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Primary Vitrectomy With Silicone Oil or SF6 for Rhegmatogenous Retinal Detachment

Macular Perfusion and Sensitivity Following Silicone Oil Tamponade Versus SF6 Gas for Primary Rhegmatogenous Retinal Detachment

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05377606
Enrollment
62
Registered
2022-05-17
Start date
2021-12-23
Completion date
2023-05-08
Last updated
2023-08-31

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Primary Vitrectomy, Rhegmatogenous Retinal Detachment

Brief summary

Rhegmatogenous retinal detachment (RRD) is the separation of the neurosensory retina from the retinal pigment epithelium caused by the presence of a break that leads to the passage of fluid from the vitreous cavity into the potential subretinal space. It is a sight threatening disease, affecting largely people 50 years or older, with an annual incidence varying between 6.3 and 17.9 people per 100,000 population, and is unfortunately increasing. Although other surgical options do exist for the repair of primary RRD, pars plana vitrectomy (PPV) has clear advantages and is certainly effective in the treatment of these patients. Several agents are used for intraocular tamponade following PPV for RRD. These agents are either silicone oil (SO) or gases like air, perfluoropropane (C3F8), sulfur hexafluoride (SF6), or perfluoroethane (C2F6). In addition to the complications uniquely peculiar to using SO, research has found out that a reduction in retinal sensitivity on microperimetry was greater in SO tamponade in comparison with gas, as well as poorer visual outcome, microvasculature damage and affection of retinal layers including ganglion cell complex (GCC) in the SO group. Even though many studies were done to compare between SO and intraocular gas tamponades with respect to many aspects, only one study compared the effects SO had on macular vasculature and anatomy in comparison with air and no study at all to date has compared the SO to SF6 gas in terms of retinal vascular changes, correlating them to thinning of GCC and macular sensitivity, which is precisely the main aim of the current study.

Detailed description

Rhegmatogenous retinal detachment (RRD) is the separation of the neurosensory retina from the retinal pigment epithelium (RPE) caused by the presence of a break that leads to the passage of fluid from the vitreous cavity into the potential subretinal space. It is a sight threatening disease, affecting largely people 50 years or older, with an annual incidence varying between 6.3 and 17.9 people per 100,000 population, and is unfortunately increasing. Although other surgical options do exist for the repair of primary RRD, viz. scleral buckling and pneumatic retinopexy, primary pars plana vitrectomy (PPV) has clear advantages and is certainly effective in the treatment of these patients, with a primary success rate of 85%, making it the leading management modality. Several agents are used for intraocular tamponade following PPV for RRD, in order to provide surface tension across the retinal breaks thus preventing the ingress once more of fluid into the subretinal space, giving time for the permanent seal provided by the retinopexy done whether photocoagulation or cryopexy. These agents are either silicone oil (SO) or gases like air, perfluoropropane (C3F8), sulfur hexafluoride (SF6), or perfluoroethane (C2F6). In addition to the complications uniquely peculiar to using SO, research has found out that a reduction in retinal sensitivity on microperimetry was greater in SO tamponade in comparison with gas, as well as poorer visual outcome, microvasculature damage and affection of retinal layers including ganglion cell complex (GCC) in the former group leading to the so-called Silicone Oil-Related Visual Loss (SORVL). Even though many studies were done to compare between SO and intraocular gas tamponades with respect to many aspects, only one study by Zhou et al in 2020 compared the effects SO endotamponade had on macular vasculature and anatomy in comparison with sterilized air tamponade and no study at all to date has compared the SO to SF6 gas in terms of retinal vascular changes, correlating them to thinning of GCC and macular sensitivity, which is precisely the main aim of the current study.

Interventions

PROCEDUREPars plana vitrectomy with silicone oil

Silicone oil will be used at the end of primary vitrectomy. OCT, OCTA and microperimetry will be done 2 months later. Silicone oil will be removed at 3 months. Finally, the OCT, OCTA, and microperimetry will be repeated once more after 4 months from the vitrectomy.

PROCEDUREPars plana vitrectomy with SF6

Sulfur hexafluoride (SF6) will be used at the end of primary vitrectomy. OCT, OCTA, and microperimetry will be done 2 months and 4 months after surgery.

Sponsors

Cairo University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Caregiver)

Masking description

Surgeon will be masked to the tamponading agent (silicone oil or gas) till the end of the operation when either agent will be injected.

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Primary rhegmatogenous retinal detachment

Exclusion criteria

* Macula-on retinal detachment * Change of decision of type of endotamponade used intraoperatively * Giant retinal tear * Proliferative vitreoretinopathy worse than grade B * Recent lens surgery within the previous 3 months prior to presentation * Prior vitreoretinal surgery * Macular hole * Signs of epiretinal membrane * Diabetic retinopathy * Macular degeneration or other macular disorders * Inferior retinal breaks between 4 and 8 o'clock * History of uveitis * History of glaucoma

Design outcomes

Primary

MeasureTime frameDescription
Macular perfusion - SVPAt 2 and 4 months following primary vitrectomyComparison of superficial retinal capillary vascular density between the different treatment arms.
Macular perfusion - DVPAt 2 and 4 months following primary vitrectomyComparison of deep retinal capillary vascular density between the different treatment arms.
Macular perfusion - FAZAt 2 and 4 months following primary vitrectomyComparison of foveal avascular zone area between the different treatment arms as a measure of macular perfusion.

Secondary

MeasureTime frameDescription
Macular sensitivityAt 2 and 4 months following primary vitrectomyComparison of macular sensitivity between the different treatment arms using macular microperimetry.
Retinal reattachment rateAt 4 months following primary vitrectomyComparison of single-operation anatomical success (retinal reattachment) rate between the different treatment arms
Thickness of ganglion cell complexAt 2 and 4 months following primary vitrectomyComparison of the thickness of ganglion cell complex in microns between the different treatment arms using optical coherence tomography (OCT)
Best corrected visual acuityAt 2 and 4 months following primary vitrectomyComparison of best corrected visual acuity between the different treatment arms using standard Snellen charts.

Countries

Egypt

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026