Convergence insufficiency symptom survey (CISS) scores are predictive of severity and number of clinical signs of convergence insufficiency in young adult Africans

PURPOSE: This study aimed to investigate the correlation between convergence insufficiency symptom survey (CISS) score and the signs of convergence insufficiency (CI) and to evaluate the sensitivity and specificity of the CISS to predict CI and ametropia among young adult university students. METHOD: This prospective cross-sectional clinic-based study included 300 first year university students (mean age = 21.58 (SD ± 2.2) years) who consecutively reported for eye examination. Participants were administered the CISS questionnaire and investigated for the signs of CI. Diagnosis of CI was based on presence of three or four signs. The correlation between the CISS score and the signs of CI were determined and Receiver Operation Characteristics (ROC) curves were used to evaluate sensitivity and specificity. RESULTS: There were significant correlations between CISS score and the clinical signs of CI namely NPC break (r(s) = 0.622, p = 0.0001), NPC recovery (r(s) = 0.620, p = 0.0001), near exophoria (r(s) = 0.434, p = 0.0001), near PFV blur (r(s) = -0.359, p = 0.0001), near PFV break (-0.306, p = 0.0001), near PFV recovery (r(s) = -0.326, p = 0.0001) and gradient AC/A ratio (r(s) = -0.290, p = 0.0001). There was a significant positive correlation between CISS score and the number of clinical signs of CI (r(s) = 0.575, p-value = 0.0001). The CISS had good sensitivity (AOC = 0.882) to predict CI and poor sensitivity (AOC = 0.642) to predict ametropia. CONCLUSION: The CISS score is correlated with the severity and number of signs of CI in young adult Ghanaian university students. Its use in addition to clinical investigative testing may give a definitive diagnosis of symptomatic CI.