Comparison of two methods for composite score generation in dry eye syndrome.
OBJECTIVE
To compare two methods of composite score generation in dry eye syndrome (DES).


METHODS
Male patients seen in the Miami Veterans Affairs eye clinic with normal eyelid, corneal, and conjunctival anatomy were recruited to participate in the study. Patients filled out the Dry Eye Questionnaire 5 (DEQ5) and underwent measurement of tear film parameters. DES severity scores were generated by independent component analysis (ICA) and latent class analysis (LCA).


RESULTS
A total of 247 men were included in the study. Mean age was 69 years (SD 9). Using ICA analysis, osmolarity was found to carry the largest weight, followed by eyelid vascularity and meibomian orifice plugging. Conjunctival injection and tear breakup time (TBUT) carried the lowest weights. Using LCA analysis, TBUT was found to be best at discriminating healthy from diseased eyes, followed closely by Schirmer's test. DEQ5, eyelid vascularity, and conjunctival injection were the poorest at discrimination. The adjusted correlation coefficient between the two generated composite scores was 0.63, indicating that the shared variance was less than 40%.


CONCLUSIONS
Both ICA and LCA produced composite scores for dry eye severity, with weak to moderate agreement; however, agreement for the relative importance of single diagnostic tests was poor between the two methods.
Miami Veterans Administration Medical Center (VAMC), Miami, Florida.
Craig
C
See
Richard A
RA
Bilonick
William
W
Feuer
Anat
A
Galor
D000368:Aged; D000369:Aged, 80 and over; D003228:Conjunctiva / Q000378:metabolism / Q000473:pathology*; D003315:Cornea / Q000378:metabolism / Q000473:pathology*; D015352:Dry Eye Syndromes / Q000175:diagnosis* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013666:Tears / Q000737:chemistry*; D014728:Veterans
composite score; dry eye syndrome; independent components analysis; latent class analysis