Intraocular Pressure and Calculated Diastolic Ocular Perfusion Pressure during Three Simulated Steps of Phacoemulsification In Vivo

• Published in: Investigative ophthalmology & visual science Vol. 50; no. 6; pp. 2927 - 2931
• Main Authors: Zhao, Yune, Li, Xingyu, Tao, Aizhu, Wang, Jianhua, Lu, Fan
• Format: Journal Article
• Language: English
• Published: Rockville, MD ARVO 01-06-2009; Association for Research in Vision and Ophtalmology
• Subjects: Adult; Aged; Aged, 80 and over; Biological and medical sciences; Blood Pressure - physiology; Choroid - blood supply; Diastole; Eye - blood supply; Eye and associated structures. Visual pathways and centers. Vision; Female; Fundamental and applied biological sciences. Psychology; Humans; Intraocular Pressure - physiology; Male; Medical sciences; Middle Aged; Ophthalmology; Optic Nerve - blood supply; Phacoemulsification; Regional Blood Flow - physiology; Retinal Vessels - physiology; Transducers, Pressure; Vertebrates: nervous system and sense organs; Eye; In vivo; Diastolic pressure; Treatment; Ocular; Perfusion; Surgery; Ophthalmology; Phacoemulsification; Intraocular pressure
• ISSN: 0146-0404; 1552-5783
• DOI: 10.1167/iovs.08-2996

To investigate the fluctuations of directly measured intraocular pressure (IOP) and induced diastolic ocular perfusion pressure (DOPP) during three simulated steps of phacoemulsification in vivo.
Twenty-five eyes of 25 patients who underwent phacoemulsification were evaluated. A pressure transducer was inserted into the anterior chamber to measure IOP directly. The cortical cleanup and viscoelastic removal, nuclear disassembly, and anterior capsular polishing stages of phacoemulsification were simulated. Baseline, static, and dynamic IOP measurements at each stage were conducted before a routine phacoemulsification procedure was performed. DOPP was determined as the difference between diastolic blood pressure and IOP.
The directly measured IOP fluctuated from 13 +/- 4.7 to 96 +/- 6.2 mm Hg during the simulated steps of phacoemulsification (repeated-measurement ANOVA, P < 0.001). It was elevated more than 39 mm Hg compared with the baseline in static and dynamic measurements (post hoc, P < 0.001). Static DOPPs were lower than 0 mm Hg in all cases during simulated cortical cleanup and viscoelastic removal and in 19 cases during simulated nuclear disassembly. Dynamic DOPPs were lower than 0 mm Hg in 14 cases during simulated cortical cleanup and viscoelastic removal.
IOP and DOPP fluctuate widely during simulated steps of phacoemulsification. Further studies may be needed to establish the effect of the transient fluctuations in DOPP on visual function.