Review of Small Gauge Vitrectomy: Progress and Innovations

Tap and inject of intravitreal antibiotics versus pars plana vitrectomy for post-cataract surgery endophthalmitis: a meta-analysis

BACKGROUND

The efficacy and safety of initial tap and inject (T/I) compared with pars plana vitrectomy (PPV) for acute postoperative bacterial endophthalmitis following cataract surgery is unclear. Understanding the comparative safety and efficacy of initial T/I and initial PPV can provide context for treatment decision making in this setting.

METHODS

A systematic literature search was performed on Ovid MEDLINE, EMBASE, and the Cochrane Library from January 1990 to January 2021. Comparative studies reporting on final best-corrected visual acuity (BCVA) following initial T/I or PPV in patients with infectious endophthalmitis secondary to cataract surgery were included. Cochrane's Risk of Bias in Non-Randomized Studies of Interventions (ROBINS-I) was used to evaluate the risk of bias, and GRADE criteria were used to assess certainty of evidence. A random-effects model was used for meta-analysis.

RESULTS

Seven nonrandomized studies reporting on 188 eyes at baseline were included in this meta-analysis. Initial T/I achieved a significantly better BCVA at last study observation than initial PPV (weighted mean difference [WMD] = -0.61 logMAR; 95% CI, -1.19 to -0.03; p = 0.04; I2 = 89%; n = 7 studies; GRADE = very low). The incidence of enucleation was similar between initial T/I and initial PPV (risk ratio [RR] = 0.73; 95% CI, 0.09-6.25; p = 0.78; I2 = 4%; n = 2 studies; GRADE = very low). The risk of retinal detachment was similar between treatment modalities (RR = 0.29; 95% CI, 0.01-5.94; p = 0.42; I2 = 52%; n = 2 studies; GRADE = very low).

CONCLUSIONS

The quality of evidence in this setting is limited. T/I had a significantly better BCVA at last study observation than initial PPV. Safety profiles were similar between T/I and PPV.

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.

Primary Vitrectomy versus Tap and Inject for Fungal Endophthalmitis: Meta-Analysis and Comparison with Data from a Reference Centre

PURPOSE

We aimed to compare the visual outcomes after pars plana vitrectomy (PPV) versus tap and inject (T&I) in fungal endophthalmitis (FE) reported in the literature and to compare the findings from the literature with data from a reference centre.

METHODS

We performed a systematic review and meta-analysis of studies reporting the use of PPV versus T&I in FE. We also performed a retrospective review of the clinical records of patients with endophthalmitis from a reference centre in Colombia.

RESULTS

We included 13 studies with 334 eyes; 53.59% received PPV and 46.4% received T&I. The overall relative risk of improving ≥ 2 lines in PPV versus T&I was 0.98 (95% confidence interval [CI] 0.80-1.22; p = 0.88) with a mean difference of final visual acuity of 0.26 (95% CI 0.12-0.63; p = 0.18). There were no significant differences in subgroup analysis. Data from the reference centre included 32 endophthalmitis cases, 15.6% of which had a fungal aetiology (80% received PPV and 20% T&I). There were no significant differences in the subgroup analysis.

CONCLUSIONS

Based on the findings from the literature and the reference centre, T&I is noninferior to PPV. This is the first meta-analysis in the literature evaluating these effects in FE. It is necessary to execute new prospective randomised controlled studies in patients with endophthalmitis.

Comparison of cognitive workload and surgical outcomes between a three-dimensional and conventional microscope macular hole surgery

BACKGROUND

Performing a surgical task subjects the surgeon to multitudinal stressors, especially with the newer 3D technology. The quantum of cognitive workload using this modern surgical system in comparison to the Conventional microscope system remains unexplored. We evaluate the surgeon's cognitive workload and the surgical outcomes of macular hole(MH) surgery performed on a 3D versus a Conventional microscope operating system.

METHODS

50 eyes of 50 patients with MH undergoing surgery using the 3D or Conventional microscope visualization system. Cognitive workload assessment was done by real-time tools(Surgeons' heart rate [HR] and oxygen saturation[SPO2]) and self-report tool(Surgery Task Load Index[SURG-TLX] questionnaire) of three Vitreoretinal surgeons. Based on the SURG-TLX questionnaire, an assessment of the workload was performed.

RESULTS

Of the 50 eyes, 30 eyes and 20 eyes underwent surgery with the Conventional microscope and the 3D system, respectively. No difference was noted in the MH basal-diameter(p = 0.128), total surgical-duration(p = 0.299), internal-limiting membrane(ILM) peel time(p = 0.682), and the final visual acuity (VA; p = 0.515) between the two groups. Both groups showed significant improvement in VA(p < 0.001) with a 90% closure rate at one-month post-surgery. Cognitive workload comparison, the intraoperative HR(p = 0.024), total workload score(P = 0.005), and temporal-demand dimension(p = 0.004) were significantly more in Conventional microscope group as compared to 3D group. In both the groups, the HR increased significantly from the baseline while performing ILM peeling and at the end.

CONCLUSION

The surgeon's cognitive workload is markedly reduced while performing macular hole surgery with a 3D viewing system. Moreover, duration of surgery including ILM peel time, MH closure rates, and visual outcomes remains unaffected irrespective of the operating microscope system.

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.

Hybrid 23/25-Gauge Direct Perfluorocarbon Liquid-Silicone Oil Exchange

PURPOSE

To describe a novel technique for direct perfluorocarbon liquid (PFCL)-silicone oil exchange that aims to reduce the inherent risk of intraoperative intraocular pressure spike.

METHODS

We use the conventional setup for passive PFCL-silicone exchange, but intentionally create a mismatch between the passive PFCL aspiration and the active silicone injection that favors the PFCL extrusion. This is achieved by converting one port to a large gauge one-23 or 20-gauge.

RESULTS

We did not note the occurrence of high intraocular pressure spikes with this technique as noted by disk pallor or attenuated vessels.

CONCLUSION

A hybrid 23/25-gauge technique for direct PFCL-silicone oil exchange is safe and reduces the risk of intraoperative intraocular pressure spike.

Cataract Formation Following Pars Plana Vitrectomy in the Pediatric Population

PURPOSE

To analyze post-vitrectomy cataract formation in the pediatric population to elucidate the number of phakic children requiring cataract surgery following vitreous surgery and the perioperative factors affecting cataract development in these patients.

