Confocal Microscopy of Epithelial and Langerhans Cells of the Cornea in Patients Using Travoprost Drops Containing Two Different Preservatives

Abstract

The recently developed confocal cornea microscopy offers the opportunity to examine pathologies of the cornea and to gain insight into the activity of innate immunity. We aimed to investigate the corneal epithelial and Langerhans cell (LC) densities along with dry eye parameters in primary open-angle glaucoma (POAG) subjects, treated with either of two commercially available travoprost 0.004 % topical medications containing different preservatives. (1: benzalkonium chloride 0.015 % (TravBAK) and 2: polyquaternium-1 (PQ) 0.001 % (TravPQ). Consecutive case series of nineteen POAG patients on TravBAK (mean age: 64.8 ± 13.6 years), nineteen POAG patients on TravPQ (mean age: 66.8 ± 11.3 years) and nineteen age-matched healthy control subjects (63.8 ± 8.2 years). Ocular surface disease index (OSDI), lid parallel conjunctival folds (LIPCOF), Schirmer test (ST) and tear break up time (TBUT) were assessed, and then corneal epithelial and LC densities were investigated with confocal microscopy. Tear production was significantly reduced in both glaucoma patient groups compared to healthy individuals (p < 0.05). TBUT was significantly reduced and epithelial cell densities were significantly greater in patients treated with TravBAK compared to healthy individuals (p < 0.05 for all). LC densities were greater in both glaucoma groups compared to control subjects (p < 0.05 for all). Travoprost therapy may compromise ocular surface. The limited alertness of the corneal immune system found in patients with TravPQ can be considered as indicators of a less disturbed ocular surface and better controlled corneal homeostasis.

In Vivo Distribution of Corneal Epithelial Dendritic Cells in Patients With Glaucoma

“…The deep stimulating effect of BAK on DCs was further supported by a recent confocal study in which BAK-preserved travoprost induced a higher corneal DC density than polyquad-preserved travoprost. 29 Because we did not find significant differences between preserved PGA and preserved b-blockers or between PF PGA and PF b-blockers, we cannot determine whether the preservative or the active compound played the main role in the final DC increase. However, because preserved PGA produced the highest degree of DCs stimulation, one may hypothesize that, even though both preservative and active compound are required to recruit DCs, PGA appear more triggering that b-blockers.…”

Dry Eye and Corneal Langerhans Cells in Systemic Lupus Erythematosus

“…In vivo confocal corneal microscopy can provide an in vivo method to detect LCs in the corneal epithelium [ 13 – 15 ]. Pathological conditions, various forms of injuries [ 16 ], or minor stimuli to the cornea (such as contact lens wear [ 17 ] or chronic use of antiglaucoma eye drops [ 18 ]) may induce LCs to undergo maturation with the formation of dendrite-like processes [ 17 , 18 ]. During this maturation LCs migrate from the periphery to the area concerned with further LC influx toward the central cornea [ 17 ].…”

Corneal Immune Cells Are Increased in Patients With Multiple Sclerosis

“…Similarly, IC density was increased in patients with glaucoma but differed depending on the formulation of topical travaprost therapy used for the treatment of glaucoma. 35 Despite adjusting for the loss of corneal nerves in patients with MS, 18,19 the near-nerve distance was greater in patients with RRMS, suggesting that the reduced interaction between ICs and nerves was only partly due to a loss of nerves. A reduced association between ICs and subbasal nerves has also been reported in patients with fibromyalgia.…”