EARLY POSTOPERATIVE HYPOTONY AFTER 25-GAUGE SUTURELESS VITRECTOMY WITH STRAIGHT INCISIONS

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.

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.

Epidemiology of Acute Endophthalmitis after Intraocular Procedures: A National Database Study

OBJECTIVE

To describe the causes of postoperative acute endophthalmitis at the national level longitudinally.

DESIGN

Cohort study from 2009 to 2018 in France.

PARTICIPANTS

Patients diagnosed with acute endophthalmitis after intraocular procedures.

METHODS

The French medical-administrative database was used. Endophthalmitis cases and intraocular procedures were identified based on billing codes in all French hospitals and private practices.

MAIN OUTCOME MEASURES

The incidence of acute endophthalmitis within 42 days of the procedure.

RESULTS

From January 1, 2009, to October 31, 2018, 7522 cases of acute endophthalmitis occurred after 14 438 854 intraocular procedures. Most cases occurred after standalone cataract surgery (4808 cases for 7 316 077 procedures; 63.92%), followed by after intravitreal (IVT) injections (1296 cases for 5 455 631 IVT injections; 17.23%), vitreoretinal surgery (698 for 442 263 procedures; 9.28%), anterior segment surgery (245 cases; 3.26%), combined cataract and vitreoretinal surgery (191 cases; 2.54%), cornea surgery (142 cases; 1.89%), and glaucoma surgery (80 cases; 1.06%). The overall incidence of acute endophthalmitis was 1 per 1920 procedures (0.0521%; 95% confidence interval [CI], 0.0520-0.0522). The surgery with the highest incidence of endophthalmitis was scleral and globe surgery, with an incidence of 0.1827% (95% CI, 0.1757-0.1898), followed by vitreoretinal surgery combined with cataract surgery, with an incidence of 0.1685% (95% CI, 0.1663-0.1706). The incidence of endophthalmitis after IVT injections was stable over the study period, and patients receiving IVT injections were the oldest, aged 75.4 years (standard deviation, 12.0 years; P < 0.001). The onset of endophthalmitis after IVT procedures, i.e, after receiving IVT injections or undergoing vitreoretinal surgery, was earlier than that after the other procedures (P < 0.001).

CONCLUSIONS

The profile of patients referred for acute endophthalmitis has been evolving over the past decade, with a decrease in the raw number of endophthalmitis cases after cataract surgery as opposed to an increase in the number of patients presenting with endophthalmitis after IVT injections.

The Clinical and Safety Outcomes of 27 Gauge Pars Plana Vitrectomy in Eyes With Macular Hole

Objective To report the clinical, visual, and safety outcomes of 27 gauge pars plana vitrectomy (27G PPV) in eyes with full thickness and lamellar macular hole (MH).  Methodology This retrospective cross-sectional study, conducted at the ophthalmology department of Shifa International Hospital, Islamabad, was done on 89 eyes of 85 patients who underwent 27G PPV for full-thickness and lamellar MH with a postoperative follow-up period of six months.  Results The mean age was 61.9 ± 17.3 years with 57.3% being males. Most of the eyes had idiopathic stage III full-thickness MH (n=34, 38.2 %). The total mean operating time was 42.5 ± 19.8 minutes. During surgery, 48 (53.9%) eyes had concurrent phacoemulsification. Hexafluoroethane was the most commonly used tamponade agent (n=81, 91%). Postoperatively, the primary closure rate was 93.2% (n=83) while the final closure rate was 100% (n=6) either by prolonged posturing (n=3, 3.3%) or by an additional procedure involving autologous internal limiting membrane (ILM) transplant (n=3, 3.3%). The complication rate was 2.2% including iatrogenic retinal tear (n=1, 1.1%) and raised IOP (n=1, 1.1%). The overall best-corrected visual acuity (BCVA) improved significantly from 1.20 ± 0.67 to 0.31 ±0.17 (p=<0.001). Conclusion As per this study, 27G PPV is a practical and efficient surgical system with substantial anatomical success, minimal complication, and considerable visual recovery rates in eyes with full thickness and lamellar MH. We suggest 27G PPV with ILM peeling and medium-acting intraocular gas as the standard procedure for MH.

Intravitreal dexamethasone: variation of surgical technique and prevention of ocular complications with ASOCT follow-up

PURPOSE

To verify the correct decision-making procedure on performing an intravitreal injection by investigating the in vivo wound morphology and evolution of 22-gauge wounds after dexamethasone oblique injection with anterior segment optical coherence tomography (OCT).

DESIGN

Prospective, observational consecutive case series.

METHODS

Subjects underwent a dexamethasone injection at University Eye Clinic of Turin. All the injections have been performed in an oblique (aka beveled or angled) fashion. Patients were divided according to the number of injections already performed with dexamethasone. Group 1 consisted of patients at the first injection, group 2 of patients at a second or more injection always in the same quadrant, and group 3 of patients at the second or more injection in a different quadrant. The incisions were imaged with the Heidelberg SPECTRALIS OCT device on postoperative days 1, 8, and 15. The main outcome measure was wound structure/characteristics (e.g., presence of gaping) as evaluated with OCT. Surgical and ocular parameters were also recorded.

RESULTS

Thirty-three consecutive patients were investigated. OCT demonstrated closed wounds in all eyes on postoperative days 1, 8, and 15. In all patients, the external (entry) side of the incision was seen as a gape; however, the rest of the wound was closed. No complications were recorded in the different patients during the follow-up. In patients of group 1, we identified the scleral pathway in 10 eyes at day 1. At 8 days in 9 of 10 eyes, the sclera had returned to its restitutio ad integrum. In patients of group 2, the scleral pathway was recognizable on the first day of control; in 7 patients, this was accompanied by the presence of intrascleral edema with peri-wound fluid. At the 8-day checkup, 3 eyes still showed signs attributable to the intrascleral pathway accompanied by peri-wound edema. In group 3, it was possible to identify the intrascleral pathway in 8 patients. There were no signs of intrascleral peri-wound edema or other anatomical changes in 9 patients as early as the first day. In the 8-day follow-up, the signs of scleral edema were absent in the single patient who presented them. At 15 days, there were no signs of scleral pathway in all eyes analyzed.

CONCLUSIONS

Speaking of intravitreal injections of slow-release dexamethasone, the technique that involves moving the conjunctiva and a beveled or angled sclerotomy after a careful choice of the injection site, paying attention to vary the quadrant involved with each puncture, reduces the number of days of closure of the sclera via and the scleral damage, thus protecting the patient from complications. For the future, it is hoped that the operating microscope and intraoperative OCT will be used on every occasion.