METHODS

Eyes of pediatric patients that underwent phakic pars plana vitrectomy (PPV) with no prior cataract in a 10-year period were included. Analyses evaluated relationships between patient age and time to cataract surgery, as well as contributing factors for cataract formation. Final visual outcomes were also examined. Outcomes were collected for patient age at first vitrectomy, indication for vitrectomy, use of tamponade agents, history of ocular trauma, cataract status, and time to cataract surgery from first vitrectomy.

RESULTS

Of 44 eyes analyzed, 27 (61%) were noted to have some degree of cataract formation. Of these, 15 (56%; 34% of total eyes) underwent cataract surgery. Use of octafluoropropane (P = .04) or silicone oil (P = .03) positively correlated with the need for cataract surgery in the total study group. Patients requiring cataract surgery had worse endpoint visual acuities than those who did not undergo surgery (P = .02), although this difference becomes less significant in follow-up over 2 years (P = .30). Patients who had cataracts but did not need cataract surgery showed an improvement in visual acuity (P = .04), but this was not demonstrated in patients who did need cataract surgery (P = .90).

CONCLUSIONS

Pediatric eye care providers should be aware of the significant risk of cataract formation following a phakic PPV. [J Pediatr Ophthalmol Strabismus. 2023;60(6):421-426.].

High-speed Beveled Tip Versus Standard Tip Vitrectomy Probe: A Prospective Randomized Clinical Trial

Purpose

To compare the efficiency of the advanced ultravit beveled vitrector probe (10,000 cuts per minute) to the current standard ultravit highspeed (7500 cuts per minute) vitrector probe.

Methods

A prospective, randomized controlled trial was conducted on patients undergoing routine vitrectomy surgery for epiretinal membrane, full-thickness macular hole, and vitreous opacities. Patients were randomly assigned to undergo PPV with the ultravit highspeed probe (Probe 1) or the advanced ultravit beveled probe (Probe 2). The main outcome measure was time to completion of core vitrectomy and vitreous base shave.

Results

Forty patients were enrolled in this study, 20 in each cohort. The average time to completion of core vitrectomy was 10.4 +/- 1.8 min in the Probe 1 cohort compared to 9.7 +/- 2 min in the Probe 2 cohort (P = 0.21). The average time to completion of vitreous base shave was 9.6 +/- 2.7 min in the Probe 1 cohort compared to 9.4 +/- 1.8 min in the Probe 2 cohort (P = 0.39).

Conclusion

In the current study, the advanced ultravit beveled probe was noninferior to the ultravit highspeed vitrectomy probe when looking at the time to completion of core vitrectomy and vitreous base shave. The increased cut rate did not affect the efficiency of vitreous removal.

Ophthalmic surgery in New Zealand: analysis of 410,099 surgical procedures and nationwide surgical intervention rates from 2009 to 2018

BACKGROUND

Surgical intervention rates (SIR) provide a proxy measure of disease burden, surgical capacity, and the relative risk-benefit ratio of surgery. The current study assessed decade trends in ophthalmic surgery and calculated SIRs for all major classes of commonly performed ophthalmic procedures in New Zealand.

METHODS

Retrospective population-based analysis of all ophthalmic surgical procedures performed in New Zealand from 2009 to 2018. National and regional datasets from public and private health sectors and industry were analysed. SIRs were calculated for all major ophthalmic procedures, and subgrouped by patient demographics.

RESULTS

There were 410,099 ophthalmic surgical procedures completed with a 25.3% overall increase over 10 years. Procedures were mostly government-funded (51%, n = 210,830) with 71% of patients aged over 64 years. Cataract surgery (78%, n = 318,564) had the highest mean SIR (703/100,000/year) and increased by 25% during the study period, consistent with population growth in the over 64 years old age group. Vitrectomy surgery had the second highest mean SIR (67/100,000/year) and increased by 50%, well above national population growth during the study period. Other SIRs included conjunctival lesion-biopsy (38/100,000/year), glaucoma (33/100,000/year), strabismus (20/100,000/year), dacryocystorhinostomy (10/100,000/year), and keratoplasty surgery (4/100,000/year).

CONCLUSIONS

This comprehensive review of New Zealand ophthalmic surgery reports increasing SIRs that cannot be explained by population growth alone. Cataract surgery numbers increased year on year consistent with the increase in the over 64 years old population. Vitrectomy surgery growth exceeded that of the national population, including those over 64 years.

Clinical Factors and Outcomes of Acute-Onset Endophthalmitis Following Small-Gauge Pars Plana Vitrectomy Surgery

BACKGROUND AND OBJECTIVES

Describe risk factors, findings, and outcomes of acute endophthalmitis (AE) following small-gauge pars plana vitrectomy (PPV).

PATIENTS AND METHODS

This was a retrospective single-center, nonrandomized study of post-PPV AE patients from 2013 to 2021. All received vitreous biopsy before treatment. Patients were divided into cohorts: 1) PPV within 3 days of diagnosis (Urgent-PPV), and 2) no urgent PPV (Other-treatment [Tx]). Main outcome was best-corrected visual acuity (BCVA) at 6 months.

RESULTS

Twenty-one patients were analyzed. Epiretinal membrane was most common indication for PPV (48%). Incidence was 0.074%. Culture-positive rate was 57%. For final BCVA, there was no significant (P = 0.85) difference between Urgent-PPV (median = 0.40 logMAR) and Other Tx cohorts (median = 0.35 logMAR). Sclerotomy wounds were not sutured in 71% of patients. Approximately 24% and 38% of patients analyzed had either no tamponade or partial tamponade, respectively.

CONCLUSION

Tamponade agents and sclerotomy suturing may be important factors when evaluating post-small-gauge PPV-associated AE. Further studies are necessary for clarification. [Ophthalmic Surg Lasers Imaging Retina 2023;54:xx-xx.].

FLUIDIC PERFORMANCE OF A DUAL-ACTION VITRECTOMY PROBE COMPARED WITH A SINGLE-ACTION PROBE

PURPOSE

To assess flow rates, nearfield effects, and traction of a dual-cutting 20,000 cpm vitrectomy probe (HYPERVIT, Alcon) versus a single-cutting 10,000 cpm probe (Advanced ULTRAVIT, Alcon).

