The Safety Outcomes of 27 Gauge Vitrectomy for Posterior Segment Disease in High Myopia

Study Overview
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Brief Summary
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In recent decade, a major improvement in vitreoretinal surgery was the use of small gauge surgical systems that improved the safety of vitrectomy and also reduced the surgical time. However, there were still some concerns regarding small gauge vitrectomy system, especially 27-gauge system, in the stability of its instruments and the efficacy of removing vitreous during surgery. Although there were some studies that had reported the surgical outcomes of 27G vitrectomy system, none had focused on patients with high myopia. The highly myopic patients usually had thinner sclera, which was a risk factor for wound leakage after sutureless vitrectomy, they also had longer axial length which would make the surgical procedure more difficult especially in macular surgery. Based on previous clinical finding, gas leakage was 36.4% in 25G , while 27G sclerotomy showing less leakage comparing to larger gauge sclerotomy, the investigators believe 27G may have its clinical advantages in overcoming the thinner sclera of high myopia, and show the superiority of leakage control. Hypothesis: The 27G vitrectomy system has lower sclerotomy wound leakage rate compared with 25G system

Official Title
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The Safety Outcomes of 27 Gauge Vitrectomy for Posterior Segment Disease in High Myopia

Conditions
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Wound Complication, High Myopia, Vitrectomy

Intervention / Treatment
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* Device: 27G
* Device: 25G


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: Highly myopic patients (axial length 26 31mm) Diagnosed with vitreoretinal pathology that require vitrectomy Never received vitrectomy before Exclusion criteria: Surgical planning including scleral buckling during operation Surgical planning including combined phacoemulsification Surgical planning including the use of silicone oil and/or perfluorocarbon liquid Previous ocular surgery involving conjunctival manipulation and scarring such as pterygium removal/trabeculectomy Previous vitrectomy Previous ocular trauma involving corneal/corneoscleral/scleral/conjunctival full thickness laceration Medical history with known connective tissue disease(s) Age younger than 20 years old

Ages Eligible for Study
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Minimum Age: 20 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 27 gauge system<br>study group, using 27G vitrectomy system | Device: 27G<br>* using 27G vitrectomy system to perform standard transconjunctival sutureless vitrectomy<br>|
| Active Comparator: 25 gauge system<br>control group, using 25G vitrectomy system | Device: 25G<br>* using 25G vitrectomy system to perform standard transconjunctival sutureless vitrectomy<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of intraoperative sclerotomy site wound leakage | The incidence of intraoperative sclerotomy site wound leakage | immediately at the end of surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of postoperative sclerotomy site wound leakage | postoperative complication | post-operation day 1, 3, week 1, month 1, 3, 6 | 
| Incidence of hypotony | intraoperative and postoperative complication | post-operation day 1, 3, week 1, month 1, 3, 6 | 
| Incidence of endophthalmitis | postoperative complication | post-operation day 1, 3, week 1, month 1, 3, 6 | 
| Incidence of instrument bending | intraoperative complications | during operation | 
| Incidence of subconjunctival hemorrhage | postoperative complication | post-operation day 1, 3, week 1, month 1, 3, 6 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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vitrectomy, high myopia, wound leakage