Friction-Related Dry Eye Disease Mainly Affects Ophthalmic Lipid Components

The subset of patients with dry-eye disease (DED) who have friction-related disease (FRD) appear to have significantly affected lipid components, according to results of a cross-sectional comparative study, published in The Ocular Surface.

FRD involves frictional force between the eyelid and the ocular surface and includes superior limbic keratoconjunctivitis (SLK), lid wiper epitheliopathy (LWE), and conjunctivochalasis. These conditions can result in both mechanical trauma and consequent inflammation during blinking, both of which can worsen DED. 

This study was conducted at the Yonsei University College of Medicine in South Korea between 2019 and 2020. Patients (N=550) with a new diagnosis of DED were evaluated for disease subtype and clinical features were compared between the patients with FRD (n=175) and non-FRD (n=375) DED. The patients with FRD and non-FRD DED were aged mean 59.8±18.1 and 54.7±18.2 years (P =.002) and 27.4% and 30.4% were men, respectively.

During clinical assessment, the FRD cohort was associated with a higher prevalence of aqueous deficiency (54.3% vs 23.7%; P <.001), significant meibomian gland dysfunction (MGD; 79.4% vs 19.5%; P <.001), meibomian gland dropout rate (mean, 30.5% vs 14.1%; P <.001), shorter noninvasive keratographic tear break-up time (NIKBUT-1; mean, 5.9 vs 7.3 s; P <.001), smaller tear meniscus height (TMH; mean, 227.8 vs 241.7 μm; P =.008), and more advanced DED disease (group 4: 46.3% vs 8.8%; group 3: 33.1% vs 10.7%; P <.001) compared with the non-FRD group, respectively.

In a correlation analysis, MGD (r, 0.574; P <.001), aqueous-deficient disease (r, 0.302; P <.001), meibomian gland dropout rate (r, 0.270; P <.001), NIKBUT-1 (r, 0.184; P <.001), and TMH (r, 0.113; P =.008) were correlated with FRD.

The DED factors that were significant predictors for FRD included significant MGD (adjusted odds ratio [aOR], 12.270; 95% CI, 7.720-19.501 P <.001) and aqueous deficiency (aOR, 2.306; 95% CI, 1.432-3.714; P =.001). Compared with DED group one, groups four (aOR, 28.727; 95% CI, 15.711-52.524; P <.001), three (aOR, 15.628; 95% CI, 8.590-28.432; P <.001), and two (aOR, 3.484; 95% CI, 1.613-7.524; P =.001) were more likely to present with FRD DED.

Overall, FRD was positively related with age (aOR, 1.021; 95% CI, 1.009-1.033; P <.001) and meibomian gland dropout rate (aOR, 1.017; 95% CI, 1.010-1.023; P <.001) and negatively related with NIKBUT-1 (aOR, 0.898; 95% CI, 0.849-0.950; P <.001) and TMH (aOR, 0.995; 95% CI, 0.991-0.999; P =.039).

FRD is highly associated with MGD and the meibomian gland dropout rate, according to the study. This suggests that FRD may be mainly affected by lipid components. Aqueous deficiency and TMH also had a good, but relatively lower, association with FRD compared with MGD and meibomian gland dropout rate, the researchers explain.

“Although the classical DED classification does not reflect FRD, each disease included in FRD is widely accepted as a major deteriorating factor of DED resulting from mechanical trauma and consequent inflammation during blinking,” the researchers explain.

The major limitation of this study was the cross-sectional design which did not allow for causal relationships to be evaluated.