Importance of intraocular pressure measurement at 6:00 a.m. in bed and in darkness in suspected and glaucomatous patients

Abstract

Importance of intraocular pressure measurement at 6:00 a.m. in bed and in darkness in suspected and glaucomatous patients A importância da medida da pressão intraocular às 6 horas no leito e no escuro em suspeitos e portadores de glaucoma SEBASTIÃO (1)(2)(3)(4) . Recently, it was demonstrated in the Advanced Glaucoma Intervention Study (AGIS) that long-term IOP fluctuation is associated with a progression of visual field loss in patients with low mean IOP but not in patients with high mean IOP (5) .This fact has been well- ABSTRACTPurpose: To assess the importance of intraocular pressure measurement obtained at 6:00 a.m. in bed and darkness for the diagnosis and intraocular pressure control of primary open-angle glaucoma.Methods: Retrospective analysis of the daily curve of intraocular pressure of suspects and glaucomatous patients under treatment. Suspects were classified as intraocular pressure values ranging from 19 to 24 mmHg in isolated measurements and/or cup/disc ratio ≥ 0.7 in one or both eyes and/or asymmetry of cup/disc ratio ≥ 0.3 and a normal visual field. Each daily curve of intraocular pressure comprised five to seven IOP measurements with Goldmann applanation tonometer at 9:00 a.m., 12:00 p.m., 3:00 and/or 6:00 and 10:00 p.m. and/or 12:00 a.m. and in the following day morning at 6:00 a.m. in supine position in bed and in darkness with Perkins tonometer before the patient had stood up. Only the daily curves of intraocular pressure that presented an intraocular pressure peak (difference between the higher and the lesser intraocular pressure value) >6 mmHg were analyzed. In these daily curves, the average intraocular pressure and the standard deviation were calculated. The average intraocular pressure and standard deviation values were compared with the normal superior limits: average + two standard deviation of average intraocular pressure and standard deviation of intraocular pressure daily curve from normal patients of the same age group. Daily curves were considered abnormal when their average intraocular pressure and standard deviation values were above the normal superior limits. Secondary and congenital glaucoma were excluded. Results: Daily curves of intraocular pressure of 565 eyes were analyzed; 361 suspected eyes and 204 eyes with primary open-angle glaucoma. In suspects, 64.3% presented an intraocular pressure peak at 6:00 a.m. in bed. In primary open-angle glaucoma, 68.6% presented an intraocular pressure peak at 6:00 a.m. in bed. In 5.3% of the suspects and in 5.9% of primary open-angle glaucoma patients, the daily curve of intraocular pressure profile was inverted (lesser intraocular pressure at 6:00 a.m.). Conclusion: Intraocular pressure peaks at 6:00 a.m. were responsible for the diagnosis of preperimetric glaucoma in 64.3% of suspects and revealed inadequate intraocular pressure control in 68.6% of eyes with primary openangle glaucoma. The daily curve of intraocular pressure including the intraocular pressure measurement at 6:00 a.m. in bed and in darkness is of vital importance...

Intraocular pressure fluctuation and glaucoma progression: what do we know?

“…One definition refers to the difference between the highest and lowest IOP values over a given period, with measurements occurring on different days 14. Alternatively, numerous studies define IOP fluctuation as the SD in IOP over a given time 1 2 11 13 15–22…”

“…Another continually referenced issue is that single IOP measurements reflect IOP only at a given instant, which could alter IOP-related calculations 13 14 28 62 63. Multiple studies report that peak IOPs tend to occur outside of normal office hours, limiting the use of office hour curves 8 36 53 54 64.…”

Correlation and agreement between the 24-hour diurnal tension curve, the water-drinking test, and the postural-change test in glaucoma patients

“…However, it is well known that IOP measurements during office hours underestimate the IOP peak over 24 hours. 11,23 Finally, some authors have established strong correlations between the IOP peak obtained in the 24-hour DTC and the WDT, 6 but none aimed at investigating the agreement between the measurements. Sakata et al performed a WDT and 24-hour DTC in 33 normal tension glaucoma patients, and found a moderate correlation (r = 0.422) between the IOP peaks detected by both methods.…”

Use of machine learning to predict the risk of early morning intraocular pressure peaks in glaucoma patients and suspects

“…Later, Drance reported that almost half of glaucoma patients had IOP peaks at 6 a.m., which were detected through a 24-hour IOP curve (4) . The IOP peaks frequently occur upon waking and can be detected at 6 a.m. in darkness and with the patient in a supine position (5,6) . Because of the difficulties in taking measurements for the 24-hour IOP curve in clinical practice, the diurnal IOP curve was proposed as an option to evaluate the IOP profile of glaucoma patients.…”