[Postoperative endophthalmitis-a review of literature]

Postoperative endophthalmitis is one of the most feared complications for ophthalmologists, and the number of infections after intraocular procedures have been increasing. Nonetheless, a prompt intervention can result in the recovery of vision. In the past, endophthalmitis after cataract surgery was accountable for the majority of cases but is becoming less frequent due to the progress of surgical techniques and demographic developments with a steadily increasing number of intravitreal injections. In this article, the different forms of postoperative endophthalmitis are assessed in terms of pathophysiology and their specific characteristics depending on their etiology.

Comparison of safety and effectiveness between 23-gauge and 25-gauge vitrectomy surgery in common vitreoretinal diseases

PURPOSE

To assess and compare safety and effectiveness between 23-gauge and 25-gauge vitrectomy systems for the treatment of common vitreoretinal diseases in non-vitrectomized eyes.

METHODS

Retrospective evaluation of patients who underwent pars plana vitrectomy from April 2018 to December 2019 at the Department of Ophthalmology and Optometry at the Medical University of Vienna (MUV) for the following indications: macular epiretinal membrane, macular hole, macular lamellar hole, vitreous hemorrhage, vitreous opacities, vitreomacular traction syndrome and macular edema.

RESULTS

201 eyes of 195 patients that underwent 23-gauge (n = 105 eyes) or 25-gauge (n = 96 eyes) vitrectomy were included in this study. The mean best-corrected visual acuity (BCVA) improved at 1-3 months postoperatively and beyond 3 months in both gauge groups. Risk of any complication within 1 month postoperatively was lower in the 25-gauge group, but the difference was statistically not significant (HR [95% CI]: 0.95 [0.53; 1.70], p = 0.85). Intraocular pressure less than 5 mmHg was observed in 2 eyes (2%) in the 23-gauge group at the first postoperative day. Intraocular pressure elevation over 25 mmHg occurred in 5 eyes (2 eyes, 2%, in 23-gauge and 3 eyes, 3%, in 25-gauge group) at postoperative day 1, between 7 and 28 days in 5 cases (2 eyes, 2%, in 23-gauge and 3 eyes, 3%, in 25-gauge group), and in 2 eyes (2%) of the 23-gauge group at postoperative day 145 and 61, respectively. Retinal detachment occurred in 1 eye (1%) in the 23-gauge and in 3 eyes (3%) in the 25-gauge group. We did not observe any cases of endophthalmitis.

CONCLUSION

Results in terms of safety, surgical success and visual outcomes for the treatment of common vitreoretinal surgery indications seem to be comparable between 23-gauge and 25-gauge vitrectomy systems, indicating that the two gauge systems can be used equally in the clinical routine.

INCIDENCE AND RISK FACTORS FOR HYPOTONY AFTER 25-GAUGE PARS PLANA VITRECTOMY WITH NONEXPANSILE ENDOTAMPONADE

PURPOSE

The purpose of this study was to assess the incidence and risk factors for early postoperative hypotony after 25-gauge pars plana vitrectomy with nonexpansile endotamponade.

METHODS

A retrospective study of consecutive patients who underwent 25-G pars plana vitrectomy. Hypotony was defined as an intraocular pressure of 5 mmHg or less after surgery and ocular hypertension as an intraocular pressure greater than 21 mmHg.

RESULTS

Overall, 307 eyes of 307 patients with a mean age of 61.7 ± 14.3 of which 56.7% were males were included. Hypotony was identified in 5.2% of cases (n = 16) at Day 1 and 0.7% (n = 2) at Week 1 with no hypotony-related complications. The hypotony group had a higher number of previous vitreoretinal surgeries (1.5 ± 1.1 vs. 0.4 ± 0.7, P < 0.001) and a higher prevalence of preoperative ocular hypertension (22.2% vs. 4.8%, P = 0.02), pseudophakia (77.8% vs. 48.4%, P = 0.01), silicone oil removal (61.1% vs. 8.3%, P < 0.001), and external diathermy performed (55.6% vs. 20.1%, P = 0.001). In stepwise multivariate analysis, significant parameters were silicone oil removal (R = 16.34%, odds ratio 13.45, P < 0.001), pseudophakia (R = 5.69%, odds ratio 3.65, P = 0.03), and younger age (R = 2.68%, odds ratio 0.96, P = 0.04).

CONCLUSION

Silicone oil removal is a significant risk factor for early postoperative hypotony after 25-G pars plana vitrectomy.

Research Trends and Hotspot Analysis of Conjunctival Bacteria Based on CiteSpace Software

OBJECTIVE

To sort out the literature related to conjunctival bacteria and summarize research hotspots and trends of this field.

MATERIALS AND METHODS

The relevant literature data from 1900 to 2019 was retrieved from the Web of Science Core Collection database. After manual selection, each document record includes title, author, keywords, abstract, year, organization, and citation. We imported the downloaded data into CiteSpace V (version 5.5R2) to draw the knowledge map and conduct cooperative network analysis, discipline and journal analysis, cluster analysis, and burst keyword analysis.

RESULTS

After manual screening, there were 285 relevant papers published in the last 28 years (from 1991 to 2019), and the number is increasing year by year. The publications of conjunctival bacteria were dedicated by 1381 authors of 451 institutions in 56 countries/regions. The United States dominates this field (82 literatures), followed by Germany (23 literatures) and Japan (23 literatures). Overall, most cited papers were published with a focus on molecular biology, genetics, nursing, and toxicology. Most papers fall into the category of ophthalmology, veterinary sciences, and pharmacology and pharmacy. The only organized cluster is the "postantibiotic effect," and the top 5 keywords with the strongest citation bursts include "postoperative endophthalmiti(s)," "infectious keratoconjunctiviti(s)," "conjunctiviti(s)," "resistance," and "diversity".

CONCLUSION

The global field of conjunctival bacteria has expanded in the last 28 years. The United States contributes most. However, there are little cooperation among authors and institutions. Overall, this bibliometric study organized one cluster, "postantibiotic effect", and identified the top 5 hotspots in conjunctival bacteria research: "postoperative endophthalmiti(s)," "infectious keratoconjunctiviti(s)," "conjunctiviti(s)," "resistance," and "diversity". Thus, further research focuses on these topics that may be more helpful to prevent ocular infection and improve prophylaxis strategies to bring a benefit to patients in the near future.

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.

Complications of vitreoretinal surgery

PURPOSE OF REVIEW

The present article reviews the most common and most serious vision-threatening and life-threatening complications of vitreoretinal surgery.

RECENT FINDINGS

Serious complications after vitreroretinal surgery are rare. Endophthalmitis for example has recently been estimated to occur in 0.08% of small gague vitrectomy. Other complications such as cataract are almost unavoidable, becoming visually significant in up to 80% of patients. The introduction of smaller gauge vitrectomy systems has reduced surgical times, conjunctival scarring and inflammation, and the rate of some complications such as retinal tears. Ocular venous air embolism is an exceedingly rare complication that is potentially life threating and therefore important for all vitreoretinal surgeons to be aware of.

