See also comment(s) by Tony Realini •
BACKGROUND/OBJECTIVES: To evaluate seasonal fluctuations in intraocular pressure (IOP) in primary open-angle glaucoma (POAG) and its associated factors. SUBJECTS/METHODS: POAG patients treated only with glaucoma eye drops were enroled. Winter and summer IOPs were evaluated. The Seasonal fluctuation rate of IOP was defined as follows: (mean winter IOP-mean summer IOP)/mean IOP in all seasons. Multiple linear regression analysis was used to explore factors associated with the seasonal IOP fluctuation rate including: age, gender, family history of glaucoma, type of glaucoma, number of eye drops, type of eye drops, mean deviation (MD) value, MD slope, disc haemorrhage, central corneal thickness and spherical equivalent. RESULTS: Winter IOP was higher than summer IOP in 204 POAG eyes of 204 patients, including 162 eyes with normal tension glaucoma (NTG) (13.2 ± 2.7 vs. 12.0 ± 2.3 mmHg, P < 0.001). The mean age and follow-up duration were 63.3 ± 11.4 years and 140.0 ± 66.9 months. Initial MD and MD slope were -2.1 ± 3.4 dB and -0.07 ± 0.50 dB/year, respectively. POAG was positively associated with the rate of seasonal IOP fluctuations compared to NTG (β = 5.29, P = 0.013). Family history, and timolol and carteolol use were also factors associated with the IOP fluctuation rate (β = -6.27, P = 0.007; β = 4.94, P = 0.030; and β = 4.51, P = 0.042, respectively). CONCLUSIONS: We confirmed seasonal IOP fluctuations in POAG. Type of glaucoma, family history of glaucoma, and β-blocker use might influence IOP fluctuations.
Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan. firstname.lastname@example.org.Full article
6.1.3 Factors affecting IOP (Part of: 6 Clinical examination methods > 6.1 Intraocular pressure measurement; factors affecting IOP)