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Intraocular pressure measurement in patients with previous LASIK surgery using pressure phosphene tonometer
Arthur C K Cheng1, Dexter Y L Leung, Eva Y Y Cheung
1Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, University Eye Center, Hong Kong Eye Hospital, Hong Kong, China.
Purpose:
To compare intraocular pressure (IOP) assessment in post-LASIK patients using non-contact tonometry, pressure phosphene tonometry and applanation tonometry.
Methods:
Sixty-two consecutive LASIK patients were analysed preoperatively and postoperatively with non-contact, pressure phosphene and applanation tonometry. Comparisons among these values were assessed with paired sample Student t-test, Pearson's correlation test and Bland-Altman plotting.
Results:
There was no significant difference for preoperative IOP measurement between non-contact, pressure phosphene and applanation tonometry. The mean +/-SD difference between the preoperative non-contact tonometry and postoperative pressure phosphene tonometry IOP measurements was 0.80 +/- 2.77 mmHg (P < 0.01). Postoperative applanation tonometry significantly underestimated IOP measurement by 5.45 +/- 2.96 mmHg (P < 0.001) and postoperative non-contact tonometry significantly underestimated IOP measurement by 9.96 +/- 2.25 mmHg (P < 0.001).
Conclusion:
Pressure phosphene tonometry may provide an alternative method for the assessment of IOP in post-LASIK patients.
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