SUMMARY

Though vitreoretinal surgery is well tolerated and effective, it is inevitable that all surgeons will experience complications and are therefore best served by understanding the potential complications, strategies to reduce the likelihood of them occurring, and ways to address them when they do happen.

Comparative study of straight vs angled incision in 27-gauge vitrectomy for epiretinal membrane

Purpose

The purpose of this study was to compare straight and angled incisions in 27-gauge microincision vitrectomy in patients with epiretinal membrane (ERM).

Methods

Seventy-three eyes of 68 patients with ERM who underwent straight (35 eyes) or angled incision (38 eyes) for 27-gauge microincision vitrectomy were retrospectively evaluated.

Results

No statistically significant difference was found between the two groups in postoperative logarithm of minimal angle of resolution best-corrected visual acuity. The intraocular pressure and rate of hypotony 1 day postoperatively did not differ between the straight- and angled-incision groups (intraocular pressure: 11.5 vs 13.4 mmHg, respectively; rate of hypotony: 20% vs 8%, respectively). Surgical wound closing occurred by postoperative day 10 in both groups.

Conclusion

A straight incision is as safe and useful in ERM vitrectomy as an angled one.

25-gauge vitrectomy and gas for the management of rhegmatogenous retinal detachment

AIMS

To evaluate the anatomical and functional results in patients with rhegmatogenous retinal detachment (RRD) who underwent 25-gauge pars plana vitrectomy (PPV) with gas tamponade.

MATERIALS AND METHODS

A retrospective evaluation of 126 eyes of 126 patients (79 men, 47 women) with RRD who underwent 25-gauge PPV with gas tamponade (13% C3F8 in 87 eyes, 20% SF6 in 39 eyes). 113 patients (89.7%), were operated on under local anaesthesia, 13 patients (10.3%) under general anaesthesia. Macula was detached in 85 eyes (67.5%). 53 eyes had pseudophakic RRD, 73 eyes were phakic. Anatomical success of the primary intervention, change in best corrected visual acuity (BCVA) and incidence of complications were assessed. An average follow-up period is 7.2 months (6-15).

RESULTS

With single operation, retinal attachment was achieved in 125 eyes (99.2%); the final anatomical success was 100%. The initial mean BCVA was 0.89 logMar (2.00 to 0.00); at the end of the follow-up period, it improved to 0.23logMAR (1.00 to -0.10), P < 0,0001. During the first post-intervention day, hypotony of the eye below 10 mmHg was observed in 1 patient (0.8%); on the contrary, intraocular pressure was temporarily increased to 25 mmHg and more in 36 patients (28.6%).

CONCLUSION

The surgical treatment of RRD using 25-gauge PPV with expansive gas tamponade renders excellent anatomical results and improvement in BCVA. The incidence of complications and necessity of sclerotomy suturing are low.

Outcomes of transconjunctival sutureless 27-gauge vitrectomy for vitreoretinal diseases

AIM

To evaluate the safety and efficacy profile of 27-gauge (27G) pars plana vitrectomy (PPV) for the treatment of various vitreoretinal diseases.

METHODS

The clinical outcomes of 61 eyes (58 patients) with various vitreoretinal diseases following 27G PPV were retrospectively reviewed.

RESULTS

Surgical indications included rhegmatogenous retinal detachment (n=24), full-thickness macular hole (n=12), diabetic retinopathy (n=11), vitreous hemorrhage (n=6), Eales disease (n=4), pathological myopia-related vitreous floater (n=2), and macular epiretinal membrane (n=2). The mean follow-up was 166.4±61.3d (range 98-339d). The mean logMAR best-corrected visual acuity (BCVA) improved from 1.7±1.1 [0.02 decimal visual acuity (VA) equivalent] preoperatively to 1.2±1.0 (0.06 decimal VA equivalent) at the last postoperative visit (P<0.001). The mean operative time was 49.9min. With the exception of complicated cataract in one eye, no intraoperative complications were encountered. No case required conversion to conventional 20-, 23- or 25G instrumentation in all surgical maneuvers except for silicone oil infusion, which required a 25G oil injection syringe. Postoperative complications included transient ocular hypertension, vitreous hemorrhage, persistent intraocular pressure elevation, subconjunctival oil leakage, and recurrent retinal detachment. No cases of hypotony, endophthalmitis, and sclerotomy-related tears were observed.

CONCLUSION

The current results suggest that 27G PPV system is a safe and effective treatment for various vitreoretinal diseases. When learning to perform 27G PPV, surgeons may encounter a learning curve and should gradually expand surgical indications from easy to pathologically complicated cases.

Postoperative Endophthalmitis: A Review of Risk Factors, Prophylaxis, Incidence, Microbiology, Treatment, and Outcomes

Postoperative endophthalmitis is one of the most feared complications of intraocular surgery. The most common types of intraocular surgeries performed worldwide are cataract extraction, glaucoma drainage implants/trabeculectomy, and pars plana vitrectomy. This review will focus on the clinical features, risk factors, prophylaxis, and treatment of endophthalmitis in these three main intraocular surgeries.

Comparison of clinical outcome between 23-G and 25-G vitrectomy in diabetic patients

PURPOSE:

To compare the clinical outcomes and complications between 23-G and 25-G vitrectomy in patients with diabetic vitreous hemorrhage (VH).

MATERIALS AND METHODS:

A retrospective comparative study comprising 69 eyes (36 eyes in 23-G group and 33 eyes in 25-G group) of 65 patients who underwent vitrectomy with air tamponade for diabetic vitreous hemorrhage (VH) with at least 6 months of follow-up was conducted.

RESULTS:

There were no significant differences between the two groups in age, gender, bilaterality, type of diabetes, presence of hypertension, lens status, and previous argon laser photocoagulation state (P > 0.05). Best-corrected visual acuity (BCVA) of both groups at postoperative 1 month logarithm of the minimum angle of resolution (logMAR) (1.06 ± 0.99, 0.90 ± 0.96), 3 months logMAR (1.07 ± 0.93, 0.83 ± 0.85), and 6 months logMAR (1.03 ± 0.89, 0.83 ± 0.85) significantly improved from the preoperative BCVA logMAR (2.03 ± 0.83, 2.15 ± 0.99) for 23-G group, 25-G group, respectively (P < 0.0001). There was no significant difference in BCVA between the two groups preoperatively and at 1, 3, and 6 months postoperatively (P = 0.566, 0.506, 0.333, and 0.445, respectively), incidence of intraoperative wound suturing (21.4%, 15.2%), postoperative hypotony (0.0%, 0.0%), early postoperative VH (POVH) (11.1%, 15.2%), late POVH (5.6%, 0.0%), retinal detachment (2.8%, 6.1%), neovascular glaucoma (92.8%, 9.1%), and endophthalmitis (0.0%, 0.0%) for 23-G group, 25-G group, respectively (P > 0.05).

