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Abstract #15921 Published in IGR 2-3
Impression and applanation tonometry in irregular corneas: comparison with intraocular needle tonometry
Madjlessi F; Marx W; Reinhard T; Althaus C; Sundmacher ROphthalmologe 2000; 97: 478-481
PURPOSE: During the past four years, the authors have demonstrated in eyes with corneal pathology that applanation tonometry (Goldmann, Perkins) generally delivers falsely low measurements compared to intraocular needle tonometry. The aim of this study was to evaluate whether impression tonometry (Schioetz) is more precise than applanation tonometry in determining the intraocular pressure in eyes with corneal disorders. PATIENTS AND METHODS: In 75 eyes with suspected glaucoma and various corneal disorders, the authors performed applanation tonometry and impression tonometry before intraocular needle tonometry. Applanation tonometry was repeated after impression tonometry to unveil a possible tonography effect. Intraocular needle tonometry was performed thereafter. RESULTS: Applanation tonometry results were 4.1 ± 5.3 mmHg below intraocular pressure as determined by intraocular needle tonometry. Impression tonometry results were also lower: 4.3 ± 6.8 mmHg (5.5 g), 4.3 ± 6.4 mmHg (7.5 g), and 4.8 ± 7.0 mmHg (10.0 g). The differences between applanation tonometry and impression tonometry were statistically not significant. In contrast, all the differences between extraocular tonometry procedures and intraocular needle tonometry were statistically highly significant (p < 0.001). CONCLUSIONS: In corneal pathology neither applanation tonometry nor impression tonometry deliver reliable results, on average. Only intraocular needle-tonometry delivers reliable results in these eyes.LA: German
Dr. F. Madjlessi, Universitäts-Augenklinik Düsseldorf, Düsseldorf, Germany
Classification:
6.1 Intraocular pressure measurement; factors affecting IOP (Part of: 6 Clinical examination methods)
