Analysis of the circadian rhythm of intraocular pressure in stable and progressive forms of primary open-angle glaucoma

Abstract

Purpose. To analyze the daily dynamics and the parameters of intraocular pressure circadian rhythm (IOP CR) in patients with primary open-angle glaucoma (POAG) (stable and progressive forms) and determine chronobiological regularities of glaucoma progression depending on the patterns of restructuring the daily dynamics of IOP CR and body temperature.Material and methods. The study included 75 POAG patients, of which 35 had a stable form (S-POAG) and 40 had a rapidly progressing form (P-POAG). The control group was composed of 80 subjects without POAG. The index of retinal ganglion cell loss measured by optical coherence tomography (OCT) was used as a criterion of POAG progression. IOP was measured by the patients themselves for 72 hours at 7 time points (3 am, 8 am, 11 am, 2 pm, 5 pm, 8 pm, and 11 pm, who used an Icare ONE portable intraocular pressure tonometer for individual use.Results. IOP daily dynamics was distributed differently in the different groups. In S-POAG, the peak values were mainly reached in the morning hours, while the minimum values were observed at night. In P-POAG, the peak values of IOP were contrariwise recorded at night. In both POAG groups, an increase of irregular fluctuation share was noted, which indicated a decrease of the CR contribution to the IOP CR. Moreover, in POAG, a change in the phase ratio between the IOP CR and CR of body temperature was observed. For IOP CR phase violation manifestations, the threshold value of GCS global loss index was determined at 10–15 % according to OCT data.Conclusion. IOP daily dynamics were shown to differ in S-POAG and P-POAG patients. In both groups. Signs of desynchronization were detected. The ganglion retinal cell global loss index can be used to determine phase disturbances of IOP CR.