with nonclearing VH were randomized to receive PPV with normalized IOPs of 15 mmHg (Group I: 32 eyes), 25 mmHg (Group II: 32 eyes) and 35 mmHg (Group III: 31 eyes) at the end of surgery. The grade of vitreous opacity and best-corrected visual acuity (BCVA) on postoperative day 1, week 1, month 1 and month 3 were compared with a mixed model for repeated measures analysis.

RESULTS

All 3 groups achieved significant improvement on postoperatively in BCVA (p < 0.01) and vitreous opacity (p < 0.01) compared with the baseline. The group difference was significant at the end of week 1 and showed a trend of higher IOP set at the end of PPV with better anatomical (p < 0.01) and visual recovery (p < 0.01). However, at postoperative month 1 and month 3, equivalent anatomical (month 1: p = 0.56; month 3: p = 0.36) and visual outcomes (month 1: p = 0.16; month 3: p = 0.88) were obtained in the 3 groups. The average effect of IOP on BCVA (group II versus group III: effect size (ES): 0.41, p < 0.01; group I versus group III: ES: 0.66, p < 0.01) and vitreous opacity (group II versus group III: ES: 0.70, p < 0.01; group I versus group III: ES:1.09, p < 0.01) over the course of the study period was statistically significant. The only postoperative complication was recurrent VH in two patients allocating in group I and II, respectively.

CONCLUSIONS

A relatively higher IOP set at the end of vitrectomy resulted in a more stable and rapid recovery with fewer complications in patients with non-complex VH.

Comparative analysis of 23-, 25-, and 27-gauge forceps stiffness and related displacement

PURPOSE

To test the stiffness and displacement of different vitreous forceps. Physical features and deformation after multiple procedures were also measured.

METHODS

Eleven different 23-, 25-, and 27-gauge vitreous forceps were studied. The measurements were repeated loading the probe at different distances from the tip: at the top of the tip and 10 and 20 mm from the tip, respectively. For each probe, 10 successive identical bending tests were performed. The total length and the internal and external diameters of each forceps were also measured.

RESULTS

A total of 330 successive identical bending tests were performed. No progression in deformation after the repeated measurements was recorded (p > 0.05). In each gauge group, displacement differences were detected according to the manufacturing metal properties, the total length, and the thickness of the shaft wall. A minimal adequate model to describes forceps displacements in terms of their significant predictors, such as gauge, model, and load distance from the tip, was created.

CONCLUSION

We provided a precise assessment of the stiffness and displacement of different vitreous forceps to enable surgeons to select the optimal instrument according to the benefits and limitations of each forceps.

Fluid Dynamic Assessment of Hypersonic and Guillotine Vitrectomy Probes in Viscoelastic Vitreous Substitutes

Purpose

To assess the fluidics of 23-gauge (G) large-port (L) and tear drop-port (TD) hypersonic vitrectomy probes (HVPs) compared with guillotine vitrectomy probes (GVPs) of various calibers (23G, 25G, and 27G) and geometries (single and double blades). Also, to identify the working parameters that provide the best balance between acceleration and flow rate, and, for HVPs, to measure temperature variations in the fluid.

Methods

We used particle image velocimetry to measure flow fields in balanced salt solution and viscoelastic artificial vitreous. We analyzed acceleration, kinetic energy, and volumetric flux. The parameters considered were vacuum pressure, ultrasound stroke, and cut rate. Temperature measurements were taken using an infrared thermal camera.

Results

The flow rate was significantly higher for HVPs than GVPs. With both probes, flow rate and acceleration increased with vacuum pressure. Flow rate depended weakly on the ultrasound stroke or cut rate. In HVPs, the acceleration peaked at a stroke of 30 µm, whereas in GVPs it peaked at a cutting rate of 4000 to 5000 cuts per minute (cpm). The HPV/TD combination generated higher flow rates and lower accelerations than did HPV/L. The increase in temperature was small.

Conclusions

Under the present experimental setup and medium, HVPs offered better fluidics compared with GVPs in terms of flow and acceleration; however, the flow structure for HVPs is more complicated and unsteady. The HPV/TD combination produced larger flows than did the HPV/L combination and slightly smaller accelerations. HPVs generated a small temperature increase.

Translational Relevance

In the tested artificial vitreous, HVPs were found to be more efficient in terms of generating lower acceleration for a given flow rate. The slight increase in temperature observed with HVPs is unlikely to be clinically significant.