METHODS

Flow rates were evaluated for 25+ and 27+ gauge probes using balanced salt solution or porcine cadaver vitreous (biased open, 50/50, and biased closed duty cycles). Probes were suspended in an open beaker, and flow rates were calculated using a precision balance. Nearfield effects and flow pulsatility were assessed using a validated simulation model based on experimental microparticle image velocimetry. Traction was assessed by attaching vitreous to a cantilever beam and measuring the deflection of the beam.

RESULTS

For HYPERVIT probes, aqueous flow rates were similar across all cutting rates. Vitreous flow rates increased with increasing cutting rates. At maximum cutting rates, aqueous flow was 62%-67% greater (25+) and 63% greater (27+) with HYPERVIT versus Advanced ULTRAVIT ( P < 0.05); vitreous flow was 44%-47% greater (25+) and 26%-32% greater (27+) with HYPERVIT versus Advanced ULTRAVIT ( P < 0.05). Nearfield effects were reduced, and peak traction forces were significantly lower for HYPERVIT versus Advanced ULTRAVIT ( P < 0.05).

CONCLUSION

Significantly greater aspiration flow, reduced nearfield effects, and reduced traction were observed with dual-action versus single-action probes.

Mechanical Property Comparison of 23-, 25-, and 27-Gauge Vitrectors across Vitrectomy Systems

OBJECTIVE

To investigate the mechanical properties of 23-, 25-, and 27-gauge vitrectomy vitrectors across 3 different vitrectomy systems to inform surgical techniques.

DESIGN

An experimental study that did not involve any human subjects.

METHODS

Nine vitrectors (3 each of 23-, 25-, and 27 gauge) from Alcon, Dutch Ophthalmic Research Center (DORC), and Bausch & Lomb (B/L) were measured. Measurements were performed using electroforce displacement at the tip and 15 mm from the tip. Five measurements were performed at each location, and fully elastic deformation was ensured.

MAIN OUTCOME MEASURES

The main parameter being measured was the force in grams (gf) necessary to deflect the vitrectors vertically downward by 1 mm, either at the tip of the vitrector or 15 mm from the tip.

RESULTS

A total of 90 measurements were performed. Across brands, B/L demonstrated the least stiffness at both the tip and at the 15-mm point for 23-gauge (8.0±0.3gf, 67.3±1.0gf), 25-gauge (6.8±0.3gf, 60.5±0.4gf), and 27-gauge (3.3±0.1gf, 33.9±0.5gf) vitrectors. Although there was only a small decrease in the stiffness in the 25-gauge vitrector compared with the 23-gauge vitrector at the 15-mm point, this difference was statistically significant for Alcon (P < 0.001), DORC (P < 0.001), and B/L (P < 0.001).

CONCLUSIONS

Based on this study, 25-gauge vitrectors, although larger than the 27-gauge vitrectors and less stiff than the 23-gauge vitrectors, may offer favorable compromise between stiffness and gauge size. However, surgeon experience, preference, and the type of surgery being performed should be paramount when making the final vitrector selection. Knowledge of these mechanical properties may aid surgeons in choosing between gauge size and vitrectomy system to optimize their comfort and efficiency.

Preoperative oral diazepam for intraoperative blood pressure stabilisation in hypertensive patients undergoing vitrectomy under retrobulbar nerve block anaesthesia: study protocol for a randomised controlled trial

Background

As a type of local anaesthesia, retrobulbar nerve block is often used in vitrectomy, with patients remaining conscious during the operation. The increase in systolic blood pressure (SBP) caused by tension and fear during the operation—especially in patients with a history of hypertension—can negatively impact the safety of the procedure, resulting in suprachoroidal haemorrhage or retinal haemorrhage. Diazepam has a sedative effect and can relieve tension during surgery. This study aims to evaluate the efficacy and safety of diazepam for intraoperative BP stabilisation in hypertensive patients under retrobulbar anaesthesia during surgery.

Methods

This single-centre, double-blind, randomised controlled and parallel clinical trial will include 180 hypertensive patients who will undergo vitrectomy with nerve block anaesthesia. Study participants will be randomly allocated in a 1:1 ratio to intervention (patients receiving oral diazepam before the operation) and control (patients receiving oral placebo before the operation) groups. The primary outcome is the effective rate of intraoperative BP control (systolic BP during operation maintained at <160mmHg at all timepoints). The secondary outcomes are the proportion of patients with SBP ≥180 mmHg at any timepoint from operation to 1 h post-operation, the change of mean systolic blood pressure and mean heart rate during operation from baseline, as well as the number of patients with intraoperative and post-operative adverse reactions within 12 weeks of surgery. The logistic regression model will be performed to compare the outcomes.

Discussion

This study will evaluate the efficacy and safety of diazepam for intraoperative BP stabilisation in hypertensive patients under nerve block anaesthesia during surgery. The results of this trial will reveal whether diazepam has a significant effect on intraoperative BP stability in patients with a history of hypertension who require vitrectomy. If the results of this trial are significant, a large-scale multi-centre clinical trial can be designed.

Trial registration

Chinese Clinical Trial Registry (ChiCTR) ChiCTR2100041772. Registered on 5 January 2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06686-y.

Peripheral Circumferential Retinal Detachment after Pars Plana Vitrectomy: Complications and Management

Purpose: This study aimed to evaluate treatment outcomes and complications of peripheral circumferential retinal detachment (PCD) after successful vitrectomy. Methods: Eyes diagnosed with PCD after pars plana vitrectomy (PPV) were retrospectively reviewed. The patient demographic data, complications, management, and treatment outcomes were collected and analyzed. Results: The mean follow-up duration was 18.0 ± 11.9 months. BCVA ranged from light perception to 0.1 (median: counting fingers at 40 cm). Major complications included rubeosis iridis (seven eyes), vitreous hemorrhage (five eyes), hyphema (five eyes), corneal decompensation (three eyes), hypotony (two eyes), and neovascular glaucoma (two eyes). All eyes underwent peripheral retinectomy to remove the detached retina and release traction. Complete retinal reattachment was achieved in all eyes. The final BCVA ranged from hand motion to 0.1 (median: counting fingers at 30 cm). Conclusion: PCD may be associated with delayed-onset complications, causing severe loss of vision. Proper management, including peripheral retinectomy, may preserve visual function.

Early vitrectomy in eyes with non-diabetic vitreous hemorrhage

Background:

Optimal management of non-diabetic vitreous hemorrhage (NDVH) is controversial, and reliability of B-scan ultrasonography in detecting retinal tears (RTs) has been reported to be highly variable by previous literature.

