is about 1 in 300. Retinal detachment is more common in those with severe myopia (above 5–6 diopters), as their eyes are longer, their retina is thinner, and they more frequently have lattice degeneration. The lifetime risk increases to 1 in 20. Myopia is associated with 67% of retinal detachment cases. Patients with a detachment related to myopia tend to be younger than non-myopic detachment patients. Retinal detachment can occur more frequently after surgery for cataracts. The estimated of risk of retinal detachment after cataract surgery is 5 to 16 per 1000 cataract operations. The risk may be much higher in those who are highly myopic, with a frequency of 7% reported in one study. Young age at cataract removal further increased risk in this study. Long term risk of retinal detachment after extracapsular and phacoemulsification cataract surgery at 2, 5, and 10 years was estimated in one study to be 0.36%, 0.77%, and 1.29%, respectively. Tractional retinal detachments can also occur in patients with proliferative diabetic retinopathy or those with proliferative retinopathy of sickle cell disease. In proliferative retinopathy, abnormal blood vessels (neovascularization) grow within the retina and extend into the vitreous. In advanced disease, the vessels can pull the retina away from the back wall of the eye causing a traction retinal detachment. Although retinal detachment usually occurs in one eye, there is a 15% chance of developing it in the other eye, and this risk increases to 25–30% in patients who have had cataracts extracted from both eyes. Symptoms of rhegmatogenous retinal detachment A retinal detachment is commonly but not always preceded by a posterior vitreous detachment which gives rise to these symptoms: flashes of light (photopsia) – very brief in the extreme peripheral (outside of center) part of vision a sudden dramatic increase in the number of floaters Sometimes a detachment may be due to atrophic retinal holes in which case it may not be preceded by photopsia or floaters. Although most posterior vitreous detachments do not progress to retinal detachments, those that do produce the following symptoms: a dense shadow that starts in the peripheral vision and slowly progresses towards the central vision the impression that a veil or curtain was drawn over the field of vision straight lines (scale, edge of the wall, road, etc.) that suddenly appear curved (positive Amsler grid test) central visual loss Treatment of rhegmatogenous retinal detachment General Principles Find