[Skip to Content]
[Skip to Content Landing]
Article
March 1996

The Prognostic Utility of the Silicone Study Classification SystemSilicone Study Report 9

Author Affiliations

From the Doheny Eye Institute (Drs Lean and Lopez) and the Department of Preventive Medicine (Dr Azen, Mr Qian, and Ms Lai), University of Southern California, Los Angeles; the Department of Ophthalmology, Duke University Eye Center, Durham, NC (Dr McCuen); for the Silicone Study Group. A list of the participants in the Silicone Study Group appears at the end of Silicone Study Report 1 (Arch Ophthalmol. 1992;110:770-779).

Arch Ophthalmol. 1996;114(3):286-292. doi:10.1001/archopht.1996.01100130282009
Abstract

Objective:  To evaluate the reproducibility and the prognostic utility of the Retina Society and Silicone Study Classification Systems in eyes after surgery for severe proliferative vitreoretinopathy (PVR).

Design:  Subgroup analysis of the Silicone Study—a randomized, multicentered, surgical trial.

Setting:  Community and university-based ophthalmology clinics.

Materials:  Three hundred forty eyes with preoperative and intraoperative evaluations using both systems of grading PVR (reproducibility study), and 287 eyes with preoperative and intraoperative evaluations using both systems of grading PVR and with a 24-month follow-up examination (prognosis study).

Interventions:  Vitrectomy for PVR with long-acting perfluoropropane gas or silicone oil as the intraocular tamponade.

Outcome Measures:  Retinal reattachment, visual acuity (≥5/200), intraocular pressure, corneal clarity, and the need for reoperation.

Results:  The reproducibility of the Silicone Study Classification System was 64% (type of contraction), 77% (number of clock hours), 67% (posterior PVR), 88% (anterior and posterior PVR), and 94% (anterior, posterior, and subretinal PVR). The reproducibility of the Retina Society Classification System was 99%. Using the Silicone Study Classification System, location of PVR predicted visual acuity (P=.004, χ2 test for trend) and hypotony (P=.03, χ2 test for trend). Using the Retina Society Classification System, the grade of PVR predicted only visual acuity (P=.01, χ2 test for trend). For eyes with anterior and posterior PVR, there was a decreasing trend in successful visual acuity outcome with increasing severity of PVR (from C-3 to D-3, P=.02, χ2 test for trend).

Conclusions:  Although the classification of PVR using the Silicone Study Classification System was not reproducible for the type of contraction or for posterior PVR, identification of the anteroposterior extent of the PVR was prognostic of visual acuity and hypotony at 24 months. The joint knowledge of the location of PVR (using the Silicone Study Classification System) and the tightness of the funnel for retinas with 9 to 12 clock hours involved by fixed folds (using the Retina Society Classification System) has prognostic utility for eyes with anterior and posterior PVR.

References
1.
The Silicone Study Group.  Vitrectomy with silicone oil or sulfur hexafluoride gas in eyes with severe proliferative vitreoretinopathy: results of a randomized clinical trial: Silicone Study Report 1 . Arch Ophthalmol . 1992;110:770-779.Article
2.
The Silicone Study Group.  Vitrectomy with silicone oil or perfluoropropane gas in eyes with severe proliferative vitreoretinopathy: results of a randomized clinical trial: Silicone Study Report 2 . Arch Ophthalmol . 1992;110:780-792.Article
3.
McCuen BW, Azen SP, Stern W, et al.  Vitrectomy with silicone oil or perfluoropropane gas in eyes with severe proliferative vitreoretinopathy: results in group 1 versus group 2: Silicone Study Report 3 . Retina . 1993;13:279-284.Article
4.
Barr CC, Lai MY, Lean JS, et al.  Postoperative introcular pressure abnormalities in the Silicone Study: Silicone Study Report 4 . Ophthalmology . 1993;100:1629-1635.Article
5.
Blumenkranz MS, Azen SP, Aaberg TM, et al.  Relaxing retinotomy with silicone oil or long acting gas in eyes with severe proliferative vitreoretinopathy: Silicone Study Report 5 . Am J Ophthalmol . 1993;116:557-564.
6.
Hutton WL, Azem SP, Lee MBF, et al.  The effects of silicone oil removal in the Silicone Study: Silicone Study Report 6 . Arch Ophthalmol . 1994;112:778-785.Article
7.
Abrams GW, Azen SP, Barr CC, et al.  The incidence of corneal abnormalties in the Silicone Study: Silicone Study Report 7 . Arch Ophthalmol . 1995;113:764-769.Article
8.
Lean JS, Stern WH, Irvine AR, et al.  Classification of proliferative vitreoretinopathy used in the Silicone Study . Ophthalmology . 1989;96:765-771.Article
9.
Retina Society Terminology Committee.  The classification of retinal detachment with proliferative vitreoretinopathy . Ophthalmology . 1983;90:121.Article
10.
Azen SP, Boone DC, Barlow W, et al.  Methods, statistical features and baseline results of a standardized, multicentered ophthalmologic surgical trial: the Silicone Study . Control Clin Trials . 1991;12:438-455.Article
11.
Retina Society Terminology Committee.  An updated classification of retinal detachment with proliferative vitreoretinopathy . Am J Ophthalmol . 1991;112:159-165.
×