The glaucoma symptom scale: A brief index of glaucoma-specific symptoms

Objective: To develop a brief symptom survey specific for persons with glaucoma, the Glaucoma Symptom Scale (GSS). Design: Cross-sectional study of symptoms, functional impairment, and vision-targeted health-related quality of life among persons with glaucoma. Patients: A sample of 147 persons with glaucoma among a broad range of treatment categories from 4 tertiary care glaucoma centers and 44 persons without eye disease enrolled from the same 4 centers. Main Outcome Measures: Participants completed a modified version of the Ocular Hypertension Treatment Study 10-item symptom checklist. Participants also completed 2 vision-specific measures, the National Eye Institute Visual Function Questionnaire and the VF-14. Participants underwent a clinical evaluation, including ocular and medical history, dilated ophthalmic examination, and Humphrey 24-2 automated visual field testing. Results: The GSS has 2 underlying domains that demonstrate sufficient internal consistency reliability for between-group comparisons: The GSS discriminates well between persons with and without glaucoma. Additionally, tests of association with clinical markers of glaucoma severity support the clinical validity of the measure and tests of association with established vision-targeted measures provide evidence of construct validity. Conclusion: The simplicity, brevity, and psychometric properties of the GSS support its use in clinical practice and research to quantify symptoms in patients with glaucoma and to assist in investigations concerning the effect of glaucoma and treatments.