Complete Recovery of Visual Acuity As the Main Goal of Treatment in Patients with Dysthyroid Optic Neuropathy

Introduction: To evaluate the effectiveness of methylprednisolone (MP) and surgical treatment in achieving complete reversal of dysthyroid optic neuropathy (DON) and predictive factors of this therapy.

Material And Methods: The group consisted of 10 patients (18 eyes) with DON. The diagnosis of DON was based on at least two criteria from the following: (i) deterioration of visual acuity (VA< 1.0), (ii) loss of colour vision, (iii) optic disc swelling, and/or (iv) signs of DON in magnetic resonance imaging (presence of apical crowding and/or optic nerve stretching). A complete recovery of DON was defined as the normalisation of VA (VA = 1.0), normal colour vision, and reversal of optic disc swelling. A significant improvement was defined as improvement of VA of at least 0.2. The consecutive steps of treatment of DON consisted of: (i) first-line treatment - intravenous MP pulse therapy (3 × 1 g); (ii) second-line treatment - endoscopic intranasal orbital decompression of medial wall; (iii) additional treatment - additional MP therapy and/or surgical decompression.

Results: A significant improvement in VA could be achieved in the majority of patients; a complete recovery was noted in 22.2%, 33.3%, and 66.7% of eyes after first-line, second-line, and additional treatment, respectively. Positive predictive factors were: younger age (p = 0.049), shorter duration of DON (p = 0.035), and a higher Graves' orbitopathy clinical activity score (p = 0.035).

Conclusions: By using combination therapy (intravenous MP pulse therapy and surgical decompression), a complete recovery can be achieved in the majority of patients with DON.