Data on vitrectomy. 1  Patients with proliferative retinopathy have a 33% risk of a vitreous haemorrhage at some time. 2  About 25% of these haemorrhages are recurrent or severe and need a vitrectomy. 3  After vitrectomy about 20% bleed needing a washout.  After vitrectomy, 33% have vision better than 6/18. 3% develop rubeotic glaucoma.
The Earth's atomospheric ozone layer is located in the tropopause, which is located just. above the troposphere. The tropopause is the bottom limit of the stratosphere several. miles above the surface of the Earth.
Ozone layer is present in the stratospheric stage of the atmosphere. If the ozone layer in the stratosphere is brought as it is on to the surface of the earth then it will form one inch thick layer. Depletion of ozone layer has become a major issue recently. Loss of ozone layer will lead to many human health problems. The serious problem among the health issues is skin cancer.