The Silicone Study

June 23, 2005 updated by: National Eye Institute (NEI)

To compare, through a randomized, multicenter surgical trial, the postoperative tamponade effectiveness of intraocular silicone oil with that of an intraocular long-acting gas (initially sulfur hexafluoride [SF 6 ], later perfluoropropane [C 3 F 8 ]) for the management of retinal detachment complicated by proliferative vitreoretinopathy (PVR), using vitrectomy and associated techniques.

To evaluate the ocular complications that result from the use of silicone oil and gas.

Study Overview

Detailed Description

The treatment of retinal detachment complicated by PVR remains controversial. Although some cases are managed successfully by pars plana vitrectomy and with temporary tamponade provided by intraocular gas, others eventually redetach with this technique. Preliminary reports indicate that prolonged tamponade with liquid silicone results in improved anatomical success, but the eventual visual outcome may be prejudiced by silicone-related complications, particularly glaucoma and keratopathy. The addition of hydraulic reattachment by simultaneous fluid/gas exchange to vitrectomy surgery has proved to be an important development. Although complications are few with these procedures, subsequent redetachment is frequent.

The Silicone Study was a randomized trial to investigate the relative merits of silicone oil or gas as tamponade modalities. All study patients underwent vitrectomy and were randomized intraoperatively either to silicone oil or to gas. Two groups of eyes were entered into the study: eyes that had not had a prior vitrectomy (Group 1) and those that had undergone previous vitrectomy outside the study (Group 2).

A critical element in the study was a standardized surgical procedure for PVR. This surgical procedure, intended to relieve retinal traction with vitrectomy techniques, was followed by assessment of the relief provided by an intraocular air tamponade. The eye was randomized to silicone oil or gas only after completion of the entire surgical procedure to eliminate investigator bias that might develop through knowledge of the treatment modality. Patients were examined 5 to 14 days following the randomization and again at 1, 3, 6, 12, 18, 24, and 36 months after that date. Repeated surgery was permitted for either treatment modality. The Fundus Photograph Reading Center staff processed and analyzed photographs taken at all the clinics, graded the preoperative severity of PVR on the basis of baseline visit photographs, and confirmed the macular status at followup visits.

End points of the study were visual acuity of 5/200 or greater and macular reattachment for 6 months following the final surgical procedure. The successful outcomes and complication rates of the two modalities were compared.

Study Type

Interventional

Phase

  • Phase 3

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Eligibility criteria included but were not limited to PVR of Grade C-3 or greater according to the Retina Society Classification and visual acuity of light perception or better.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

September 1, 1985

Study Registration Dates

First Submitted

September 23, 1999

First Submitted That Met QC Criteria

September 23, 1999

First Posted (Estimate)

September 24, 1999

Study Record Updates

Last Update Posted (Estimate)

June 24, 2005

Last Update Submitted That Met QC Criteria

June 23, 2005

Last Verified

October 1, 1999

More Information

Terms related to this study

Other Study ID Numbers

  • NEI-39

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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