Sutureless intrascleral fixation using different three-piece posterior chamber intraocular lenses: a literature review of surgical techniques in cases of insufficient capsular support and a retrospective multicentre study

We present a literature review of surgical techniques of intraocular lens placement in eyes with insufficient capsular support, focusing on the most recent publications, together with a retrospective multicentre consecutive case series analysis of 103 eyes undergoing pars plana vitrectomy and sutureless intrascleral (SIS) fixation of a standard three-piece PCIOL. Many different approaches appear in the literature without any specific procedure achieving superior outcomes. Advantages and disadvantages vary between techniques. Common complications related to IOL fixation techniques were as follow: anterior chamber IOL: transient/permanent corneal oedema (9-66.6%), uveitis (1.1-39.3%); iris-fixated IOL: pupil ovalization (16-47.7%); and sutured scleral-fixated IOL: suture breakage/exposure (6.1-11%), vitreous haemorrhage: (5.5-16.6%). In our retrospective case series, indications for surgery were postoperative aphakia in 50 eyes (49%), IOL dislocation in 38 eyes (37%) and natural lens dislocation in 15 eyes (14%). Scleral tunnels for haptic fixation were created with (28 eyes, 27.2%) or without (75 eyes, 72.8%) 25 gauge trocar cannulas. Complications included transient hypotony (n = 20; 19.4%), corneal decompensation (n = 7; 6.7%), IOL dislocation (n = 6; 5.8%), cystoid macular oedema (n = 5; 4.8%), vitreous haemorrhage (n = 4; 3.8%) and retinal detachment (n = 4; 3.8%). Mean best corrected visual acuity improved from logMAR 0.65 to 0.36 at the final visit (p = 0.001). In conclusion, SIS fixation provides good anatomical and functional outcomes; however, complications can occur. The number of surgical approaches for IOL dislocation described in the literature indicates that optimal treatment remains to be found.

Critical analysis of techniques and materials used in devices, syringes, and needles used for intravitreal injections

Intravitreal injections have become the most commonly performed intraocular treatments worldwide. Because intravitreal injections may induce severe adverse events, such as infectious and noninfectious endophthalmitis, cataract, ocular hypertension, vitreous hemorrhage, or retinal detachment, appropriate awareness of the materials and techniques used are essential to reduce these sight-threatening complications. This review provides insights into the needles, syringes, silicone oil coating, sterilization methods, devices to assist intravitreal injections, scleral piercing techniques using needles, syringe handling, anesthesia, and safety issues related to materials and techniques. It is paramount that physicians be aware of every step involved in intravitreal injections and consider the roles and implications of all materials and techniques used. The ability to understand the theoretical and practical circumstances may definitely lead to state-of-the-art treatments delivered to patients. The most important practical recommendations are: choosing syringes with as little silicone oil as possible, or, preferably, none; avoiding agitation of syringes; awareness that most biologics (e.g., antiangiogenic proteins) are susceptible to changes in molecular properties under some conditions, such as agitation and temperature variation; understanding that improper materials and techniques may lead to complications after intravitreal injections, e.g., inflammation; and recognizing that some devices may contribute to an enhanced, safer, and faster intravitreal injection technique.

Hybrid 23/27 Gauge Vitrectomy - Combining the Charm of 27G with the Efficacy of 23G

Background

Minimally invasive transconjunctival sutureless vitrectomy (MIVS) has evolved into the standard of care, smaller incisions thought to result in lower ocular surface trauma and shorter times to recovery. The currently most relevant limitations in macular surgery may be light intensity and 27G instrument stability. Therefore, we thought to compare standard 23 and 27G vitrectomy with a hybrid technique using one 23G and two 27G ports regarding surgical times and short-term outcomes.

Methods

This retrospective comparison included 90 single-center consecutive cases of eyes undergoing elective micro-invasive vitrectomy for epiretinal membranes or idiopathic macular holes between October 2017 and June 2018. The main criteria for the comparison were total surgical time as primary outcome parameter and treatment-demanding intra- and postoperative complications along with recovery of best-corrected visual acuity (BCVA) and central retinal thickness (CRT) from prior to surgery to 1 month thereafter as secondary parameters as independent parameters for the recovery from the pre-existing pathology and the surgical trauma.

Results

Surgical times were shorter with 23G and 23/27G compared to 27G (23G: 38.4±13.1; 27G: 48.1±15.3; 23/27G: 34.9±9 mins; p=0.0005) with no differences in BCVA and CRT outcomes. Switching from 27G to a larger port size was not necessary in any instance. Cryotherapy was applied in 15%, 30%, and 22.5% to suspected retinal pathologies, beyond these, in 5%, 0%, and 7.5% for retinal tears. Four postoperative retinal detachments occurred (4.4%), one in the 23G and three in the 23/27G group requiring re-vitrectomy.

Conclusion

In this exploratory case series, 23/27G hybrid vitrectomy, combining the advantages of 23G and 27G techniques, resulted in shorter surgical times without evident disadvantages. The combination with cataract surgery was unproblematic.

