Vitreous mobility during the posterior vitreous detachment initiation demonstrated by pseudo-motion optical coherence tomography

Purpose

To document the anatomical changes occurring at the vitreoretinal interface during early posterior vitreous detachment (PVD).

Methods

Wide-angle and pseudo-motion optical coherence tomography (OCT) were obtained on 27 normal eyes during the early stages of age-related PVD. The wide-angle examination in a static phase consisted of montaged conventional OCT images. GIF-formatted pseudo-animation was generated with OCT images acquired initially in a static eye state, followed by scans immediately after ocular excursions.

Results

Initial stages of PVD included peripheral PVD with (stage 1a) or without (stage 1b) interposed material between the posterior vitreous cortex and the retina, and perifoveal PVD expanding to the periphery (stage 2). All stage 1 PVDs presented anterior to the papillomacular vitreous liquefaction. All eyes demonstrated mobility of the vitreous gel at the anterior face of the vitreous liquefaction; however, the adherent cortical vitreous layer comprising the posterior wall of the lacuna showed no mobility. Mobility of the posterior vitreous cortex was not present in eyes with stage 1a PVD and increased with the progression of the stage of PVD (p = 3.60×10⁻⁶).

Conclusion

During nonpathological PVD, macula is protected from tractional insults conveyed by mobile vitreous due to overlying vitreous liquefaction. However, the vitreoretinal interface anterior to the lacunae experiences tractional forces until vitreoretinal separation occurs. These observations reinforce the hypothesis that vitreous liquefaction, vitreous mobility, and vitreoschisis formation contribute to PVD initiation and support that premacular lacunae protect the macula during PVD initiation and early progression.