M. Babic

Dynamic contour tonometry and goldman applanation tonometry in eyes with keratoconus

PURPOSE The dynamic contour tonometer is a nonapplanation contact tonometer designed to be largely independent of the structural properties of the cornea. Theoretically, it may measure intraocular pressure most accurately in abnormally thinner corneas. This study compares intraocular pressure measurements by dynamic contour tonometry with Goldman applanation tonometry in eyes with normal corneas and eyes with advanced keratoconus. METHODS A comparative case series. Subjects underwent intraocular pressure measurements by dynamic contour tonometry, Goldman applanation tonometry, ultrasonic pachymetry, and slit scanning topography. EXCLUSION CRITERIA any ocular pathology other than keratoconus, previous corneal or refractive surgery, stromal scarring due to acute hydrops, or any other corneal opacities. RESULTS Ten patients with keratoconus were included in Group A, and 12 normal patients composed Group B according to the pre-established criteria. The mean Goldman tonometry measurement in group A was 10.3 +/- 1.8 mm Hg and group B was 14.3 +/- 0.75 mm Hg. (P = 0.024). In group A, the mean measurement with the dynamic contour tonometer was 14.6 +/- 2.09 mm Hg, and in group B, it was 17.4 +/- 3.1 mm Hg (P = 0.026). The difference between both methods of measurement in group A was statistically significant (P < 0.0002). CONCLUSION Intraocular pressure readings with dynamic contour tonometry in the keratoconus group were significantly higher than Goldman measurements and lower when compared to the control group. As there are no published manometric studies in eyes with keratoconus, these lower intra-ocular readings with the dynamic contour tonometry could be related to the discrepancy between the radius of corneal curvature and its tip, the significant thinning of the cornea, or other corneal biomechanical abnormalities related to advanced keratoconus.

Reproducibility of the water drinking test in treated glaucomatous patients

To evaluate the reproducibility of intraocular pressure peaks and fluctuation elicited during the water drinking test in treated glaucomatous patients with a long follow‐up interval.

Reproducibility of the Mean, Fluctuation, and IOP Peak in the Diurnal Tension Curve

Purpose:To verify the reproducibility of the mean, peak, and fluctuation of intraocular pressure (IOP) observed during modified diurnal tension curves (mDTC) performed on ocular hypertensive and primary open-angle glaucoma patients. Methods:Prospective analysis of 88 eyes from 88 ocular hypertensive and primary open-angle glaucoma patients subjected to 2 consecutive mDTCs (IOP measurements obtained at 8:00 AM, 11:00 AM, 2:00 PM, and 4:00 PM) on 2 consecutive days. Mean IOP was calculated as the average of all IOP measurements obtained during each mDTC. Peak and minimum IOP levels were considered as the highest and lowest IOP level during each mDTC, respectively. IOP fluctuation was calculated using 2 different approaches: the difference between IOP peak and minimum IOP detected during each mDTC and as the SD of all mDTC measurements. Reproducibility was assessed using the intraclass correlation coefficient (ICC). Results:IOP fluctuation between 2 days in the modified diurnal curve, calculated as the difference between peak IOP and minimum IOP and as the SD of all mDTC measurements, was less reproducible than the mean IOP and peak IOP (ICC values 0.60, 0.62, 0.91, and 0.85, respectively; all ICC values, P<0.001). Conclusions:Mean IOP and peak IOP observed during the mDTC had good reproducibility, whereas the reproducibility of IOP fluctuation was only fair.

Twenty-four-hour repeatability of diurnal intraocular pressure patterns in glaucomatous and ocular hypertensive individuals

OBJECTIVE: To verify the 24-hour repeatability of diurnal intraocular pressure patterns in glaucomatous and ocular hypertensive individuals. METHODS: A prospective analysis of 88 eyes from 88 ocular hypertensive or open-angle glaucoma patients was conducted on diurnal tension curves obtained by the same examiner on two consecutive days. The intraclass correlation coefficient test was used for statistical analysis. RESULTS: Eighty-eight eyes from 88 patients were analyzed. Fifty-seven patients (64.8%) were female. The mean age of all participants was 68.7 (SD 10.8, range 51–79) years. The intraclass correlation coefficient values for measurements at 8 AM, 11 AM, 2 PM, and 4 PM were 0.80, 0.82, 0.83, and 0.86, respectively (all intraclass correlation coefficient values, p<0.001). CONCLUSION: Diurnal intraocular pressure data collected on a single day characterize the diurnal intraocular pressure variability over 24 hours in primary open-angle glaucoma and ocular hypertensive patients.