advertisement
Editors Selection IGR 8-4
Clinical glaucoma: NPG - IOP
Comment by John Liu on:
15103 Diurnal variation of intraocular pressure in suspected normal-tension glaucoma, Hasegawa K; Ishida K; Sawada A et al., Japanese Journal of Ophthalmology, 2006; 50: 449-454
See also comment(s) by Arthur Sit •Fluctuation in intraocular pressure (IOP) is an important issue in the diagnosis and treatment of glaucoma. Despite the fact that minute-to-minute telemetric recording of IOP is now a reality in conscious, freely moving laboratory animals, no such technology will be ready in the near future for human clinical use. Our understanding of 24-hour IOP variation in various types of glaucoma still depends on carefully performed data collections under controlled conditions. As one such attempt, Hasegawa et al. (1057) reviewed 24-hour data of sitting IOP, measured by Goldmann tonometer, in a very large group of Japanese normal-tension glaucoma patients seen in their clinic with a long follow-up period. The results confirmed previous observations in normal-tension glaucoma patients with smaller sample sizes and shorter follow-up periods. A consensus is that a significant percentage of normal-tension glaucoma patients have their IOP peaks outside office hours.
As indicated by the authors, the 24-hour IOP curve observed in the present study may not represent what was happening in real life. Day and night measurements of IOP in their patients were all performed in the sitting position. At night, a supine position should be closer to a real life situation than a sitting position. In another recent study also involving Japanese normal-tension glaucoma patients1 a composite 24-hour IOP curve based on sitting IOP during the day and supine IOP at night showed that many more patients had IOP peaks, frequently above the commonly accepted IOP range for normal-tension glaucoma, during the sleep period. While attention should be given to IOP outside office hours in normal-tension glaucoma patients, the clinical significance of sitting IOP reading at night is uncertain.
