Electrolyte, Nitric Oxide and Oxidative Stress Levels of Aqueous Humor in Patients with Retinal Detachment and Silicone Oil Tamponade

Purpose: To enlighten the pathogenesis of silicone oil (SiO)-related complications via measuring aqueous humor levels of electrolytes, nitric oxide (NO), and oxidative stress in SiO, retinal detachment (RD), and control groups. Materials and Methods: In this prospective study, 56 patients were grouped as SiO (n = 29), RD (n = 12), and control (n = 15). The results of pre- and post-operative ophthalmological examinations, aqueous humor electrolyte and NO levels, total antioxidant and oxidant status (TAS, TOS) and oxidative stress index (OSI) were analyzed. Results: SiO group had a higher mean Na+ level compared to controls (144.77 +/- 11.48 vs 137.56 +/- 6.57 mmol/kg, p = .02). Also, the mean Na+ and Cl- levels of RD group were higher than controls (149.04 +/- 12.05 vs. 137.56 +/- 6.57 mmol/kg, p = .02, 115.2 +/- 7.79 vs 106.23 +/- 8.99 mmol/kg, p = .031 for Na+ and Cl-, respectively). The mean NO level of RD group was higher than that of SiO group (51.07 +/- 19.56 vs. 34.07 +/- 13.84 mu M, p = .009). The mean TAS and TOS were lower in SiO group compared to controls (1.92 +/- 0.64 vs. 2.49 +/- 0.56 mu molTroloxEqv./L, p = .021, 34.98 +/- 26.55 vs. 61.46 +/- 22.69 mu molH(2)O(2)Eqv./L, p = .004 for TAS and TOS, respectively). Intraocular retention time of SiO demonstrated positive correlation with post-operative visual acuity (logMAR) and negative correlation with TOS. Conclusions: Elevated aqueous humor Na+ and Cl- in RD patients might reflect abolished function of ion channels on detached retina. Increased Na+ and lack of NO response to elevated intraocular pressure in SiO-filled eyes might contribute to secondary cataract and glaucoma formation. SiO is associated with low levels of oxidative stress in aqueous humor; however, increased intraocular retention time of SiO is related to a poor visual outcome.