Surgical Decision Making in Intermittent Distance Exotropia Using the Newcastle Control Score

Abstract

Abstract: : Purpose: To describe the application of a novel scoring system for grading the severity of intermittent distance exotropia to decisions about surgical correction in this condition. Methods: The Newcastle Control Score is a novel, 8 point rating scale for grading the severity of Intermittent Distance Exotropia (IDEX). The score was first tested for interobserver reliability and then applied retrospectively to a cohort of 77 patients aged 1 - 11 years, with a minimum of 6 months follow up, who were treated either surgically or conservatively for IDEX. Scores were allocated for surgical cases based on the last preoperative visit and for non surgical cases based on their presenting severity. Cure was defined as a score of 0 or 1 (outcome 1) or 0, 1 or 2 (Outcome 2) on the last recorded visit. Cure rates were analysed for each preoperative (surgical cases) or presenting (non surgical cases) score. Results: Interobserver reliability was good (r = 0.892). Cure rates varied between 41 and 50% (outcome 1) and 50 – 68% (outcome 2) for surgical cases and from 0 – 13% (outcome 1) and 0 – 25% (outcome 2) for non surgical cases. No patient with a presenting score of 4 or greater achieved a cure without surgical intervention. Conclusions: The Newcastle Control Score for Intermittent Distance Exotropia is a reliable method for grading the severity of intermittent distance exotropia and can be applied to decisions about surgical intervention. Patients with a score of 4 or more are unlikely to attain a cure without surgical intervention Control Scores vs. Cure Rates for Surgical and Non Surgical Cases of IDEX  

Keywords: strabismus: treatment • esotropia and exotropia