Abstract
Purpose:
Meibomian glands secrete lipid into the tear film, thereby preventing excessive evaporation of the tear film by forming a thin oily layer on the tear film.The surface temperature in the tarsal conjunctiva was significantly lower in patients with MGD than those in normal controls(Arita R, et al. Arch Ophthalmol. in press). The purpose of this study was to investigate the blood flow in the eye lids and the surface temperature in the tarsal conjunctiva and to examine the correlation between the blood flow and the surface temperature in the tarsal conjunctiva and ocular surface parameters in patients with MGD.
Methods:
Twenty five eyes of 25 patients (11men, 14women; mean ± standard deviation of age, 74.2±10.3 years) who were diagnosed as obstructive MGD and30 eyes of30 healthy volunteers (18 men, 12 women; 64.6±14.4 years) as a control group. The blood flow in the eyelid was measured with a newly developed blood flow meter using a red light. The surface temperature of the central cornea, andupper and lower tarsal conjunctiva was measured using ocular surface thermography. Changes in meibomian glands were scored using non-contact meibography (meibo-score, 0-6). Lid margin abnormality (0-4), superficial punctuate keratopathy (SPK) (0-9), and meibum (0-3) was scored. Tear film breakup time (BUT) was measured. This study was approved by the institutional review board of Itoh clinic and adhered to the tenets of the Declaration of Helsinki.
Results:
The blood flow in the eye lid was significantly lower in patients with MGD than in normal controls (P<0.0001)The surface temperature of the upper /lower palpebral conjunctiva (32.2±0.4,32.0 ±0.5°C) was significantly lower in patients with MGD than in normal controls (33.8±0.3, 33.9 ±0.4°C) (P<0.0001,P<0.0001, respectively ). Blood flow in the eyelids had a significant negative correlation with the meiboscore(r=-0.7765, P<0.0001), the surface temperature in the upper/lower tarsal conjunctiva( r=-0.7725, P<0.0001, r=-0.7605, P<0.0001), ocular symptom score(r=-0.7072, p<0.0001), lid margin abnormality score(r=-0.6824, P<0.0001), SPK(r=-0.6505, P<0.0001), BUT(r=0.2975, P=0.0289), and meibum(r=-0.7864, P<0.0001).
Conclusions:
Blood flow in the eye lids was decreased in patients with obstructive MGD. Decreased blood flow is a likely cause of obstructive MGD.
Keywords: 486 cornea: tears/tear film/dry eye •
479 cornea: clinical science •
474 conjunctiva