Accuracy of Spectral Domain Optical Coherence Tomography of the Macula for Detection of Complete Posterior Vitreous Detachment

Abstract Purpose To assess the accuracy of macular spectral domain optical coherence tomography (OCT) in detecting complete posterior vitreous detachment (PVD). Design Evaluation of diagnostic test or technology using a retrospective comparative study. Subjects 175 eyes in 175 patients (111 female, 64 male; mean age = 65 years) with pre-operative OCT within 90 days of vitrectomy. Methods PVD status on preoperative macular OCT was compared to PVD determination during vitrectomy. Attached vitreous was identified on OCT by visualizing the posterior vitreous cortex or the premacular bursa. Complete PVD was identified by the absence of these findings, and was considered a positive outcome for the purpose of analysis. Main Outcome Measures Sensitivity, specificity, positive predictive value, and negative predictive value of macular OCT for detection of complete PVD compared to findings at surgery. Results Of the 38 eyes graded as complete PVD on OCT, 20 eyes were found to have pre-existing PVD at the time of surgery (true positives), and 18 eyes were found to have attached vitreous at the time of surgery (false positives). Of the 137 eyes graded as attached vitreous on OCT, 129 eyes had attached vitreous at the time of surgery (true negatives), and 8 eyes had pre-existing PVD at the time of surgery (false negatives). The sensitivity of OCT for detecting complete PVD was 71% and the specificity was 88%. In the study population, the positive predictive value of an OCT scan showing complete PVD was 53% while the negative predictive value of an OCT scan showing attached vitreous was 94%. Conclusions If the premacular bursa or posterior vitreous cortex are visualized on macular OCT, an accurate determination of attached vitreous can be made. The diagnosis of complete PVD by macular OCT is less accurate and requires ultrasound.