Abstract
Abstract: :
Purpose:: The aim of this study was to evaluate routine ophthalmic data to identify clinically useful risk factors for progressive visual field loss in patients with primary open angle glaucoma (POAG) already receiving intra-ocular pressure lowering treatments. Methods: A retrospective cohort study design was used. The study cohort was identified by sequential recruitment of eligible POAG patients from a Hospital Eye Service glaucoma follow-up clinic. Routine ophthalmic data for all subjects were obtained from case records with the knowledge that baseline clinical data had been collected in a standardised manner. Standardized proforma based information was available from routine case record data collection. Progression was explicitly defined according to the AGIS visual field defect scoring system. Variables evaluated as candidate risk factors for progression were assessed by survival analysis. Factors exerting a significant effect on survival (log rank test, p<0.10) were subsequently tested in a Cox proportional hazards model. Results: A cohort of 108 eligible POAG patients was followed over an average of 2.6yrs, with an average visual field inter-test interval of 7 months. The incidence rate of progressive loss amongst the cohort was 4.70 cases per 100 person years. Increasing age was found to be associated with a small but significantly increased risk of glaucomatous visual field defect progression, with a hazard ratio of 1.08 (95% CI 1.01 to 1.15) for each additional year of age. Visual field progression was also weakly associated with male sex (p=0.047) and IOP of 30 mmHg or more at any time over the course of follow-up (p=0.090). Conclusions: Identification of risk factors associated with progressive glaucoma provides important prognostic information and is valuable for informing both type and aggressiveness of treatment intervention. Knowledge of progression rate in groups of patients already receiving treatment is important for health care service organisation.
Keywords: clinical (human) or epidemiologic studies: ris • clinical (human) or epidemiologic studies: pre • visual fields