Tear film normalization test: a new diagnostic test for dry eyes.
OBJECTIVE
To evaluate the normalization of the tear film (tear film normalization test [TNT]) as a diagnostic test for dry eye syndrome.


METHODS
The uncorrected distance vision of 20 patients with dry eyes (40 eyes) and 20 normals (40 eyes) before and after instillation of carboxymethyl cellulose 0.5% (CMC; Refresh Plus; Allergan, Irvine, CA) was recorded. We used study early treatment diabetic retinopathy (ETDRS) vision charts to test vision in each eye. Tear film breakup time (TBUT), presence or absence of superficial punctate erosions (SPE), tear film meniscus height, meibomian gland function, and ocular surface disease index (OSDI) questionnaire scores were evaluated.


RESULTS
CMC improved visual acuity in the dry eye group (P < 0.0001). Response operator's curve (ROC) analysis showed that vision improvement of 2 lines or more after tear normalization was associated with an 82.5% (95% CI: 66.6%-92.1%) sensitivity and 100% (95% CI: 89.1%-100%) specificity for dry eye. There was a significant correlation between vision improvement and OSDI score in the dry eye group (P = 0.003).


CONCLUSIONS
The TNT is a highly sensitive and specific test for dry eyes and is available in every eye care professional's office. The more symptomatic the dry eye, the greater the improvement.
Latkany
Robert
R
Center for Ocular Tear Film Disorders, Laser and Corneal Surgery Associates, New York, NY 10022, USA. relief@dryeyedoctor.com
Lock
Barbara G
BG
Speaker
Mark
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002266:Carboxymethylcellulose Sodium / Q000008:administration & dosage*; D002648:Child; D003941:Diagnostic Techniques, Ophthalmological; D015352:Dry Eye Syndromes / Q000175:diagnosis* / Q000378:metabolism; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009883:Ophthalmic Solutions / Q000008:administration & dosage*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013666:Tears / Q000378:metabolism*; D014792:Visual Acuity / Q000502:physiology*
D009883:Ophthalmic Solutions; D002266:Carboxymethylcellulose Sodium