Long-term Surgical Outcomes in the Sagging Eye Syndrome

Background/aims: Strabismus due to sagging eye syndrome (SES) caused by age-related connective tissue involution is now an established cause of diplopia in older people. High suspicion of the condition results in early recognition, often obviating extensive neurological investigations and enabling surgical correction of the strabismus. Methods: This retrospective study reviewed surgical results in 93 patients (40 males) of average age 68 +/- 12 years, who had small-angle strabismus due to SES, during the 20-year period 1994-2014. Results: In central gaze, mean distance pre-operative esotropia was 4.2 +/- 7.5 Delta (mean, SD), while mean hypertropia was 4.7 +/- 5.9 Delta. Surgeries comprised medial rectus (MR) recession; lateral rectus (LR) resection; plication, imbrication, and superior transposition of the LR to the superior rectus (SR) for esotropia; and graded vertical rectus tenotomy (GVRT) or vertical muscle recession for hypertropia. Mean post-operative immediate and long-term deviation after 316 +/- 265 months average follow-up was 0.2 +/- 1.2 Delta and 1.1 +/- 2.7 Delta esotropia (both distance), respectively, and 0.00 Delta and 1.1 +/- 2.7 Delta, respectively, for hypertropia. Strabismus recurred in 19 cases. Conclusions: Progressive connective tissue involution in SES may occasionally result in symptomatic recurrences of the small-angle strabismus in about 20% of patients, irrespective of surgical procedures performed, possibly because of progressive involutional changes. This risk should be disclosed pre-operatively.