While the 6-weekly regimen was less effective in improving the clinical activity score or exophthalmos than the higher dose regimen, it is an acceptable treatment choice for patients with marginal or lower clinical activity scores.
A study that compared lower dose 6-weekly and higher dose 12-weekly intravenous methylprednisolone (IVMP) regimens for treating moderate-to-severe, active thyroid-associated orbitopathy found that, while the 6-weekly regimen was less effective in improving the clinical activity score or exophthalmos compared with the higher dose regimen, it is an acceptable treatment choice for patients with a marginal or lower clinical activity scores,1 according to lead author Kenneth KH Lai, MD, Department of Ophthalmology, Tung Wah Eastern Hospital, and the Department of Ophthalmology and Visual Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
The higher dose regimen in this patient population has been associated with some severe side effects such as cardiovascular and liver failure.2,3 “The optimal IVMP regimen is still debatable. It is important to balance the indications, dose-related efficacies and complications during IVMP prescription,” the authors commented.
To resolve the dosing question, they conducted a retrospective comparative study of patients treated with IVMP between January 2011 and July 2021 at the Thyroid Eye Clinic, the Chinese University of Hong Kong.
The outcome measures were the clinical activity score, exophthalmos, extraocular muscle motility, marginal reflex distance, best-corrected visual acuity (BCVA), intraocular pressure (IOP), need for additional treatment, and treatment-associated complications, the authors recounted.
Sixty-five patients (63% women; mean age, 50 years) with moderate-to-severe, active thyroid-associated orbitopathy were included in the study; 22 patients received 6-weekly treatments of IVMP and 43 received 12-weekly treatments of IVMP.
The patients who received the higher 12-weekly dose had significantly lower clinical activity scores at 6, 12, and 52 weeks (P = 0.0279, P = 0.00228, and P = 0.0228, respectively) compared with the lower dose 6-weekly regimen; patients in the higher dose group also had significantly (P = 0.0453 and P = 0.0347, respectively) more improvement of the exophthalmos at 6 and 12 weeks compared with the lower dose group.
The 2 treatment groups were comparable regarding the improvement in diplopia, marginal reflex distance 1 and 2, and extraocular muscle motility. The final BCVA and IOP values did not differ significantly from the baseline values.
More patients in the 6-weekly group (P = 0.00169) required additional treatments including IVMP with/without orbital radiotherapy. The patients in the lower dose not requiring additional treatment had a lower presenting clinical activity score (P = 0.0193) than those who required additional treatment. The total numbers of adverse events were comparable between the two groups, the authors reported.
The investigators summarized, “We showed that patients who did not require additional treatment after using a lower dose 6-weekly IVMP regimen were associated has lower presenting clinical activity scores. The low dose 6-weekly IVMP regimen is especially relevant in patients with active disease with a lower presenting clinical activity score of less than 4. For patients with a presenting clinical activity score of 4 or higher, a second 6-weekly course or the high dose 12-weekly IVMP regimen should be considered. Clinical trials are required to evaluate the use of activity-based individualized IVMP regimens for patients with thyroid-associated orbitopathy.”