@article {1608585, title = {Alterations in corneal nerves in different subtypes of dry eye disease: An in vivo confocal microscopy study}, journal = {Ocul Surf}, volume = {22}, year = {2021}, month = {2021 Aug 15}, pages = {135-142}, abstract = {PURPOSE: To evaluate corneal subbasal nerve alterations in evaporative and aqueous-deficient dry eye disease (DED) as compared to controls. METHODS: In this retrospective, cross-sectional, controlled study, eyes with a tear break-up time of less than 10\ s were classified as DED. Those with an anesthetized Schirmer{\textquoteright}s strip of less than 5\ mm were classified as aqueous-deficient DED. Three representative in vivo confocal microscopy images were graded for each subject for total, main, and branch nerve density and numbers. RESULTS: Compared to 42 healthy subjects (42 eyes), the 70 patients with DED (139 eyes) showed lower total (18,579.0\ {\textpm}\ 687.7\ μm/mm2 vs. 21,014.7\ {\textpm}\ 706.5, p\ =\ 0.026) and main (7,718.9\ {\textpm}\ 273.9 vs. 9,561.4\ {\textpm}\ 369.8, p\ \<\ 0.001) nerve density, as well as lower total (15.5\ {\textpm}\ 0.7/frame vs. 20.5\ {\textpm}\ 1.3, p\ =\ 0.001), main (3.0\ {\textpm}\ 0.1 vs. 3.8\ {\textpm}\ 0.2, p\ =\ 0.001) and branch (12.5\ {\textpm}\ 0.7 vs. 16.5\ {\textpm}\ 1.2, p\ =\ 0.004) nerve numbers. Compared to the evaporative DED group, the aqueous-deficient DED group showed reduced total nerve density (19,969.9\ {\textpm}\ 830.7 vs. 15,942.2\ {\textpm}\ 1,135.7, p\ =\ 0.006), branch nerve density (11,964.9\ {\textpm}\ 749.8 vs. 8,765.9\ {\textpm}\ 798.5, p\ =\ 0.006), total nerves number (16.9\ {\textpm}\ 0.8/frame vs. 13.0\ {\textpm}\ 1.2, p\ =\ 0.002), and branch nerve number (13.8\ {\textpm}\ 0.8 vs. 10.2\ {\textpm}\ 1.1, p\ =\ 0.002). CONCLUSIONS: Patients with DED demonstrate compromised corneal subbasal nerves, which is more pronounced in aqueous-deficient DED. This suggests a role for neurosensory abnormalities in the pathophysiology of DED.}, issn = {1937-5913}, doi = {10.1016/j.jtos.2021.08.004}, author = {Cox, Stephanie M and Kheirkhah, Ahmad and Aggarwal, Shruti and Abedi, Farshad and Cavalcanti, Bernardo M and Cruzat, Andrea and Hamrah, Pedram} }