Abstract
Purpose: :
Clinical interpretation of the results of randomised controlled trials depends on understanding their generalizability to clinical practice. Staging systems are required to stratify or characterise the study population according to disease severity to allow comparable comparison between interventions. In glaucoma, the most common method used to categorise glaucoma severity is using visual field testing with standard automated perimetry (SAP). Although various staging systems have been developed in recent years, there is no consensus on a standardised staging system. The aim of this systematic review was to identify and evaluate the performance of visual field staging systems (VFSS) for classification of glaucoma severity.
Methods: :
MEDLINE, MEDLINE in Process, EMBASE, SCOPUS and Health Technology Assessment (HTA) Database (to March 2009) were systematically searched for observational studies or randomised controlled trials conducted in adult glaucoma participants, published in English, reporting use of with VFSS solely based on SAP. Only studies that used categorised level of glaucoma severity were included. In addition, reference lists were scanned to identify additional studies describing development or modified versions of VFSS and/or comparative studies on the VFSS performance. Two reviewers independently evaluated studies for inclusion and evaluated the VFSS, using a newly designed quality assessment tool that included items assessing characteristics, performance and practicality of a VFSS.
Results: :
Twenty-four VFSS were identified where twenty were monocular and four were binocular. Hodapp-Anderson-Parrish classification, Brusini GSS2, Trible 2000 and Bascom Palmer GSS were designed to overcome effects of cataract. Paucity of evidence on performance of the VFSS was seen particularly on the test-retest reliability where reporting was only available for AGIS, CIGTS and Brusini GSS2. Mean Deviation (MD) and Aulhorn-Karmeyer classification can be used for both Humphrey and Octopus perimetry data. The highest total score was attained by Brusini GSS2.
Conclusions: :
Several VFSS have been reported. However, lack of data on their performance is a major hurdle for selecting a standardised staging system for glaucoma clinical trials. A comparison of the performance of the identified staging systems needs to be undertaken.
Keywords: visual fields • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • clinical (human) or epidemiologic studies: outcomes/complications