CONCLUSION:

25-G vitrectomy is as effective for PDR as 23-G vitrectomy.

Vitreoretinal instruments: vitrectomy cutters, endoillumination and wide-angle viewing systems

There have been many advances in vitreoretinal surgery since Machemer introduced the concept of pars plana vitrectomy, in 1971. Of particular interest are the changes in the vitrectomy cutters, their fluidics interaction, the wide-angle viewing systems and the evolution of endoillumination through the past decade and notably in the last few years. The indications of 27-gauge surgery have expanded, including more complex cases. Cut rates of up to 16,000 cuts per minute are already available. New probe designs and pump technology have allowed duty cycle performances of near 100% and improved flow control. The smaller vitrectomy diameter can be positioned between narrow spaces, allowing membrane dissection and serving as a multifunctional instrument. Enhanced endoillumination safety can be achieved by changing the light source, adding light filters, increasing the working distance and understanding the potential interactions between light and vital dyes commonly used to stain the retina. Wide-angle viewing systems (contact, non-contact or a combination of both) provide a panoramic view of the retina. Non-contact systems are assistant-independent, while contact systems may be associated with better image resolution. This review will cover some current aspects on vitrectomy procedures, mainly assessing vitrectomy cutters, as well as the importance of endoillumination and the use of wide-angle viewing systems.

Endophthalmitis After Pars Plana Vitrectomy: Clinical Features, Risk Factors, and Management Outcomes

PURPOSE

To report the clinical presentations, risk factors, and outcomes of endophthalmitis after pars plana vitrectomy at 4 tertiary eye care centers of an institute in South India.

DESIGN

A retrospective case series.

METHODS

The records of 38,591 patients undergoing vitrectomy were reviewed using the coding assigned by the medical records department. Consecutive cases diagnosed as endophthalmitis after pars plana vitrectomy (PPV) between 1990 and 2014 for various indications were analyzed.

RESULTS

The clinical incidence of postvitrectomy endophthalmitis was 0.052%, and culture-positive incidence of postvitrectomy endophthalmitis was 0.031%. Twelve cases (60%) were culture positive. Mean presenting vision was 2.16 ± 1.51 logMAR (Snellen equivalent 20/2890). Seventeen eyes had received sutureless vitreous surgery (15 cases 23G, 2 cases 25G) and 3 eyes had received 20G suture-assisted vitreous surgery (P < 0.0001). The odds of developing endophthalmitis in sutureless versus sutured vitrectomy were 25.14 [95% confidence interval (CI), 7.37-85.84] (P < 0.0001) and those of developing endophthalmitis in sutureless surgery versus sutured with final tamponade of Ringer lactate (RL) were 19.53 (95% CI, 5.37-71.03) (P < 0.0001). In sutureless surgeries, the odds of developing endophthalmitis in RL tamponaded eyes versus non-RL ones was 4.39 (95% CI, 1.67-11.56) (P = 0.002). Mean interval between vitreous surgery and endophthalmitis was 4 ± 6.89 days; median, 1.5 days. Mean postoperative vision was 1.7 ± 1.36 logMAR (Snellen equivalent 20/1002) (P = 0.31).

CONCLUSIONS

Endophthalmitis after vitrectomy is an acute presentation. Sutureless surgery, especially with aqueous tamponade, has a higher risk. The visual outcome is relatively poor.

Subconjunctival Injection of Viscoelastic Material for Leaking Sclerotomy in Transconjunctival Sutureless Vitrectomy

Aim. To evaluate the effectiveness of subconjunctivally injected viscoelastic material (VEM) for the self-sealing of leaking sclerotomy in transconjunctival sutureless vitrectomy (TSV). Methods. This was a prospective interventional series. Subconjunctival injection of VEM was performed in eyes showing leaking sclerotomy at the end of TSV in selected cases. This procedure was performed in 24 consecutive eyes from 24 patients scheduled for 23- or 25-gauge TSV with phacoemulsification for various vitreoretinal diseases combined with cataracts. Results. Among the 24 eyes, 13 cases were scheduled for 23-gauge TSV, while 11 cases were scheduled for 25-gauge TSV. The average number of injection sites per eye was 1.7 ± 0.9 in the 23-gauge cases and 1.5 ± 0.7 in the 25-gauge cases. Leakage was most commonly observed at the vitrector site of the sclerotomy, while little leakage was observed at the illuminator site. There were no cases of postoperative hypotony. Conclusion. Subconjunctival injection of VEM was simple and effective for the self-sealing of leaking sclerotomy after TSV in selected cases.

Comparison of the effects of 23-gauge and 25-gauge microincision vitrectomy blade designs on incision architecture

Purpose

To compare the effects of different 23- and 25-gauge microincision vitrectomy trocar cannula entry systems on incision architecture.

Methods

We tested one ridged microvitreoretinal (MVR), one non-ridged MVR, one pointed beveled, and one round-tipped beveled blade (n=10 per blade design per incision type). Each blade’s straight and oblique incision architecture was assessed in a silicone disc simulating the sclera. Wound leakage under pressure and endoscopic observations were conducted on sclerotomy sites of isolated porcine eyes (n=4 per blade design) after simulated vitrectomy.

Results

Differences in blade design created distinct incision architecture. Incisions were linear with the ridged MVR blade, flattened “M-shaped” with the non-ridged MVR blade, asymmetrical chevron-shaped with the pointed beveled blade, and curved with the round-tipped beveled blade. With the exception of oblique entry incision thickness, both MVR blade designs created thinner incisions than the beveled blades at entry and exit sites. Only the ridged MVR blade created incisions with no leakage. Vitreous incarceration was observed with all trocar cannula systems.

Conclusion

Wound closure in porcine eyes was similar with all blades despite differences in incision architecture. Wound leakage occurred at low to moderate infusion pressures with most blades; no wound leakage was observed with ridged MVR blades.

Retrospective Comparison of 25- and 23-Gauge Microincision Vitrectomy Surgery and 20-Gauge Vitrectomy for the Repair of Macular Hole Retinal Detachment

PURPOSE

To compare the anatomical and functional outcomes of 25- and 23-gauge microincision vitrectomy surgery (25G and 23G MIVS) instrumentation with the standard 20G pars plana vitrectomy (20G PPV) system in the treatment of primary macular hole retinal detachment (MHRD).

DESIGN

A retrospective comparative study.

METHODS

Forty-six eyes of 45 patients with MHRD underwent pars plana vitrectomy from March 1, 2006 to April 31, 2011. Fourteen, 13, and 19 eyes underwent 20G PPV, 23G MIVS, and 25G MIVS, respectively. The analysis included characteristics of the patients, single operation reattachment rate, final reattachment rate, closure rate of the macular hole, and rate of complications. The median follow-up period was 273 days.

