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

Li Li Tan,Philip B Morgan

doi:10.4172/2155-9570.1000587

Abstract

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.

Highlights

While there are many tests available for dry eye disease (DED), it is well understood that eye care practitioners generally rely on a battery of tests for its diagnosis [1]
The situation is further complicated in that DED is multifactorial, determining the cause of dry eye with minimal clinical signs is difficult, and there is a lack of correlation between symptoms and objective tests [4,5]
Ocular surface temperature (OST) measurement with infrared (IR) ocular thermography is indicative of the tear film and its stability [9,10]

Summary

Introduction

While there are many tests available for dry eye disease (DED), it is well understood that eye care practitioners generally rely on a battery of tests for its diagnosis [1]. Conventional clinical tests for DED diagnosis include fluorescein tear break-up time, corneal fluorescein staining, and meibomian gland evaluation [3] and it is generally agreed that there is a lack of consistency between such measures [2,3]. The situation is further complicated in that DED is multifactorial, determining the cause of dry eye with minimal clinical signs is difficult, and there is a lack of correlation between symptoms and objective tests [4,5]. We have not previously considered the correlation between T4 with dry eye symptoms and conventional objective clinical dry eye tests; the diagnostic performance of combining this form of thermographic measure with conventional approaches has not previously been studied.

Methods

Results

Conclusion