The 100 Most Cited Articles on Vitrectomy: A Bibliographic Perspective

PURPOSE

To analyze the 100 most-cited articles on pars plana vitrectomy (PPV).

DESIGN

Bibliographic study.

METHODS

Literature search using the bibliographic databases of the ISI Web of Knowledge, limited to research articles published between 1971 and 2018 in peer-reviewed journals of ophthalmology.

MAIN OUTCOME MEASURE

Number of citations since publication.

RESULTS

The 100 most-cited articles on PPV were published in 11 different ophthalmology journals, with 73 of them published in Ophthalmology (n = 31), American Journal of Ophthalmology (n = 26), and Archives of Ophthalmology (n = 16). They originated from 14 different countries, predominantly from the United States (n = 64), and 99 of them were written in English. Their topics cover a wide spectrum of retinal conditions that vary from decade to decade as the technique of PPV evolved and became applicable to more indications.

CONCLUSIONS

This bibliographic study provides a unique historic perspective of the development of PPV and its applications from its introduction to its current status.

Prevalence of silicone oil droplets in eyes treated with intravitreal injection

Objective

To assess the number of eyes with silicone oil in the vitreous after intravitreal injection.

Methods

This cross-sectional, comparative study was divided into 2 groups: (1) treatment—eyes subjected to antiangiogenic therapy; (2) control—no history of intravitreal injection. Subjects were assessed regarding age, gender, clinical diagnosis, lens status, visual acuity and number of previous intravitreal injections. All eyes underwent a meticulous slit-lamp and ultrasound examination for the identification of silicone oil. ImageJ software was used to quantify the index of silicone oil (IOS) by ultrasonography.

Results

Sixty-seven eyes (30 controls, 37 treated) were included. Slit-lamp examination found silicone oil droplets in 25 out of 37 (67.57%) treated eyes and in none of the control group. Ultrasonography identified silicone oil in 28 out of 37 (75.68%) treated eyes and in 1 out of 30 (3.33%) controls. An observed agreement of 85.07% and a Cohen’s Kappa coefficient of 69.10% (p < 0.0001) between ultrasonography and biomicroscopy were found. Wilcoxon test showed a statistically significant difference (p = 0.0006) in IOS between controls (0.41 ± 0.43%) and treated eyes (2.69 ± 2.55%). Spearman’s correlation test (0.61; p < 0.0001) showed that the greater the number of injections, the higher the IOS.

Conclusions

Silicone oil droplets were found in the majority of the eyes previously treated with antiangiogenic intravitreal injection. The greater the number of injections, the higher the likelihood of finding silicone oil. An improvement in the technique of injection and better-quality syringes post-injection silicone oil droplets.

Patients' Experience of Anxiety and Pain during Retrobulbar Injections prior to Vitrectomy

Purpose

The purpose of this study was to evaluate the correlation between pain associated with retrobulbar block and anxiety levels before the injection.

Methods

This prospective observational, noninterventional study included consecutive patients who received a retrobulbar block by a single surgeon prior to undergoing 25G PPV at the Department of Ophthalmology, Rambam Health Care Campus, between April 2016 and August 2017. Patients plotted their anxiety levels (scale 0–10) using the visual analogue scale for anxiety (VASA), and immediately after receiving the injection, they plotted their experienced level of pain (scale 0–10) using the visual analogue scale for pain (VAS), with scores ≥7 defined as severe.

Results

Overall, 48 eyes of 48 patients aged 68.4 ± 10.3 years were included, of which 62.5% were of male gender. Severe anxiety and pain were experienced by 10.4% and 12.5%, respectively. There was a significant correlation between VASA and VAS scores (r = 0.43, p=0.002) with no other preprocedural parameters demonstrating a significant association with the VAS score. In multivariate analysis, the VASA score was the only factor that was significant (p=0.01), and a patient with a severe VASA score was 20 times more likely of experiencing severe pain (p=0.006). The ROC curve analysis revealed an area under the curve of 0.89 (p < 0.001), and a VASA score >4 demonstrated a sensitivity of 83.3% and a specificity of 73.8% in predicting severe pain.

Conclusions

Approximately 10% of patients experience severe anxiety and pain during retrobulbar blocks. Considering the importance of compliance, reducing anxiety and premedication may be considered, particularly in high-risk patients (VASA score > 4).

Design Parameters for a Small-Gauge Fragmatome

Purpose

Manufacturers of surgical instrumentation have increasingly sought to decrease the size of ophthalmic surgical instruments. We have used finite element modeling to model the stress and strain present in a fragmatome as a function of driving frequency and fragmatome dimensions.

