J Korean Ophthalmol Soc.  2009 May;50(5):749-755. 10.3341/jkos.2009.50.5.749.

Measurements of Dynamic Contour Tonometry After Penetrating Keratoplasty and EpiLASIK

• Lee SJ
• Lee HS
• Joo CK

• KMID: 2212315
• DOI: http://doi.org/10.3341/jkos.2009.50.5.749

Abstract

PURPOSE:To analyze the clinical results of Goldmann applanation tonometry (GAT) and Pascal dynamic contour tonometry (PDCT) and the influences of central corneal thickness and keratometric power in eyes that underwent EpiLASIK or penetrating keratoplasty.
METHODS
Measurements of intraocular pressure by GAT and PDCT as well as keratometric power and central corneal thickness were measured in 45 eyes that underwent penetrating keratopasty and 63 eyes that underwent EpiLASIK. These parameters were also measured in healthy eyes with no specific disorders to create a control group.
RESULTS
In the keratoplasty group, the PDCT results were significantly higher than the GAT results by 1.22+/-2.84 mmHg (p=0.006), but neither method showed a significant correlation with CCT or keratometric power. In the EpiLASIK group, PDCT was higher as 3.45+/-2.35 mmHg than GAT, and the corrected results of GAT were not different from the results of PDCT. In the control group, GAT was affected by central corneal thickness and keratometric power, but PDCT showed no significant relationship with these two factors.
CONCLUSIONS
After EpiLASIK or penetrating keratoplasty, both of which change CCT and keratometric power, IOP cannot be accurately measured by GAT. In these patients, PDCT may play an important clinical role since it is less affected by corneal properties.

Keyword

EpiLASIK; Intraocular pressure; Keratoplasty; Pascal dynamic contour tonometry

MeSH Terms

Corneal Transplantation
Eye
Humans
Intraocular Pressure
Keratoplasty, Penetrating
Manometry
Peptides
Peptides

Figure

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  Figure 1. Schematic diagram of Non-applanating contour-matched tip of the Pascal tonometer. When the match is achieved, the sensor tip embeddd in tip measures38

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  Figure 2. Difference between PDCT and GAT IOP measurements, plotted against the mean of the two measurements. The measurements obtained by these two techniques were found to be within ±5.61 mm Hg of each other in 95% of cases (PPKP group).

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  Figure 3. Effect of CCT on PDCT and GAT in Epi-LASIK group Cross and dotted line represents PDCT result and its estimated regression line according to CCT. PDCT does not correlate with CCT in contrast to GAT. Dotted line (PDCT); IOP=0.005× CCT+13.725 (R2=0.009, p-value=2.479), Solid line (GAT); IOP= 0.029× CCT–0.597 (R2=0.266, p-value=0.000).

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  Figure 4. Difference between PDCT and GAT IOP measurements, plotted against the mean of the two measurements. The measurements obtained by these two techniques were found to be within ±4.62 mmHg of each other in 95% of cases (EpiLasik group).

Reference

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