Abstract
Purpose :
To quantify the levels of MMP-9 in patients with significant inflammatory disease using a novel TearLab device, and to compare results with a commercial InflammaDry test.
Methods :
Subjects with a variety of significant inflammatory states, including moderate to severe dry eye, iridocyclitis, uveitis, anterior scleritis, GVHD, and others were recruited at a tertiary eye care center. Subjects were first evaluated with the TearLab Discovery MMP-9 system (TL) then by a Quidel InflammaDry (ID) strip with a second masked operator. Subjects had no active infection of the eye and had not used topical eye medication within the last two hours, although all subjects used some combination of topical corticosteroids, anti-inflammatory compounds and preservative free artificial tears. TL data were machine generated. ID data were qualitatively estimated at the time of measurement, then background-subtracted peak areas were quantified with a MATLAB script. Values above 2,000 ng/mL were truncated to 2,000 ng/mL.
Results :
45 eyes of 27 subjects were tested (F=13, M=14, age=59.1±16.2 years). There was a 95.6% qualitative concordance between the two methods (> 40 ng/mL cutoff). The TL mean was 1124±808 ng/mL, range 16-2000 ng/mL, while the ID estimate was 773±699 ng/mL range 16–2000 ng/mL. 38 TL and 37 ID results were above the 101 ng/mL activity noted by Chotikavanich et al. [IOVS, July 2009, Vol. 50, No. 7] for TFOS DEWS Grade III severity. Both devices exhibited a seemingly bimodal distribution with clusters of results around 200 ng/mL and 2,000 ng/mL, suggesting that the inflammatory state of patients may vary between acute and chronic states, and that a semi-quantitative result would benefit clinicians as compared to a qualitative output. Of interest, although underpowered, it should be noted that subjects with OU meibomian gland disease exhibited an almost 2.2-fold increase in MMP-9 as compared to a combined group of subjects who presented with variations of scleritis, uveitis or iritis (1,421±809 ng/mL vs. 651±636 ng/mL, n=6 vs. n=11, p<0.001, using data from both instruments to improve estimate).
Conclusions :
Quantifying the inflammatory status of a patient’s tear film, even if semi-quantitative, may yield critical information as to disease severity and therapeutic efficacy.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.