RESULTS

Preoperative characteristics were similar in the 3 groups. The single operation success rate was 11 (79%) of 14 for 20G PPV, 10 (77%) of 13 for 23G MIVS, and 14 (74%) of 19 for 25G MIVS (P = 0.95). The closure rate of the macular hole was 9 (64%) of 14 for 20G PPV, 9 (69%) of 13 for 23G MIVS, and 11 (58%) of 19 for 25G MIVS (P = 0.78). One hundred percent of patients achieved final reattachment after multiple surgeries, excluding 2 patients who dropped out during the follow-up period. Rates of visual recovery and complications, including hypotony, were similar for all 3 procedures.

CONCLUSIONS

The outcomes of 25G and 23G MIVS for the management of MHRD did not differ significantly from 20G PPV. Microincision vitrectomy surgery may be considered an alternative treatment, even for MHRD.

Endophthalmitis following pars plana vitrectomy: a literature review of incidence, causative organisms, and treatment outcomes

Endophthalmitis following pars plana vitrectomy is a very uncommon cause of endophthalmitis. Cases reported over the last decade show a decrease in incidence over time. To optimize visual outcome, early diagnosis and treatment are essential. In this review we report a summary of the incidence of endophthalmitis following vitrectomy, various risk factors for their occurrence, the microbiological profile and the visual outcomes post treatment.

Factors predicting duration of intraocular gas presence after 23-gauge transconjunctival sutureless vitrectomy for rhegmatogenous retinal detachment

BACKGROUND AND OBJECTIVE

To investigate factors predicting duration of intraocular gas presence in 23-gauge transconjunctival sutureless vitrectomy.

PATIENTS AND METHODS

Retrospective review of 130 eyes that underwent 23-gauge transconjunctival sutureless vitrectomy. At the end of surgery, gas exchange and sclerotomy massage to promote self-sealing were performed. If sclerotomy leakage was suspected despite sclerotomy massage, a suture was placed. Factors predicting duration of intraocular gas presence in 23-gauge transconjunctival sutureless vitrectomy were examined using multiple regression analysis. An F value greater than 2 and P value less than 0.05 were considered statistically significant.

RESULTS

Significant factors were axial length (F = 7.08; P < .05) and IOP on postoperative day 1 (F = 4.35; P < .05). Age, operation time, preoperative IOP, and number of sutured sclerotomies were not statistically significant.

CONCLUSION

Factors predicting duration of intraocular gas presence in 23-gauge transconjunctival sutureless vitrectomy were axial length and postoperative IOP on day 1.

Evaluation of Wound Morphology of Sclerotomy Sites of Sutureless Vitrectomy Using Spectralis Anterior Segment Optical Coherence Tomography

PURPOSE

The aim of the study was to evaluate wound morphology in vivo in eyes undergoing sutureless vitrectomy.

DESIGN

This was a prospective consecutive case series.

METHODS

Twenty eyes undergoing sutureless vitrectomy were evaluated using anterior segment optical coherence tomography on days 1, 15, and 30. Ten eyes each belonged to 23-gauge (group A) and 25-gauge (group B). Scans were taken on the incision sites. Group A cases were further divided into group A1 and A2 on the basis of the surgical time of less than 15 minutes' and more than 15 minutes' duration, respectively.

RESULTS

On day 1, the mean outer and inner incision diameters in group A were 236.6 and 146 µm, and those for group B were 118.6 and 90 µm. A significant decrease (P < 0.0001) in both the port sizes was observed in both groups' follow-up. Group B showed significant decrease (P < 0.0001) in the port sizes on l follow-up as compared with group A. Group A1 had smaller incision size as compared with group A2 on the first postoperative day, although not statistically significant(P > 0.05).

CONCLUSIONS

In both groups, the sclerotomy incisions showed good healing at 1-month duration. The 25-gauge sclerotomies showed better healing characteristics of wound morphology as compared with the 23-gauge sclerotomies.

Diathermy of leaking sclerotomies after 23-gauge transconjunctival pars plana vitrectomy: a prospective study

PURPOSE

To evaluate the efficacy of bipolar diathermy in ensuring closure of leaking sclerotomies after complete 23-gauge transconjunctival sutureless vitrectomy.

METHODS

In this prospective, interventional case series, in 136 eyes of 136 patients with at least one leaking sclerotomy at the end of a complete 23-gauge transconjunctival sutureless vitrectomy, external bipolar wet-field diathermy was applied to leaking sclerotomies, including the conjunctiva and sclera. Intraoperative wound closure, and postoperatively, at 6 hours, 1 day and 3 days, sclerotomies leakage, intraocular pressure, hypotony, and hypotony-related complications were evaluated.

RESULTS

Intraoperative closure was achieved in 231 of 238 leaking sclerotomies (97%) that received diathermy. One of these with postoperative leakage needed suture. Compared with baseline (14.4 ± 2.8 mmHg), mean intraocular pressure was lower at 6 hours (13.2 ± 3.8 mmHg, Tukey-Kramer P < 0.001) and not different at 24 hours or 72 hours. Hypotony (intraocular pressure <5 mmHg) was observed in 6 eyes (4.5%) at 6 hours, in 2 (1.5%) at 24 hours, and in none at 3 days. Logistic regression analysis showed that, 6 hours postoperatively, hypotony was related to younger age (≤50 years) at surgery (P = 0.031). No hypotony-related complications were recorded.

CONCLUSION

Bipolar wet-field diathermy of sutureless sclerotomies is an effective method for ensuring a leaking sclerotomies closure.

Safety of 20-gauge transconjunctival sutureless vitrectomy

PURPOSE

To study the safety of 20-gauge transconjunctival sutureless vitrectomy.

METHODS

Clinical data of patients who underwent 20-gauge transconjunctival sutureless vitrectomy for the first time, for various disorders, were reviewed retrospectively. The main outcome measures were the number of sclerotomies requiring suturing as well as the intra- and postoperative complications.

RESULTS

A total of 179 operations were performed. Indications for vitrectomy included 68 idiopathic epiretinal membranes, 26 macular holes, 23 phakic and 16 pseudophakic retinal detachments, and 46 various other, less common etiologies. Of these 179 operations, 166 (93%) were sutureless. Of the 537 sclerotomies created, 25 (5%) received a single transconjunctival-scleral suture. Intraoperative complications included premature dislodging of the cannulas in 2 sclerotomies and an iatrogenic horseshoe tear at 1 sclerotomy site. Postoperative complications comprised transient hypotony in 14 cases, subconjunctival gas in 2 cases, and choroidal effusion in 1 case. No serious complications (such as endophthalmitis) were observed.

CONCLUSION

20-gauge transconjunctival sutureless vitrectomy can be considered safe, as the intra- and postoperative complications observed are neither numerous nor significant. Sclerotomies appear to be safe and relatively easy to perform, without compromising the advantages of sutureless surgery.

