Intraocular pressure measurements with Goldmann applanation tonometry and dynamic contour tonometry in eyes after IntraLASIK or LASEK

Background and methods: Myopic photorefractive surgery induces a reduction in central corneal thickness, which may lead to underestimation of intraocular pressure. This retrospective clinical study compared intraocular pressure measurements obtained by Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT-Pascal) in eyes undergoing myopic intralaser-assisted in situ keratomileusis (IntraLASIK) or laser-assisted subepithelial keratomileusis (LASEK).

Results: Of a total of 51 eyes, 21 underwent LASEK and 30 underwent IntraLASIK. By GAT, mean preoperative intraocular pressure was 16.2 ± 1.99 mmHg and postoperatively was 10.84 ± 1.45 mmHg. By DCT, mean preoperative intraocular pressure was 15.9 ± 2.08 mmHg and postoperatively was 16.1 ± 2.3 mmHg. Both preoperative and postoperative differences between measurements made by GAT and DCT were found to be statistically significant (P < 0.04 and P < 0.01, respectively). GAT and DCT readings were unaffected by type of surgery (P = 0.74 and P = 0.46, respectively).

Conclusion: Postoperative GAT measurements were lower than those obtained by DCT. The difference between preoperative and postoperative DCT measurements was minimal, so DCT may be preferable for the measurement of intraocular pressure in eyes undergoing myopic IntraLASIK or LASEK.