Objectives:

To report outcomes of conservative versus surgical management of NDVH and reliability of B-scan ultrasonography in detecting RTs and rhegmatogenous retinal detachment (RRD).

Design:

Retrospective observational single-center cohort study.

Methods:

Ninety-six consecutive NDVH from 96 eyes (96 patients) with minimum follow-up duration of 12 months were included.

Results:

Seventy-two eyes (75%) underwent early pars plana vitrectomy (PPV), 19 (20%) were managed conservatively and 5 (5%) underwent late PPV. Initial mean best corrected visual acuities (BCVAs) were 1.95 ± 1.19, 1.19 ± 1.38, and 1.14 ± 1.04 logMAR respectively, the difference was statistically significant (p = 0.039). Mean final BCVAs were 0.92 ± 1.19, 0.59 ± 0.87, and 1.25 ± 1.89 logMAR, respectively, the difference was not significant (p = 0.447). When comparing initial and final BCVAs, the difference was significant only in the early PPV group (p = 0.00001) and was not significant in the conservative group (p = 0.066) and in the late PPV group (p = 0.46). Complications included RRD (n = 2) and re-bleed in vitrectomized cavity (n = 1) in the early surgical group, need for additional laser or cryoretinopexy to RTs (n = 2), retinal detachment (n = 1), neovascular glaucoma (n = 1), persistent vitreous hemorrhage (n = 2) in the conservative group. B-scan ultrasound showed preoperative 11.53% sensitivity and a 60.0% positive predictive value for diagnosing retinal tears (RTs) in NDVH.

Conclusion:

The benefit of early PPV in NDVH seems to outweigh the risks of surgery, especially in the context of low sensitivity of B-scan in identifying RTs, and significant improvement in final BCVA following surgery may occur. NDVH should be promptly referred to vitreoretinal services, as surgery may be a safer and more advisable option.

Pars Plana Vitrectomy Port Sizes: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND OBJECTIVE

The uptake of small-gauge (SG; ie, 23-gauge [23-G], 25-gauge [25-G], and 27-gauge [27-G]) pars plana vitrectomy (PPV) has grown. We aim to investigate the advantages and disadvantages of various PPV port sizes in a meta-analysis of randomized controlled trials (RCTs).

MATERIALS AND METHODS

A systematic literature search was performed for RCTs comparing PPV port sizes for any indication. Weighted mean differences (WMDs) and risk ratios (RRs) were calculated, and meta-analysis was performed with random-effects models.

RESULTS

A total of 1,678 eyes from 22 RCTs were included. Risk-of-bias assessment found some concerns in 13 studies. Compared with 20-gauge PPV, there was no significant difference in the final or change in best-corrected visual acuity (BCVA; five studies analyzed each) relative to that of SG PPV. SG PPV was associated with a significantly greater incidence of hypotony (RR = 3.79; 95% confidence intervals [CI], 2.02 to 7.10; P < .0001; six studies) and choroidal detachment (RR = 5.65; 95% CI, 1.01 to 31.71; P = .05; three studies). Compared with 25-G PPV, there was no significant difference in BCVA at any time point with 23-G (two studies), and significantly more frequent port suturing was required with 23-G (RR = 0.46; 95% CI, 0.25 to 0.84; P = .01; two studies). Compared with 25-G PPV, 27-G was associated with a significantly better final BCVA (WMD = -0.06 logMAR; 95% CI, -0.11 to -0.01; P = .02; five studies) and a significantly lengthened surgery (WMD = 4.11 minutes; 95% CI, 0.18 to 8.05; P = .04; three studies).

CONCLUSIONS

There was no significant difference in visual or surgical outcomes following 20-gauge PPV relative to SG PPV (Grading of Recommendations, Assessment, Development, and Evaluation recommendation: low certainty), and there was an increased risk of postoperative complications with SG PPV (moderate certainty). Compared with 25-G PPV, 23-G required more frequent port suturing (moderate certainty), whereas 27-G may be associated with a better final BCVA but longer surgery (low and moderate certainty, respectively). [Ophthalmic Surg Lasers Imaging Retina. 2022;53:152-158.].

Additive Manufacturing of a Miniature Functional Trocar for Eye Surgery

Stereolithography is emerging as a promising additive manufacturing technology for a range of applications in the medical domain. However, for miniature, medical devices such as those used in ophthalmic surgery, a number of production challenges arise due to the small size of the components. In this work, we investigate the challenges of creating sub-millimeter features for a miniature, functional trocar using Stereolithography. The trocar cannula system is used in eye surgery to facilitate a passage for other instruments. A standard trocar consists of a hollow cannula and a flexible check valve. The research was performed in two stages: in the first stage we investigated the effect of different materials and print settings on the current design of the cannula and the valve separately, and in the second stage we used these findings to optimize the design and production process. After the first investigation, it became apparent that even though the dimensions of the trocar are within the feature size range of Stereolithography, all hollow features tended to fuse shut during printing. This effect appeared regardless of the materials or print settings, and can be attributed to refraction of the laser source. In order to circumvent this, we identified two potential strategies: (1) increasing the negative space surrounding features; and (2) decreasing the surface area per layer. By applying these strategies, we tested a new design for the cannula and valve and managed to 3D print a functional trocar, which was tested in an artificial eye. The design of the 3D printed trocar allows for further personalization depending on the specific requirements of both patient and surgeon. The proposed strategies can be applied to different applications to create miniature features using Stereolithography.

Comparisons of flow dynamics of dual-blade to single-blade beveled-tip vitreous cutters

INTRODUCTION

To compare the flow dynamics of the dual-blade to the single-blade beveled-tip vitreous cutters.

METHODS

The aspiration rates of balanced salt solution (BSS) and swine vitreous were measured for the 25-gauge and 27-gauge dual- and single-blade vitreous cutters. The flow dynamics of BSS and diluted vitreous mixed with fluorescent polymer at the maximal cutting rates and the reflux of BSS were measured in images obtained by a high-speed camera. The distal end of the cutter was defined as the head end.

RESULTS

The aspiration rates of BSS and vitreous by the 25- and 27-gauge dual-blade cutters were significantly higher than those of both single-blade cutters at the maximal cutting rate (all P≤0.01). The mean aspiration flow of BSS in front of the port from a lateral view was significantly faster for both dual-blade cutters than for both single-blade cutters (P=0.003, P=0.019). The angle of the mean flow of BSS of both dual-blade cutters was from the distal end (P<0.001, P<0.001) but that of the single blade-cutters was from the proximal end. The velocity and angle of the mean reflux flow of both types of cutters were not significantly different. The mean aspiration flow of diluted vitreous was significantly faster for 25-gauge dual-blade cutters with the angle more from the proximal end and 27-gauge dual-blade cutters more from the distal end than both single-blade cutters (P=0.018, P=0.048).