Light-activated, in situ forming gel for sustained suprachoroidal delivery of bevacizumab

A light-activated polycaprolactone dimethacrylate (PCM) and hydroxyethyl methacrylate (HEMA) based gel network was developed to sustain the release of stable, active bevacizumab (an anti-VEGF antibody used to treat choroidal neovascularization) and used to assess sustained ex vivo delivery in rabbit eyes and in vivo delivery in rat eyes following in situ gel formation in the suprachoroidal space. PCM was synthesized from polycaprolactone diol (PCD) and evaluated using NMR spectroscopy. PCM was used to cross-link HEMA in the presence of 365 nm UV light and 2,2-dimethoxy-2-phenylacetophenone (DMPA) as a photoinitiator. Bevacizumab was entrapped in the gel using three different cross-linking durations of 3, 7, and 10 min. In vitro release of bevacizumab in PBS pH 7.4 at 37 °C during a 4 month study was quantified using a VEGF-binding based ELISA. The stability of released bevacizumab was monitored by size exclusion chromatography (SEC) and circular dichroism. Alexa Fluor 488 dye conjugated bevacizumab mixed with polymers was injected suprachoroidally in rabbit eyes to study the effect of different cross-linking durations on the spread of the dye conjugated bevacizumab. In vivo delivery was assessed in Sprague-Dawley (SD) rats by injecting Alexa Fluor 488 dye conjugated bevacizumab mixed with polymers followed by cross-linking for 10 min. Spread in the rabbit eyes and in vivo delivery in rat eyes was monitored noninvasively using a fundus camera and Fluorotron Master. The formation of PCM was confirmed by the disappearance of hydroxyl peak in NMR spectra. A cross-linking duration of 10 min resulted in a burst release of 21% of bevacizumab. Other cross-linking durations had ≥62% burst release. Bevacizumab release from 10 min cross-linked gel was sustained for ∼4 months. Release samples contained ≥96.1% of bevacizumab in the monomeric form as observed in SEC chromatograms. Circular dichroism confirmed that secondary β-sheet structure of bevacizumab was maintained after release from the gel. As the cross-linking duration was increased to 10 min, the gel/antibody was better confined at the injection site in excised rabbit eye suprachoroidal space. Delivery of Alexa Fluor 488 dye conjugated bevacizumab was sustained for at least 60 days in the suprachoroidal space of SD rats. PCM and HEMA gel sustained bevacizumab release for 4 months and maintained the stability and VEGF-binding activity of bevacizumab. Therefore, light-activated PCM and HEMA gel is suitable for in situ gel formation and sustained protein delivery in the suprachoroidal space.

A systematic review of endophthalmitis after microincisional versus 20-gauge vitrectomy

BACKGROUND

Endophthalmitis is a rare but severe complication of vitrectomy.

CLINICAL RELEVANCE

Post-surgical endophthalmitis is suspected to be more frequent after microincisional (23- and 25-gauge) compared with standard (20-gauge) vitrectomy.

METHODS

We conducted a systematic review of studies that compared microincisional and standard vitrectomy by searching MEDLINE and EMBASE up to November 2012. We used the Bayesian meta-analysis method to compute the odds ratio (OR) of endophthalmitis. We conducted subgroup analyses to compare the effect of different incision types and use of perioperative antibiotics.

RESULTS

We identified 3 small randomized and 18 nonrandomized studies that reported 68 cases of endophthalmitis in 148 643 participants. The overall OR of endophthalmitis for microincisional versus standard vitrectomy was 2.3 (95% credible interval [CrI], 0.8-5.8). We found an increased risk of endophthalmitis using a microincisional straight approach compared with standard vitrectomy (OR, 15.1; 95% CrI, 2.01-179), but not for a beveled approach (OR, 0.82; 95% CrI, 0.23-2.28). The OR of studies that reported on mixed microincision was between these 2 values (OR, 4.4; 95% CrI, 1.32-14.3). We estimated that the overall rate of endophthalmitis with 20-gauge vitrectomy was 3 cases in 10 000 procedures, and the probability that a beveled microincision increases the rate of endophthalmitis to more than 6 or 9 events was small (no more than 5% or 1%, respectively).

CONCLUSIONS

We did not find an increased risk of endophthalmitis for microincisional vitrectomy compared with standard vitrectomy. The beveled approach seems to be safer than a straight approach, supporting the current recommendation of its adoption in microincisional vitrectomy. However, these findings must be interpreted cautiously because of the small number of endophthalmitis events reported from included studies.

In vivo comparison of 23- and 25-gauge sutureless vitrectomy incision architecture using spectral domain optical coherence tomography

Purpose. To investigate the in vivo incision architecture using spectral domain optical coherence tomography (SD-OCT) in 23-gauge and 25-gauge transconjunctival sutureless pars plana vitrectomy (TSPPV). Methods. A prospective observational study of 22 eyes of 22 patients that underwent three-port 25-gauge (10 eyes) or 23-gauge (12 eyes) TSPPV was performed. The three sclerotomies sites in each eye were analyzed by Corneal Adapter Model (CAM) RTVue SD-OCT (Optovue Inc., Fremont, CA, USA) with wound cross-section images (longitudinal and transversal) on days 1, 7, and 30 postoperatively. Transversal and longitudinal length, location, angle between the conjunctival surface tangent and the incision plane, and architecture deformations were evaluated. Results. All patients (22 eyes) completed the study and surgeries lasted less than 60 minutes. All wounds were obliquely performed, 23-gauge mean angle was 23 ± 5°, and 25-gauge angule was 21 ± 4°. Twenty-three-gauge sclerotomy transversal mean length was 1122 ± 242 μm and 25-gauge transversal sclerotomy mean length was 977 ± 174 μm; 23-gauge longitudinal mean length was 363 ± 42 μm and 25-gauge longitudinal sclerotomy mean length was 234 ±19 μm; 23-gauge open wound thickness mean was 61 ± 28 μm and 25-gauge open wound thickness mean was 22 ± 6 μm. All results were statistically significant (P < 0.05). No vitreous incarceration or silicone oil residue was observed in incision sites with both gauges. Conclusions. The 23-gauge and 25-gauge architectural wound constructions were well visualized using CAM SD-OCT. Statistical differences between the two gauges were observed throughout the study period.

[Sclerotomies analysis using Spectral Domain OCT in sutureless vitrectomies complicated by endophthalmitis]

INTRODUCTION

Transconjunctival sutureless vitrectomy is a recent advance in vitreoretinal surgery. Some authors have reported an increased risk of postoperative hypotony and endophthalmitis and recommend the creation of oblique incisions, intended to be self-sealing, so as to reduce these risks. However, there is still a debate about the best architecture for transconjunctival sutureless incisions.

