Accuracy of Spectral-Domain OCT of the Macula for Detection of Complete Posterior Vitreous Detachment

Abstract

To assess the accuracy of macular spectral-domain OCT in detecting complete posterior vitreous detachment (PVD). Evaluation of diagnostic test or technology using a retrospective comparative study. One hundred seventy-five eyes in 175 patients (111 women and 64 men; mean age, 65 years) with preoperative OCT within 90 days of vitrectomy. Posterior vitreous detachment status on preoperative macular OCT was compared with PVD determination during vitrectomy. Attached vitreous was identified on OCT by visualizing the posterior vitreous cortex or premacular bursa. Complete PVD was identified by the absence of these findings and considered a positive outcome for the purpose of analysis. Sensitivity, specificity, positive predictive value, and negative predictive value of macular OCT for detection of complete PVD compared with findings at surgery. Of the 38 eyes graded as showing complete PVD on OCT, 20 eyes were found to have pre-existing PVD at the time of surgery (true-positive results), and 18 eyes were found to have attached vitreous at the time of surgery (false-positive results). Of the 137 eyes graded as showing attached vitreous on OCT, 129 eyes had attached vitreous at the time of surgery (true-negative results), and 8 eyes had pre-existing PVD at the time of surgery (false-negative results). 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%, whereas the negative predictive value of an OCT scan showing attached vitreous was94%. 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.