Abstract
Abstract: :
Purpose:Diplopia is a frequent symptom of Graves’ ophthalmopathy. Many different measures of diplopia and ocular motility have been used in randomized controlled trials in Graves’ ophthalmopathy. The most valid measurement tool for diplopia in Graves’ ophthalmopathy is not known. Studies evaluating how changes in diplopia symptoms in Graves’ patients correlate with changes in objective measurements have not been published. We sought to determine whether subjective changes in diplopia in Graves’ ophthalmopathy patients were associated with changes in measurements of area of diplopia fields, range of extraocular muscle motion and extraocular muscle volume on CT imaging. Methods: Forty–two patients with moderate Graves’ ophthalmopathy participated in a randomized clinical trial of orbital radiotherapy. At baseline and at 12–month follow–up, patients were queried about the frequency of diplopia symptoms and measurements of extraocular muscle range of motion, area of diplopia fields and volume of extraocular muscle on computed tomography (CT) imaging were taken. Subjects whose diplopia had lessened in frequency were compared to those whose diplopia had increased in severity or remained unchanged. The extraocular muscle range of motion, area of diplopia fields and volume of extraocular muscles were compared for the two groups using the rank sum test. Results:Data were available for 40 out of 42 patients at the 12–month visit. Eleven patients reported an improvement in frequency of diplopia symptoms (Group A) and 29 reported stable or worsening of diplopia symptoms (Group B). Comparing data at the 12–month visit to the initial visit, there was no statistically significant difference in extraocular muscle range of motion (37.9+ 48.0 cm2 for Group A and 8.3 + 38.6 cm2 for Group B, p=0.096, area of diplopia fields (–13.6 + 19.4 cm2 for Group A, –9.2 + 29.4 for Group B, p=0.639) or extraocular muscle volume on CT imaging (–1.3 + 1.4 ml for Group A, –2.0 + 3.8 for Group B, p=0.575). Conclusions: Improvement in diplopia symptoms does not correlate with objective parameters used to detect change in extraocular muscle involvement in patients with Graves’ ophthalmopathy. However, the variability of the data may have limited the power to detect a difference. Nevertheless, these data provide useful information for planning studies to further evaluate the relationship between subjective and objective measures of motility in patients with Graves’ ophthalmopathy.
Keywords: clinical (human) or epidemiologic studies: outcomes/complications • orbit • strabismus