CONCLUSION

The dual-blade beveled-tip vitreous cutters improve the efficiency of the vitrectomy procedures and maintain the distal aspirating flow by the beveled-tip.

Tylectomy Safety in Salvage of Eyes with Retinoblastoma

Simple Summary

The role of organ-conserving surgery has not been explored in retinoblastoma as it has been in other cancers, such as breast cancer lumpectomy, partial nephrectomy for kidney cancer, and partial orchiectomy for testis cancer. This is largely accounted for by the high mortality of extraocular retinoblastoma compared to intraocular retinoblastoma, and fear of iatrogenic tumor spread with intraocular surgery. We propose the little-known word “tylectomy” (“tulos”, Greek for “lump”) to describe the surgical resection of retinoblastoma. Through review of consecutive patients treated by our team between 2012–2014, we compared survival of patients with eye salvage, including tylectomy, to those who had eye salvage without tylectomy or primary enucleation. We found that patients who had tylectomy had superior survival compared to those who had eye salvage without tylectomy (96% vs. 90%), and comparable survival to those with primary enucleation (96% vs. 95%). Our study supports tylectomy as a safe contribution to retinoblastoma management.

Abstract

Intraocular surgery is tabooed in retinoblastoma management, due to the concern of lethal extraocular spread. We reviewed the outcomes of consecutive children with intraocular retinoblastoma diagnosed at 29 Chinese centers between 2012–2014. We compared the outcomes of three categories of treatment: eye salvage including tylectomy (Group I), eye salvage without tylectomy (Group II), and primary enucleation (Group III). A total of 960 patients (1243 eyes) were diagnosed: 256 in Group I, 370 in Group II, and 293 in Group III; 41 patients abandoned treatment upfront. The estimated 5-year overall survivals (OS) were, for Group I, 94%, for Group II 89%, and for Group III 95%. The estimated 5-year disease-specific survivals (DSS) were, for Group I, 96%, for Group II 90%, and for Group III 95%. Patients in Group I had a significantly higher 5-year DSS than patients in Group II (p = 0.003) and not significantly different than patients in Group III (p = 0.367). Overall survival was not compromised by the inclusion of tylectomy in eye salvage therapy compared to eye salvage without tylectomy or primary enucleation. Disease-specific survival was better when tylectomy was included in eye salvage treatments. Tylectomy as part of multimodal treatment may contribute to the care of retinoblastoma patients with chemotherapy-resistant tumor, eyes with concomitant ocular complications, or at the risk of treatment abandonment.

TAP AND INJECT VERSUS PARS PLANA VITRECTOMY FOR POSTPROCEDURAL ENDOPHTHALMITIS: A Meta-analysis

PURPOSE

To compare the visual outcomes after prompt pars plana vitrectomy (PPV) with tap biopsy and intravitreal antimicrobial injection to treat postinjection and postsurgery endophthalmitis.

METHODS

The Cochrane Central Register of Controlled Trials, Ovid MEDLINE, and Ovid Embase databases were searched for articles published between January 2010 and November 2020. Two independent reviewers selected articles and extracted data. We analyzed data in RevMan 5.3 and assessed methodological quality using the Cochrane ROBINS-I tool. The mean improvement in visual outcome was compared between PPV and intravitreal antimicrobial injection as a relative risk of improving ≥2 lines and a mean logarithm of the minimal angle of resolution difference in improvement.

RESULTS

Fifteen retrospective case series (1,355 eyes), of which 739 eyes (55%) received intravitreal antimicrobial injection and 616 (45%) received PPV as initial treatment, were included. The overall relative risk of improving 2 or more lines in PPV in comparison with intravitreal antimicrobial injection was 1.04 (95% CI 0.88-1.23; P = 0.61; I2 = 0%) with a mean difference of 0.04 (95% CI -0.18 to 0.27; P = 0.69; I2 = 0%). The results stayed robust when subgroup analysis based on causative procedure for endophthalmitis was performed.

CONCLUSION

Intravitreal antimicrobial injection is noninferior to PPV for the treatment of postcataract operation, postinjection, and post-PPV endophthalmitis.

Outcomes of 25-gauge pars plana vitrectomy for cytomegalovirus retinitis-related retinal detachment

Purpose:

The purpose of this study is to evaluate the anatomical and functional outcomes of 25-gauge (G) pars plana vitrectomy (PPV) in patients with cytomegalovirus retinitis (CMVR)-related rhegmatogenous retinal detachment (RRD).

Methods:

Single-center retrospective consecutive case series of patients who underwent 25-G PPV for CMVR-related RRD repair with a minimum follow-up of 3 months. Complete anatomic success was defined as the complete attachment of retina including the periphery. Best-corrected visual acuity (BCVA) of ≥20/400 was defined as functional success.

Results:

Sixteen eyes of 15 patients were included in the study. Eleven patients were human immunodeficiency virus positive, three patients had hematological malignancies, and one patient suffered from dyskeratosis congenita. The mean follow-up was 20.5 ± 17.4 months (range 3–60 months). Complete anatomical success was seen in 15 eyes (93.75%). One eye had a residual inferior detachment with attached macula. Silicone oil was used as tamponade in 15 eyes and C₃F₈ gas in one eye. The mean change in BCVA was statistically significant, preoperative LogMAR BCVA was 2.05 ± 0.94 while the final follow-up postoperative LogMAR BCVA was 1.03 ± 0.61 (P < 0.001). Thirteen eyes (81.25%) had final BCVA ≥20/400.

Conclusion:

Microincision vitrectomy surgery can achieve excellent retinal reattachment rates in post-CMVR RRDs without significant intraoperative and postoperative complications. The visual outcome varies depending on the status of the optic disc and macula. Majority of the patients maintained functional vision.