Methods

Finite element calculations using the COMSOL Multiphysics system v3.5 were used to elucidate the influence of wall thickness, length, and excitation frequency on a titanium fragmatome tube with outer diameters of 20, 23, 25, and 27 gauge.

Results

By coupling structural mechanics, fluid mechanics, and acoustical physics, we were able to determine the eigenfrequencies (resonant frequencies) as well as parameters in which the von Mises stress in a fragmatome tube exceeds the yield strength, leading to destruction of the instrument.

Conclusion

Solid fragmatomes have far fewer possible failure modes than fragmatomes with a standard wall thickness. Eigenfrequency analysis and finite element calculations can be critical in predicting potentially catastrophic designs in modern surgical instruments.

Translational Relevance

Instruments developed for microsurgical applications cannot always simply be scaled down versions of conventional instruments. Such an approach can lead to potentially dangerous intraoperative failures, such as a fragmatome shattering inside the eye. Modern engineering techniques are increasingly necessary to investigate potential instrument failure mechanisms and to optimize device performance in a design in silico before in vivo testing.

The effect of multiple vitrectomies and its indications on intraocular pressure

Background

To assess the relationship between different indications for trans pars plana vitrectomies (PPV’s) and the intraocular pressure (IOP), and the effect of multiple PPV’s on the IOP. We also examined whether there were differences in the number of IOP-lowering medications or surgeries before and after PPV.

Methods

A retrospective study including all patients that underwent at least one PPV in the period from 2001 till 2014 at our clinic. Medical records of all patients were reviewed and clinically relevant data were entered in a database. Generalized estimating equations models for repeated measurements were used to examine the effect of the number of PPV’s on the IOP and on the risk of undergoing glaucoma surgery, for each of the indications for PPV.

Results

Of 1072 PPV’s 447 eyes fulfilled the inclusion criteria. The IOP increased with 3.0 mmHg after a PPV with indication retinal detachment (p < 0.001), but remained stable after PPV for epiretinal membrane (p = 0.555), macular hole (p = 0.695), and vitreous hemorrhage (p = 0.787). At the end of the follow-up period the number of IOP-lowering medications was significantly higher compared to baseline, except in the macular hole group (p = 0.103). Also, the number of eyes that underwent glaucoma surgery was significantly higher compared to the fellow (not-operated) eyes (p < 0.001). There was a significant association between the number of PPV’s and the final IOP for the indication retinal detachment (p = 0.009), and between the number of PPV’s and glaucoma surgery (odds ratio [95% confidence interval]: 2.60 [1.62–4.15]).

Conclusions

The IOP rises significantly after PPV with indication retinal detachment. This association was not found for other indications for PPV. Also, the risk of IOP-lowering surgeries was higher after PPV, but not different between the PPV indications. The IOP should be monitored carefully after PPV, since there may be a higher risk of secondary glaucoma.

IN VITRO FLOW ANALYSIS OF NOVEL DOUBLE-CUTTING, OPEN-PORT, ULTRAHIGH-SPEED VITRECTOMY SYSTEMS

PURPOSE

To analyze the performance and flow characteristics of novel double-cutting, open-port, 23-, 25-, and 27-gauge ultrahigh-speed vitrectomy systems.

METHODS

In vitro fluidic measurements were performed to assess the volumetric aspiration profiles of several vitrectomy systems in basic salt solution and egg white.

RESULTS

Double-cutting open-port vitrectomy probes delivered stable aspiration flow rates that were less prone to flow variation affected by the cutting speed. Increase in cutting frequency to the maximum level resulted in flow reduction of less than 10% (0.0%-9.5%). Commercially available 23-, 25-, and 27-G double-cutting probes exhibited higher egg-white and basic salt solution flow rates at all evaluated cut rates, with aspirational efficiencies being 1.1 to 2.9 times the flow rates of standard single-blade vitrectomy probes of the same caliber at the maximum preset vacuum. The highest relative differences were observed at faster cut rates.

CONCLUSION

The newly introduced double-cutting open-port vitrectomy probes delivered stable aspiration flow rates that were less prone to flow variation affected by the cutting speed. The fluidic principle of constant flow even at the highest cut rates and low vacuum levels might impact surgical strategies, especially when performing manipulations close to the retina.

