Comparing tear film stability prolongation evaluated by Javal-Schiotz keratometer and slitlamp

To innovatively compare the tear film stability assessed noninvasively by Javal-Schiotz keratometer (tear deformation time [TDT]) and invasively by slitlamp (invasive tear breakup time [I-TBUT]).

Tear deformation time and I-TBUT were assessed in only 1 eye of 100 healthy young participants aged from 18 to 25 years (mean±standard deviation=20.49±1.80). Healthy ocular surface was considered as inclusive criteria. Nonparametric statistical analysis was performed to compare the TDT with I-TBUT and reveal correlation between them.

The TDT values (mean: 22.84±20.14 sec) were significantly higher than the I-TBUT (mean: 15.73±8.89 sec) data (P=0.027). Neither TDT nor I-TBUT was affected by gender of the subjects. A significant direct correlation was detected between the TDT and I-TBUT data (Spearman ρ=0.458, P<0.0001). Neither I-TBUT nor TDT showed a significant relationship with age and sex factors.

Our findings indicated that tear stability prolongation results obtained by TDT technique were significantly higher than the I-TBUT method outcomes. Noninvasive nature, easiness, basal tear film evaluation, availability, inexpensiveness, Fluorescein nonuse, and accessibility in the clinic (no need for para-clinical equipment) are benefits of the TDT technique. Future studies must be aimed at evaluating validity and reliability of the TDT technique on normal and dry eye populations.