Seasonal Variation and Trend of Intraocular Pressure Decrease Over a 20-Year Period in Normal-Tension Glaucoma...

Area of Science:

• Ophthalmology
• Glaucoma Research
• Ocular Physiology

Background:

• Normal-tension glaucoma (NTG) is a common form of glaucoma where optic nerve damage occurs despite intraocular pressure (IOP) within the statistically normal range.
• Understanding the long-term trends and seasonal variations of IOP in NTG patients is crucial for effective disease management and monitoring.

Purpose of the Study:

• To investigate the 20-year trend of seasonal variation in intraocular pressure (IOP) among patients diagnosed with normal-tension glaucoma (NTG).
• To analyze real-world data from a large patient registry to identify long-term IOP patterns in NTG.

Main Methods:

• A retrospective cohort study analyzing 49,007 data points from 1774 NTG patients over a 20-year period (1997-2016).
• Monthly mean IOP was calculated and data was grouped into five 4-year intervals for trend analysis.
• Nonlinear multiple regression analysis was employed to assess seasonal variations in IOP.

Main Results:

• A statistically significant continuous decrease in mean IOP was observed over the 20-year study period (P < .001).
• The annual mean IOP was highest in the earliest group (1997-2000) and lowest in the most recent group (2013-2016) (P < .001).
• Distinct seasonal variations in IOP were consistently present across all study periods and patient groups (P < .001).

Conclusions:

• Real-world longitudinal data from the Kyoto Prefectural University of Medicine Glaucoma Registry demonstrates a continuous decline in IOP among NTG patients over two decades.
• These findings underscore the presence of significant seasonal fluctuations in IOP that persist alongside the overall decreasing trend in NTG patients.