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Abstract #15349 Published in IGR 1-3
Intraocular pressure measurement in patients with instrastromal corneal ring segments
Tran DB; Zadok D; Carpenter M; Kom TS; Twa MD; Schanzlin DJJournal of Refractive Surgery 1999; 15: 441-443
PURPOSE: To study the measurement of intraocular pressure after implantation of Intacs (ICRS) intrastromal corneal ring segment, a device that is positioned circumferentially in the peripheral corneal stroma to correct myopia. The device changes the corneal curvature by shortening arc length. Since the ring segments are made of polymethylmethacrylate, this may cause localized changes in corneal elasticity so intraocular pressure measurement may be affected. METHODS: the authors measured the intraocular pressure of 12 eyes in which the ICRS had been in place longer than six months. They used Goldmann applanation and Tono-Pen tonometers over the central corneal and the paracentral corneal areas. They also measured the intraocular pressure with the Tono-Pen applanated directly over the intrastromal corneal ring segments. RESULTS: The resulting intraocular pressure measurements were similar for the Tono-Pen tonometer readings over the central cornea, paracentral cornea, and the Goldmann applanation tonometer readings over the central cornea (p < 0.01). The measurements using the Goldmann applanation tonometer on the paracentral corneal area showed artificially elevated intraocular pressure in the 40 to 60 mmHg range. The authors were not able to obtain consistent results when they measured the intraocular pressure using the Tono-Pen on the corneal area directly overlying the intrastromal corneal ring segment implants. CONCLUSIONS: Consistent intraocular pressure measurements on eyes with the ICRS can be obtained with the Goldmann applanation tonometer over the central corneal area or with the Tono-Pen tonometer over the central or paracentral corneal areas.
Dr. D.B. Tran, Shiley Eye Center, University of California at San Diego, La Jolla, CA 92093; USA
Classification:
2.2 Cornea (Part of: 2 Anatomical structures in glaucoma)
6.1 Intraocular pressure measurement; factors affecting IOP (Part of: 6 Clinical examination methods)