Idiopathic epiretinal membrane surgery: safety, efficacy and patient related outcomes

This review aims to give to the reader an overview selectively oriented on safety and efficacy of surgery, providing concise and direct answers about crucial questions of trainees and experts. Surgery for idiopathic epiretinal membrane (ERM) is a safe and effective procedure that can achieve long-term stable postoperative visual and anatomical improvement, with an overall low recurrence and complication rate. Young patients, with a short onset of symptoms and with better initial visual acuity achieve higher levels of visual outcome. The preoperative degree of metamorphopsia is the prognostic factor for their postoperative degree. Successful results may be obtained in eyes with specific optical coherence tomography criteria, such as thin ganglion cell layers, thin internal plexiform layer, longer photoreceptors outer segment, regular ellipsoid zone and cone outer segment tips line, and without ectopic inner foveal layer. Internal limiting membrane peeling demonstrates positive anatomical and functional outcomes, but final positions about its safety remain controversial.

VISUAL AND ANATOMICAL OUTCOMES AFTER DIABETIC TRACTION AND TRACTION-RHEGMATOGENOUS RETINAL DETACHMENT REPAIR

PURPOSE

To evaluate visual and anatomical outcomes of diabetic tractional retinal detachment repaired with pars plana vitrectomy.

METHODS

Operative records were used to retrospectively identify all patients with tractional retinal detachments secondary to proliferative diabetic retinopathy surgically repaired with pars plana vitrectomy between November 1, 2009, and January 1, 2015 at the LAC + USC (Los Angeles County + University of Southern California) Medical Center.

RESULTS

A total of 403 eyes with diabetic tractional retinal detachment in 359 patients were included. Successful reattachment of the retina was achieved in 87.6% of eyes after one surgery and 92.6% of eyes at the final follow-up. Best-corrected visual acuity at the final follow-up improved two or more lines in 56.3% of eyes, was stable in 23.8% of eyes, and decreased two or more lines in 19.9% of eyes. Eyes repaired with 23-gauge and 25-gauge vitrectomy systems had similar success rates as eyes treated with 20-gauge instrumentation (P = 0.73). Eyes receiving silicone oil tamponade had lower single-surgery reattachment rates (77.6% vs. 87.6%; P = 0.013), lower reattachment rates at the final follow-up (85.7% vs. 92.6%; P = 0.048), and higher rates of vision loss (34.7% vs. 19.9%; P < 0.0001) but were more likely to have concurrent rhegmatogenous detachment (47.0% vs. 21.3%; P < 0.0001) and macula involving detachment (74.5% vs. 60.0%; P < 0.0001).

CONCLUSION

In this large, single-center retrospective study of patients with advanced diabetic tractional retinal detachment, vitrectomy achieved excellent anatomical outcome and improved or stabilized vision in 80.1% of eyes. Smaller gauge vitrectomy systems were found to have similar outcomes to 20-gauge instrumentation.

Outcomes of 25-gauge vitrectomy with relaxing retinectomy for retinal detachment secondary to proliferative vitreoretinopathy

Purpose

The aim of this study is to evaluate visual and anatomic outcomes of 25-gauge vitrectomy with relaxing retinectomies for complex retinal detachment (RD) secondary to proliferative vitreoretinopathy (PVR).

Methods

A single-center, retrospective case series of 44 patients who had undergone a 25-gauge vitrectomy with a relaxing retinectomy for the treatment of combined RD and PVR was performed. Pre-operative characteristics, intraoperative techniques, and outcomes were analyzed. The rates of attachment, complications, and visual acuity were analyzed. Institutional Review Board/Ethics Committee approval was obtained and the described research adhered to the tenets of the Declaration of Helsinki.

Results

At the final follow-up, 27 eyes (61%) had attachment after one surgery, 41 eyes (93%) ultimately had attached retinas, 3 eyes (7%) had hypotony, 3 eyes had become phthisical (7%), and 24 eyes (56%) had improved visual acuity. After stratifying by visual outcomes, 20/400 or better BCVA was not associated with age (p=0.66), RD etiology (p=0.61), pre-operative hypotony (p=0.60), nor size of retinectomy (p=0.48). Patients achieving 20/400 vision or better were statistically more likely to be pseudophakic (p=0.024) and have silicone oil removal (p<0.0001).

Conclusions

The use of 25-gauge vitrectomy and relaxing retinectomy provides a high rate of reattachment and improved visual acuity.

Release of silicone oil and the off-label use of syringes in ophthalmology

BACKGROUND/AIMS

To assess silicone oil (SO) release by different brands of syringes used for intravitreal injection under different handling conditions.

METHODS

Eight syringes were analysed: from the USA, Terumo 0.5 mL, Becton-Dickinson (BD) Tuberculin 1 mL, BD Luer-lok 1 mL, BD Ultra-Fine 0.3 mL and Exel Insulin 0.3 mL; from Germany, Braun Omnifix-F 1 mL and Braun Injekt-F 1 mL and from Spain, BD Plastipak 1 mL. The impact of air, priming the plunger, agitation by flicking and fluid temperature on SO release were assessed by light microscopy. Fourier transform infrared spectroscopy (FTIR) was performed to identify the molecular compound in each syringe.

