Abstract
Purpose :
The origin of vitreous traction as a mechanism in vitreomacular traction syndrome (VMTS) and macular hole (MH) remains controversial. The purpose of this study is to demonstrate the posterior vitreous mobility following eye movements in patients with epiretinal membranes (EM), VMTS and MH, using an optical coherence tomography (OCT) eye tracking system.
Methods :
The study design is prospective, consecutive interventional case series. All investigations adhered to the tenets of the Declaration of Helsinki. Recruited were 10 eyes with EM, 5 eyes with VMTS and 24 eyes with MH. Following baseline scans, patients were instructed to perform vertical and horizontal eye movements. Immediately after each set of motions an OCT scan registered to the baseline image using the eye tracking system. These OCT images were then overlaid using picture-editing software, thereby documenting the changing configuration of the posterior vitreous as well as its position relative to static retina.
Results :
Retinochoroidal structures in all 36 eyes examined coincided well in overlaid images. In patients with MH, 22/24 eyes (92%) had duplication of the posterior cortical vitreous. The extent of duplication (indicating mobility) was increased with increasing vitreous separation and as the stage of MH increased (75% in stage 0; 80% in stage 1; 100% in both stage 2 and 3). In four of five eyes with VMTS, there was no change in relative position of posterior vitreous. One eye with VMTS demonstrated transformation of posterior vitreous configuration associated with the motion of adherent vitreous gel. There was no change in position of the EM in all 10 eyes relative to the fixed retinal structure.
Conclusions :
Our observation clearly demonstrates that dynamic forces, as imparted by fluid currents and the mobile vitreous body, exist significantly in MH development, in contrast to EM or VMTS. This indicates flexibility and mobility of posterior vitreous along the fluid currents induced by ocular motions, suggesting less contributory of vitreous shrinkage. We thus offer novel mechanistic insights, that there is indeed a greater contribution of dynamic forces to the pathogenesis of idiopathic macular holes than has been previously appreciated.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.