Evaluation of wound closure using different incision techniques with 23-gauge and 25-gauge microincision vitrectomy systems. Retina. 2008;28:242-248. [PMID: 18301029 DOI: 10.1097/iae.0b013e318156dea3]

Conjunctival Pigmentation Following Pars Plana Vitrectomy (PPV) for Rhegmatogenous Retinal Detachment: Risk Factors and Outcomes

Purpose: To investigate the incidence and the risk factors for conjunctival pigmentation at the sclerotomy sites following valved and non-valved cannula pars plana vitrectomy (PPV) performed by different surgical techniques.

Methods: This is a prospective observational study which included 70 eyes of 70 patients who underwent PPV for rhegmatogenous retinal detachment with follow-up visits at 1, 3, 6, 12, and 24 months. Twenty-eight eyes were operated using 25G non-valved cannulas (Group A), 22 eyes using 25G non-valved cannulas (Group B), and 20 eyes using 25G valved cannulas (Group C). The evaluated clinical parameters include the surgical technique, the patients' age, the number of retinal tears, the tamponade agent, the presence of residual sub-retinal fluid (SRF), and the duration of postoperative posturing.

Results: Group A was associated with significant conjunctival pigmentation at up to 6 months after PPV. Sulfur hexafluoride (SF6) gas tamponade was associated with less conjunctival pigmentation at 3 months follow-up visit [odds ratio, OR 0.09 (95% confidence interval, CI 0.01; 0.67)], whereas the presence of residual SRF was a significant risk factor for postoperative pigmentation at 1-year follow-up visit [OR 5.89 (95% CI 1.84; 23.12)]. The area of measured pigmentation was also positively correlated to the number of retinal tears at all follow-up visits over 2 years. Six patients presented with conjunctival pigmentation at 2 years follow-up visit.

Conclusion: New vitrectomy techniques with valved cannulas prevent the postoperative appearance of conjunctival pigmentation. The number of retinal tears, the presence of SRF, and the use of long-standing tamponade agents were the most significant predisposing factors. The post-vitrectomy conjunctival pigmentation gradually reduces over time.

Septum-sparing minimally invasive technique for levator advancement surgery in aponeurotic ptosis

PURPOSE

To evaluate the outcome of small incision levator advancement with septum-sparing technique and compare it with standard levator advancement.

METHODS

The surgical findings and clinical data of patients with aponeurotic ptosis who underwent small incision or standard levator advancement surgery in our clinic between 2018 and 2020 were analyzed retrospectively. For both groups; age, gender, systemic and ophthalmic comorbidities, levator function, preoperative and postoperative margin-reflex distance, change in margin-reflex distance after surgery, symmetry between the eyes, follow-up time, perioperative and postoperative complications (under/overcorrection, contour irregularity, lagophthalmos) were all evaluated and recorded.

RESULTS

The study included 82 eyes, 46 from 31 patients in Group I who had small incision surgery, and 36 from 26 patients in Group II who had standard levator surgery. There was no statistically significant difference in surgical success between the two groups (80% and 81% respectively, p = 0.692). The levator function and preoperative margin-reflex distance correlated positively with surgical success.

CONCLUSION

Small incision levator advancement is a less invasive procedure than standard levator advancement because of the smaller skin incision and preservation of orbital septum integrity, but it requires good knowledge of eyelid anatomy and experience in eyelid surgery. In patients with aponeurotic ptosis, this surgery can be performed as a safe and effective surgical technique with a similar success rate as standard levator advancement.

Intraoperative choroidal detachment during small-gauge vitrectomy: analysis of causes, anatomic, and visual outcomes

INTRODUCTION

To investigate the incidence and causes of intraoperative choroidal detachment (CD) during small-gauge vitrectomy, as well as the anatomic and visual outcomes.

METHODS

We retrospectively reviewed the medical records of 1026 consecutive patients who underwent small-gauge vitrectomy from June 2017 to December 2018 at Zhongshan Ophthalmic Centre, Guangzhou, China. Data on the presence, location, and extent of intraoperative CD and its relationship to the infusion cannula were collected. Patient demographic characteristics and postoperative anatomic and visual outcomes were also assessed.

RESULTS

A total of six cases were found to have intraoperative CD, including two with serous CD, three with limited haemorrhagic CD, and one with CD caused by inadvertent perfusion of gas during air/fluid exchange. Retraction of the infusion cannula and acute ocular hypotony were found to be the main causes of intraoperative CD in five out of the six cases. The best-corrected visual acuity of all cases significantly improved after the surgery.