Endophthalmitis management study. Report #1. Protocol

To date, the Endophthalmitis Vitrectomy Study (EVS) has remained the hallmark of evidence-based management of acute bacterial endophthalmitis after cataract surgery with an intraocular lens. In the last quarter-century since its publication, several studies have reported that the microbiological spectrum of endophthalmitis is not the same across the world; there is emerging antibiotic resistance of gram-negative microorganisms to the EVS recommended antibiotics; there are newer molecules that could cross the blood-retinal barrier; the advances in vitreous surgery have become safer than before, and there are newer methods of microbiological evaluation. One of the often-mentioned drawbacks of the EVS was not recruiting grossly infected eyes with poor visibility of the iris and vitreous. Keeping these factors in mind, a new prospective multi-centered randomized study, the Endophthalmitis Management Study (EMS), is designed. The EMS will recruit all post-cataract surgery endophthalmitis patients irrespective of severity (including suspected fungal infection); the EMS will use quantifiable inflammatory score instead of the presenting vision to allocate for surgery, randomize the eyes to two different combinations of intravitreal antibiotics and use the newer microbiological diagnostic techniques. We believe the EMS findings will complement the EVS recommendations.

Intraocular biopsy in uveitis

An intraocular biopsy is performed for diagnostic, prognostic and investigational purposes. Biopsies help to confirm or exclude malignancies and differentiate inflammatory from infectious processes. Histopathological analysis is the final verdict in unresponsive uveitis, atypical inflammation, metastases and masquerade syndromes. Advances and refinement of techniques in cytopathology, immunohistochemistry, microbiological and molecular biologic study offer much more than just diagnosis. They provide prognosis based on cell characteristics and are helpful in planning treatment and intervention. Many biopsy procedures have evolved to provide more safety and minimise complications thus improving the quality of specimens or samples available for analysis. The type of biopsy and technique adopted varies based on the clinical suspicion, size and location of lesions. In uveitis, a working diagnosis of intraocular inflammation is made on clinical examination and laboratory investigations and ancillary tests. Malignancy and uveitis is interlinked and masquerade syndromes are among the commonest indications for biopsy and analysis of specimen. The various types of intraocular biopsies include aqueous tap, fine needle aspiration biopsy, vitreous biopsy, iris and ciliary body, and retinochoroidal biopsy. They will be reviewed in this article with respect to current perspective

Comparison of 27-gauge and 25-gauge vitrectomy in the management of tractional retinal detachment secondary to proliferative diabetic retinopathy

OBJECTIVE

To compare surgical outcomes between 27 and 25-gauge vitrectomy in proliferative diabetic retinopathy (PDR) with tractional retinal detachment (TRD).

METHODS

This retrospective study was conducted to compare the intraoperative status, operation time, use of instruments, endotamponade substance, wound suture number, and iatrogenic break, between 27 and 25-gauge vitrectomy in 43 eyes afflicted by PDR with TRD. The post-surgical results, best-corrected visual acuity, intraocular pressure, recurrent vitreous haemorrhage, and re-operation rate were regularly followed up for 6 months.

RESULTS

Patients in the 25 and the 27-gauge groups did not differ significantly in terms of pre-surgical conditions, such as age, gender, pre-existing glaucoma, best-corrected visual acuity (BCVA) and the severity of their TRD. The mean operation time was 56.7 minutes in the 27-gauge group and 63.7 minutes in the 25-gauge group (p = 0.94). There is significantly less use of micro forceps in the 27-gauge group (p = 0.004). No difference between micro scissors and chandelier usage were noted; neither was their difference in iatrogenic retinal breaks. Significantly fewer wound sutures were noted in the 27-gauge group (p < 0.001). The post-operative results revealed no significant difference in ocular hypertension, hypotony, BCVA improvement, recurrent vitreous haemorrhage and re-operation rate.

CONCLUSIONS

The 27-gauge vitrectomy system offers comparable surgical outcomes in PDR with TRD. The 27-gauge vitrectomy system is suitable for complicated retinal surgery.

Outcomes of 25-gauge pars plana vitrectomy with encircling scleral band for acute retinal necrosis-related rhegmatogenous retinal detachment

Purpose

The aim of this study was to evaluate the anatomic and functional outcomes of 25-gauge pars plana vitrectomy (25G PPV) with encircling scleral band (ESB) in patients with acute retinal necrosis (ARN)-related rhegmatogenous retinal detachment (RRD).

Methods

Single-center retrospective interventional case series of patients who underwent 25G PPV with ESB for ARN-related RRD. Complete anatomic success was defined as the complete attachment of retina after primary PPV. Functional success was measured by the final best-corrected visual acuity (BCVA) ≥20/400. Intraoperative and postoperative complications were also noted.

Results

14 eyes of 13 patients were included in the study. Six patients (46.1%) were immunocompromised. The mean follow-up was 23.64 ± 9.95 (range 6-42) months. Silicone oil was used as tamponade in 13 eyes and C3F8gas in one eye. After the primary PPV, complete anatomical success was seen in all eyes (100%), however, one eye developed phthisis bulbi after silicone oil removal (SOR). Statistically significant improvement of BCVA was seen, from LogMAR 2.03 ± 0.29 preoperatively to LogMAR 1.57 ± 0.63 postoperatively (p-value 0.014). Six eyes (42.9%) had functional success. Nine eyes (64.3%) had improvement in vision while 4 eyes (28.6%) maintained preoperative vision. 10 eyes (71.4%) underwent cataract surgery, nine eyes (64.3%) underwent SOR while 2 eyes (14.3%) had epiretinal membrane (ERM) under oil during follow-up.

Conclusion

25G PPV combines the advantages of minimally invasive vitrectomy surgery while offering improved anatomic outcomes in patients with ARN-related RRD. The functional outcome varies depending on the status of the optic disc and macula.

FLOW DYNAMICS OF BEVELED-TIP AND FLAT-TIP VITREOUS CUTTERS

PURPOSE

To compare the flow dynamics of beveled-tip to that of flat-tip vitreous cutters.

METHOD

The aspiration rates of balanced salt solution and swine vitreous were measured for 25-gauge and 27-gauge beveled-tip and flat-tip vitreous cutters. Fluorescent polymer microspheres were mixed with balanced salt solution to make the flow visible. The flow dynamics at maximal cutting rates and reflux of balanced salt solution were measured with video images of a high-speed camera.

