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

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

Study Overview

• Status: Unknown
• Conditions: Vitrectomy; High Myopia; Wound Complication
• Intervention / Treatment: Device: 27G; Device: 25G

• Study Type: Interventional
• Enrollment (Anticipated): 108
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Tso-Ting Lai, MD; Phone Number: 0972651992; Email: b91401005@ntu.edu.tw
• Study Contact Backup: Name: Yi-Ting Hsieh, MD, PhD; Phone Number: 0972655018; Email: ythyth@gmail.com

Study Locations

• Taiwan
  • Taipei, Taiwan, 100
    • National Taiwan University Hospital
    • Contact: Chung-May Yang; Phone Number: 分機:65187；GSM:51547; Email: chungmay@ntu.edu.tw

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion criteria:

1. Highly myopic patients (axial length 26~31mm)
2. Diagnosed with vitreoretinal pathology that require vitrectomy
3. Never received vitrectomy before

Exclusion criteria:

1. Surgical planning including scleral buckling during operation
2. Surgical planning including combined phacoemulsification
3. Surgical planning including the use of silicone oil and/or perfluorocarbon liquid
4. Previous ocular surgery involving conjunctival manipulation and scarring such as pterygium removal/trabeculectomy
5. Previous vitrectomy
6. Previous ocular trauma involving corneal/corneoscleral/scleral/conjunctival full thickness laceration
7. Medical history with known connective tissue disease(s)
8. Age younger than 20 years old

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 27 gauge system; study group, using 27G vitrectomy system	Device: 27G; using 27G vitrectomy system to perform standard transconjunctival sutureless vitrectomy
Active Comparator: 25 gauge system; control group, using 25G vitrectomy system	Device: 25G; using 25G vitrectomy system to perform standard transconjunctival sutureless vitrectomy

What is the study measuring?

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

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
total vitrectomy time	total vitrectomy time	during operation
total surgical time	total surgical time	during operation
visual outcomes	best-corrected visual acuity and visual acuity changes	post-operation month 1, 3, 6
Incidence of anatomical success	anatomical success, such as restoration of normal foveal contour, reattachment of retina	post-operation month 1, 3, 6

Collaborators and Investigators

• Sponsor: National Taiwan University Hospital
• Collaborators: Alcon Research

Study record dates

Study Major Dates

• Study Start (Anticipated): April 1, 2020
• Primary Completion (Anticipated): February 1, 2021
• Study Completion (Anticipated): August 1, 2021

Study Registration Dates

• First Submitted: April 19, 2020
• First Submitted That Met QC Criteria: April 22, 2020
• First Posted (Actual): April 24, 2020

Study Record Updates

• Last Update Posted (Actual): April 24, 2020
• Last Update Submitted That Met QC Criteria: April 22, 2020
• Last Verified: April 1, 2020

More Information

Terms related to this study

• Keywords: vitrectomy; high myopia; wound leakage
• Additional Relevant MeSH Terms: Eye Diseases; Refractive Errors; Myopia
• Other Study ID Numbers: 201907025RINB

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes