A new noninvasive tear stability analysis system for the assessment of dry eyes.

Purpose: This was a prospective case-control study conducted to evaluate the effectiveness of the Tear Stability Analysis System (TSAS) for the assessment of patients with dry eye.
Methods: The TSAS can take 10 consecutive corneal topograms at one per second for 10 seconds. Examinations using the TSAS were conducted in 26 eyes of 26 healthy control subjects and in 27 eyes of 27 patients with dry eye. Examinations were also conducted in 14 eyes of 14 patients before and after the insertion of punctum plugs. Surface regularity and asymmetry indices (SRI, SAI), as well as new tear stability regularity and asymmetry indices (TSRI, TSAI), derived from SRI and SAI, were analyzed.
Results: The mean SRI and SAI in dry eyes were significantly greater than in control eyes (P < 0.05). The time-wise change of SRI and SAI was significantly different between dry eyes and control eyes (P < 0.05). TSRI and TSAI in dry eyes were also significantly greater than in control eyes. Punctum plug insertion was associated with a significant decrease in SRI and SAI (P < 0.05).
Conclusions: TSAS was effective in objectively assessing the tear stability in patients with dry eye. This system may be useful in noninvasive diagnosis of dry eye and evaluation of treatment effects.