advertisement
Abstract #6371 Published in IGR 3-2
Tonometry after laser in situ keratomileusis treatment
Duch S; Serra A; Castanera J; Abos R; Quintana MJournal of Glaucoma 2001; 10: 261-265
PURPOSE: To assess the reliability of intraocular pressure (IOP) measurements by Goldmann applanation tonometry versus pneumotonometry after laser in situ keratomileusis for myopia. PATIENTS AND METHODS: In this prospective study, corneal Goldmann applanation tonometry and pneumotonometry measurements were made in 118 eyes of 60 patients before and one and three months after undergoing laser in situ keratomileusis for myopia. Manifest refraction, ultrasonic corneal thickness measurements, and keratometry readings were also obtained. RESULTS: Preoperative IOP showed a good correlation between Goldmann applanation tonometry and pneumotonometry values (Pearson r = 0.71; p < 0.001), although Goldmann applanation tonometry readings were slightly higher at low IOP values and slightly lower at high IOP values. After a mean stromal ablation depth of 77.1 μm, mean IOP by Goldmann applanation tonometry decreased significantly (p < 0.001) from a preoperative value of 14.8 ± 11.9 to 11.9 ± 2.1 and 11.7 ± 1.7 mmHg after one and three months, respectively. Mean pre- and post-laser in situ keratomileusis measurements by pneumotonometry were similar (p = 0.8). Differences in postoperative IOP measurements by Goldmann applanation tonometry and pneumotonometry were statistically significant. After three months, there was poor correlation between Goldmann applanation tonometry and pneumotonometry IOP values (Pearson r = 0.58). Postoperative IOP decrease in applanation tonometry correlated with changes in keratometry, spherical equivalent, and central corneal thickness. Regression analysis showed a decreased of 2.9 mmHg per 70 μm reduction in central corneal thickness. CONCLUSIONS: Contact pneumotonometry measured the IOP reliably after laser in situ keratomileusis for myopia, whereas Goldmann applanation tonometry underestimated the IOP. This may be important in the treatment of future glaucoma.
Dr S. Duch, Francisco Carbonell 44, atico 2, E-08034 Barcelona, Spain
Classification:
6.1 Intraocular pressure measurement; factors affecting IOP (Part of: 6 Clinical examination methods)
8.4 Refractive surgical procedures (Part of: 8 Refractive errors in relation to glaucoma)
