Pathogenesis and treatment of Graves’ orbitopathy: new insights
Thyroid Eye Disease or Graves’ orbitopathy (GO) is the most frequent orbital disease and one of the most frequent eye diseases at present. GO is a very complex autoimmune disorder with a multifarious presentation, a very disabling course in its more severe manifestations and with a treatment requiring every tool and trick an experienced orbitologist has in stock.
In the late eighties of the last century, consensus was reached about a general management plan consisting of both medical and surgical interventions. The introduction of parameters for disease activity allowed for an evidence based choice between the two options. In the years to come, many randomized clinical trials were performed, which so far resulted in the achievement that intravenously administered high dose methyl-prednisolone offers the best chances for patients with active disease. Although efficacious in up to 80% of patients, the outcome results must not be overestimated. Exophthalmos reduction, for instance, is exceptional.
Surgical rehabilitation consists of orbital decompression, squint surgery and eyelid corrections. Numerous papers have shown that orbital decompression is an effective and relatively safe procedure to reduce proptosis. The outcome depends on the number and extent of the removal of the bony walls of the orbit and whether orbital fat is removed. The most common complication is induction of diplopia.
Consensus on the treatment of squint in GO-patients still has to be achieved. In fact, in this field, very little has been published. Not before last year, a first proposal of success criteria for patients with squint within the framework of GO appeared. We are now waiting for comparative studies.
May be one of the greatest challenges for the orbital surgeon is putting the eyelids of GO-patients in their right positions. Several techniques are in use.
Slowly, progress is made unrevealing the immunologic cause of GO. Volumetric and other studies show that two different pathways seem to be involved: an early extraocular muscle inflammation and a late adipogenesis pathway.
At present new generations of anti-inflammatory and immunoregulatory drugs are studied. So far, we are unable to identify new victims of GO and launch prevention strategies. Except of course of discouraging smoking!