Complete recovery of visual acuity as the main goal of treatment in patients with dysthyroid optic neuropathy

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