Screening Evaporative Dry Eyes Severity Using an Infrared Image

Abstract

Background. Dry eye disease (DED) is a multifactorial and one of the most common problems treated in an ophthalmic outpatient clinic. Due to the variability in presentation, diagnosis of DED consists of a combination of subjective and objective clinical tests. The purpose of this study was to assess the effectiveness of a handheld smartphone-based infrared thermal (IRT) camera for screening symptomatic evaporative DED. Methods. This observational sex-matched control study assessed IRT images of 184 right eyes (46 normal and 138 DED) of 184 participants. Evaporative DED was assessed using noninvasive tear breakup time, fluorescein staining, and the Chinese version of the ocular surface disease index (C-OSDI) questionnaire and categorized into their respective dry eye symptomology group (none, mild, moderate, or severe). The ocular surface temperature (OST) at 8 anatomical regions of interest (ROI) (nasal conjunctiva, nasal limbus, nasal cornea, central cornea, inferior cornea, temporal limbus, temporal cornea, and temporal conjunctiva) were measured and compared using a handheld smartphone-based IRT camera. The effectiveness of these 8 ROIs OST in detecting varying severity of DED was evaluated in terms of correlations with severity of DED and their area under the curve (AUC). Results. OST at the 8 anatomical ROI was significantly higher in DED participants than in the non-DED group ( p < 0.05 ) except for inferior cornea, temporal limbus, and temporal conjunctival regions (>0.05). Analyzing 8 anatomical ROIs revealed that the nasal limbus had the highest Pearson correlation with the severity of DED (0.64, p < 0.001 ). Additionally, the nasal limbus ROI achieved the highest AUC of 0.79 (CI: 0.73–0.85; p < 0.05 ), sensitivity, and specificity (0.96 and 0.91) when comparing its ability to discriminated DED vs. non-DED eyes. Conclusions. Rather than a diagnostic tool, handheld smartphone-based IRT images can be considered as a rapid, noninvasive, and hygienic screening tool in discriminating DED and non-DED and potentially alleviating inconvenience experienced during conventional tests.

Applications of Infrared Thermography in Ophthalmology

“…Ocular surface temperature is influenced by multiple conditions, one of the most studied being dry eye [ 39 , 40 ], which will be discussed in a special section. Due to the inflammatory and vascular processes associated with allergic conjunctivitis, it is possible to identify thermographic changes in the ocular surface in patients with allergic conjunctivitis.…”

“…In recent years, the number of reports on the use of thermography as an auxiliary diagnostic method for dry eye has increased [ 19 , 26 , 39 , 44 , 45 , 67 , 68 , 69 , 70 , 71 , 72 , 73 ].…”

“…In addition, other studies did not observe a difference in temperature between dry eye and healthy subjects [ 29 , 45 , 71 ], which again could be due to the technology used (infrared radiation) or because only the central corneal temperature was measured; likewise, there is controversy about the most appropriate region to discriminate between patients with dry eye vs. healthy subjects. Initially, it was considered that the central corneal region was the most important [ 77 ]; however, Zhang et al recently studied patients with evaporative DED and, although they found that all regions (except the inferior corneal region) showed higher temperatures in patients with dry eye, the region with the best diagnostic performance was the nasal region and best correlation with the severity of DED [ 39 ]. In addition, the difference between the central corneal temperature and the sclerocorneal limbus temperature is greater in patients with dry eye than in healthy controls [ 72 ].…”

Comparison of non-pharmaceutical treatments for evaporative dry eye: a randomised controlled study protocol

“…Heated eye mask (HEM) has been shown to improve symptoms of dry eye as the heat transmitted by the mask to the MGs can result in increased liquefication of meibum and promote its release 7 19. The temperature of the eyelids’ surface varies from 33° to 37°C 20 21. The melting range of meibomian expressibility, on the other hand, falls between 19.5°C and 33.8°C for normal individuals and between 32.2°C and 35.3°C for individuals with MGD 22…”

Management of Post-LASIK Dry Eye with Intense Pulsed Light in Combination with 0.1% Sodium Hyaluronate and Heated Eye Mask

“…Additionally, decrease in conjunctival goblet cells has also been proposed to exacerbate post-LASIK DE [ 8 , 9 ] . Similar to DED [ 10 ], the post-LASIK DE state has been hypothesized to be related to inflammation [ 11 , 12 ]. In addition, changes to the corneal shape due to LASIK have also been reported to negatively alter the interaction among the eyelids, ocular surface and tear film distribution [ 13 ].…”