Comparison of flow cytometry with the surgeon regarding ability to predict the ultimate success of surgery for proliferative vitreoretinopathy

S. W. Cousins and P. E. Rubsamen
Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami School of Medicine, Fla.

OBJECTIVE: To analyze vitreous specimens obtained from human eyes with proliferative vitreoretinopathy (PVR) by use of flow cytometery (FC) to compare the capacity of FC with that of the surgeon's in predicting the ultimate outcome after PVR surgery. METHODS: Thirty-one vitreous aspirates were obtained at vitrectomy or from postoperative fluid-gas exchanges for complicated retinal detachment due to PVR. Samples were analyzed by FC for the concentration of total and proliferating cells. These measurements were compared with the surgeon's preoperative prognosis (good, poor, or indeterminate) for the ultimate result. At 12 weeks, the eyes were evaluated for clinical outcome. An unsuccessful outcome was one in which the retina was attached with macular pucker or hypotony or was anatomically detached. Anatomic attachment of the retina anterior and posterior to the scleral buckle without these findings was considered a successful outcome. RESULTS: Flow cytometry was capable of quantifying the concentration of total and proliferating cells in eyes with PVR. Eyes destined for an ultimately successful outcome demonstrated fewer total and proliferating cells than did eyes destined for an unsuccessful outcome. No differences were observed between eyes destined for development of macular pucker and those destined for anatomic redetachment. The surgeon was able to accurately predict a good or a poor outcome in 64.5% of the cases, with a sensitivity of 92% and a specificity of 89%. Using the total number of recovered cells, FC was able to correctly predict a good or a bad outcome with a 77% accuracy, whereas the surgeon was able to do so with a 65% accuracy. Combining the surgeon's prediction with the result of FC increased the diagnostic power of the prediction to 87%. CONCLUSIONS: The diagnostic power of FC was similar to that of the surgeon's in predicting ultimate outcome, but the two techniques probably evaluate different features of the disease process. The combination of the two techniques was the most powerful approach to the prediction of ultimate outcome after PVR surgery.