RESULTS

The aspiration rates of balanced salt solution of the 25-gauge and 27-gauge beveled-tip cutters were significantly higher than that of the flat-tip cutters at 7,500 cut/min (P = 0.0001, P = 0.038, respectively). The aspiration rate of swine vitreous by the 25-gauge beveled-tip cutter was significantly higher than that of the flat-tip cutters (P = 0.006). The mean aspiration flow in front of the cutter was significantly faster for both beveled-tip than flat-tip cutters (P = 0.003, P = 0.023). The angle of the mean aspiration flow of both beveled-tip cutters was turned to the proximal side (P = 0.004, P = 0.003). The mean reflux flow of both beveled-tip cutters was significantly faster than that of the flat-tip cutters (P = 0.006, P = 0.006).

CONCLUSION

The beveled-tip cutters have a greater velocity of aspirating frontal and proximal flow resulting in higher aspiration rates and greater reflux flow velocity.

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 S4^HPS (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.

Impact of different manufacturers and gauge sizes on the performance of backflush needle

The present study aimed to identify the factors regulating aspiration rate (AR) of backflush needles and to compare those factors across various backflush needles from different manufacturers. The 27-gauge (27G), 25-gauge, and 23-gauge backflush needles from four different manufacturers, Alcon, MedOne, VitreQ, and DORC, were used for this experiment. AR was measured at four different aspiration vacuum levels: 100, 200, 400, and 650 mmHg. AR was significantly increased as the aspiration vacuum level increased when both aspirating balanced salt solution (BSS) and ethylene glycol; however, 27G products from VitreQ and MedOne were unable to aspirate ethylene glycol at the low aspiration vacuum level of 100 mmHg. When aspirating BSS at the high aspiration vacuum level of 650 mmHg, a smaller gauge number generally resulted in a significantly higher AR. AR, inner diameter, and cross-sectional area in Alcon products were significantly larger in any gauge, and the shaft length of Alcon products was significantly shorter than those of other manufacturers’ products in any gauge. Cross-sectional area negatively correlated with the degree of shaft deflection (r² = 0.21, p = 0.042). These results imply that AR differs significantly among backflush needles and among companies depending on the shaft cross-sectional area.

Outcomes of primary rhegmatogenous retinal detachment repair with extensive scleral-depressed vitreous removal and dynamic examination

There are multiple surgical approaches to the repair of rhegmatogenous retinal detachment (RRD). Here, we evaluated the outcomes of small-gauge pars plana vitrectomy (PPV), alone or in combination with scleral buckle (SB-PPV), for RRD repair using a standardized technique by 3 vitreoretinal surgeons: “extensive” removal of the vitreous with scleral depression and dynamic examination of the peripheral retina. One hundred eighty seven eyes of 180 consecutive patients treated for primary RRD by three vitreoretinal surgeons at a tertiary academic medical center from September 2015 to March 2018 were analyzed. Most RRDs occurred in males (134 [71.3%] eyes), affected the left eye (102 [54.3%]), and were phakic (119 [63.3%]). PPV alone was performed in 159 eyes (84.6%), with a combined SB-PPV used in the remaining 29 eyes (15.4%); focal endolaser was used in all (100%) cases. The single surgery anatomic success rate was 186 eyes (99.5%) at 3 months, and 187 (100%) at last follow up. Overall best-corrected visual acuity (BCVA) had significantly improved at 3 months ([Snellen 20/47] P<0.00005) and last follow up ([Snellen 20/31] P<0.00005), as compared to day of presentation ([Snellen 20/234]). Our findings suggest that “extensive” removal of the vitreous and dynamic peripheral examination with scleral depression may lead to high single surgery success in primary uncomplicated RRD repair.

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.

A novel, low-cost and practical illumination approach for bimanual vitrectomy

OBJECTIVE

The present study aims to describe a novel, low-cost, transconjunctival sutureless bimanual vitrectomy illumination approach and evaluate its surgical outcome.

METHODS

Thirty-six eyes of 36 patients who underwent pars plana vitrectomy with the above-mentioned technique were included in this study. Four trocars were placed in superotemporal, inferotemporal, inferonasal and superonasal quadrants. A piece (23 mm) was cut from 30G intravenous cannula and a 30 mm endoillumination probe was placed inside this sleeve. This design limited the entry of the light probe into the vitreous cavity to 7 mm and provided a safe illumination by the assistant without the risk of damaging the retinal tissue.

RESULTS

Thirty-six eyes of 36 patients were included (24 male, 12 female, mean age: 58.4±14.3 years) in this study. Thirty patients had rhegmatogenous retinal detachment (six of these patients with coexisting choroidal detachment), four patients had diabetic tractional retinal detachment, one patient had a nucleus drop and one patient had an intraocular foreign body. The mean follow-up time after pars plana vitrectomy (PPV) was 5.05±4.4 months. LogMAR best-corrected visual acuity improved significantly after PPV (p<0.001). Postoperative complications included recurrent detachment in two eyes, hypotony in one eye and endophthalmitis in one eye. The transient rise in intraocular pressure was observed in 19 patients, but there was no significant difference between the preoperative and postoperative mean IOP in the long term follow-up.

CONCLUSION

This bimanual vitrectomy system provided favorable outcomes without increasing the cost of standard PPV. The advantage of this system over the chandelier illumination include the reduction in glare, the possibility to change the direction of the light during the surgery to better illuminate the surgical site and the lower cost. This approach can be used in any vitrectomy system (20G, 23G, 25G, and 27G) by changing the size of the IV cannula.

Outcome of primary rhegmatogenous retinal detachment using microincision vitrectomy and sutureless wide-angle viewing systems

Background

To evaluate the efficacy of micro-incision vitrectomy surgery (MIVS) using Lumera and Resight non-contact sutureless wide-angle viewing systems (WAVS) for primary rhegmatogenous retinal detachment (RRD), and to analyze the anatomical and visual outcomes.

Methods

The retrospective, non-comparative, interventional case series reported here was conducted from June 2014 through November 2016. Enrolled patients presented with primary RRD and received MIVS with/without cryopexy by one surgeon using the Lumera and Resight non-contact sutureless WAVS. All patients were followed-up for a minimum of 12 months. Variables collected included patient demographics, best-corrected visual acuity, and macular status. The number and position of retinal break(s), and the use of cryopexy, were also recorded. Outcome measures included operative time, single-operation anatomical success rate, final anatomical success rate, recurrent rate, postoperative best-corrected visual acuity, and surgical complications. The end points were operative time, anatomical outcome, and functional outcome.

