A corneal ulcer is an ocular emergency that raises high-stakes questions about diagnosis and management. Four corneal experts provide a guide to diagnostic differentiators and timely treatment, focusing on the types of ulcers most likely to appear in your waiting room. When a large corneal ulcer is staring you in the face, time is not on your side.
Siderosis, also called welder's lung, is a lung disease caused by breathing in iron or iron oxide dust. Siderosis is considered to be an occupational illness because people breathe in the iron dust at work. The condition usually shows up on X-rays as small, opaque spots on the worker's lungs.
Avascular necrosis (AVN) of the femoral head is a pathologic process that results from interruption of blood supply to the bone. AVN of the hip is poorly understood, but this process is the final common pathway of traumatic or nontraumatic factors that compromise the already precarious circulation of the femoral head. Femoral head ischemia results in the death of marrow and osteocytes and usually results in the collapse of the necrotic segment. (See also the Medscape Reference article Imaging in Avascular Necrosis of the Femoral Head, as well as Hip Arthroscopy in Staging Avascular Necrosis of the Femoral Head on Medscape News.)