Temperature control during pars plana vitrectomy

Purpose: To evaluate the impact of temperature-controlled pars plana vitrectomy (PPV) on structural and functional outcomes in a rabbit eye model in vivo. Methods: Ten healthy New Zealand White rabbits underwent temperature-controlled PPV in the right eye (group A), using a device specifically designed to heat the infusion fluid/air and integrated into the vitrectomy machine, and conventional PPV in the left eye (group B). Both eyes received ophthalmic examination and electroretinography (ERG) before and 1 week postoperatively. After 1-week ERG, rabbits were enucleated and then sacrificed. Histological and immunohistochemical examinations were performed on enucleated eyes and expression of glial fibrillary acidic protein (GFAP) and vimentin investigated. Results: Postoperatively, only group B showed significantly decreased amplitude and increased latency of a-wave at 3 cd·s/m2 (p = 0.001 and 0.005, respectively). Significant increase of b-wave latency at 0.01 cd·s/m2 was detected in both groups (p = 0.019 and 0.023, respectively). Postoperatively, amplitude of oscillatory potentials (OPs) increased significantly in group A (p = 0.023) and decreased in group B. In both groups, OPs latency significantly increased at 1-week test (P < 0.05). A greater number of eyes without structural retinal alterations was detected in group A compared to group B (6 vs 5, respectively). GFAP expression was higher in group B than group A, even if the difference was not statistically significant. Conclusion: Temperature-controlled PPV resulted in more favorable functional and structural outcomes in rabbit eyes compared with conventional PPV, supporting the potential beneficial role of the intraoperative management of intraocular temperature in vitreoretinal surgery.