Abstract
Abstract: :
Purpose: To determine if there is a significant difference between measurements of IOP with and without fluorscein dye. Methods: Applanation tonometry measurements of 100 eyes with and without flourescein dye Results: The mean applanation IOP of the non– flourescein group was .51Hg less than the flourescein group but if 1 mmHg is considered clinically relevant to therapy that difference is not statistically significant. Conclusions: Applanation tonometry measurements without the use of flourescein dye are clinically acceptable.Our intention in this study was to demonstrate the difference, if any, between measuring IOP with and without the aid of fluorescein dye. Prior to conducting the study, we determined that in order to detect a 1.0 mmHg difference between the two measurements with a Power of 0.80 that we would need approxiamately 180 data points. We measured the IOP of 100 eyes, with three consecutive measurements of each eye with fluorescein (Group 1) and without fluorescein (Group2). All measurements were conducted by a single ophthalmologist in his office on two consecutive days. The mean IOP of Group 1 was 15.48 mmHg (SD 4.09) and the IOP of Group 2 was 15.99 (SD 4.23). The average difference between the groups was 0.51 mm Hg. The data was analyzed by preforming a 2 group T–test using PASS statistical software. The analysis showed that there was significant difference between the two groups (alpha = 0.47). However, without changing our set parameters, we determined that if we allowed for a difference of 1 mmHg to be considered clinically irrelavant (i.e. mean of 14 for group 1, and mean of 15 for group 2), the difference in means was not statistically significant (alpha 0.03). In addition, the standard deviation of the mean IOP in the non–flourescein group was less than the flourescein group. Since clinical management is not often altered based solely on difference in IOP of 1 mmHg and treatment is not based entirely on absolute IOP values, we propose that the use of fluorescein does not offer any significant advantage over non–use of fluorescein when measuring IOP in the clinical setting.
Keywords: intraocular pressure • detection • clinical (human) or epidemiologic studies: risk factor assessment