Related Experiment Video
Updated: May 24, 2026
Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential
Published on: May 25, 2020
Comparison of Goldmann applanation and dynamic contour tonometry before and after cataract surgery
Mitja A Heinrich1, Timo Eppig, Achim Langenbucher
1Department of Ophthalmology, Otto-von-Guericke-University Magdeburg, Germany.
Purpose:
To validate changes in intraocular pressure (IOP) after phacoemulsification with intraocular lens (IOL) implantation without pressure-lowering surgery in previously unoperated eyes of normal and glaucoma patients.
Setting:
University Eye Clinic, Otto-von-Guericke-University, Magdeburg, Germany.
Design:
Cohort study.
Methods:
The IOP in both eyes of patients was determined by Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT) 1 to 2 days before and after uneventful unilateral surgery. Central corneal thickness was used to correct raw GAT readings.
Results:
Of the 50 patients having unilateral phacoemulsification, 29 had had cataract extraction in the contralateral eye. The mean baseline IOP was 17.4 ± 4.4 mm Hg (GAT) and 16.6 ± 2.9 mm Hg (DCT). Postoperatively, the GAT IOP decreased to 16.4 ± 6.5 mm Hg and the DCT IOP increased slightly to 17.1 ± 4.1 mm Hg. The mean tonometer difference (ΔIOP = GAT - DCT) amounted to ΔIOP(pre) = +0.75 ± 2.69 mm Hg in phakic eyes and ΔIOP(post) = -0.70 ± 3.76 mm Hg in pseudophakic eyes (P=.0011). Consistent results were found in pairs of phakic eyes and pseudophakic eyes (mean IOP 18.0 ± 4.8 mm Hg [GAT] and 17.0 ± 3.3 mm Hg [DCT]). In fellow eyes, the mean GAT reading was 13.4 ± 4.4 mm Hg and the mean DCT value, 14.8 ± 2.4 mm Hg. ΔIOP(phakic) was +1.04 ± 2.75 mm Hg and ΔIOP(pseudophakic) was -1.48 ± 2.78 mm Hg (P=.00000021).
Conclusions:
The GAT IOP readings in pseudophakic eyes seemed to be falsely low. Hence, special attention in the screening, diagnosis, and management of glaucoma is necessary.
