A Prospective, Randomized, Double-blind, Placebo-controlled Study of Orbital Radiotherapy for Graves' Ophthalmopathy.

CONTEXT: Although widely used for more than 85 years, the efficacy of radiotherapy for Graves' ophthalmopathy (GO) has not been established convincingly. OBJECTIVE: To evaluate the efficacy of radiotherapy for GO. DESIGN: Prospective, randomized, internally controlled, double-blind clinical trial in a tertiary care academic medical center. PARTICIPANTS: The patients were ethnically diverse males and females over age 30 seen in a referral practice. The patients had moderate, symptomatic Graves' ophthalmopathy (mean clinical activity score, 6.2) but no optic neuropathy, diabetes, recent steroid treatment, previous decompression, or muscle surgery. Forty-two of 53 consecutive patients were enrolled after giving informed consent and fulfilling study entry criteria. Eleven eligible patients declined to participate because of inconvenience, desire for alternative therapy, or concern about radiation. INTERVENTION: One randomly selected orbit was treated with 20 Gy of external beam therapy; sham therapy was given to the other side. Six months later, the therapies were reversed. MAIN OUTCOME MEASURES: Every 3 months for 1 year, we measured the volume of extraocular muscle and fat, proptosis, range of extraocular muscle motion, area of diplopia fields, and lid fissure width. Effective treatment for GO will modify one or more of these parameters. RESULTS: No clinically or statistically significant difference between the treated and untreated orbit was observed in any of the main outcome measures at 6 months. At 12 months, muscle volume and proptosis improved slightly more in the orbit that was treated first. CONCLUSIONS: In this group of patients, representative of those for whom radiotherapy is frequently recommended, we were unable to demonstrate any beneficial therapeutic effect. The slight improvement noted in both orbits at 12 months may be the result of natural remission or of radiotherapy, but the changes are of marginal clinical significance.

Retinal microvascular abnormalities in patients treated with external radiation for graves ophthalmopathy.

BACKGROUND: A prospective study was conducted to determine if external ionizing radiation could favorably influence the orbital manifestations of Graves ophthalmopathy. Diabetes and untreated systemic hypertension were exclusion criteria. Radiation was directed to the orbits of 42 affected patients using 0.2 rad (20 Gy) delivered in 10 doses of 0.02 rad (2 Gy). Patients were periodically examined during a 3-year interval. OBJECTIVE: To report retinal microvascular abnormalities observed in our study cohort. METHODS: Fundus findings documented with ophthalmoscopy, stereoscopic color photography, and stereoscopic fluorescein angiography prior to radiation were compared with similarly documented findings approximately 3 years following radiation. RESULTS: Prior to orbital radiation, retinal microvascular abnormalities were identified in 2 patients. The abnormalities were present bilaterally in one patient and unilaterally in the other. During the course of the study, microvascular abnormalities developed de novo in the unaffected retina of the latter patient while the retinopathy in the fellow eye progressed. Retinal microvascular abnormalities and their sequelae developed de novo in both eyes in 2 more patients. In addition to the radiation, other confounding factors known to be associated with microvascular retinopathy (uveitis, inadequately controlled systemic hypertension, and borderline blood glucose levels) were identified among the 3 patients whose eyes developed new retinal microvascular abnormalities. CONCLUSIONS: Whether the retinal microvascular abnormalities observed in these patients were caused or aggravated by external beam irradiation cannot be precisely ascertained. However, the observed progression and de novo development of retinal microvascular abnormalities within 3 years of orbital radiation raise concern that 0.2 rad (20 Gy) delivered to the orbit in 10 doses of 0.02 rad (2 Gy) may aggravate existing retinal microvascular abnormalities or cause radiation retinopathy in some patients with Graves disease. These findings and the failure of external beam radiation with 0.2 rad (2000 cGy) to favorably affect Graves ophthalmopathy, as demonstrated in a previous study, have led us to discourage further treatment of Graves ophthalmopathy with radiation.

The aftermath of orbital radiotherapy for graves' ophthalmopathy.

OBJECTIVE: To determine whether long-term improvement could be observed after orbital radiotherapy for Graves' disease; in addition, to evaluate ancillary treatments needed for those who have received radiotherapy, to search for late-emerging adverse consequences of radiotherapy, and to relate orbital changes to serum levels of thyroid-stimulating immunoglobulin (TSI). DESIGN: Three-year follow-up of noncomparative interventional case series. PARTICIPANTS: Forty-two patients. INTERVENTION: All patients had received orbital radiotherapy within 6 months of study entry. Twelve months after study entry, patients were free to select any additional treatment for their ophthalmopathy. MAIN OUTCOME MEASURES: Need for surgery, steroid therapy, volume of extraocular muscles and fat, proptosis, area of diplopia fields and range of extraocular muscle motion, volume changes after decompression and correlations of eye findings with serum TSI levels, retinal status. RESULTS: Half of the patients elected to have a surgical procedure on their eyes or orbits. Among patients who were not decompressed, we found only slight improvement in some of the main outcome measures. TSI did not positively correlate with baseline status or with any observed change in major outcome measures. After orbital decompression, the volumes of both muscle and fat increase, but bony orbital volume increases more and proptosis diminishes. Retinal microvascular abnormalities consistent with radiation retinopathy developed de novo in five eyes of three patients within 3 years of radiation therapy. CONCLUSIONS: In this 3-year uncontrolled follow-up phase, limited evidence for a clinically significant improvement was observed, which may be the result of treatment or of natural remission. In either case, the changes are of little clinical significance. Because it is neither effective nor innocuous, radiotherapy does not seem to be indicated for treatment of mild to moderate ophthalmopathy.