MATERIALS AND METHODS

We report two cases of acute endophthalmitis occurring after 23 and 25 gauge transconjunctival sutureless vitrectomy. We analyzed the scleral incisions using the anterior segment module of the Spectralis(®) OCT. To our knowledge, this is the first direct description of the appearance of sclerotomies associated with endophthalmitis.

RESULTS

The anterior segment module of Spectralis(®) OCT permitted a high-resolution evaluation of the architecture of the scleral incisions. We found straight, gaping incisions with misaligned edges and vitreous incarceration.

DISCUSSION

By way of these two case reports and a review of the literature, we discuss the contribution of anterior segment OCT in the analysis of scleral incision architecture in sutureless vitrectomy. Our findings are consistent with those reported in the literature. The presence of a direct incision, wound gap or edge misalignment are associated with an increased risk of early leakage and postoperative hypotony.

CONCLUSIONS

The anterior segment module of the Spectralis(®) OCT is a valuable tool for non-invasive, painless and high-resolution documentation of sutureless vitrectomy incisions. It allows for causal analysis and better understanding of the conditions associated with endophthalmitis after sutureless vitrectomy.

Incidence of iatrogenic peripheral retinal breaks in 23-gauge vitrectomy for macular diseases

PURPOSE

To assess the incidence of iatrogenic peripheral retinal breaks in 23-gauge vitrectomy for macular diseases and to compare it with 20-gauge vitrectomy.

METHODS

Retrospective, comparative, interventional case series. We compared the incidence of iatrogenic peripheral retinal breaks in 176 eyes undergoing 23-gauge vitrectomy between January 2007 and November 2009 (23-gauge group) and 153 eyes undergoing 20-gauge vitrectomy between January 2004 and June 2006 (20-gauge group) for either idiopathic macular holes or idiopathic epiretinal membranes. All surgeries were performed by one surgeon at a single hospital. Main outcome measure was the incidence rate of iatrogenic peripheral retinal breaks discovered intraoperatively and postoperatively.

RESULTS

Iatrogenic peripheral retinal breaks occurred in 1 eye in the 23-gauge group and in 11 eyes in the 20-gauge group during surgery. Additional iatrogenic retinal breaks were found in 1 eye in the 23-gauge group and in 2 eyes in the 20-gauge group within 1 month after surgery. The overall incidence of iatrogenic peripheral retinal breaks was 1.1% (2 of 176) in the 23-gauge group and 8.5% (13 of 153) in the 20-gauge group. The difference was statistically significant (P = 0.0023).

CONCLUSION

The incidence of iatrogenic peripheral retinal breaks during vitrectomy for macular diseases is significantly lower in 23-gauge vitrectomy than in 20-gauge vitrectomy.

Primary 23-gauge sutureless vitrectomy for rhegmatogenous retinal detachment

Aims:

To report a prospective non-comparative consecutive interventional study on the safety and efficacy of 23-Gauge transconjunctival sutureless pars plana vitrectomy for primary rhegmatogenous retinal detachment (RRD).

Materials and Methods:

Fifty eyes of 50 consecutive patients were recruited between June 2007 and January 2008. All surgeries were performed using the one-step 23-Gauge system with angled incisions. The surgical protocol consisted of a minimum of eight clinical visits: baseline, 1 day, 1 week, 1-, 3- and 6- months after the initial surgery. The endpoints were anatomical, functional results and complications arising from the surgery.

Results:

Anatomical success was achieved in 82% of cases (41 out of 50) with single surgery and rose to 98% (49 out of 50) with additional surgery. Mean visual acuity improved from logMAR 0.48(SD 0.36) to 0.26(SD 0.31), P < 0.001. Two cases with ocular hypotony, defined as an intraocular pressure ≤ 6mmHg, that were associated with a choroidal detachment were seen.

Conclusions:

Acceptable anatomical and functional success rates can be achieved with primary 23-Gauge transconjunctival sutureless vitrectomy for RRD. We found that the approach technique is different from conventional vitrectomy and the complications arising from post surgical hypotony and leakage from sclerotomies are potentially higher compared to 20-Gauge vitrectomy.

Profound postoperative hypotony with globe collapse after 25-gauge pars plana vitrectomy

PURPOSE

To report a series of cases of profound hypotony with globe collapse on postoperative day 1 after sutureless 25-gauge pars plana vitrectomy and to identify common risk factors for this complication.

METHODS

Retrospective chart review of three patients. Ocular history and surgeries, preoperative diagnosis, operative technique, postoperative and final visual acuities, reformation intervention, and need for additional surgery were reviewed.

RESULTS

Three cases were reviewed. Patient ages were 22, 53, and 53 years. All patients had a history of a rhegmatogenous retinal detachment repaired by surgery and all had at least one vitrectomy. Two had a prior scleral buckle and two had pathologic myopia. All patients underwent sutureless 25-gauge pars plana vitrectomy. No patient had intraocular air, gas, or silicone oil tamponade. All patients presented on postoperative day 1 with globe collapse, hand motion vision, and scleral infolding. All patients underwent office-based injection of sterile balanced salt solution or air. One patient required an additional procedure-operative closure of sclerotomies and intraocular gas tamponade. All three patients attained a final Snellen visual acuity of 20/50 or 20/60.

CONCLUSION

These cases represent a small fraction (0.12%) of patients who underwent 25-gauge pars plana vitrectomy by one surgeon. Patients had several risk factors, including severe eye disease, prior retinal detachment repair, prior vitrectomy, pathologic myopia, and lack of intraocular tamponade. In patients with several risk factors, consideration should be given for intraocular gas or air injection or sclerotomy closure.

Study of intraocular pressure after 23-gauge and 25-gauge pars plana vitrectomy randomized to fluid versus air fill

PURPOSE

To determine if a difference in intraocular pressure (IOP) exists after small-gauge pars plana vitrectomy randomized to fluid versus 80% sterile air fill.

METHODS

Ninety-two eyes undergoing 23-gauge and 25-gauge transconjunctival pars plana vitrectomy were randomized to fluid versus air fill, and IOP was measured at 5 different time points.

RESULTS

There is no difference in the mean IOP for eyes undergoing small-gauge pars plana vitrectomy randomized to fluid versus air fill after vitrectomy. Using 23-gauge instrumentation, the mean immediate and 2-hour postoperative IOPs were statistically lower than the mean preoperative IOP. The mean Postoperative Day 1 and Week 1 IOPs were statistically higher than the mean immediate postoperative IOP. Using 25-gauge instrumentation, the mean IOP was not statistically different at any time points in the 2 groups. When comparing 23-gauge with 25-gauge instrumentation, the immediate postoperative IOP was statistically lower and the rate of suture closure for sclerotomies was higher for 23-gauge vitrectomy.

CONCLUSION

When performing 23-gauge or 25-gauge pars plana vitrectomy, there was no difference in mean IOP for fluid- versus air-filled eyes. However, the mean IOP in the immediate postoperative period was statistically lower, and there was a higher rate of suture closure for 23-gauge compared with 25-gauge instrumentation.

