27-gauge Vitrectomy Wound Integrity: a Prospective, Randomized Trial Comparing Angled Versus Straight Entry

Study Overview
=================
Brief Summary
-----------------
To prospectively compare clinical outcomes using straight (perpendicular) versus angled trocar insertion during 27 gauge pars plana vitrectomy surgery for epiretinal membrane Primary Endpoints: Sclerotomy suture rates and incidence of suture blebs at the end of 27 gauge MIVS. Secondary Endpoints: Rate of postoperative wound-related complications such as hypotony, choroidal detachments, endophthalmitis, and sclerotomy-related retinal tears with a minimum follow-up of 30 days.

Detailed Description
-----------------
Microincision vitrectomy surgery (MIVS) has largely replaced use of conventional, 20-gauge vitrectomy, offering more rapid visual recovery, decreased postoperative pain and inflammation, and reduced surgical time with use of smaller diameter instruments1. Most recently, 27 gauge vitrectomy instrumentation has been introduced2, offering an additional small gauge option to the currently available 23, 25, or 25+ gauge systems. Initial experience with small gauge MIVS yielded mixed results, with early reports noting increased rates of wound-related postoperative complications including hypotony, choroidal detachments, endophthalmitis, and sclerotomy-related retinal tears3,4. However, with more experience and instrument modifications, outcomes with MIVS improved1,3. In a 2010 Ophthalmic Technology Assessment report by the American Academy of Ophthalmology, outcomes of MIVS were found comparable to that of 20 gauge vitrectomy benchmarks5. Prior studies have established that a two-stage, angled incision results in improved wound integrity with 23, 25, and 25+ MIVS systems6,7, helping to prevent complications such as post-operative endophthalmitis and hypotony. However, in the two clinical series describing outcomes of 27 gauge MIVS, a one-stage, perpendicular wound construction was performed without complication in a series of 31 patients2,8. Thus far, direct comparison between wound construction techniques (one-stage, perpendicular or two-stage, angled) has not been evaluated. The purpose of this study is to prospectively compare clinical outcomes using straight, one-stage (perpendicular) versus angled, two-stage trocar insertion during 27 gauge minimally invasive vitrectomy surgery (MIVS). The design of the study will be a randomized, clinical trial. Primary outcomes will be sclerotomy suture rates and incidence of suture blebs at the end of 27 gauge MIVS surgery for epiretinal membrane and macular pucker indications (no air or gas tamponade). Secondary endpoints will include rate of postoperative wound-related complications such as hypotony, choroidal detachments, endophthalmitis, and sclerotomy-related retinal tears with a minimum of 30 days follow-up.

Official Title
-----------------
27-gauge Vitrectomy Wound Integrity: a Prospective, Randomized Trial Comparing Angled Versus Straight Entry in Fluid-filled Vitrectomized Eyes

Conditions
-----------------
Epiretinal Membrane

Intervention / Treatment
-----------------
* Device: 27-gauge vitrectomy wound construction


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients older than 18 years old undergoing 27 gauge vitrectomy surgery with membrane peel for epiretinal membrane Willing and able to comply with clinic visits and study-related procedures Provide signed informed consent Exclusion Criteria: History of previous vitrectomy surgery in the study eye. History of previous ocular surgery other than cataract extraction in the study eye. Requirement of an air or gas (SF6, C3F8) bubble at the conclusion of 27 gauge MIVS surgery. Aphakia, ACIOL, unstable PCIOL, and/or lenticular or zonular instability. Glaucoma requiring IOP lowering medications. Pre-existing ocular inflammation/uveitis. Any concurrent intraocular condition in the study eye that, in the opinion of the investigator, could either require medical or surgical intervention during the 12 week study period to prevent or treat visual loss that might result from that condition. Examples include infectious conjunctivitis, keratitis, and/or scleritis.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Angled incision<br>Patients in this arm will undergo 27-gauge vitrectomy wound construction using angled (tunnel-like) incisions for trocar entry. | Device: 27-gauge vitrectomy wound construction<br>* Conventional, 3-port pars plana vitrectomy with membrane peeling is performed for epiretinal membrane indication. Angled and straight trocar entry will be directly compared.<br>|
| Active Comparator: Straight Incision<br>Patients in this arm undergo 27-gauge vitrectomy wound construction using straight (perpendicular) incisions for trocar entry. | Device: 27-gauge vitrectomy wound construction<br>* Conventional, 3-port pars plana vitrectomy with membrane peeling is performed for epiretinal membrane indication. Angled and straight trocar entry will be directly compared.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of sclerotomy site suturing and suture bleb formation |  | Minimum follow-up 30 days. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of post-operative, wound related complications | Rate of complications including hypotony, choroidal detachment, and endophthalmitis | Minimum follow-up of 30 days | 
| Change in mean intraocular pressure | Measured in mm Hg by tonometry | Minimum follow-up of 30 days | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
27-gauge Pars plana vitrectomy