Purpose:
There are a variety of studies in the literature that have correlated the association between OST and various eye diseases, e.g glaucoma, dry eye syndrome, retinal vein occlusion and diabetic retinopathy. Many of these studies have demonstrated a small, but statistically significant temperature difference, on the order of 0.5 º C. The purpose of this study was to determine if there are differences of similar magnitude that can be attributable to previous cataract surgery with intraocular lens placement when compared to phakic eyes.
Methods:
A total of 56 eyes from 28 patients were imaged and analyzed. A Flir T400 (Flir, Boston, MA), 320x240 pixel, digital thermal camera was used to take simultaneous digital and thermal photographs. The images were all analyzed with the Flir Webviewer (www.flir.com). A total of five points were measured on each cornea. We used this average of five corneal temperature measurements to attempt to minimize any bias on the basis of conjunctival vascularity.
Results:
We evaluated sixteen patients with pseudophakia and noted that their average OST was 34.97 º C (range 31.575 to 37.525 º C), when looking at the difference between OST and forehead temperature we noted that on average the OST was 0.14 º C (range -2.425 to + 1.225 º C) warmer than the forehead temperature. This was compared with phakic patients who had an average OST of 34.23 º C (range 30.6 to 36.85 º C) and that the difference from the forehead on average was 0.31 º C cooler (range -3.75 to +1.8 º C).
Conclusions:
We have noted in our study that ocular surface temperature differences are often small and can be significantly affected by the phakic status of the patient, something that has not been controlled for in prior studies. Infrared thermography is an exciting technology will have numerous clinical application in both ophthalmology and medicine in general as the technology continues to improve and devices become more and more clinically accessible.
Keywords: cornea: clinical science • imaging/image analysis: clinical