CONCLUSION

The incidence of intraoperative CD during small-gauge vitrectomy is low; the predominant causes are retraction of the infusion cannula and acute ocular hypotony. Immediate awareness and timely closure of the incision may contribute to a better surgical prognosis.

Comparison of Visual and Anatomic Outcomes Following RRD Surgery Using 23-Gauge Versus 25-Gauge Vitrectomy: PRO Study Report No. 12

BACKGROUND AND OBJECTIVE

Most surgeons now utilize small-gauge (23- or 25-gauge) pars plana vitrectomy (PPV) with or without scleral buckling for repair of rhegmatogenous retinal detachments (RRD), in addition to primary scleral buckle (SB), but comparative data between the two gauges are limited.

PATIENTS AND METHODS

This study is an analysis of primary RRD repairs comparing 23- versus 25-gauge vitrectomy for PPV or combination PPV/SB from January 1, 2015, through December 31, 2015, across multiple institutions. The primary outcome was single-surgery success and secondary outcomes included postoperative complications.

RESULTS

There were 1,932 eyes that met inclusion criteria. There was no statistically significant difference in single-surgery success (82.9% vs. 83.8%; P = 0.6329). There were similar rates of postoperative hypotony, endophthalmitis, vitreous hemorrhage, and choroidal detachment. The findings were similar when analyzing only eyes that underwent primary PPV without SB.

CONCLUSION

Both 23- and 25-gauge vitrectomy systems have similar anatomic and visual outcomes in the primary repair of RRD. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:70-76.].

Vitreous incarceration in sutured vs non-sutured sclerotomies after 25-gauge macular surgery

OBJECTIVES

To study the patterns of vitreous incarceration in sutured vs non-sutured sclerotomies in patients subjected to 25-gauge macular surgery.

METHODS

A prospective study of 135 eyes affected by epiretinal membrane or macular hole. Vitreal disposition was evaluated via ultrasound biomicroscopy (UBM) at the sclerotomy sites between 30 and 40 days after surgery, once the tamponade had completely disappeared.

RESULTS

In total, 349 sclerotomies (86.2%) of 99 patients were non-sutured while 56 sclerotomies (13.8%) of 36 patients were sutured at the end of the surgical procedure. Among the 36 patients with sutured sclerotomies, 15 out of 36 (41.6%) had at least two sclerotomies sutured. All the sclerotomy sites were evaluated (405 sclerotomies). Sclerotomy suture was significantly associated with a less aggressive pattern of vitreal incarceration (OR: 0.16, 95% CI: 0.07-0.35, p < 0.001). Compared to preoperative values, day 1 post operative IOP was not significantly different in patients with sutured sclerotomies, while patients with non-sutured sclerotomies had a significantly lower day 1 post operative IOP.

CONCLUSIONS

In 25-gauge macular surgery, UBM evaluation documented a higher rate of postoperative vitreous incarceration in the non-sutured sclerotomies, confirming the previously postulated role of the residual vitreous, left at the end of the surgery, in closing the sclerotomy site.

INCIDENCE OF ENDOPHTHALMITIS AFTER VITRECTOMY: A Systematic Review and Meta-analysis

PURPOSE

The purpose of this study was to review the literature reporting rates of postoperative endophthalmitis after pars plana vitrectomy and investigate whether modern microincision vitrectomy surgery (MIVS) increases the postoperative endophthalmitis rate, compared with traditional 20-gauge (20 G) vitrectomy.

METHODS

A comprehensive literature search was performed to identify studies describing the incidence of post-pars plana vitrectomy endophthalmitis. A meta-analysis of comparative studies reporting the endophthalmitis rates after MIVS versus 20 G vitrectomy was also conducted.

RESULTS

A total of 31 studies reported 199 endophthalmitis cases in 363,544 participants (0.05%). The incidence of endophthalmitis after 20 G vitrectomy was 0.04% (88/229,435), compared with 0.03% (8/27,326) after 23 G and 0.11% (33/29,676) after 25 G. The meta-analysis demonstrated that the incidence of endophthalmitis was higher after MIVS (23 G/25 G) compared with 20 G vitrectomy (odds ratio = 3.39, 95% confidence interval, 1.39-8.23). In a subgroup analysis, we also found an increased risk of endophthalmitis after 25 G compared with 20 G vitrectomy (odds ratio = 4.09, 95% confidence interval, 2.33-7.18), but not for 23 G versus 20 G (odds ratio = 1.14, 95% confidence interval, 0.47-2.78).

CONCLUSION

The incidence of post-pars plana vitrectomy endophthalmitis was low, with no significant differences between 23 G MIVS and 20 G vitrectomy, but 25 G MIVS may result in a higher postoperative endophthalmitis rate.

