Table 5.

Spearman’s Rho (ρ) coefficients between relative composition of sphingolipids and dry eye (DE) symptoms and signs

Spearma n’s ρ	DE Symptoms		MGD/DE Signs
	DEQ-5	OSDI	Meibomian Quality	Eyelid Vascularity	Meibomian Dropout	Meibomian Plugging	TBUT	Fluorescein Stain	Schirmer Test	MMP
In meibum (% pmole)
Cer	−0.12	−0.24	−0.21	0.10	0.17	0.10	0.03	0.13	0.11	0.18
Cer/SM	−0.10	−0.25	−0.29*	0.13	0.13	0.09	0.03	0.13	0.08	0.20
Hex-Cer	0.03	−0.10	−0.34*	0.15	0.06	0.003	0.15	0.0	0.09	−0.08
Hex-Cer/SM	0.0	−0.16	−0.39**	0.18	0.05	0.04	0.14	0.06	0.08	0.005
SM	0.03	0.23	0.51***	−0.25	0.02	0.0	−0.11	−0.18	−0.004	−0.22
Sph	0.28	0.11	−0.56***	0.19	−0.23	−0.01	0.08	0.19	−0.14	0.13
Sa	0.07	−0.08	−0.42**	0.10	−0.16	−0.02	0.07	0.10	−0.19	−0.002
In tears (% pmole)
Cer	−0.008	−0.06	−0.07	0.04	−0.03	−0.11	−0.12	−0.03	−0.49***	0.02
Cer/SM	0.08	0.08	−0.14	−0.01	−0.08	−0.11	−0.06	−0.006	−0.40**	0.04
Hex-Cer	0.05	0.12	0.27	−0.30*	0.27	0.25	−0.09	0.19	0.51***	0.18
Hex-Cer/SM	0.09	0.17	0.25	−0.31*	0.26	0.25	−0.06	0.19	0.51***	0.12
SM	−0.20	−0.36*	0.18	0.19	0.03	−0.03	−0.08	−0.20	−0.04	−0.02
Sph	0.07	0.22	0.46**	−0.27	0.28	0.20	−0.05	0.41*	0.59***	0.002
S1P	0.31*	0.41**	−0.21	−0.06	−0.07	−0.007	0.15	0.06	0.29*	−0.005

DE=Dry Eye, SPL=total sphingolipid, Cer=ceramide, Hex-Cer=hexosyl ceramide, SM=sphingomyelin, Sph=sphingosine, Sa=sphinganine, S1P=sphingosine 1-phosphate, TBUT=Tear Break-Up Time, MMP=Matrix Metallopeptidase-9, OSDI=Ocular Surface Disease Index, DEQ-5=Dry Eye Questionnaire, ρ Rho=coefficient for dependent variables

^*Statistically significant difference at p-values <0.05

^**p-value <0.01

^***p-value <0.001.