One third of patients with hyperthyroidism or thyrotoxicosis, also known as Graves disease, develop what is commonly known as proptosis or protruding eyes. Proptosis occurs due to an immunological activation of the cells that compose the connective tissues of the muscles around the eyes where matter and water accumulate. The manifestation of protruding eyes happens in 2% of women; it occurs ten times less frequently in men. Patients with proptosis can be submitted to orbit decompression surgery, once the condition has been stabilized for 3 to 6 months. There are various alternatives for treating this condition; however, our experience at the Instituto Cirugía Orbitofacial shows that balanced orbit decompression produces fewer complications and scars, and it produces the best results.
How is the surgery performed?
The balanced orbit decompression surgery or balanced two wall decompression surgery consists of eliminating the bone of the medial orbit wall or orbital lamina of the ethmoid bone. This is achieved through an endoscopic surgery in which a lens is introduced through the nose to perform the removal. This part of the surgery is performed by an ear, nose, and throat surgeon, preferably with a subspecialty in endoscopy.
The procedure is combined with a lateral decompression performed by the plastic surgeon specialized in facial orbit through a very small incision in the side corner that permits access to the entire lateral wall next to the internal portion of the orbit. Then it is reduced by using a special bit that wears down the bone methodically. The purpose of this process is to create greater space so that the orbital content could decompress.
The bones that compose the lateral orbital wall are the frontal bone, the greater wing of the sphenoid bone and the zygomatic bone inferiorly. Once the bone of the ethmoid plaque is removed and the lateral orbit wall is reduced in size, several cuts are made to the periosteal tissue that covers the orbit. This allows the fat and orbit muscles to decompress to the new space provided. In many occasions, this surgery can achieve that the eye recede approximately 4 to 6 mm which allows better coverage of the ocular surface while improving the person’s appearance. It also diminishes eye dryness and inflammation.
The greatest benefit of balanced orbit decompression is prevention of ocular deviations that produce double vision. Double vision is a frequent complication that occurs with other types of orbit decompression methods.