RESULTS

Five hundred and sixty syringes were analysed. Terumo 0.5 mL and BD Ultra-Fine 0.3 mL released more SO than all others. BD Luer-lok 1 mL, BD Plastipak and Braun Omnifix-F 1 mL released little SO; BD Tuberculin 1 mL, Exel 0.3 mL and Braun Injekt-F 1 mL released the least SO. Priming the syringe and different temperatures did not significantly affect SO release. Agitation by flicking caused a significantly higher proportion of samples to have SO droplets and an increased number of oil droplets. Air had an additive effect on the release of oil in the agitation groups. FTIR identified polysiloxane in all syringes but Injekt-F.

CONCLUSION

Syringes commonly used for intravitreal injections frequently release SO droplets, especially when agitated by flicking. To avoid unnecessary ocular risks, syringes should not be agitated before intravitreal injection. It is desirable that syringes be manufactured specifically for ophthalmic use.

Release of silicone oil droplets from syringes

BACKGROUND

Intravitreal silicone oil droplets have been found in the vitreous. The aim of this study is to compare the rates of silicone oil released by different brands of commonly used syringes for intravitreal injection after agitation by flicking.

METHODS

Three models of two brands of syringes were analyzed for their rates of silicone oil release: Saldanha Rodrigues (SR) 1 mL insulin syringe (SR, Brazil, syringe 1), Becton-Dickinson (BD) Plastipak 1 mL insulin syringe (Brazil, syringe 2), and BD Safety-Glide 1 mL insulin syringe (USA, syringe 3). All syringes were tested under four different conditions: positive control (fluid with addition of silicone oil) without agitation (group 1, n = 5); positive control with agitation (group 2, n = 3); fluid only without agitation (group 3, n = 5); and fluid only with agitation (group 4, n = 5). Masked graders performed all analyses using light microscopy.

RESULTS

All syringes (1, 2, and 3) released silicone oil droplets in the positive control group regardless of the agitation status (groups 1 and 2). When no oil was added and the syringes were not agitated, only syringe 1 released silicone oil droplets (40% of samples). After agitation, syringes 1 and 3 released silicone oil droplets in all samples. Quantitative analysis showed a significantly (P = 0.011; 11.2 ± 2.9 vs. 0.6 ± 0.9, respectively) higher mean number of silicone oil droplets released by syringe 1 after agitation compared to no agitation. Syringe 1 also had significantly (P = 0.002, 11.2 ± 2.9 vs. 0.0 ± 0.0 vs. 2.2 ± 0.8, respectively) more droplets than syringes 2 and 3 after agitation.

CONCLUSIONS

Syringes commonly used for intravitreal injections frequently release silicone oil droplets when agitated by flicking, especially the SR insulin ones. We recommend that they not be agitated at the time of intravitreal injection and that the manufacturers consider producing syringes adapted for intraocular use.

Fluidics of Single and Double Blade Guillotine Vitrectomy Probes in Balanced Salt Solution and Artificial Vitreous

PURPOSE

To assess the fluidics of double-vitreous cutter blade (DB) compared with single-blade (SB) guillotine with 23-, 25-, and 27-gauge vitrectomy probes. To assess flow characteristics and flow rates in viscous and viscoelastic fluids.

METHODS

We used Particle Image Velocimetry to measure the flow field close to the tip of each cutter probe and we derived kinematic quantities of interest, such as kinetic energy and acceleration. We performed measurements both on a balanced salt solution (BSS) and on a viscoelastic artificial vitreous (AV).

RESULTS

The flow rate is significantly higher with DB than SB vitrectomy probes, for a given pumping pressure and cutting rate. The fluid flow observed is very different between BSS and AV tests.

CONCLUSIONS

The DB has more efficient fluidics than SB vitrectomy probe in all tested conditions. Fluid acceleration depends on the cutting frequency, especially in the case of measurements in AV. The flow rate strongly depends on the pressure and it is little affected by the cutting frequency, in a range of clinical interest. The 27-G DB produces flow rates similar to the 23- and 25-G SB, with significantly smaller acceleration. The flow induced in the AV is different from that in BSS and oscillates at different frequencies.

TRANSLATIONAL RELEVANCE

DB cutters prove to be more efficient in terms of lower acceleration for a given flow rate. The latter is mainly controlled by aspiration pressure and less by cut rates. The influence of vitreous rheology deserves further investigations.

FIRST-IN-HUMAN CLINICAL STUDY TO INVESTIGATE THE EFFECTIVENESS AND SAFETY OF PARS PLANA VITRECTOMY SURGERY USING A NEW HYPERSONIC TECHNOLOGY

PURPOSE

Investigate the effective performance and safety of a new hypersonic vitrector technology.

