A NOVEL METHOD TO OXYGENATE INTRAOCULAR IRRIGATION FLUIDS WITH AN IN-LINE OXYGENATOR RAHUL N. KHURANA, MD,* YUN-HSIANG CHANG, MD,*† AARON C. BARNES, MS,* GILDO Y. FUJII, MD,* EUGENE DE JUAN JR, MD,* MARK S. HUMAYUN, MD, PHD* Purpose: We describe a novel method to oxygenate intraocular irrigation solutions involving an in-line oxygenator. Methods: Either lactated Ringer (LR) solution or balanced salt solution (BSS) was oxygenated with the FE390 Stainless In-line Oxygenation Assembly (Beer, Beer, and More Beer, Concord, CA). After running a 100-mL of solution through the in-line oxygenator, oxygen saturation was measured with a dissolved oxygen meter. A control experiment involving the oxygenator without oxygen perfusion was performed. Paired t-tests were used to compare oxygen saturation changes before and after oxygenation. Results: In comparison with the original BSS, there was an increase in oxygen saturation of 162  47% (n = 40; P  0.05). Without oxygenation perfusion, there was only a 24  14% (n = 40) increase in oxygen levels in BSS, which was significantly lower than that in treated BSS (P  0.05). In comparison with the original LR solution, there was an increase in oxygen saturation of 208  21% (n = 40; P  0.05). Without oxygenation perfusion, there was only a 21  9% (n = 40) gain in oxygen saturation in the control LR solution, which was statistically lower as well (P  0.05). Conclusion: The in-line oxygenator is an efficient tool for oxygenating BSS and LR solution. It represents a potential efficient and convenient method to oxygenate irrigating solutions for vitreoretinal surgeries. RETINA 27:83– 86, 2007 H ypoxia is a major cause of cellular injury in ischemia because tissue stores of oxygen are limited in relation to other nutrients. 1 Animal studies have demonstrated that oxygen delivered into the vit- reous can prolong retinal function during times of ischemia. 2,3 Javaheri et al 4 further showed that oxy- genation of balanced salt solution (BSS) as the intraoc- ular irrigating solution during vitrectomy in rabbits resulted in faster returns to baseline electroretinogram values. As a result, a variety of methods have been proposed to deliver oxygen into the vitreous. 2–5 We describe a novel method to oxygenate intraocular ir- rigating fluids during vitreoretinal surgeries. Materials and Methods A FE390 Stainless In-line Oxygenation Assembly (Beer, Beer, and More Beer, Concord, CA) was se- lected as the in-line oxygenator (Fig. 1). It is a small, portable device used to oxygenate fluids to ferment From *Doheny Retina Institute, Doheny Eye Institute, Depart- ment of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California; and †Department of Ophthalmology, Tri-service General Hospital, National Defense Medical Center, Taipei, Taiwan. Supported by Research to Prevent Blindness, Inc., New York, NY. Presented at the Association for Research in Vision and Ophthalmology Annual Meeting; May 5, 2005; Ft. Lauderdale, FL. Reprint requests: Mark S. Humayun, MD, PhD, 1450 San Pablo Street, Room 3600, Los Angeles, CA 90033; e-mail: humayun@usc.edu 83