Abstract
Purpose:
The aim of this in-vivo study is to compare the effect of the prostaglandin analogues preserved with either 0.015% or 0.001% benzalkoium chloride (BAK) or polyquaternium-1 0.001% (PQ) on the ocular surface of the rabbit eyes.
Methods:
Forty white rabbits were randomized to receive once daily instillation of tafluprost 0.0015% preserved with 0.001% BAK (TF-BAK), travoprost 0.004% with 0.015% BAK (TR-BAK) or 0.001% PQ (TR-PQ), or preservative-free artificial tears in one eye for 4-week period. Tear samples collected from the 40 rabbits were analyzed by enzyme-linked immunosorbent assays (ELISA) for the presence of inflammatory cytokines: interleukin (IL)-1β and IL-6 on day 14. After 4-week instillation, the harvested cornea and bulbar conjunctiva were evaluated by light and transmission electron microscopy (TEM).
Results:
In the tear sample ELISA, IL-6 was significantly increased in TF-BAK and TR-BAK groups compared to controls and TR-PQ group; however, IL-1β level was not significantly different among 4 groups. Rabbits treated with TR-BAK showed decreased goblet cell density of conjunctiva and increased piknotic change and vacuolization of corneal epithelial cells on light microscopy; similar change occurred but was less severe in TF-BAK group. The TR-PQ group showed similar results to the controls. In the TEM, the destruction of the microvillar architecture of conjunctiva and cornea was most prominent in the TR-BAK group.
Conclusions:
Preservatives included in the anti-glaucoma eye-drops produced different ocular surface changes according to the concentration and type in the rabbits. Prostaglandin analogues preserved with higher level of BAK may cause more harmful effects on the ocular surface than PQ-preserved medications.
Keywords: 503 drug toxicity/drug effects •
637 pathology: experimental