A pituitary tumour is a tumour of the pituitary gland, which is a small, oval-shaped gland located near the optic nerve. Healthy pituitary glands control and regulate various glands that are responsible for growth and other functions in the body, including the production of breast milk and stimulation of the ovaries and testes.

How do pituitary tumours form?

Like tumours elsewhere in the body, pituitary tumours are caused when the normal division of cells is interrupted, leading to uncontrolled cell growth. These mutated cells form either benign or malignant tumours, with the latter describing cancerous growths that are capable of spreading to other parts of the body. Pituitary tumours are almost always benign, meaning they don't spread, and are classed as either secreting or non-secreting. Secreting tumours release excessive pituitary hormones, resulting in conditions ranging from gigantism to infertility.

Can pituitary tumours affect my vision?

Yes. However, vision problems are typically rare when pituitary tumours are small and only become apparent once the tumour gets larger. In these cases, vision symptoms may manifest in one or both eyes. People can experience various problems, depending on which part of the eye system the tumour affects. There may be reduced peripheral vision on both sides, which can often be difficult for sufferers to detect if the symptoms progress gradually. Pituitary gland tumours may also cause double vision. This is due to the tumour putting pressure on the nerves that help control eye movement. When the eyes cannot align properly, it leads to double images being sent to the brain.

Can pituitary tumour-related eye problems be treated?

Surgery is often required to remove as much of the pituitary tumour as possible when vision loss has occurred. Some tumours may first be treated with radiation to see if this resolves the problem without surgery being necessary. The results of surgery may vary. In most cases, vision is substantially improved following the removal of pituitary tumours, but vision loss can also be permanent in severe cases. Where double vision is the primary problem, there are a number of solutions. A common temporary treatment is to block the vision in one eye, with an eye patch for example, which prevents the brain from seeing two images. If the misalignment is extremely minor, prisms can be placed in glasses to shift images and minimise double vision. However, corrective surgery on the eye muscles may be needed in extreme cases where there has been no improvement for double vision over a protracted period.