Abstract
Purpose :
Modulation of posterior vitreous attachment is an area of significant interest as posterior vitreous detachment (PVD) is a critical first step in vitreoretinal surgery but can be very challenging, especially in young or diabetic patients. A necessary step in developing new therapies for vitreous modulation is an effective benchtop model. No literature to date identifies a quantifiable assessment of posterior vitreous adhesion that is also clinically applicable. We mimicked surgical methods to induce vitreous detachment in clinical practice, developing a method valuable in translation to clinical research.
Methods :
Basic Saline Solution (BSS) for negative control or Plasmin of different concentrations (2, 3, or 5U) was injected into post-mortem porcine eyes. Plasmin can pharmacologically induce PVDs. Eyes were placed in 37°C water bath for 1 hour. Posterior vitreous adhesion was assessed by utilizing the Alcon Constellation system and 23G Vitrectomy pack to quantify, through the minimum vacuum required to induce a PVD, ease of detachment around the optic disc and in the periphery. Independently, standard milligram weights were lifted using the same 23G vitrector.
Results :
Our data from the standard weights shows that the vitrector vacuum directly relates to the maximum possible lifted mass with an R2 value of 0.99. The average minimum vacuum necessary to induce a PVD was 395± 28 mmHg for 0U of plasmin, 385± 58 mmHg for 2U of plasmin, 265± 53 mmHg for 3U of plasmin, and 145± 28 mmHg for 5U of plasmin. We demonstrated a dose-dependent response curve with increasing amounts of plasmin leading to a lower minimum vacuum necessary to induce a PVD.
Conclusions :
As expected, there was a dose-dependent response curve demonstrating a relationship between increasing plasmin and decreasing posterior vitreous adhesion. The force exerted by the vacuum was verified independently using objects of known mass. We believe that this model offers significant benefits over prior work as it minimizes confounding manipulations and offers a quantitative assessment that is translatable to the clinic.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.