Comparison of 27-gauge versus 25-gauge vitrectomy results in patients with epiretinal membrane: 6-month follow-up

PURPOSE

To compare the 27G versus 25G vitrectomy in patients with epiretinal membrane (ERM).

PATIENTS AND METHODS

Sixty pseudophakic eyes of 60 consecutive patients treated by pars plana vitrectomy (PPV) using 27G (30 eyes) or 25G (30 eyes) were prospectively evaluated including eye's inflammation, surgery time, ERM + ILM removal time and complications. Additionally, 1, 3, 7, 14, 30, 90 and 180 days after PPV, the following were estimated: intraocular pressure (IOP), sclerotomy wound closure time, distance best corrected visual acuity (DBCVA), foveal macular thickness (FMT) and surgically induced astigmatism (SIA).

RESULTS

The eye's inflammation resolved within 30 days after surgery in both groups. The surgery and ERM + ILM times were longer in the 27G group (p ≤ 0.02). The most common postoperative complication was hypotony in both groups, more common in 25G group (23.3% vs. 10% of eyes). In 27G group, the mean IOP prior to 180 days postoperatively was higher (p < 0.05) and the sclerotomy wound closure time was shorter (p < 0.001). Mean DBCVA values (7, 14, 30 days after surgery) were significantly better in 27G group (p < 0.001). The mean FMT values were similarly and significantly reduced in both groups 1 day postoperatively (p < 0.05) as compared to preoperative values and then stabilized during follow-up. Mean SIA was lower in 27G group 30, 90 and 180 days after surgery (p < 0.001).

CONCLUSION

The use of 27G PPV in patients with ERM significantly reduced sclerotomy wound closure time and surgically induced astigmatism, better stabilized intraocular pressure and allowed to achieve faster visual acuity improvement, as compared to 25G PPV.

VITREOUS INCARCERATION IN SCLEROTOMIES AFTER VALVED 23-, 25-, OR 27-GAUGE AND NONVALVED 23- OR 25-GAUGE MACULAR SURGERY

PURPOSE

To study the patterns of vitreous incarceration at sclerotomy sites by ultrasound biomicroscopy in patients subjected to valved or nonvalved small-gauge pars plana vitrectomy.

METHODS

A prospective comparative study of 88 eyes affected by epiretinal membrane and macular hole. Patients were divided into four groups: valved or nonvalved 23-gauge (16 eyes each) and valved or nonvalved 25-gauge (20 eyes each); their vitreal disposition was compared by ultrasound biomicroscopy. Vitreal disposition was also assessed in 16 eyes of 16 patients subjected to valved 27-gauge pars plana vitrectomy.

RESULTS

Three vitreal patterns were identified: P0 (vitreous not visible or vitreous strand distant from the sclerotomy site), P1 (vitreous strand parallel to and in contact with the sclerotomy site), and P2 (vitreous strand entrapped in the sclerotomy site). The effect of valved trocar use on vitreous incarceration seemed to be somewhat beneficial, but no statistically significant effect could be shown (odds ratio: 0.85, 95% confidence interval: 0.42-1.74, P = 0.657). Similarly, no differences in vitreous incarceration were shown among vitrectomy gauges (23, 25, or 27) both in a model including valved trocars only (P = 0.858) and in a model with all available data (P = 0.935).

CONCLUSION

In 23- and 25-gauge macular surgeries, postoperative vitreous incarceration does not seem to be reduced using valved cannulas and was similar to that observed in 27-gauge surgery.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Valved 25-Gauge Cannula for Vitreous Tap and Injection

BACKGROUND AND OBJECTIVES

To describe a technique that reduces patient discomfort by using a valved 25-gauge trocar for vitreous tap and intravitreal injection of medications in previously vitrectomized eyes with suspected infectious endophthalmitis.

PATIENTS AND METHODS

A commercially available 25-gauge valved entry system is used to enter the vitreous cavity. A 25-gauge needle attached to a syringe is used to obtain a vitreous specimen for microbiological access and administer intravitreal injections of antibiotics and steroids. No vitreous volume is lost during these procedures because of the cannula's valve. At the completion of the tap and injections, the cannula is removed with forceps and the single wound tamponaded with a cotton-tipped applicator.

RESULTS

With this method, a vitreous tap and injection of pharmacologic agents only requires one piercing through the sclera, instead of the usual four piercings.

CONCLUSION

With this new technique, it is possible to enhance patient comfort, decreased pain, and reduce trauma to the conjunctiva. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:916-917.].

27-gauge and 25-gauge vitrectomy day surgery for idiopathic epiretinal membrane

BACKGROUND

This study compared the postoperative outcomes of 27-gauge (G) and 25-G vitrectomy performed for the treatment of idiopathic epiretinal membrane (ERM).