METHODS

Postapproval, prospective, single-arm, noncomparative, open-label study at one clinical site in India.

INDICATIONS

macular hole (9/20), vitreous hemorrhage (7/20), vitreomacular traction (3/20), and vitreomacular traction with pseudomacular hole (1/20). Safety endpoints included intraoperative and postoperative adverse events. Effective performance endpoints were surgeon-rated effectiveness, range of surgical time, and device settings. Other performance measures were preoperative and postoperative best-corrected visual acuity, slit-lamp and indirect ophthalmoscopy, applanation tonometry, color fundus photography, fundus fluorescein angiography, and spectral domain optical coherence tomography.

RESULTS

Core vitreous removal (20/20 subjects), peripheral vitreous removal (18/20), and posterior vitreous detachment induction (13/15) surgeries were successfully completed. Total surgical time was 22.5 minutes to 106 minutes. Serious adverse events through 3 months were 2 device-associated retinal tears and detachment (one intraoperative) and one unrelated postoperative enlargement of macular hole with subretinal fluid.

CONCLUSION

This first-in-human study suggests that this new hypersonic vitrector technology is a promising alternative to commercially available guillotine vitrectors. The hypersonic vitrector was effective in core vitreous removal in all cases. Larger-scale studies are required to expand on our initial findings for induction of a posterior vitreous detachment or peripheral vitrectomy.

Application of Laser Flare Photometry in the Quantification of Blood-Aqueous Barrier Breakdown after Micro-incision Vitrectomy

Purpose: The purpose of the study is to quantify aqueous flare using laser flare photometry (LFM) in patients undergoing 25-G pars plana vitrectomy (PPV) and assess the need for postoperative topical corticosteroid administration . Methods: Prospective evaluation of 50 eyes (50 patients) was performed using LFM until day 30 postoperative. Duration of surgery, indication of PPV, and use of laser and/or cryotherapy were noted. Topical corticosteroids were used if mean LFM values were >50, or if there was anterior chamber fibrin. Results: Mean age of the subjects was 48.62 ± 10.07 years. The preoperative LFM value for 50 subjects was 17.42 ± 25.20. Topical corticosteroids were initiated in only 22 patients. The LFM values of subjects were not different from baseline at 1 month whether or not the subjects received corticosteroids (p > 0.106). Conclusions: With 25-G PPV, there is minimal breakdown of blood-aqueous barrier. LFM helps in monitoring postoperative inflammation, obviating the need for topical corticosteroids in significant number of patients.

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.

Hybrid 20/23-G pars plana vitrectomy in endophthalmitis and trauma: a strategic approach

PURPOSE

To assess the safety and efficacy of hybrid vitreous surgery combining active 23-G ports with a sutured 20-G 6-mm infusion cannula for performing vitrectomy in endophthalmitis and trauma.

METHODS

This is a retrospective analysis of 10 eyes with endophthalmitis and 10 eyes with trauma requiring vitreous surgery, having corneal clarity suitable for vitrectomy and best-corrected visual acuity (BCVA) greater than or equal to light perception. All patients underwent hybrid 20/23-G vitrectomy. Intraoperative notes were analyzed for peroperative complications. The BCVA and retinal status at 3 months were analyzed.

RESULTS

In the endophthalmitis group, patients ranged from 5 to 85 years of age and showed varied etiologies. Retinal detachment was present in 5 eyes, which received silicone oil tamponade. Mean preoperative logMAR visual acuity (VA) was 2.29 ± 0.45, which improved to 1.10 ± 0.72 at 3 months postoperatively (p<0.001). Trauma cases ranged from 21 to 75 years of age. Retinal detachment was present in 9 out of 10 eyes, all of which received silicone oil tamponade. Preoperative logMAR VA was 2.26 ± 0.71, which improved to 1.33 ± 0.50 postoperatively (p<0.001). At 3 months postsurgery, the retina was attached in all eyes in both groups.

CONCLUSIONS

The longer sutured 20-G cannula was easier to visualize through fibrin, exudates, and hemorrhage and did not slip out or enter the suprachoroidal space in any of our cases. The 23-G active ports and vitrectomy cutter enhanced safety and efficacy. Hybrid vitrectomy enabled safe surgery in these difficult cases.

Outcomes of transconjuctival sutureless 27-gauge vitrectomy for stage 4 retinopathy of prematurity

AIM

To report our initial experience with lens-sparing vitrectomy for stage 4 retinopathy of prematurity using the 27-gauge (G) system.

