PT  - JOURNAL ARTICLE
AU  - Tommy C Y Chan
AU  - Cong Ye
AU  - Kwok Ping Chan
AU  - Kai On Chu
AU  - Vishal Jhanji
TI  - Evaluation of point-of-care test for elevated tear matrix metalloproteinase 9 in post-LASIK dry eyes
AID  - 10.1136/bjophthalmol-2015-307607
DP  - 2016 Sep 01
TA  - British Journal of Ophthalmology
PG  - 1188--1191
VI  - 100
IP  - 9
4099  - http://bjo.bmj.com/content/100/9/1188.short
4100  - http://bjo.bmj.com/content/100/9/1188.full
SO  - Br J Ophthalmol2016 Sep 01; 100
AB  - Aim To evaluate the performance of a point-of-care test for detection of matrix metalloproteinase 9 (MMP-9) levels in post-laser-assisted in situ keratomileusis (LASIK) dry eyes.Methods A comparative study between patients with mild to moderate post-LASIK dry eyes and age-matched normal subjects was conducted. Ocular surface disease index (OSDI), tear break-up time (TBUT), and tear film MMP-9 and total protein levels were compared between the two groups. A point-of-care test device (RPS InflammaDry, Sarasota, Florida, USA) was utilised to confirm elevated MMP-9 levels in tear film.Results Fourteen post-LASIK dry eyes and 34 normal eyes were included. There was no significant difference in age and gender between both groups (p>0.175). The OSDI was significantly higher (25.5±7.7 vs 7.4±2.5; p<0.001) and TBUT levels were significantly lower (5.4±0.9 vs 13.5±2.3; p<0.001) in patients with dry eye compared with normal subjects. The tear film MMP-9 levels were 52.7±32.5 ng/mL in dry eyes and 4.1±2.1 ng/mL in normal eyes (p<0.001). MMP-9 levels were >40 ng/mL in 7/14 (50.0%) post-LASIK dry eyes. The InflammaDry was positive in 8/14 (57.1%) post-LASIK eyes. All positive cases had tear film MMP-9 levels ≥38.03 ng/mL. Agreement between InflammaDry and MMP-9 was excellent with Cohen κ value of 0.857 in post-LASIK dry eyes.Conclusions Only half of post-LASIK dry eyes were found to have significant inflammation associated with elevated MMP-9. The OSDI is useful to non-specifically identify patients with symptomatic dry eye while the InflammaDry determined which patients with dry eye were associated with significant inflammation that may guide therapeutic management decisions.