METHODS

The study design was single center, retrospective, interventional case series. Two hundred consecutive eyes that underwent primary vitrectomy for ERM (27-G vitrectomy in 100 eyes and 25-G vitrectomy in 100 eyes) were studied for 6 months. In all eyes, scleral tunnels were made using angle incisions, and air or gas exchange was performed.

RESULTS

There were no significant differences in age, spherical diopter power, as well as preoperative Early Treatment Diabetic Retinopathy Study (ETDRS) score, central retinal thickness (CRT), and intraocular pressure between the 27-G and 25-G groups. The proportions of simultaneous cataract surgery (27-G vs. 25-G: 82% vs. 90%), air-filled eyes (99% vs. 98%), and scleral wound suture at the end of surgery (0% vs. 0%) were not significantly different between two groups. The mean operation time for vitrectomy was significantly (P = 0.0322) longer by 4 min for 27-G (37 min) compared to 25-G (33 min) vitrectomy. Gain in ETDRS score was significantly (P = 0.0421) better in 27-G group (4.7 ± 8.1 letters) compared to 25-G group (1.1 ± 13.6 letters) at 1 month post-vitrectomy, but not significantly different at 3 and 6 months (P = 0.0835 and 0.0569, respectively). Decrease in CRT was significantly (P = 0.0354) greater in 27-G group (-24.2 ± 50.0 μm) compared to 25-G group (-8.0 ± 48.6 μm) at 1 month post-vitrectomy, but not significantly different at 3 and 6 months (P = 0.6059 and 0.1725, respectively). On postoperative day 1, hypotony (≤ 6 mmHg) was observed in 2 eyes in 27-G group and 6 eyes in 25-G group, while ocular hypertension (≥ 25 mmHg) was found in 4 eyes in 27-G group and 11 eyes in 25-G group, with no significant differences between two groups. Postoperative complications requiring treatment occurred in one eye (vitreous hemorrhage) in 27-G group, and in two eyes (vitreous hemorrhage and retinal detachment in one eye each) in 25-G group.

CONCLUSIONS

Although 27-G vitrectomy requires operation time of 4 min longer compared to 25-G vitrectomy for ERM surgery, using the 27-G system results in earlier recovery of visual acuity, CRT improvement and stabilized ocular pressure.

Review of Small Gauge Vitrectomy: Progress and Innovations

Purpose. To summarise the surgical advances and evolution of small gauge vitrectomy and discuss its principles and application in modern vitreoretinal surgery. The advent of microincisional vitrectomy systems (MIVS) has created a paradigm shift away from twenty-gauge vitrectomy systems, which have been the gold standard in the surgical management of vitreoretinal diseases for over thirty years. Advances in biomedical engineering and surgical techniques have overcome the technical hurdles of shifting to smaller gauge instrumentation and sutureless surgery, improving surgical capabilities and expanding the indications for MIVS.

Perioperative changes of the intraocular pressure during the treatment of epiretinal membrane by using 25- or 27-gauge sutureless vitrectomy without gas tamponade

Purpose

The purpose of this study was to compare perioperative intraocular pressures (IOPs) in 25- or 27-gauge microincision vitrectomy surgery (MIVS) and to evaluate the stability of postoperative sclerotomy closure.

Materials and methods

This is a retrospective review of 147 eyes treated for epiretinal membrane by using 25- or 27-gauge MIVS as the initial vitrectomy (25-gauge phacovitrectomy [25-P group]: 73 eyes, 25-gauge vitrectomy alone [25-A group]: 15 eyes, 27-gauge phacovitrectomy [27-P group]: 47 eyes, and 27-gauge vitrectomy alone [27-A group]: 12 eyes). Statistical analyses of perioperative IOPs on preoperative day (PreOp), postoperative day (POD)1, POD2, postoperative week 1, and postoperative month 1 were performed.

Results

All self-sealing sclerotomies were obtained without gas tamponade at the end of surgery. Also, no significant differences were noted in the age and axial length among the 4 groups and in the surgical time between 25-P and 27-P groups and between 25-A and 27-A groups. Significant decreases in IOP were found at POD1 and POD2 in the 25-P, 25-A, and 27-P groups compared with PreOP, but not in the 27-A group.

Conclusion

Even though surgeons confirm that there is no leakage from sutureless sclerotomy and that a normal IOP is preserved at the end of 25- or 27-gauge MIVS, there is a possibility of postoperative sclerotomy leakage on the day of the surgery. Furthermore, postoperative sclerotomy self-sealing of the MIVS in previous intraocular lens implantation cases is considered to be acquired easily than that in phacovitrectomy.

