title: Monthly measurements of intraocular pressure in normal, ocular hypertensive, and glaucoma male subjects of same age group.
abstract: BACKGROUND
  Recently it has been shown that environmental conditions have a significant influence on intraocular pressure (IOP). Due to differences in inherent constitution, diet and environmental conditions, there is a clear need for well collected IOP data in different countries and ethnic groups. The seasonal variation of IOP has never been described in Pakistani subjects.
  
  
  METHODS
  IOP was measured each month over the course of 12 months with the Goldmann applanation tonometer in normal, ocular hypertensive, and glaucoma male subjects.
  
  
  RESULTS
  In all groups, the average intraocular pressures in the winter months were highest, while lowest in summer months. The intraocular pressures of spring and autumn months were nearly the same. The intraocular pressure levels in these seasons were between the IOP levels in summer and winter seasons. The difference between highest and lowest IOP was 1.4 +/- 0.2, 3.1 +/- 1.4, and 2.3 +/- 1.1 mmHg, in normal, ocular hypertensive, and glaucoma subjects, respectively. The ups and downs of intraocular pressure were greater in the ocular hypertensive subjects than in the glaucoma patients.
  
  
  CONCLUSIONS
  This study confirms that season influences IOP, and concludes that seasonal influence is highest in ocular hypertensive than in normal and glaucoma subjects. As compared to other nations, effect of seasons on IOP seems to be somewhat less pronounced in Pakistan.
authors.affiliation: Department of Physiology, Rawalpindi Medical College, Rawalpindi, Pakistan.
authors.forename: I A
authors.initials: IA
authors.lastname: Qureshi
authors.forename: X R
authors.initials: XR
authors.lastname: Xi
authors.forename: I H
authors.initials: IH
authors.lastname: Khan
authors.forename: X D
authors.initials: XD
authors.lastname: Wu
authors.forename: Y B
authors.initials: YB
authors.lastname: Huang
mesh_terms: D005901:Glaucoma / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D009798:Ocular Hypertension / Q000503:physiopathology*; D012621:Seasons