The role and limitations of common silicone oil filling: Since Cibis first used silicone oil as vitreous cavity filler in 1962, after continuous technical improvements, vitrectomy combined with silicone oil filling has now become an important means of treating retinal detachment, especially severe retinal detachment, enabling many patients with retinal detachment to recover, but the specific gravity of silicone oil is lighter than that of water, and the patient needs to adopt a However, silicone oil has a lighter specific gravity than water, and the patient needs to be in a prone position after the filling procedure in order to exert parietal pressure on the posterior retina. There is essentially no parietal pressure on the underlying peripheral retina. The prolonged prone position causes discomfort and even great pain to the patient. For patients with good general condition, although they feel painful, they can still tolerate it in order to complete the treatment, but for some older and fatter patients, especially those who suffer from hypertension, heart disease and other serious systemic diseases, they cannot accept ordinary silicone oil filling treatment because they cannot bear the effect of prone position on the whole body, and they can only give up the treatment if there is no other way. For such patients, the emergence of heavy silicone oil is obviously a boon. The characteristics of heavy silicone oil: The so-called heavy silicone oil is formed by changing a group in the silicone oil molecule and mixing the silicone oil with other substances to form a substance with a specific gravity slightly heavier than water. The heavy silicone oil that I have used clinically is the substance named “Densiron-68”, which is made by dissolving 30.5% F6H8 (perfluorooctane) in 69.5% 5000mPas silicone oil. Its physical properties are: (1) transparent homogeneous liquid (2) density 1.06g/cm3 (3) refractive index 1.387 (4) viscosity 1400mPas (5) surface tension 40.82mN/m. Indications, effects and complications of heavy silicone oil filling: the indications of heavy silicone oil filling for the eye are basically the same as those of ordinary silicone oil filling, better for the fissure below and posterior pole, and better for the fissure above. It is better for the cleft holes below and at the posterior pole, and can also treat the cleft holes above, with the same effect as ordinary silicone oil for the cleft holes below. The main difference between heavy silicone oil filling and normal silicone oil filling is that it is not necessary to adopt the prone position, especially for those who cannot adopt the prone position due to the general condition. These patients mainly include: (1) elderly patients (2) patients with serious systemic diseases such as heart disease and hypertension (3) patients who cannot or do not want to adopt the prone position due to obesity and fear of psychology. The treatment effect of heavy silicone oil filling is the same as that of ordinary silicone oil. Time of heavy silicone oil filling: If the retina is well reset, the silicone oil can be removed 2~3 months after the operation, if the condition requires and the complications are not serious, it can also be extended for more than 6 months, my longest observation case is 9 months. Complications of heavy silicone oil filling: Densiron-68 is relatively less stable because of the synthesis of the two substances, so it is easier to emulsify, which is a disadvantage compared with ordinary silicone oil, but in the influence of heavy silicone oil emulsification factors and silicone oil, the patient’s high activity, young age, metabolism is an important factor in accelerating emulsification, some children in the injection of heavy silicone oil within a month can see obvious emulsification . However, for senior patients with more serious systemic diseases such as heart disease and hypertension, because these patients are less active, the time of emulsification is not too early and the emulsification is not too serious, thus the effect is also better and it is an effective method to treat retinal detachment in these patients. Other patients who use heavy silicone oil also need to reduce their activities and adopt a supine position more often to reduce complications such as emulsification and improve the treatment effect. Other complications caused by heavy silicone oil are similar to those caused by regular silicone oil.