Results

In total, 110 eyes from 110 patients (68 men and 42 women) were treated. Of these, 103 (93%) eyes were reattached after primary vitrectomy. One hundred ten eyes (100%) reached final anatomical success. The mean operative time was 50.55 min. Multivariate analyses were performed with best model selection principle based on general linear model by Akaike Information Criteria for detecting possible factors related to operation time, and with multivariate logistic regression analysis for revealing probable clinical parameters which might influence the anatomical outcome after first operation and final visual outcome. Intraoperative cryopexy and multiple breaks increased operative time significantly. More favorable BCVA was significantly correlated with shorter operation time and the preoperative macula-on status. Multivariate logistic regression on the group of patients who have received the cataract surgery revealed that the pre-operative BCVA is a significant factor which can predict the visual outcome after MIVS.

Conclusions

The outcome of primary RRD repaired by MIVS using the Lumera and Resight sutureless WAVS was not inferior to any other published method. This instrument combination resulted in a relatively rapid and comfortable procedure without serious postoperative complications. Cryopexy and multiple breaks affected operative time significantly. Shorter operative times and preoperative macula-on status are associated with better final visual outcomes.

One-year outcomes of 27-gauge versus 25-gauge pars plana vitrectomy for uncomplicated rhegmatogenous retinal detachment repair

Background

27-gauge (27G) and 25-gauge (25G) transconjunctival sutureless vitrectomy (TSV) were considered equal about safety, effectiveness and vitrectomy time for the treatment of rhegmatogenous retinal detachment (RRD), although larger and long-term comparative studies are needed to confirm previous knowledge. Furthermore, a combined comparison of time duration of surgery and vitreous removal was never performed. Our purpose was to compare the safety and efficacy of 27G versus 25G TSV for the treatment of uncomplicated RRD over a 1-year follow-up.

Methods

A 12-months single-center prospective, randomized, interventional study of 92 consecutive patients was performed. 46 patients underwent 27G TSV (Group 1) and 46 underwent 25G TSV (Group 2). Primary outcomes were primary and final reattachment rate, and final functional success (visual acuity ≥ 20/200, 1 LogMar). Secondary outcomes were the surgical and vitrectomy time. Complications were recorded.

Results

All functional and morphologic data at baseline and at all follow-up time points up to 12 months after surgery were available for only 88 patients. Four patients in Group 1 dropped out of the study after surgery. There was no significant difference in baseline characteristics between the two groups. Primary and final reattachment rates were 90.5% and 100% in Group 1, and 95.6% and 100% in Group 2, respectively (p > .05, p > .05, respectively). Visual acuity improved from 1.5 ± 1.09 LogMar to 0.38 ± 0.55 LogMar in Group 1 (p < .001) and 1.2 ± 0.9 LogMar to 0.49 ± 0.53 LogMar in Group 2 (p < .001), without significant difference between the groups (p > .05). The surgical time was 73.2 ± 11.3 min with 27G TSV and 64.4 ± 9.5 min with 25G TSV (p = .0001). The vitrectomy time was 19.9 ± 3.8 min with 27G TSV and 20.8 ± 3.8 min with 25G TSV (p > .05). One single case of choroidal detachment occurred.

Conclusions

Reattachment rates, functional success and vitrectomy time were comparable between 27G and 25G TSV for RRD. Surgical time was significantly longer using 27G vitrectomy.

Surgical outcomes of microincision vitrectomy surgery in eyes with retinal detachment secondary to retinopathy of prematurity in Indian population

Purpose:

To analyze and report outcomes of microincision vitrectomy surgery (MIVS) for Stage 4 and 5 retinopathy of prematurity (ROP).

Methods:

Medical records of 202 eyes of 129 premature children undergoing MIVS for Stage 4/Stage 5 ROP between January 2012 and April 2015 were evaluated. The primary outcome measure was the proportion of eyes with anatomical success (defined as attached retina at the posterior pole at last follow-up). Complications associated with MIVS were noted and analysis of risk factors associated with poor anatomical outcome was also done using logistic regression.

Results:

Mean age of presentation of babies with Stage 4 ROP (2.9 ± 1.75 months) was lower than those with stage 5 disease (5.62 ± 2.55 months) (P < 0.005). One hundred seventeen eyes (56% or 58%) had Stage 5, 38 (19%) had Stage 4a, and 47 (23%) Stage 4b. Ninety-four eyes (47%) had received prior treatment (laser and/or anti-vascular endothelial growth factors [VEGF]). Lens-sparing vitrectomy (LSV) was performed in 58 (29%) eyes while lensectomy with vitrectomy (LV) was performed in 144 (71%) eyes. At a mean follow-up of 32.5 weeks, 102 (50.5%) eyes achieved anatomical success, including 74% eyes in Stage 4a and 4b and 33% in Stage 5. Complications included intraoperative break formation (19%), postoperative vitreous hemorrhage (28%), raised intraocular pressure (12.7%), and cataract progression (2.4%). Factors significantly associated with favorable anatomical outcome were Stage 4 disease (vs. Stage 5) (odds ratio [OR] 5.8; confidence interval [CI] =2.6–13.8, P < 0.005), prior treatment (laser ± anti-VEGF) (OR 2.5; CI 1.4–4.7, P < 0.005) surgery with 25G MIVS (vs. 23G) (OR: 1.7; CI = 0.98–3.00, P = 0.05) and LSV (vs. LV) (OR 7; CI = 3.4–14.6, P < 0.005). Retinal break was significantly associated with poor anatomical outcome (OR 0.21; CI = 0.09–0.5, P < 0.005).

Conclusion:

MIVS along with wide angle viewing systems allow surgeons to effectively manage ROP surgeries while at the same time reducing complication rate in these eyes which have complex pathoanatomy and otherwise grim prognosis.

Endoscopy for Pediatric Retinal Disease

Endoscopic vitrectomy is a useful and unique adjunct to microincision vitreoretinal surgery. The optical properties of endoscopy allow for some clinically advantageous approaches that are not possible with regular microscope viewing systems, namely, the ability to both bypass optically signficant anterior segment opacities and directly visualize dificult-to-access retroirideal, retrolental, and anterior retinal structures in their natural anatomical configuration. The surgical benefits include improved surgical access to the pars plana, pars plicata, ciliary sulcus, ciliary body, and peripheral lens, along with unique access to anterior traction in complex pediatric anterior detachments, particularly in retinopathy of prematurity. This review will focus on the development and surgical utility of intraocular endoscopy, provide an update on its current uses in the era of microincision vitreoretinal surgery, and highligh its role in pediatric vitreoretinal diseases.