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

<b>Purpose</b>: 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. <b>Materials and Methods</b>: In this prospective study, 56 patients were grouped as SiO (<i>n</i> = 29), RD (<i>n</i> = 12), and control (<i>n</i> = 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. <b>Results</b>: SiO group had a higher mean Na⁺ level compared to controls (144.77 ± 11.48 vs 137.56 ± 6.57 mmol/kg, <i>p</i> = .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, <i>p</i> = .02, 115.2 ± 7.79 vs 106.23 ± 8.99 mmol/kg, <i>p</i> = .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 μM, <i>p</i> = .009). The mean TAS and TOS were lower in SiO group compared to controls (1.92 ± 0.64 vs. 2.49 ± 0.56 μmolTroloxEqv./L, <i>p</i> = .021, 34.98 ± 26.55 vs. 61.46 ± 22.69 μmolH₂O₂Eqv./L, <i>p</i> = .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. <b>Conclusions</b>: 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.