[Retrobulbar irradiation for Graves' ophthalmopathy -- long-term results]

Significance of retrobulbar irradiation in patients suffering form Graves' ophthalmopathy, though established since almost one century, is subject of scientific debate. The present study investigated the effect of retrobulbar irradiation using a standardized protocol focussing on long term results.

Between 1981 and 1997, 104 patients treated by retrobulbar irradiation (10 to 20 Gray) due to Graves' disease. Twenty-nine of these underwent irradiation as sole treatment (mean follow-up 57 months), while in the remaining 75, it was combined with a systemic steroid treatment (mean follow-up 40 months). Patients were evaluated regarding proptosis, intraocular pressure, lid signs, motility as well as subjective assessment of double vision and retrobulbar pain.

While proptosis remained unchanged, lid signs, chemosis and intraocular pressure showed slight and statistically significant improvement. However, these findings were considered to be clinically insignificant. Retrobulbar pain was improved in 75 % of patients. 25 % of patients showed improved motility, 75 % remained stable, and in none of them was there a deterioration of ductions. Results proved stable even in long-term follow-up. 25 % per cent of patients underwent a surgical procedure one year after radiotherapy.

In our series, we could not demonstrate an additional benefit of systemic steroids when combined with retrobulbar irradiation. Up to sixteen years after treatment, no treatment-related adverse reaction was seen. We found a remarkable improvement in ocular motility. This holds even more true in comparison to the natural course of the condition. Retrobulbar irradiation seems to shorten the duration of the disease, thus allowing earlier performance of eventual rehabilitative surgery.