Abstract
Abstract: :
Purpose: To compare intraocular pressure (IOP) in patients with keratoconus (KC), pellucid marginal degeneration (PD) and unilateral penetrating keratoplasty (PK) for KC or PD, by applanation tonometry (AT), Tono–Pen tonometry (TP) and Pascal Dynamic Contour Tonometry (DCT). Methods: Patients with KC, PD or PK who are 18 years or older were included. IOPs were measured by AT, TP and DCT after routine examination. Severity of ectasia was assessed by means of steepest curve by corneal topography and maximal thinning. For patients with the same diagnosis in both eyes, the more severely affected eye was included. Measurements were compared by difference of means. Preliminary results: Twenty–one eyes of 13 patients were enrolled; 7 males and 6 females. Mean age was 48.8±16 years. Twelve eyes had KC, 8 eyes had a PK for KC and 1 eye had PD. DCT gave the highest IOP measurements followed by AT and TP respectively. The differences of mean IOP between TP and DCT and TP and AT were statistically significant, while the difference between AT and DCT was not. Conclusions: DCT is a newly FDA–approved device which measures IOP independent of corneal thickness, corneal curvature and ocular rigidity. DCT gave the highest IOP readings when compared to AT and TP in this study, but the difference between AT and DCT was not significant. TP gave significantly lower Results: DCT may be helpful in IOP measurement in eyes with KC and PD. TP may underestimate the IOP.
Keywords: cornea: clinical science • keratoconus • intraocular pressure