Graefe’s Archive for Clinical and Experimental Ophthalmology
Published online May 2, 2022
About 50% of patients diagnosed with open-angle glaucoma will eventually develop it in both eyes. In some countries, patients can be hospitalized for 24-hour monitoring of IOP to capture elevations that may occur outside of office hours. Previously, Dakroub et al. developed an extraction tool for manually charted IOP curves (HIOP-Reader), analyzed data for right eyes, and found that 24-hour monitoring is a poor tool for detecting glaucoma progression. In a subsequent study, they looked at data for left eyes to compare intereye IOP, ocular perfusion pressure, and progression parameters. They hypothesized that even though 24-hour IOP data may be flawed, both eyes are affected similarly, and thus intereye measurements may help to predict glaucoma in contralateral eyes. As in their previous study, they found that measuring IOP in one eye inadequately predicted progression, but intereye correlations were meaningful for all parameters tested.
In this study, the authors gathered 24-hour data for left eyes using the HIOP-Reader software. They explored the relationship between mean ocular perfusion pressure (MOPP) and retinal nerve fiber layer (RNFL) thickness. They determined receiver operating characteristic (ROC) curves for peak IOP, average IOP, IOP variation, and historical IOP cutoff levels to assess glaucoma progression (i.e., rate of RNFL loss). They used bivariate analysis to look for intereye relationships.
The study included 217 eyes. Per the hospital’s standard protocol, IOP measurements were obtained at 10 a.m., 2 p.m., 5 p.m., 9 p.m., and midnight. During the monitoring period, the average IOP was 14.8 ± 3.5 mm Hg, and the mean variation was 5.2 ± 2.9 mm Hg. RNFL data indicated glaucoma progression in 52% of eyes. There were no significant differences in peak IOP, average IOP, or IOP variation between those who progressed and those who did not. Except for average IOP in relation to temporal RNFL, disease progression in any quadrant was not found to correlate with peak IOP, average IOP, or IOP variation. In- and outpatient IOP readings were not sensitive or specific for detecting progression.
Moreover, the correlation of intereye parameters was moderate, and the relationship to disease progression was weak.
This research and previous work suggest that IOP data are unreliable diagnostically but that intereye findings may be clinically relevant. For most patients in this study, IOP and MOPP were similar for left and right eyes. Therefore, when substantive RNFL loss is observed in one eye, it is likely occurring in the contralateral eye as well.
The original article can be found here.