Related Experiment Video
Updated: Sep 15, 2025
Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential
Published on: May 25, 2020
Inefficacy of Longitudinal Cup-to-Disc Ratio Measurements in Identifying Glaucoma Progression
Amey Kamdar1, Felipe A Medeiros1, Swarup S Swaminathan1
1From the Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA.
Objective:
To assess whether longitudinal change in cup-to-disc ratio (ΔCDR) is predictive of glaucoma progression on optical coherence tomography (OCT) or standard automated perimetry (SAP).
Design:
Retrospective cohort study.
Subjects, Participants, And/Or Controls:
Subjects in the Bascom Palmer Glaucoma Repository.
Methods, Intervention, Or Testing:
We extracted CDRs from the electronic health record. We identified OCT and SAP tests performed within ±6 months of CDRs. Baseline and final CDRs were defined as CDRs closest to the baseline and final tests, respectively. Eyes were required to have ≥5 tests spanning ≥2 years. ΔCDR was calculated as CDR final - CDR baseline. Using ordinary least squares regression, we calculated eye-specific rates of change in OCT retinal nerve fiber layer (RNFL) and SAP mean deviation (MD). We classified eyes as progressors if they had statistically significant negative eye-specific slopes (P < .05). We then evaluated how well ΔCDR predicted progression on OCT or SAP.
Main Outcome Measures:
Area under receiver operating characteristic curve (AUC) predicting OCT or SAP progression using ΔCDR.
Results:
In the OCT analysis (N = 3313 eyes), ΔCDR ≥0.20 was observed in only 7.1% of OCT progressors and 4.8% of non-progressors (P = .04). Only 2% of the variation in OCT RNFL slopes was explained by ΔCDR. AUC was 0.55. At 90% specificity, ΔCDR had a sensitivity of 15% in detecting OCT progressors. In the SAP analysis (N=2,174 eyes), ΔCDR ≥0.20 was observed in only 7.7% of SAP progressors and 5.7% of non-progressors (P = .23). Only 1% of the variation in SAP MD slopes was explained by ΔCDR. AUC was 0.53. At 90% specificity, ΔCDR had a sensitivity of 16% in detecting SAP progressors.
Conclusions:
Longitudinal CDR data performs similar to random selection in identifying glaucoma progression on both structural and functional testing. Given this weak association, clinicians should gauge glaucomatous progression using both a comprehensive optic nerve head examination and ancillary testing.