Comparison of Transcorneal and Pars Plana Routes in Pediatric Cataract Surgery in Infants Using a 25-Gauge Vitrectomy System

PURPOSE

To demonstrate and compare the performance of the 25-gauge transconjunctival sutureless vitrectomy system via anterior (transcorneal) and posterior (pars plana) routes in congenital cataracts in infants.

METHODS

In this prospective interventional study, 12 pediatric patients younger than 1 year with bilateral congenital cataract were included to undergo cataract surgery with posterior vitreorhexis and limited anterior vitrectomy using a 25-gauge vitrectomy system. One eye of each patient was operated on by the anterior (transcorneal) route and the other by the posterior (pars plana) route. All eyes were left aphakic. Intraoperative and postoperative (12 months after surgery) results were compared between the two routes, including visual axis opacification and astigmatism. All eyes were rehabilitated with contact lenses or spectacles.

RESULTS

The 25-gauge vitrectomy system allowed excellent intraoperative control in both groups. Postoperatively, there was minimal conjunctival congestion, corneal edema, and inflammatory reaction. No intra-operative or postoperative complications were noted in any eye. All eyes had a clear visual axis 12 months after surgery. Mean spherical equivalent was 15.50 ± 2.28 diopters (D) and mean astigmatism was 0.25 ± 0.45 D in the transcorneal group, whereas in the pars plana group it was 15.46 ± 2.45 D and 0.16 ± 0.39 D, respectively, at 12 months, the difference being statistically insignificant (P > .05).

CONCLUSIONS

The 25-gauge vitrectomy system allows sutureless surgery with excellent intraoperative control and minimal postoperative inflammation and astigmatism with clear visual axis by both the transcorneal and pars plana routes.

Bacterial endophthalmitis associated with a broken and retained small-gauge vitrectomy cannula

PURPOSE

To report a case of bacterial endophthalmitis associated with a retained small-gauge vitrectomy trocar.

METHODS

Retrospective case report of a 66-year-old woman who underwent 25-gauge vitrectomy surgery for an epiretinal membrane who presented with postoperative bacterial endophthalmitis and hand motions vision 3 weeks later.

RESULTS

Aqueous and vitreous biopsy revealed Corynebacterium species sensitive to vancomycin. The patient was initially treated with intravitreal and subconjunctival injections of vancomycin, ceftazidime, and dexamethasone. Surgical exploration during a subsequent vitrectomy surgery revealed a retained, transscleral 25-gauge cannula beneath a subconjunctival abscess. The cannula was removed, and the patient was treated with vitrectomy, debridement and closure of the transscleral wound, and injection of intravitreal antibiotics. Fifteen months of follow-up revealed no recurrence of infection and improvement of vision to 20/150.

CONCLUSION

Although rare, retained small-gauge vitrectomy cannulas may lead to vision threatening ocular infection. Care should be taken to inspect both the wound and the removed trocar system to ensure complete removal of this surgical device. Detailed counts of all surgical equipment should be routinely performed at the conclusion of vitrectomy surgery.

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.

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.

25th RCOphth Congress, President's Session paper: 25 years of progress in vitreoretinal surgery

Over the past 25 years, vitreoretinal surgery has undergone considerable change in technology, techniques, and professional organisation. Many conditions that were considered untreatable in 1988 are now treated routinely by vitreoretinal surgeons. Over the same period, vitreoretinal surgery has become a separate subspecialty with its own scientific meetings and professional organisation. This article describes a noncomprehensive selection of some of the highlights of the past 25 years, including the establishment and growth of BEAVRS (British and Eire Association of Vitreoretinal Surgeons), the revolution in the management of macular holes, the development of submacular surgery, and the introduction of sutureless vitrectomy.

Tower microneedle minimizes vitreal reflux in intravitreal injection

Intravitreal injection is widely used for easy control of drug levels in posterior segment of the eye by injecting the drug directly with hypodermic needles. Patients, however, often experience complications from intravitreal injection due to repeated injections, increased intraocular pressure, and infection. In addition, injected drug reflux after intravitreal injection makes it challenging to maintain predetermined drug dose due to the drug loss through backward effusions. Here, we described that the Tower Microneedle can reduce initial reflux and bleb formation due to its smaller outer diameter compared to a traditional hypodermic needle. Furthermore, we use phenylephrine hydrochloride for pupil expansion and demonstrated that Tower Microneedle induced similar pupil expansions using only half the drug volume, in the same period of time, compared to the 31 Gauge hypodermic needle. Consequently, Tower Microneedle achieves the same therapeutic effect in the vitreous body using fewer drugs than a traditional hypodermic needle due to the decreased backward drug effusion. Tower Microneedle described herein holds great promise for intravitreal injection with less reflux and lower drug dosage.

