First, I would like to quote correctly the sentence under debate in the referenced article: “Although more than 20 drug products have undergone clinical testing in the United States for the treatment of dry eye disease, no product has been approved for this indication.”
This statement was presented in the context of the FDA-wide requirement for simultaneous demonstration of efficacy in signs and symptoms of dry eye disease. This was described in the discussion of the manuscript. Therefore, in regulatory terms, the labeling pursued for Rejena is “for the treatment of the signs and symptoms of dry eye disease.” There is no FDA-approved drug with such labeling.
As for Restasis, this product offers specifically the following labeling: “RESTASIS ophthalmic emulsion is indicated to increase tear production in patients whose tear production is presumed to be suppressed due to ocular inflammation associated with keratoconjunctivitis sicca. Increased tear production was not seen in patients currently taking topical anti-inflammatory drugs or using punctal plugs.”
The Restasis labeling would seem directed to the treatment of inflammation. That in turn would increase tear production, presumed to be suppressed by the inflammation.
In summary, there is no drug approved or labeling granted by the FDA for the treatment of signs and symptoms of dry eye disease.