Dry eye disease (DED) is like an iceberg when it comes to both diagnosis and treatment: What could be described simply as tired, burning, or irritated eyes belies a complex spectrum of disorders involving secretory and immune function dysregulation, inflammation, and a significant impact on quality of life.1
Diagnosis is complicated by the diversity of patient signs and symptoms, often occurring without strong correlation. Some patients complain of severe discomfort without displaying any of the hallmark signs of corneal damage or tear film dysfunction, while others experience only modest symptoms despite significant surface epithelial damage.
Together with myriad underlying etiologies and contributing co-morbidities, the challenge of effective therapy has remained despite decades of concerted effort.
For most clinicians, artificial tears represent the first step in the treatment of an initial presentation of DED. The choice of drop is primarily empirical and patients may go through a trial-and-error process with several products before they find symptomatic relief. Clinical assessments of drop formulations have historically focused on pairwise assessment of signs and symptoms (e.g., corneal staining and ocular discomfort) as a basis for measuring treatment efficacy.