Overview: Retinal detachment is a separation between the retina, the pigment epithelium, and the neuroepithelial layer. Retinal detachment occurs when fluid enters between the two and separates them. There are three types of retinal detachment: pore-derived, exudative and pulling, with pore-derived retinal detachment being the most common. The latter two are also referred to as non-porous retinal detachment. Some of these factors are very likely to cause retinal detachment and are therefore called susceptibility factors. The main factors are: ① Myopia: Myopic eyes are prone to vitreous degeneration and posterior detachment. Retinal degeneration such as lattice-like degeneration and pavement-like degeneration are more likely to be seen in myopic eyes. The fragility of the peripheral retina in myopic eyes, and the vitreoretinal traction, can easily lead to retinal detachment. ②Aphakic eyes: People who have cataract surgery with vitreous complications are particularly susceptible to retinal detachment. Occurrence in the latter of cataract intracapsular extraction may be related to the vitreous movement that fills the original crystal space. The large vitreous cavity increases the space for vitreous oscillation, which increases its traction on the retina. Intraoperative vitreous loss exacerbates this effect. When there is vitreous impaction, the natural condition of posterior vitreous detachment is altered, thus inducing a vitreous effect on the retina of the aphakic eye. (③) Age: In the elderly, the vitreous is mostly degenerative and liquefied, often accompanied by various retinal degenerations, and thus prone to retinal detachment. ④ Retinal degeneration: Some retinal degeneration, such as lattice-like degeneration, frost-like degeneration, and pavement-like degeneration, is particularly prone to the formation of retinal fissures. This is because degeneration decreases the adhesion of the retina and reduces the resistance to traction. ⑤ Trauma: In contusions, the moment of impact movement can temporarily deform the eye, and although the wall of the eye can comply with external forces, the vitreous cannot, at which point the base of the vitreous separates from the wall, easily producing a retinal serrated edge detachment. Perforating trauma can directly cause retinal detachment, while late vitreous proliferation can lead to traction retinal detachment. Patients with retinal detachment may experience several symptoms. Some patients can also be found during ophthalmologic examination without obvious conscious symptoms. (1) Flying mosquitoes and flashes of light: the earliest appearance. It is actually a symptom of posterior vitreous detachment. Middle-aged and elderly people, especially highly myopic patients, should be alerted to the possibility of retinal detachment when a large number of flying mosquitoes and persistent flashes in a certain direction suddenly appear. (2) Central vision loss: The degree of vision loss is related to the location, scope, time and degree of vitreous clouding of retinal detachment. In retinal detachment at the posterior pole, the visual acuity decreases sharply. When the peripheral part is first detached, it has no or little effect on central vision. Again, detailed fundus examination should be performed in high-risk patients with vision loss. (3) Visual distortion: When peripheral retinal detachment spreads to the posterior pole or shallow detachment occurs in the posterior pole, in addition to the loss of central vision, there is also visual distortion. (4) Visual field defects: When retinal detachment occurs, some sensitive patients may find visual field defects. However, only the lower visual field defect has early diagnostic value. Treatment: Surgery is the general method of retinal detachment treatment, including vitrectomy, cycloplegia, cycloplegia + extra-scleral compression, etc. For foramen ovale detachment, the purpose of surgery is to close the fissure, release the subretinal fluid and reset the detached retina to restore effective vision. For non-porous retinal detachment, the primary goal is to find the cause and target treatment. Course and prognosis: After retinal detachment occurs, the nutrition of the photoreceptor cells layer is damaged, if not reset in time, the retina will be atrophied and degenerated, and the visual impairment cannot be recovered. However, even if the retina is successfully reset after surgery, it is still difficult to improve the function. Retinal detachment that is not reset for a long time can be complicated by iridocyclitis, pupillary atresia, concurrent cataract, secondary glaucoma, and even ocular atrophy. In cases of macular detachment for more than 2 to 3 months, the recovery of vision is often not normal after the retinal dissection is reset. Therefore retinal detachment should be treated as an emergency condition. Early diagnosis and early surgery is the only way to make the prognosis better. Delayed surgery cannot save vision even if it is successful.