Miyake-Apple view of inner side of sclerotomy during microincision vitrectomy surgery

PURPOSE

To examine the inner surface of the sclerotomy during microincision vitrectomy surgery by Miyake-Apple view.

METHODS

The anterior half of porcine eyes was attached to a transparent acrylic plate with cyanoacrylate glue. Then, either a 23-gauge or a 25-gauge trocar-cannula was inserted through the sclera obliquely. The inner surface of the entrance site was observed posteriorly by Miyake-Apple view. These images were compared with the endoscopic view of two patients who underwent vitreous surgery for an epiretinal membrane.

RESULTS

When the trocar-cannula was inserted obliquely, the Miyake-Apple view showed that the ciliary epithelium at the sclerotomy site was stretched. When the trocar-cannula was inserted vertically, the ciliary epithelium was folded, and the folds remained even after the trocar was removed. Vitreous strands were seen incarcerated into the sclerotomy site. In human eyes, a folding of the ciliary epithelium was not clearly seen with the endoscopic view but the incarcerated vitreous was seen.

CONCLUSION

The Miyake-Apple view provided a precise, in vivo, observation of the inner surface of the entry site. It disclosed the morphological stress on the ciliary epithelium by the sclerotomy.

Vitreous hemorrhage after the 25-gauge transconjunctival sutureless vitrectomy for proliferative diabetic retinopathy

PURPOSE

To address the incidence, clinical course, and risk factors for postoperative vitreous hemorrhage (PVH) after a 25-gauge transconjunctival sutureless vitrectomy for proliferative diabetic retinopathy.

METHODS

A consecutive series of eyes underwent 25-gauge transconjunctival sutureless vitrectomies for proliferative diabetic retinopathy. The best-corrected visual acuities and intraocular pressures were measured, and the complications were prospectively evaluated 1 day, 1 week, 1 month, and 3 months postoperatively, then as needed.

RESULTS

The mean postoperative follow-up was 11.0 ± 6.3 months (range, 6-28 months). Of 93 eyes, 42 had PVH on Day 1 (immediate PVH) but the presence and degree of PVH did not affect visual recovery and only 4 eyes did not clear for 1 month (persistent PVH). Recurrent PVH occurred in 11 eyes. Eight eyes had hypotony on Day 1, and patients who experienced postoperative hypotony had an 11.20-fold increased risk of immediate PVH > Grade 2. In the cases that needed intravitreal tamponade, the risk of recurrent PVH was 3.03-fold higher.

CONCLUSION

After 25-gauge transconjunctival sutureless vitrectomies for proliferative diabetic retinopathy, postoperative hypotony and the need for tamponade increased the rates of immediate and recurrent PVH, respectively. Immediate PVH occurred in 45.2% of the patients but did not affect early visual recovery. A 25-gauge transconjunctival sutureless vitrectomy resulted in a favorable incidence of recurrent PVH (11.8%) during the first 6 months.

Advantages and limitations of small gauge vitrectomy

Small gauge vitrectomy utilizing 23- and 25-gauge instrumentation has definite advantages, but also limitations, due to the physics of smaller instruments and sutureless surgery. Higher infusion and aspiration pressures are needed to remove the vitreous using 23- and 25-gauge probes. The advantages include decreased surgical times, less tissue manipulation, reduced inflammation and pain postoperatively with more rapid visual recovery. A disadvantage is greater instrument flexion than 20-gauge probes, making small gauge vitrectomy more appropriate for indications such as vitreous opacities, epiretinal membranes, macular holes, and simple retinal detachments. There are also some increased complications related to small gauge vitrectomy, including dislocation of cannulas intraoperatively, early postoperative hypotony, choroidal detachment, and possibly an increased risk of infectious endophthalmitis.

Multicenter survey with a systematic overview of acute-onset endophthalmitis after transconjunctival microincision vitrectomy surgery

PURPOSE

To explore the incidence and visual outcomes of acute-onset endophthalmitis after transconjunctival microincision vitrectomy surgery (MIVS).

DESIGN

Retrospective, interventional, multicenter survey with a systematic review.

METHODS

A clinical database search was performed at 27 institutions involving 43 868 consecutive patients who underwent vitrectomy between November 2003 and October 2008 to identify all patients with endophthalmitis after vitrectomy. A systematic review of studies reporting the endophthalmitis rates after MIVS versus 20-gauge vitrectomy was conducted to assess the pooled incidence rates of postvitrectomy endophthalmitis.

RESULTS

The endophthalmitis rates from the multicenter survey were 0.034% (10 cases per 29 030 eyes) after 20-gauge vitrectomy and 0.054% (8 cases per 14 838 eyes) after MIVS, with no significant (P = .603) differences between groups. Although the incidence in 25-gauge cases (6 per 8238 eyes; 0.073%) was greater than in 23-gauge cases (2 per 6600 eyes; 0.030%), the difference was not significant (P = 0.451). Of 8 eyes in which endophthalmitis developed after MIVS, 6 eyes (75%) had a final visual acuity of 0.5 or better, and none lost light perception. By combining the results of 7 studies, including the current multicenter survey, meta-analyses from a total of 77 956 cases at the baseline showed that the pooled endophthalmitis rates after MIVS (0.08%; 95% confidence interval, 0.030% to 0.164%) and after 20-gauge vitrectomy (0.030%; 95% confidence interval, 0.012% to 0.048%) did not differ significantly (P = .207, pooled risk difference; 0.0005 [95% confidence interval, -0.0002 to 0.0012]).

CONCLUSIONS

The incidence of postvitrectomy endophthalmitis was low with no significant differences between MIVS and 20-gauge vitrectomy.

Three-step incision for 23-gauge vitrectomy reduces postoperative hypotony compared with an oblique incision

BACKGROUND AND OBJECTIVE

to assess the efficacy and safety of the newly developed three-step incision method of performing 23-gauge vitrectomy.

PATIENTS AND METHODS

a retrospective comparative study in which a consecutive series of 45 eyes that underwent the three-step incision type of 23-gauge vitrectomy was compared with a series of 27 consecutive eyes that had previously undergone the oblique incision type of 23-gauge vitrectomy.

RESULTS

no cases of postoperative hypotony (< 6 mm Hg) were noted in the three-step group compared with 3 cases (11%) in the oblique group (P = .05). The three-step incision resulted in a significantly higher mean intraocular pressure than the conventional incision on postoperative day 1 (14.1 ± 6.7 mm Hg vs 10.9 ± 3.7 mm Hg; P = .05), but there was no significant difference after 1 week.

CONCLUSION

the three-step incision for performing 23-gauge vitrectomy effectively prevented postoperative hypotony and demonstrated a safety profile comparable to that of the oblique incision.