Intraoperative endoscopic observation of sclerotomy site after cannula removal for 23-gauge vitrectomy

BACKGROUND

The purpose of this study was to determine the incidence of vitreous incarceration in sclerotomy after cannula removal during 23-gauge vitrectomy.

METHODS

Thirty-seven eyes underwent 23-gauge sutureless vitrectomy. Oblique sclerotomies were made parallel to the limbus and tangentially to the sclera. Once past the trocar sleeve, the angle was changed to 90 degrees perpendicular to the surface and the trocar and cannula inserted. Vitreous gel was removed until the intraocular edge of the infusion cannula was free from the gel. The cannula was extracted with insertion of a light probe. The sclerotomy site was evaluated endoscopically through another cannula in 32 eyes; in five eyes, another infusion tube was inserted into the cannula to maintain intraocular pressure, the original infusion was removed, and the sclerotomy site observed.

RESULTS

No vitreous incarceration occurred in 30 (94%) eyes when one cannula was removed with insertion of a light probe, and minimal incarceration occurred in two (6%) eyes. No incarceration occurred in five eyes with observation of the infusion site.

CONCLUSION

The incidence of vitreous incarceration is low when a light probe or vitreous cutter is inserted. Inserting the light probe through the cannula during its removal and creating an oblique sclerotomy may reduce vitreous incarceration.

Comparison of two scleral incision techniques in 23-gauge transconjunctival vitrectomy

BACKGROUND AND OBJECTIVE

To compare two 23-gauge transconjunctival vitrectomy incision techniques, parallel and perpendicular to the alignment of scleral fibers, in terms of hypotony and postoperative intraocular pressure (IOP).

PATIENTS AND METHODS

Fifty-three eyes of 53 patients who underwent 23-gauge one-step trocar pars plana vitrectomy were randomly assigned to undergo scleral incision parallel (group 1, 26 eyes) or perpendicular (group 2, 27 eyes) to the limbus. Patients were observed postoperatively for wound healing, leakage, endophthalmitis, IOP, and hypotony at 1 day, 1 week, and 1, 3, 6, and 9 months.

RESULTS

No difference in preoperative IOP was observed (P = .229). Postoperative IOP was significantly lower in group 2 (P = .009). Hypotony rates did not differ between the groups. Intraocular gas or silicone tamponade was used intraoperatively in 26 cases. In cases in which no gas or silicone was given (n = 27), IOP measurements were significantly lower in group 2 (P = .021). There was no difference in hypotony ratios for gas/silicone injection versus no injection (P = 1.00) or in postoperative visual acuity (P = .350). Visual acuity improved significantly in both groups at follow-up examinations.

CONCLUSION

Parallel and perpendicular incisions resulted in similar postoperative hypotony rates, but perpendicular incisions were associated with lower IOP.

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.

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.

Comparison of efficacy and safety between transconjunctival 23-gauge and conventional 20-gauge vitrectomy systems in macular surgery

Purpose

To compare the efficacy and safety of 23-gauge transconjunctival vitrectomy with the conventional 20-gauge method in idiopathic epiretinal membrane and macular hole surgery.

Methods

Sixty-one consecutive patients undergoing vitrectomy for idiopathic epiretinal membrane and macular hole were recruited to either 20- or 23-gauge vitrectomy groups and prospectively evaluated. Surgical success rates, operating time, surgery-related complications, long-term visual outcomes, and postoperative ocular surface problems are compared in the two groups.

Results

There were 31 eyes in the 20-gauge group and 33 eyes in the 23-gauge group. The macular hole closure rate after the first surgery was 83% and 90.9% in the 20-gauge and 23-gauge groups, respectively, with no significant difference between groups (p = 0.59). The success rate for idiopathic epiretinal membranes cases was 100% in both groups. There was no statistically significant difference between overall surgical times (p = 0.90). None of the patients in either group experienced postoperative complications of severe postoperative hypotony, vitreous hemorrhage or endophthalmitis, except one eye in the 20-gauge group, which was found to have retinal detachment. In both groups, statistically significant improvement in visual acuity was achieved 1-month postoperatively (p = 0.002) and thereafter at all postoperative visits (p < 0.05). The mean ocular surface scores were significantly lower in the 23-gauge group at all postoperative visits compared with the 20-gauge group scores (p = 0.001).

Conclusions

Transconjunctival 23-gauge vitrectomy appears to be as effective and safe as conventional 20-gauge vitrectomy in idiopathic epiretinal membrane and macular hole surgeries.

