The effects of Excimer Laser Assisted In-Situ Keratomileusis on Intraocular Pressure Measurements by Goldmann Tonometry -- by Jennifer Ng, O.D., Harue Marsden, O.D., Chang Kim, O.D.

Title

The effects of Excimer Laser Assisted In-Situ Keratomileusis on Intraocular Pressure Measurements by Goldmann Tonometry

Authors

Jennifer Ng, O.D., Harue Marsden, O.D., Chang Kim, O.D.

Purpose

The purpose of this study was to determine the effects of laser assisted in-situ keratomileusis (LASIK) on Goldmann applanation tonometry readings in human eyes.

Methods

The charts of 158 patients, who had bilateral LASIK performed by the same surgeon were retrospectively reviewed. Preoperative and one month postoperative intraocular pressure, ablation depth and pachometry readings were collected. Data from one eye was analyzed using paired t-test and regression analysis.

Results

There was a statistically significant decrease in mean Goldmann tonometry readings of 4.2 mm Hg + 3.6 (SD) one month following LASIK. Preoperative intraocular pressure (IOP) was the strongest predictor for change in intraocular pressure after LASIK. (P = 0.00) Regression analysis also reveals that there was a correlation between change in IOP and pachometry. (P = 0.01) Little or no correlation was found with ablation depth or postoperative IOP

Conclusion

Refractive surgery alters the accuracy of the Goldmann tonometer, causing it to underestimate IOP. There is an average decrease of 4.2 mm Hg + 3.6 (SD) in intraocular pressure following LASIK surgery