METHODS

This retrospective case series involved nine eyes of five babies with active stage 4 ROP, who underwent 27-G lens-sparing vitrectomy. Surgery was done using 27-G valved cannulas and sclerotomies were made 1.5 mm from the limbus. Bilateral sequential vitrectomy was done in eight eyes.

RESULTS

At one-year follow-up, anatomical outcome was favourable in all nine (100%) eyes. High-speed cutting and smaller sclerotomies were helpful in reducing the intra and post-operative complications.

CONCLUSION

27-G vitrectomy is well suited for stage 4 ROP surgeries.

Transscleral tunnel incision related arterial hemorrhage in 23-gauge Vitrectomy: case report

BACKGROUND

Transscleral tunnel incisions are commonly made to avoid postoperative leakage in small gauge sutureless vitrectomy. We present an unreported intraoperative complication, tunnel incision related arterial hemorrhage from sclerotomy, in 23-gauge (23G) vitrectomy.

CASE PRESENTATION

Two cases of intraocular arterial hemorrhage from superonasal sclerotomy were observed at the beginning of vitrectomy. The bleeding filled the vitreous cavity quickly and gushed out from the incision port after the involved supronasal cannula was removed. The active bleeding seemed not to stop spontaneously. We controlled the active bleeding by relocating the involved cannula, elevating the intraocular pressure and compressing the sclera wound. Post-operative intraocular hemorrhage from the sclerotomy was not found in any of the two cases.

CONCLUSIONS

We suggest that the bleeding was from injured ciliary artery when the incision crossed 3 or 9 o'clock accidently. Surgeons might avoid this complication by locating the superior incisions away from the horizontal axis, and should be aware the proper management.

Special considerations for pediatric vitreoretinal surgery

In this review, the authors present special considerations a vitreoretinal surgeon should take into account before embarking on surgery in a pediatric eye. First, the anatomy of a pediatric eye is different from an adult and changes as the child grows. This is important especially in relation to the placement of transconjunctival ports. The structural characteristics of the sclera are also different, with lower scleral rigidity found in pediatric eyes. When considering vitrectomy, a posterior pars plicata lens-sparing technique should be considered. However, this may not be possible in complicated total detachments where anterior translimbal vitrectomy may be the method of choice. Scleral buckles are preferred for certain cases, and division of the encirclage is advocated in children below the age of 2 years, once the retina has stabilized. Enzymatic vitreolysis has been described as a preoperative adjunct to enhance complete detachment of the posterior hyaloid and reduce iatrogenic retinal breaks. However, its use in pediatric eyes has been limited, and larger studies are warranted. Finally, postoperative visual rehabilitation and treatment of amblyopia are key to maximizing functional outcomes in the pediatric patient. Co-management with a pediatric ophthalmologist and enlisting the co-operation of the parents are essential.

Twenty-seven-gauge vitrectomy for combined tractional and rhegmatogenous retinal detachment involving the macula associated with proliferative diabetic retinopathy

Background

To report our experience using 27-gauge pars plana vitrectomy (PPV) system for treating patients with combined tractional and rhegmatogenous retinal detachments (CTRRD) involving the macula associated with proliferative diabetic retinopathy (PDR).

Methods

Retrospective noncomparative interventional cases series of 12 patients with CTRRD associated with PDR who underwent 3-port, transconjunctival 27-gauge PPV by a single surgeon. Main outcome measures were change in Snellen best corrected visual acuity (BCVA) and occurrence of intra- and post-operative complications.

Results

Twelve eyes from 12 patients (9 men and 3 women) underwent 27-gauge PPV. Mean follow-up was 17 months (range 8–26 months). Preoperatively, BCVA of 20/400 or better was recorded in only 2 of 12 (16.7%) eyes. Postoperatively, BCVA improved to 20/400 or better in 11 of 12 (91.7%) eyes at 6 months (P = 0.001). At last follow-up, BCVA of 20/400 or better was recorded in 10 of 12 (83.3%), in comparison to 2 (16.7%) eyes at baseline (P = 0.004). The only intraoperative complication was an iatrogenic break in 1 eye (8.3%). Postoperative complications included vitreous hemorrhage in 4 eyes (33.3%) and transient ocular hypertension in 3 eyes (25.0%). At final follow-up anatomic success was confirmed in all eyes.

Conclusion

The current study findings suggest that 27-gauge PPV is a safe and promising surgical technology for treating patients with CTRRD involving the macula associated with PDR. Smaller gauge instruments and higher cutting rates may facilitate the dissection and shaving of fibrovascular membranes, while minimizing intra- and post-operative complications.

Electronic supplementary material

The online version of this article (doi:10.1186/s40942-017-0091-x) contains supplementary material, which is available to authorized users.