Abstract
Purpose: :
To evaluate and compare the diagnostic agreement and performance for detection of glaucomatous progression between Cirrus HD-OCT Guided Progression Analysis (GPA) and HFA II Guided Progression analysis.
Methods: :
This observational cohort study included 54 eyes from 37 individuals followed for an average of 24+/-7 months. At baseline, 33% of the eyes were classified as glaucomatous, 34% of the eyes were classified as suspects, and 33% of the eyes as ocular hypertensive subjects. Images were obtained annually with the Cirrus Optic Disc Cube algorithm 200x200, along with the optic disc stereophotographs and standard automated perimetry (SAP) visual fields. Progression using conventional methods was determined by the GPA II software for SAP and by masked assessment of optic disc stereophotographs by expert graders. Images obtained with the Spectral Time Domain OCT were analyzed using the GPA software. Sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) for detection of glaucoma progression were calculated. Optic disc stereophotographs were used as reference standards. Agreement among the different methods was reported using the Kappa coefficient.
Results: :
Four of the fifty-four eyes (7.4%) showed progression by stereophotographs, during the follow-up period. The Cirrus GPA detected 3 of these eyes and the HFA II GPA only one, with a sensitivity of 75% and 25% respectively.Sixteen eyes showed progression only by the Cirrus GPA with a specificity of 68% and four eyes showed progression only by SAP with a specificity of 92%. The Cirrus GPA software obtained a larger area under the receiver operating characteristics curve (0.715) than the HFA II GPA (0.585).The measure of agreement (Kappa coefficient) between stereophotographs and Cirrus GPA and HFAII GPA was 0.158 and 0.152 respectively.
Conclusions: :
In a significant number of cases showing progression by stereophotographs, the CIRRUS OCT GPA detected glaucoma progression with high sensitivity and acceptable specificity. The diagnostic capability of Cirrus GPA detecting glaucomatous progression was better than HFA II GPA.Cirrus GPA and HFAII GPA have poor agreement with expert-assessed change in optic disc stereophotographs.The value of detecting early reduction of Retinal Nerve Fiber Layer detected by SD OCT, as well as the early progression in ocular hypertensive subjects and glaucoma suspects it is not clear. Large and longitudinal studies are needed.
Keywords: imaging/image analysis: clinical • nerve fiber layer • visual fields