Surgical management of dysthyroid strabismus through muscular weakening procedures with adjustable sutures

Background Autoimmune dysthyroidism may result in a form of restrictive strabismus characterized by a severe reduction of ocular motility and patient’s quality of life. In case of diplopia not manageable with prisms and/or in case of abnormal head position (AHP) not tolerated by patient, surgical treatment is the gold standard procedure. Methods Prospective, monocentric study. All enrolled patients presented a stable thyroidal disease from at least 6 month and were subjected to muscular recession associated with adjustable sutures. Primary endpoints of this study were subjective diplopia (evaluated with Gorman Score), residual deviation (measured in prismatic diopters, PD), field of single binocular vision (evaluated with Sullivan Score) and patients’ quality of life (evaluated with GO-QoL questionnaire). This study also investigated the influence of previous GO treatments (corticosteroids, radiotherapy and orbital decompression) on the baseline deviation and on final results. Results Forty-seven patients (31 females and 16 males with a mean age of 55,91±8,73 years) have been enrolled. Scheduled visits have been performed at baseline, 1 day after surgery, on month, 6 4 and 12 months. All patients completed one year follow-up. At baseline visit all patients presented constant diplopia (Gorman score = 1) with a mean total deviation of 36,70±14,69 PD in primary gaze, a 27,08±16,99 PD mean horizontal deviation and a 23,67±12,01 PD mean vertical deviation. One year after surgery only 2,27% of patients referred constant diplopia not manageable with prisms. Mean residual total deviation at 12 months after surgery was 3,66±6,42 PD in primary gaze while mean residual horizontal deviation was 1,89 ± 4,53 PD and mean residual vertical deviation was 3,47±5,49 PD. Field of binocular single vision expanded from 31,89± 6,67% to 83,7±3,99% while GO-QoL improved from 20,91± 4,50% at baseline to 89,22±3,22 % at one year visit. Previous CS therapy demonstrated a positive effect on vertical deviation both for baseline and final residual deviation. RT demonstrated a good influence on residual final vertical deviation; this result was better when OTD was also performed. Conclusions Muscular weakening with adjustable sutures represents a safe and an effective procedure for dysthyroid strabismus correction and usually determines a significant improvement in patients’ quality of life. Corticosteroids and Radiotherapy have a positive effect on residual deviation at one year followup especially for vertical deviation.