Partial Posterior Vitreous Detachment: New Capabilities of Improving Diagnosis and Surgical Approach Using SD-OCT

Introduction: Partial posterior vitreous detachment (PPVD) is considered the first stage of posterior vitreous detachment (PVD). Possible complications of PPVD are vitreomacular traction syndrome and macular pucker. The purpose of this study was to measure the distance between the posterior hyaloid and the internal limiting membrane using a spectral domain optical-coherence tomography (SD-OCT) device. Methods or Study Design: We examined SD-OCT images of twelve eyes of twelve patients with subclinical PPVD with foveal attachment. To quantify the vitreoretinal distance, the basic applications of SD-OCT were modified. Usually SD-OCT software traces, for every scan, two reference lines corresponding to the internal limiting membrane (ILM) and the retinal pigment epithelium (RPE)-choriocapillaris complex and a retinal thickness map was created. Conversely, manually modifying the position of the two lines, we shifted the two lines so that the inner one, which defines ILM, coincided with the posterior hyaloid, while the outer one, which defines the RPE-choriocapillaris complex, coincided with the ILM for each scan of every map. Results: Maps of retinal thickness and volume were automatically transformed into maps that represent the space between the posterior hyaloid surface and the retinal surface, expressed numerically and on a colour spectrum. Both maps overlapped on a posterior pole photograph. Ultimately, we created individual maps of the different regions of the posterior pole to obtain a single map of the entire posterior pole. The mean volume of PPVD in the eight eyes examined was 118.12 ± 4.11 mm3. Conclusions: These maps of the cavity volume of PPVD could be useful in studying the clinical progression of the early stages of PVD and assessing the efficacy of pharmacological vitreolysis. This also applies to the vitreomacular traction syndrome to evaluate the clinical progression of vitreous detachment and to identify the focal retinal points at which the detached perifoveal posterior vitreous allows safer surgical manipulation.