Influence of Tamponade on Retinal Shift in Eyes Undergoing Vitrectomy for Rhegmatogenous Retinal Detachment: A Comparison of Gas Versus Silicone Oil in a Pakistani Population

NCT07495319 | Completed

• 1 other identifier: 2025-8810-34165
• Study Type: interventional
• Target: 78
• Locations: 1 country
• Sites: 1

Brief Summary

Rhegmatogenous retinal detachment (RRD) is a vision-threatening condition with an estimated incidence of approximately 1 in 10,000 individuals annually. Pars plana vitrectomy (PPV) combined with intraocular tamponade agents such as expansile gas or silicone oil is a commonly used surgical treatment for retinal reattachment. Although anatomical success rates following PPV are high, postoperative retinal displacement has increasingly been recognized as a frequent phenomenon. Retinal displacement may lead to visual distortion, metamorphopsia, and patient dissatisfaction despite successful anatomical repair. Fundus autofluorescence (FAF) imaging allows detection of retinal vessel printings (RVPs), which appear as hyperautofluorescent lines corresponding to the previous location of retinal vessels. These findings are considered markers of postoperative retinal displacement. Several studies have suggested that the type of intraocular tamponade may influence the occurrence of retinal displacement, with some reports demonstrating higher displacement rates in eyes treated with gas tamponade compared with silicone oil. However, findings remain inconsistent across studies, and limited data exist from South Asian populations. This study aims to evaluate the influence of intraocular tamponade type on postoperative retinal displacement following PPV for primary rhegmatogenous retinal detachment in a Pakistani population. This prospective randomized comparative study was conducted at the Section of Ophthalmology and Visual Sciences, Department of Surgery, Aga Khan University Hospital, Karachi, Pakistan. Patients diagnosed with primary rhegmatogenous retinal detachment who were scheduled to undergo pars plana vitrectomy were eligible for inclusion. Participants were randomized to receive either gas tamponade (sulfur hexafluoride \[SF6\] or perfluoropropane \[C3F8\]) or silicone oil tamponade at the end of surgery. Step 1: Define the Arms ARM 1: Gas Tamponade ARM 2: Silicone Oil Tamponade All surgical procedures were performed using a standardized 25-gauge pars plana vitrectomy technique by experienced vitreoretinal surgeons. Standard surgical steps included core vitrectomy, peripheral vitreous shaving with scleral indentation, drainage of subretinal fluid, retinopexy using laser or cryotherapy, and final internal tamponade according to randomized allocation. Baseline demographic and clinical characteristics including age, gender, duration of symptoms, macular status, and presence of proliferative vitreoretinopathy were recorded preoperatively. Postoperative retinal displacement was assessed using fundus autofluorescence imaging at the 1-month follow-up visit. Retinal displacement was defined as the presence of hyperautofluorescent lines corresponding to retinal vessel printings on FAF images. The primary outcome of the study is the incidence of postoperative retinal displacement at 1 month after surgery. Secondary analyses evaluate the relationship between retinal displacement and factors such as patient age and duration of retinal detachment prior to surgery. Understanding the relationship between tamponade type and postoperative retinal displacement may help improve surgical planning and patient counseling regarding visual outcomes following retinal detachment repair.

Conditions

Retinal Detachment Rhegmatogenous; Vitrectomy; Retina Disorder

Keywords

retinal detachment; rhegmatogenous retinal detachment; fundus autofluorescence; retinal shift

Outcome Measures

Primary Outcomes (1)

• Postoperative Retinal Displacement

  Description: Presence of retinal displacement identified by fundus autofluorescence (FAF) imaging. Retinal displacement is defined as hyperautofluorescent lines corresponding to previous retinal vessel positions (retinal vessel printings, RVPs).

  1 month after surgery

Study Arms (2)

Pars plana vitrectomy with intraocular gas tamponade (20% SF₆ or 18% C₃F₈)

EXPERIMENTAL

Arm Type: Experimental Intervention Name: Pars plana vitrectomy with intraocular gas tamponade (20% SF₆ or 18% C₃F₈) Intervention Type: Procedure Intervention Description: Pars plana vitrectomy with intraocular gas tamponade (20% SF₆ or 18% C₃F₈).

Procedure: Pars plana vitrectomy

Vitrectomy with Silicone Oil Tamponade

EXPERIMENTAL

Arm Type: Experimental Intervention Name: Vitrectomy with Silicone Oil Tamponade Intervention Type: Procedure Intervention Description: Pars plana vitrectomy with intraocular silicone oil tamponade (1000 centistokes).

Procedure: Pars plana vitrectomy

Interventions

Pars plana vitrectomy PROCEDURE

Arm 1: Gas Tamponade Intervention Name: Gas Tamponade Intervention Type: Procedure Intervention Description: Participants undergo pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment, followed by intraocular gas tamponade using either 20% sulfur hexafluoride (SF₆) or 18% perfluoropropane (C₃F₈). The surgical steps include: Induction of posterior vitreous detachment (if needed) Core and peripheral vitrectomy with base shaving Drainage of subretinal fluid Optional use of perfluorocarbon liquid (PFCL) Cryotherapy or endolaser retinopexy Insertion of intraocular gas tamponade Standardized perioperative care is applied. Arm 2: Silicone Oil Tamponade Intervention Name: Silicone Oil Tamponade Intervention Type: Procedure Intervention Description: Participants undergo pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment, followed by intraocular silicone oil tamponade (1000 centistokes polydimethylsiloxane). The surgical steps include: Induction of posteri

Pars plana vitrectomy with intraocular gas tamponade (20% SF₆ or 18% C₃F₈); Vitrectomy with Silicone Oil Tamponade

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Diagnosis of primary rhegmatogenous retinal detachment (RRD).
• Planned management with pars plana vitrectomy (PPV).
• Age ≥ 18 years.
• Willingness and ability to provide written informed consent.

You may not qualify if:

• Prior vitreoretinal surgery in the study eye.
• Tractional or exudative retinal detachment.
• Media opacities (e.g., dense cataract, corneal opacity, vitreous hemorrhage) precluding fundus autofluorescence imaging.
• Any condition that, in the investigator's opinion, would preclude safe participation or compliance with study procedures.

Sponsors & Collaborators

• Wardah: lead

Study Sites (1)

Aga Khan University Hospital

Karachi, 74000, Pakistan

Location

MeSH Terms

Conditions

Retinal Diseases; Retinal Detachment

Condition Hierarchy (Ancestors)

Eye Diseases

Study Officials

• Abdul Sami Memon, FCPS

  Aga Khan University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: No masking was performed. Both participants and treating surgeons were aware of the assigned tamponade. Outcome assessment was performed using fundus autofluorescence imaging without masking.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Dr.

Model Details: This is a randomized, parallel-group study in which participants with primary rhegmatogenous retinal detachment undergoing pars plana vitrectomy are randomly assigned to one of two intervention arms: gas tamponade or silicone oil tamponade. Allocation is concealed using sequentially numbered, opaque, sealed envelopes. The primary outcome, postoperative retinal displacement, is assessed at 1 month using fundus autofluorescence imaging. ARM 1: Gas Tamponade ARM 2: Silicone Oil Tamponade

Study Record Dates

• First Submitted: March 9, 2026
• First Posted: March 27, 2026
• Study Start: April 15, 2025
• Primary Completion: December 31, 2025
• Study Completion: January 31, 2026
• Last Updated: March 31, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

PA (1)