title: Intraoperative measurement of intraocular pressure in vitrectomized aphakic air-filled eyes using the Tono-Pen XL.
abstract: The Tono-Pen XL (Bio-Rad, Santa Ana, CA) was compared with manometer readings for intraoperative measurement of intraocular pressure (IOP) in 40 eyes of 40 consecutive patients after vitrectomy, lensectomy, and fluid-air exchange. Tono-Pen readings corresponding to manometer readings of 10, 20, 30, 40, and 50 mmHg were obtained in a masked fashion with a randomized sequence of manometer readings. A correlation was obtained between the manometer and Tono-Pen readings (r = 0.96 in emmetropic eyes and r = 0.93 in myopic eyes). The regression curve that represents the calibration curve of Tono-Pen in terms of the manometer readings for air-filled vitrectomized eyes was obtained. Any Tono-Pen reading can be easily translated into the corresponding manometer reading by referring to the curve. The Tono-Pen can therefore be effectively used to accurately determine intraoperative IOP in eyes undergoing vitrectomy, lensectomy, and fluid-air exchange.
authors.affiliation: Vitreoretinal Department, Sankara Nethralaya, Medical Research Foundation, Madras, India.
authors.forename: S S
authors.initials: SS
authors.lastname: Badrinath
authors.forename: R
authors.initials: R
authors.lastname: Vasudevan
authors.forename: R
authors.initials: R
authors.lastname: Murugesan
authors.forename: S
authors.initials: S
authors.lastname: Basti
authors.forename: A D
authors.initials: AD
authors.lastname: Nicholson
authors.forename: P
authors.initials: P
authors.lastname: Singh
authors.forename: L
authors.initials: L
authors.lastname: Gopal
authors.forename: T
authors.initials: T
authors.lastname: Sharma
authors.forename: S B
authors.initials: SB
authors.lastname: Rao
authors.forename: C
authors.initials: C
authors.lastname: Abraham
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000388:Air; D001036:Aphakia, Postcataract / Q000503:physiopathology*; D002387:Cataract Extraction; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008365:Manometry / Q000295:instrumentation; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D011446:Prospective Studies; D011897:Random Allocation; D015203:Reproducibility of Results; D014065:Tonometry, Ocular / Q000295:instrumentation*; D014821:Vitrectomy