Abstract
Purpose: :
Noninvasive tear film break-up time (NIBUT) is an important tool in the assessment of patients with dry eye syndrome. Similarly, extension of NIBUT after the instillation of artificial tears is a valuable way to assess and compare the performance of these products. In this trial, the capability of Shack-Hartmann (SH) wavefront sensor technology was compared to that of the commercially available Tearscope PlusTM in measuring NIBUT.
Methods: :
In this randomized, masked, controlled trial, one drop of a new formulation of glycerin 1% or a leading product containing propylene glycol 0.3% and polyethylene glycol 0.4% was placed in either the right or left eye of 16 subjects with varying degrees of dry eye. Tearscope PlusTM NIBUT was measured at pre-instillation, and again at 15, 30, 60, and 120 minutes for all subjects. Two subjects were then studied again on a different day using wavefront sensor NIBUT; otherwise, the same methodology was employed. Results were compared to assess potential for SH wavefront sensor technology to measure the extension of NIBUT in dry eye therapeutic trials.
Results: :
The wavefront sensor performed well in this trial. The performance and ease of use was similar for both devices. The measurements obtained by the two different devices were also comparable. For example, in the subjects who had both tests, the new formulation of glycerin 1% had longer extensions of mean NIBUT's at all time points. When looking at magnitude of effect, there were also trends suggesting that the devices are comparable.
Conclusions: :
The use of a SH wavefront sensor has promise as an objective method of measuring NIBUT in dry eye patients and in assessing the performance of artificial tears. In addition, the wavefront sensor does not require a light source as bright as that used in the Tearscope PlusTM, suggesting that heat induced evaporation may be diminished. The findings were comparable between the two modalities. Both showed a superior extension of NIBUT for a new formulation of glycerin 1% compared to a well known artificial tear.
Clinical Trial: :
www.clinicaltrials.gov NCT00681265
Keywords: cornea: tears/tear film/dry eye • imaging/image analysis: clinical