LAM lung disorder is caused by overgrowth of smooth muscle

DEAR DR. ROACH

» A woman in my town wears oxygen and has something called “LAM.” What is LAM, and when should one get evaluated for it? — A.L.

DEAR READER »

Lymphangioleiomyomatosis is a rare disorder (a few people per million will have it) that can affect many organs, but most commonly the lung. It is found mostly in women.

It is neoplastic (meaning “new growth”), which makes it a relative of cancer. It can be associated with another condition, tuberous sclerosis. The underlying problem in LAM is the unregulated growth of smooth muscle cells, especially in the lungs, kidneys and lymph vessels.

The lion’s share of LAM diagnoses are made in people in their 30s and 40s. The most common symptom is shortness of breath during exercise, and it may be misdiagnosed as asthma or COPD. Cysts may be seen on films, and these can burst, causing a pneumothorax, which is an emergency. The diagnosis traditionally has been made with CT scans and biopsy, but a new blood test, VEGF-D, may reduce the need for biopsy.

Women with a history of pneumothorax should be considered for this disease, as should any woman with a diagnosis of COPD or asthma and cysts in the lungs, especially if they do not have other risk factors (such as smoking or alpha-1 antitrypsin deficiency, an underrecognized cause of chronic lung and liver problems).

LAM tends to progress slowly. Although there is no cure, LAM often can be treated with medicine, like sirolimus. Oxygen is helpful for people with low levels of it, especially with exercise.

I recommend checking the website www.thelamfoundation.org for more information.

DEAR DR. ROACH » What is the normal eye pressure for adults? Some say it’s in the single digits. — L.C.

DEAR READER » The normal eye pressure in adults, also called intraocular pressure, is between 8 and 21 mmHg (the same units as blood pressure). Elevated intraocular pressure is the biggest risk for glaucoma, a type of damage to the optic nerve. It’s not common, but people still can get glaucoma with normal intraocular pressures, which is why periodic eye exams are recommended. These exams not only check the pressure, but also look at the optic nerves. According to expert groups, eye exams by an eye professional are recommended periodically for everyone over 40.