Background <p>There were no standardized clinical criteria for the duration of silicone oil (SO) tamponade for rhegmatogenous retinal detachment (RRD). This study aimed to investigate the effect of shorter SO tamponade time on visual function recovery in patients treated with a 2-month SO tamponade (Group A) compared to a 4-month SO tamponade (Group B) for RRD.</p> Methods <p>This is a prospective randomized controlled study. A total of 67 patients were included, 34 in Group A, and 33 in Group B. Best corrected visual acuity (BCVA), complications, inflammatory cytokine in aqueous humor, electrolyte levels, choroidal vascularity index (CVI), and choroidal thickness (CT) were measured at the timing of 1 week before SO removal (before SOR) and 3 months after SOR (after SOR).</p> Results <p>After SOR, Group A showed better BCVA (<i>P = 0.002</i>), lower SO emulsification rate (<i>P &lt; 0.001</i>), and lower level of IL-1β than Group B (<i>P = 0.016</i>); other inflammatory factors were not statistically significant between the two groups. BCVA after SOR was better than before SOR in Group A <i>(P &lt; 0.001</i>). Group B CVI before SOR was lower than after SOR (<i>P = 0.013</i>). When the two groups were analyzed together, BCVA after SOR was significantly improved compared with that before SOR (<i>P &lt; 0.001</i>), and CVI after SOR was also significantly higher (<i>P = 0.021</i>); the difference in the electrolytes, CT, and CVI between the two groups was not statistically significant.</p> Conclusions <p>A 2-month SO tamponade compared with a 4-month SO tamponade for RRD can improve visual function and reduce inflammatory factors and SO emulsification after successful retinal attachment. Compared with before SOR, patients after SOR had higher BCVA and higher CVI.</p> Trial registration <p>Registration date:24/04/2022; Registration number: ChiCTR2200059077; Registration site: Chinese Clinical Trial Registry (ChiCTR).</p>