Subclinical subretinal fluid is a factor that has been of concern in recent years to affect postoperative visual acuity recovery. These patients have good retinal fissure closure and retinal in situ under indirect inspection glasses, but visual acuity improves slowly or there is visual distortion and darkening of the visual field. This subretinal fluid has been reported in the literature to occur in patients with preoperative macular detachment. Pore-derived retinal detachment is more common after scleral buckle surgery, with an incidence ranging from 16% to 75%. It can also occur after vitrectomy. Benson SE et al. 2007 reported the presence of subclinical subretinal fluid in 15 of 100 vitrectomized patients after surgery, with an average of 5.5 months of absorption, but 7 vitrectomized patients with combined ring ligation had no subretinal fluid. The new spectral-domain coherent optical tomography is faster and has higher resolution, providing reliable assurance of macular morphologic changes after retinal detachment surgery. Subclinical subretinal fluid absorption is relatively slow, with most reports ranging from 3 months to 1 year. Since the nutrition of photoreceptor cells is not affected, the recovery of vision after fluid absorption is mostly unaffected, but the recovery of vision in patients with pre-existing retinal neuroepithelial thinning or combined macular anterior membrane is not satisfactory. The reasons for prolonged submacular fluid retention after successful scleral buckling are unclear. Most believe that the slow absorption of subretinal fluid is related to its high osmolarity. The high protein content of the subretinal fluid results in slow absorption of the fluid, and the absorption will be even slower as the fluid is absorbed and the osmolarity gradually increases. However, this view is also difficult to confirm because specimens of subretinal fluid are difficult to obtain. The lower incidence and faster absorption of subretinal fluid after vitrectomy also supports this view from the other side, because vitrectomy can drain subretinal fluid more effectively and less subretinal fluid remains after surgery. It is also believed that vitrectomy is due to the release of the vitreoretinal tract, which leads to faster absorption of subretinal fluid. In addition buckling banding may affect the circulation in the submacular choroid and retina, and these hemodynamic changes may alter the polarity of the RPE, resulting in fluid leakage. The inflammatory response caused by the buckling procedure may also be another source of subretinal fluid.