Long-term Reliability of Diurnal Intraocular Pressure Patterns in Healthy Asians

PURPOSE: To determine the long-term repeatability of diurnal intraocular pressure (IOP) patterns in healthy Asian subjects without glaucoma. METHODS: Twenty-three eyes in 23 healthy Asian subjects without glaucoma underwent diurnal IOP measurements using Goldmann applanation tonometry every 2 hours from 9 AM to 11 PM during two visits that were 8 weeks apart. To validate repeatability between visits, we calculated intra-class correlation coefficients (ICCs) mean IOP, peak IOP, minimum IOP, and IOP fluctuation at each time point and expressed the results as the difference between peak IOP and minimum IOP or as the standard deviation of all diurnal IOP values in the diurnal IOP curve. RESULTS: IOP repeatability was excellent at all time points, with ICCs ranging from 0.812 to 0.946 (p < 0.001). The 9 AM IOP showed the best repeatability between visits (ICCs, 0.946). Repeatability of mean IOP, peak IOP, and minimum IOP was also excellent (ICCs ranging from 0.899 to 0.929). However, IOP fluctuations showed poor repeatability, with an ICC lower than 0.15. CONCLUSIONS: Long-term repeatability of diurnal IOP patterns in healthy Asian subjects was excellent. These findings suggest that IOP measurements at standardized times of the day will be useful for assessing the effectiveness of glaucoma therapy.

Positional Intraocular Pressure between Phakic and Pseudophakic Eyes after Cataract Surgery in a Single Eye

PURPOSE: In the present study, the dependence of intraocular pressure (IOP) on body position was compared between pseudophakic and phakic eyes after cataract surgery performed at least 3 months prior. METHODS: IOP was measured in 214 patients over 40 years of age who received cataract surgery at least 3 months prior. The present study included 104 patients who did not have any other ocular disease which could influence visual acuity or IOP. The IOP was measured in 4 different positions, sitting, supine, right decubitus, and left decubitus by a single skilled researcher using Icare tonometer. In addition, IOP was compared between the phakic and pseudophakic eyes, specifically, the dependent eye in the decubitus position. RESULTS: The comparison between the phakic and pseudophakic eyes in patients after cataract surgery in a single eye showed IOP was not different between the sitting and supine positions; however, in the decubitus position, IOP in the dependent eye was significantly higher than the non-dependent eye (p = 0.001). Additionally, regardless of lens status, IOP was significantly higher in the dependent eye than non-dependent eye. CONCLUSIONS: Both body position and lens status can affect IOP. After cataract surgery, regardless of lens status, IOP was higher in the dependent eye than non-dependent eye of patients in the decubitus position.