Effect of intravitreal gas tamponade for sutureless vitrectomy wounds: three-dimensional corneal and anterior segment optical coherence tomography study

PURPOSE

To investigate the effect of gas tamponade on wound closure and postoperative hypotony by comparing fluid-filled and gas-filled eyes after 25-gauge sutureless vitrectomy using three-dimensional corneal and anterior segment optical coherence tomography.

METHODS

Twenty-four eyes of 24 patients who underwent a 25-gauge transconjunctival sutureless vitrectomy were included in this prospective study. A total of 72 scleral wounds were observed using three-dimensional corneal and anterior segment optical coherence tomography at 3 hours and at 1, 3, 7, and 14 days postoperatively. Scleral wound closure was defined as the absence of a scleral gap at the sclerotomy site, as observed using three-dimensional corneal and anterior segment optical coherence tomography. The rate of wound closure, intraocular pressure, and the incidence of complications were compared between the fluid- and gas-filled eyes.

RESULTS

The rates of scleral wound closure at 3 hours and at 1, 3, 7, and 14 days were 26.2%, 28.6%, 35.7%, 52.4%, and 85.7% in fluid-filled eyes and 53.3%, 73.3%, 76.7%, 83.3%, and 93.3% in gas-filled eyes; these rates were significantly higher for the gas-filled eyes. The intraocular pressure was significantly higher in the gas-filled eyes than in the fluid-filled eyes on postoperative Day 1 but did not differ significantly between the 2 groups on postoperative Day 3 and thereafter.

CONCLUSION

Three-dimensional corneal and anterior segment optical coherence tomography provided clear images of 25-gauge sutureless vitrectomy wounds and revealed that the sclerotomies closed faster in gas-filled eyes than in fluid-filled eyes. Thus, gas tamponade might be effective for the closure of sutureless vitrectomy wounds.

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.

23-gauge transconjunctival sutureless vitrectomy: visual outcomes and complications

PURPOSE

To report results and complications of 23-gauge transconjunctival sutureless pars plana vitrectomy for a variety of vitreoretinal diseases.

METHODS

A prospective consecutive case series study was performed in 66 eyes of 66 patients. Indications for surgery were epiretinal membrane (n = 20), rhegmatogenous retinal detachment (n = 19: 14 pseudophakic, 5 phakic), macular hole (n = 16), vitreous hemorrhage (n = 5), cyclodialysis (n = 1), intraocular lens luxation (n = 1), asteroid hyalosis (n = 1), congenital retinoschisis (n = 1), and endophtalmitis (n = 2). Main outcome measures included visual acuity, intraocular pressure, and intra- and post-operative complications.

RESULTS

Mean patient age at time of operation was 68 ± 12 years. Overall, visual acuity improved from 1.03 ± 1.00 logMAR preoperatively to 0.32 ± 0.33 logMAR postoperatively (p < 0.01) after a mean follow-up time of 9.3 ± 4.7 months. Mean preoperative intraocular pressure was 13.9 ± 3.5 mmHg, and mean postoperative intraocular pressure was 17.9 ± 9.6 mmHg on day 1 (p < 0.01) and 14.7 ± 2.8 mmHg (p = 0.05) at final visit. Concerning complications, 2 cases of hypotony and 7 of hypertony occurred on day 1, a macular hole reopened some weeks later, and a retinal detachment recurred in one case.

CONCLUSION

23-gauge transconjunctival sutureless vitrectomy is an effective and safe technique for a variety of vitreoretinal diseases.

Endophthalmitis in the era of small gauge transconjunctival sutureless vitrectomy--meta analysis and review of literature

PURPOSE

The goal of this study was to review, evaluate, and perform a meta-analysis on the current literature that reports rates of postoperative endophthalmitis after small gauge transconjunctival sutureless vitrectomy (TSV) and compare it to 20-gauge pars plana vitrectomy (20G PPV).

METHODS

We performed an extensive review of the current literature. We included only large comparative institutional reviews. Meta-analysis of these reviews was performed.

RESULTS

We found six large retrospective comparative cases series on the 25-gauge (25G) TSV as compared to 20G PPV. The test for homogeneity for the meta-analysis indicates that the studies are not homogeneous and therefore the evidence is tentative.

CONCLUSION

We cannot conclude that 25G TSV has a higher rate of postoperative endophthalmitis compared to the 20G PPV. Future retrospective or prospective trials need to take into consideration multiple factors.

Factors affecting wound leakage in 23-gauge sutureless pars plana vitrectomy

PURPOSE

To evaluate risk factors for sclerotomy leakage in 23-gauge sutureless pars plana vitrectomy in 219 patients.

