Germany: Longitudinal analysis of intraocular pressure in healthy eyes

Abstract Purpose: The knowledge of physiology of intraocular pressure (IOP) is important for the interpretation of pathophysiological alterations of IOP in glaucoma patients. Thus, the purpose of this study was a retrospective analysis of follow-up data of IOP in normal subjects in Germany. Methods: A retrospective analysis of IOP data of 112 eyes of 112 normal subjects (age: 18–81 years) of the Erlangen Glaucoma Registry (NCT00494923; ISSN 219-5008, CS-2011) was performed. Data of normal subjects with annual visits (with a number of 2–18) were analyzed. IOP was measured by Goldmann applanation tonometry at each visit in the morning. After IOP correction by the Dresdner correction table (according to the central corneal thickness, CCT), different statistical models were applied taking in account the influence of age and gender. Results: A significant influence of age and gender was observed on CCT (p < 0.001). Additionally, age affected IOP (p = 0.0018), yet, gender did not show any dependency on IOP. A significant age effect was observed on IOPcorr without differences between female and male. Quantile analysis yielded a significant change of the 0.25 percentile of IOP (p < 0.0001) and a slightly change for the 0.75 percentile of IOP (p = 0.05) over time in women. In men, a significant change was seen for the 0.5 percentile of IOP over time (p = 0.04). Conclusion: An age-dependency on CCT and IOP was observed in the German population. Additionally, gender affected CCT, yet not IOP.