In patients with dry eye disease (DED), difficulties with tasks of daily living such as reading, driving and being on the computer may correspond to corneal fluorescein staining results, an abstract published as part of ARVO’s 2020 online meeting suggests.

Since patients with DED often report visual function issues despite having normal visual acuity (VA) measurements, a team of researchers performed a post-hoc correlation analysis on data from two independent randomized, double-masked phase II and phase IIb/III clinical trials on dry eye to investigate the correlation of corneal fluorescein staining with several dimensions of visual function.

All randomized subjects from both clinical trials were included if they had at least one data pair from the corneal staining score (total corneal fluorescein staining, NEI scale, scoring range 0-15) and one visual function parameter (subjective assessments of blurred vision, poor vision, reading, driving at night, working with computer/ATM, and objective measurements of reading speed [performed in the first investigation only]).

The study enrolled a total of 664 dry eye subjects. Participants’ results were considered despite assigned treatment. Corneal staining and corresponding visual function were recorded at five different time points over eight to 12 weeks.

In the first investigation, corneal staining was statistically significantly associated with all subjective assessments, as well as with low contrast and low print-size reading speed. In the second investigation, the correlation between total corneal staining was statistically significant with the individuals’ self-reported levels of blurred and poor vision and difficulties with reading, but was inversely associated with driving at night.

Also of note: A reduction of three units in total corneal fluorescein staining led to an estimated improvement in subjective visual function in the range of 5.2% to 13.5% in the first study, and between 13.4% and 15% in the second investigation. In the first study, the estimated improvement in reading speed with low contrast and with low print-size reading material was four words per minute (3.6%) and six words per minute (4.7%), respectively.

Overall, total corneal fluorescein staining correlated significantly and was clinically meaningful in both subjective and objective functional parameters of visual function in dry eye patients, the researchers say.