The validity and reliability of photographic documentation of proliferative vitreoretinopathy

The Silicone Study is a multicentered, randomized surgical trial designed to compare the tamponade effectiveness of silicone oil versus long-acting gas in the treatment of proliferative vitreoretinopathy (PVR) by vitrectomy and associated techniques. Fundus photographs are taken to provide documentation of the anatomic status of eyes proposed for entry and are graded at an independent Reading Center. This article describes the protocol for photographic documentation of PVR as a continuum of increasing pathology, in which the pathology may only be present in the anterior retina, and the retina is usually highly elevated. In a validity and reliability study, agreement between photographic and clinical observation within one step was obtained for 88% of the eyes; intra- and inter-observer agreement within one step was 85 and 80%, respectively. Differences between the surgeon's grade and the Reading Center's were caused about equally by disagreement regarding extent of fixed folds and width of the funnel. Rarely did peripheral folds not visible in the photographs appear to be the sole explanation of the disagreement. Differences among readers were concerned mainly with differentiation of true full-thickness fixed folds from folds due to simple redundancy of the detached retina. These results demonstrate that complicated retinal detachment (RD) can be photographically documented and independently assessed.