Relationship between vitreous temperature and posterior vitreous detachment.

The aim of this study is to examine the relationship between vitreous temperature and posterior vitreous detachment (PVD). 30 porcine eyes were hemisected to form eyecups. In 10 eyes, the vitreous was warmed to 37 ± 1°C for 1 min and cooled down to room temperature. In 10 eyes, the vitreous was warmed to 44 ± 1°C for 1 min and cooled down to room temperature. 10 eyes were kept at room temperature. The vitreous was then removed surgically by forceps. In the eyes that were kept at room temperature (n=10), and in the eyes that the vitreous was warmed to 37 ± 1°C (n=10), the vitreous removal caused significant retinal damage, detachment and fold, and choroidal detachment. In the eyes that the vitreous was warmed to 44 ± 1°C (n=10), the vitreous removal did not cause any observable changes in the retina and choroid. Therefore, the vitreous separates from the retina after warming to 44 ± 1°C. The effect is likely irreversible through vitreous liquefaction. Thermal effect might have caused PVD in some patients. Since cell death occurs at above 55-58°C, the effect can potentially be safe and beneficial in surgical separation of the vitreous. Evidence is provided to show that this technique could be safely performed in vivo in humans, and that it would lead to safer removal of the vitreous during vitrectomy with fewer post-operative complications.