METHODS

Nested case-control study involving 48 patients with wound leaks (visible on-table sclerotomy leakage requiring sutures) and 171 control subjects without wound leaks. Patients received either a conventional sclerotomy incision at 45°, which was then changed to 90° midincision, or an extremely oblique sclerotomy incision (OSI) at 10°, which was then changed to 30° midincision. Risk factors studied included age, gender, laterality, surgical duration, sclerotomy incision (OSI vs. conventional sclerotomy incision), preoperative diagnosis (macular vs. nonmacular), history of vitrectomy, and primary surgeon (attending vs. supervised resident).

RESULTS

Multivariate logistic regression analysis found significant (P ≤ 0.05) protective factors for wound leakage including OSI, macular preoperative diagnosis, no previous vitrectomy, and female gender. Surgical duration at least 45 minutes was considered a borderline risk factor.

CONCLUSION

Using an extremely OSI versus a conventional sclerotomy incision reduces the incidence of wound leakage postoperatively because of its self-sealing effect. Other factors that contribute to wound leakage, such as increased surgical duration and nonmacular diagnosis, may be indirect measurements of extensive trocar rotation, causing wound leakage despite the use of an OSI.

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.

[Three-dimensional visualization of sclerotomies with ultrasound biomicroscopy. Comparison of 20 and 23 gauge incisions on the porcine eyeball]

BACKGROUND

When pars plana vitrectomy is performed, the sizes of the sclerotomy cannula vary between 20 and 23 gauge. We examined the morphology of the scleral tunnels by ultrasound biomicroscopy additionally taking into account the incision angle.

MATERIAL AND METHODS

In each of 16 enucleated porcine eyes three 20 or 23 gauge sclerotomies with varying angles between 30 and 90° to the horizontal level were performed. The vertical 20 gauge sclerotomies were additionally sealed by 7.0 vicryl cross-stitching. The resulting scleral channels were analysed by 3-D ultrasound biomicroscopy.

RESULTS

The sclerotomies were echographically detectable in all cases. Analysis revealed that the sutured straight 20 gauge tunnels were hyporeflective in only some parts while the other incisions showed continuous hyporeflectivity along the complete channel in many cases. The smaller the instruments used and the flatter the scleral angles chosen, the smaller were the measured widths of the incision tunnels.

CONCLUSION

Imaging sclerotomies ex vivo by ultrasound biomicroscopy is reliably reproducible. In the echographic pictures straight 20 gauge incisions appeared to be safely sealed by the sutures while the nonsealed tunnels often showed continuous patency. By choosing small instruments and flat incision angles the width of the resulting scleral channels can be reduced.

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.

Nosocomial acute-onset postoperative endophthalmitis at a university teaching hospital (2002-2009)

PURPOSE

To evaluate acute-onset postoperative endophthalmitis occurring at an academic medical center and to compare rates over the last 25 years at a single institution.

DESIGN

Retrospective, consecutive case series.

METHODS

Medical records were reviewed for all patients diagnosed with acute-onset postoperative nosocomial endophthalmitis from 2002 through 2009 associated with surgery at Bascom Palmer Eye Institute.

RESULTS

The 8-year frequency of acute-onset postoperative endophthalmitis was 0.025% (14 of 56 672 intraocular surgeries). The rate was 0.028% (8/28 568) for cataract surgery and 0.011% (2/18 492) for pars plana vitrectomy (PPV). Both PPV endophthalmitis cases followed 20-gauge surgery and no cases followed small-gauge, transconjunctival PPV (n = 2262). Three cases occurred following penetrating keratoplasty (3/2788, 0.108%). The most common bacterial isolate was Staphylococcus (n = 7, 50%). Initial treatment involved ocular paracentesis (n = 8, 57%) or vitrectomy (n = 5, 36%), in combination with injection of intraocular antibiotics (n = 14, 100%). Vancomycin and ceftazidime were used in 13 eyes (93%) and intraocular steroids were given initially to 9 eyes (64%). Final visual acuity was > or =20/200 in 9 eyes (64%) and 2 eyes (14%) were no light perception. At this institution since 1984, there has been a statistically significant trend for a decreasing rate of acute-onset postoperative endophthalmitis (1984-1994: 0.09%; 1995-2001: 0.05%; 2002-2009: 0.025%; P < .001).

CONCLUSION

At a university teaching hospital involving resident, fellow, and faculty surgeons, the frequency of acute-onset postoperative nosocomial endophthalmitis is low, has not increased in the era of sutureless clear corneal cataract surgery, and has steadily decreased when compared to prior time periods from the same institution.