Purchase this article with an account.
C. M. Birt, Y. M. Buys, G. E. Trope, Toronto Area Glaucoma Society; The Influence of Central Corneal Thickness on Response to a Topical Prostaglandin. Invest. Ophthalmol. Vis. Sci. 2009;50(13):2483.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The influence of a thin central corneal thickness (CCT) on intraocular pressure (IOP) readings has been well documented. It is also possible that patients with a thinner cornea respond differently to topical medications.
83 patients had been randomized to a prostaglandin antiglaucoma medication and followed for 24 weeks. Pachymetry data were available for 75 patients, and were analyzed for a relationship between CCT and the magnitude of IOP lowering.
The mean age of the patients was 62.7 ± 10.5 years, 36 were female and 42 were male. 48 were Caucasian. The mean CCT was 562.4 +/- 41.4 microns; 37 patients fell below this figure with a mean CCT of 529.4 +/- 25.7 range (range 468 - 560) - (Thin group) and 38 fell above the mean, with a CCT of 594.7 +/- 25.5 (range 565-674) - (Thick group). At week 12, the mean IOP of the Thin group was 1.7 mm Hg lower than the mean IOP of the Thick group, which was statistically significant (p = 0.03). A correlation analysis showed a significant association between CCT and IOP reduction at week 12 (p< 0.02) but not at week 24 (p = 0.06).
Correlation analysis showed that for every 10µ increase in CCT there was 0.30 less IOP decrease between baseline and 12 weeks. Since the difference disappeared at week 24, the clinical significance is low. There were no differences between the groups in the mean difference from baseline IOP at any time point, even at week 12, suggesting that the difference in mean IOP was a chance finding. If CCT affects IOP readings thin corneas would be underestimated and thick corneas overestimated. This would tend to increase any differences between the two groups; to minimize this differences from baseline were also analyzed, and no significance was found. Therefore we do not suggest that CCT will have a significant impact on the results of introducing a topical prostaglandin.
This PDF is available to Subscribers Only