Talk about a charged subject. This sounded quite interesting though and the results are actually modest enough to be believable (as opposed to "looky, my new tool correlates just great with symptoms!")

The relationship between clinical signs and dry eye symptoms.

Eye (Lond). 2011 Jan 21. [Epub ahead of print]
Pult H, Purslow C, Murphy PJ.

1] Optometry and Vision Research, Weinheim, Germany [2] School of Optometry and Vision Sciences, Contact Lens and Anterior Eye Research (CLAER) Unit, Cardiff University, Wales, UK.
Abstract
Purpose
To evaluate (i) the relationship between traditional and new clinical tests (lid-wiper epitheliopathy (LWE), lid-parallel conjunctival folds (LIPCOF)) and dry eye symptoms in non-contact lens wearers, and (ii) that a combination of these tests can improve predictive ability for the development of dry eye symptoms.

Methods
Tear meniscus height (TMH), non-invasive break-up time (NIBUT), ocular hyperaemia, LIPCOF, phenol red thread test (PRTT), corneal and conjunctival staining, and LWE grades were observed in a cohort of 47 healthy, non-lens wearers (male=17, female=30, median age=35 years, range=19-70). Symptoms were assessed using the Ocular Surface Disease Index (OSDI).

Results
LWE was significantly correlated to both temporal and nasal LIPCOF (0.537<r<0.607, P<0.05). LIPCOF and LWE were significantly correlated to NIBUT and PRTT (r>-0.248, P<0.001). Significant correlations were found between NIBUT and TMH (r=0.461, P=0.001) and PRTT (r=0.640, P<0.001). OSDI scores were significant correlated to NIBUT, TMH, PRTT, LIPCOF, and LWE (r>∣0.31∣; P<0.05). Significant discriminators of OSDI+/- were NIBUT (area under the receiver operative characteristic curve (AUC)=0.895), TMH (0.715), PRTT (0.781), LIPCOF (temporal/nasal/Sum 0.748/0.828/0.816), and LWE (0.749). Best predictive ability was achieved by combining NIBUT with nasal LIPCOF (AUC=0.944).

Conclusions
The individual tests NIBUT, TMH, PRTT, LIPCOF, and LWE were significantly, but moderately, related to OSDI scores. The strongest relationship appeared by combining NIBUT with nasal LIPCOF.