Vitreous surgery for foraminal retinal detachment has become a common practice, but the quality of the surgery can be affected if some techniques are not well mastered. The internal surgery to release the subretinal fluid is usually the “downward pressure upward squeeze” method, that is, the heavy water is filled to the posterior edge of the hole and then the gas-liquid exchange, using the gravitational effect of the specific gravity of the heavy water than water to pressure the subretinal fluid below the level of the hole to above the posterior edge of the hole, and then the upper subretinal fluid is squeezed out of the retinal fissure using gas, during which the flute needle is placed at the the retinal fissure. Some tips can help you to put the subretinal fluid “clean”, otherwise there is no photocoagulation reaction when laser photocoagulation, and the subretinal fluid pocket appears when gas-liquid exchange. 1. When injecting heavy water, the hole should be kept high, otherwise the subretinal fluid will be driven to the opposite peripheral subretina. 2.The vitreous cortex around the hole should be treated cleanly. If the vitreous cortex on the hole cover is not removed cleanly, the hole cover can be removed together, otherwise the vitreous cortex will block the flute needle opening and affect the aspiration of subretinal fluid. 3. If there is already clouding around the crystal, which affects the posterior operation, the crystal can be removed and the anterior or posterior capsule of the crystal can be retained. Zhijun Wang, Ophthalmology Department, China-Japan Friendship Hospital Try to do without or strictly control the use of trans-scleral condensation technique. Laser photocoagulation does not have the problem of pigment epithelial cell loss, but pigment epithelial cell loss after condensation is inevitable. Whether it is silicone oil filling or long-lasting gas filling, in cases where the procedure is unsuccessful, a large dissemination of pigment cells and the resulting proliferative changes can be seen; in cases where the procedure is successful, the chance of macular anterior membrane appearance is also higher. The reasons for using the condensation technique are 1) poor response to photocoagulation, and 2) the fissure is too peripheral and cannot be seen. The reasons for the poor response to photocoagulation have already been mentioned; as for the difficulty of seeing the fissure against the periphery, it is recommended to use a wide-angle lens and compress the sclera if necessary. Some lenses allow the surgeon to press the sclera with one hand under the microscope illumination and hold the laser head in the other hand for photocoagulation, so it is easier to solve this problem.