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

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

Interventions

PROCEDURE

Pars plana vitrectomy

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

Sponsors & Collaborators

• Wardah

  lead OTHER

Principal Investigators

• Abdul Sami Memon, FCPS · Aga Khan University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2025-04-15

Primary Completion

2025-12-31

Completion

2026-01-31

Countries

• Pakistan

Study Locations