Journal of Clinical and Experimental Ophthalmology
Open Access

Abstract

Diagnostic Ability of Conventional Dry Eye Tests and their Correlation with Ocular Surface Temperature

Li Li Tan and Philip B Morgan

Objective: To study the diagnostic ability of conventional dry eye tests and their correlation with ocular surface temperature (OST) and derive the best combined objective tests for dry eye.

Methods: This was a single visit study included a few conventional dry eye tests on 62 dry eye and 82 control subjects: symptom evaluation, fluorescein break-up time (FBUT), corneal epithelial staining (CES), non-invasive break-up time (NIBUT) and tear meniscus height (TMH). OST was recorded using NEC TH9260 thermo tracer and six temperature metrics of the extreme nasal conjunctiva was studied including the temperature 10 seconds after eye opening (T4-10). Diagnostic ability was assessed by calculating sensitivity and specificity and area under the receiver operating characteristics curve (AUC).

Results: No correlation (Pearson's coefficient, -0.203 to 0.209; p>0.05) was found between Mscore, Scount, FBUT and CES with any of the temperature metrics. However, CES correlated significantly with TMH (r=0.276; p=0.030) and inversely correlated significantly with FBUT (r=- 0.258; p=0.043). Values of Mscore at 8 were found to give sensitivity of 87.1% (95% CI: 76.2 to 94.3%) and specificity of 92.7% (84.8 to 97.3%). Values of Scount at 1 were found to give sensitivity of 93.6% (84.3 to 98.2%) and specificity of 65.9% (54.6 to 76.0%). Values of FBUT at 2 s were found to give sensitivity of 58.1% (44.9 to 70.5%) and specificity of 87.8% (78.7 to 94.0%). Values of CES at grade 2 were found to give sensitivity of 71% (58.1 to 81.8%) and specificity of 59.8% (48.3 to 70.4%). Combining CES with T4-10 (series) had increased the AUC to 78% with sensitivity and specificity of 92.3% and 42.7% respectively.

Conclusion: This work validated the ability of Mscore, Scount, FBUT and CES in diagnosing dry eye and further confirmed the discordance between its signs and symptoms. Combining CES with T4-10 (series) can be future objective tests for dry eye.