Labbe A, Liang Q, Wang Z, Zhang Y, Xu L, Baudouin C, Sun X Corneal nerve structure and function in patients with non-sjogren dry eye: clinical correlations. Invest Ophthalmol Vis Sci. 2013 Aug 1;54(8):5144-50. doi: 10.1167/iovs.13-12370.
Mandahl A Hypertonic saline test for ophthalmic nerve impairment. Acta Ophthalmol (Copenh). 1993 Aug;71(4):556-9. doi: 10.1111/j.1755-3768.1993.tb04636.x.
Oliveira-Soto L, Efron N Morphology of corneal nerves using confocal microscopy. Cornea. 2001 May;20(4):374-84. doi: 10.1097/00003226-200105000-00008.
Parra A, Gonzalez-Gonzalez O, Gallar J, Belmonte C Tear fluid hyperosmolality increases nerve impulse activity of cold thermoreceptor endings of the cornea. Pain. 2014 Aug;155(8):1481-1491. doi: 10.1016/j.pain.2014.04.025. Epub 2014 Apr 28.
Qazi Y, Hurwitz S, Khan S, Jurkunas UV, Dana R, Hamrah P Validity and Reliability of a Novel Ocular Pain Assessment Survey (OPAS) in Quantifying and Monitoring Corneal and Ocular Surface Pain. Ophthalmology. 2016 Jul;123(7):1458-68. doi: 10.1016/j.ophtha.2016.03.006. Epub 2016 Apr 16.
Rahman M, Okamoto K, Thompson R, Bereiter DA Trigeminal pathways for hypertonic saline- and light-evoked corneal reflexes. Neuroscience. 2014 Sep 26;277:716-23. doi: 10.1016/j.neuroscience.2014.07.052. Epub 2014 Jul 31.
Shaheen BS, Bakir M, Jain S Corneal nerves in health and disease. Surv Ophthalmol. 2014 May-Jun;59(3):263-85. doi: 10.1016/j.survophthal.2013.09.002. Epub 2014 Jan 23.
Tepelus TC, Chiu GB, Huang J, Huang P, Sadda SR, Irvine J, Lee OL Correlation between corneal innervation and inflammation evaluated with confocal microscopy and symptomatology in patients with dry eye syndromes: a preliminary study. Graefes Arch Clin Exp Ophthalmol. 2017 Sep;255(9):1771-1778. doi: 10.1007/s00417-017-3680-3. Epub 2017 May 20.
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.