Assessment of the Pascal dynamic contour tonometer in monitoring intraocular pressure in unoperated eyes and eyes after LASIK.
OBJECTIVE
To assess the performance of the Pascal dynamic contour tonometer (PDCT) (Swiss Microtechnology AG) by comparing it to Goldmann applanation tonometry (GAT) and noncontact air tonometry (NCT) before and after laser in situ keratomileusis (LASIK).


METHODS
Vlemma Eye Institute, Athens, Greece.


METHODS
Intraocular pressure was measured in 118 eyes before and 1 and 4 weeks after LASIK using GAT, NCT, and the PDCT, which allows direct, digital, transcorneal measurement of intraocular pressure.


RESULTS
Preoperatively, central corneal thickness (CCT) correlated with GAT and NCT measurements but not with PDCT measurements. After LASIK, the mean reduction in CCT ranged from -3.0 to -171.0 microm (median 78 microm). The mean GAT measurement dropped by -4.9 mm Hg +/- 2.7 (SD) at 1 week and was -5.4 +/- 3.0 mm Hg at 4 weeks. Similar drops were observed in NCT measurements. The observed post-LASIK changes in GAT and NCT IOP measurements were not directly proportional to the change in CCT, refractive error, or mean keratometric readings. The preoperative and postoperative PDCT measurements did not differ significantly.


CONCLUSIONS
The structural corneal changes induced by LASIK appeared to influence GAT and NCT measurements but not PDCT measurements. Therefore, PDCT may be better suited for monitoring IOP in unoperated eyes and in eyes that have had LASIK.
Siganos
Dimitrios S
DS
Vlemma Eye Institute, 88 Patission Street, Athens 10434, Greece.
Papastergiou
Georgios I
GI
Moedas
Carlos
C
D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D003315:Cornea / Q000033:anatomy & histology / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D020731:Keratomileusis, Laser In Situ; D008297:Male; D008365:Manometry / Q000295:instrumentation* / Q000379:methods*; D008991:Monitoring, Physiologic; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011182:Postoperative Care; D011300:Preoperative Care; D014792:Visual Acuity