title: Conjunctival changes and inflammatory aspects in rabbits' conjunctivas induced by fixed combinations of prostaglandin analogues and timolol maleate.
abstract: BACKGROUND
  The purpose of this research is to compare the histological and immunohistochemical changes induced by fixed combinations of timolol maleate and prostaglandin analogues in the rabbit conjunctiva. Thirty left eyes of rabbits, divided into three groups, were treated for 30 days with the following combinations of drugs: bimatoprost 0.03% + timolol 0.5%, travoprost 0.004% + timolol 0.5% and latanoprost 0.005 + timolol 0.5%. The right eyes served as controls and received no medication. At the end of the experiment, after enucleation, the conjunctivas were assessed through histomorphometry (number of inflammatory and goblet cells, epithelial thickness) and immunohistochemistry (anti-actin antibody to assess the degree of fibrosis).
  
  
  RESULTS
  Histomorphometrically, there was infiltration of inflammatory cells in all the treated eyes. An increased number of goblet cells was observed with the use of all fixed combinations of prostaglandin analogues associated with timolol maleate in comparison with the control group. The combination travoprost + timolol resulted in more intense fibrosis. The effect of bimatoprost + timolol caused an intermediate reaction pattern among the other drugs, fostering higher numbers of goblet cells in the conjunctival epithelium, more than the other fixed combinations in this study. There was a difference in the comparison of goblet cells of eyes treated with bimatoprost + timolol (16.11 ± 2.42) and of those treated with latanoprost + timolol (13.18 ± 1.60) (P = 0.016).
  
  
  CONCLUSIONS
  It was found that all fixed combinations of prostaglandins analogues + timolol induce a reaction in the conjunctiva, increasing the inflammatory infiltrate.
authors.affiliation: Ophthalmology Department, Federal University of Minas Gerais, Av, Alfredo Balena, 190 3rd floor room 3005, Belo Horizonte, Minas Gerais 30130100, Brazil. nubiavanessa@gmail.com.
authors.forename: Nubia Vanessa Lima
authors.initials: NV
authors.lastname: de Faria
authors.forename: Heloisa Helena
authors.initials: HH
authors.lastname: Russ
authors.forename: Palloma
authors.initials: P
authors.lastname: Rose
authors.forename: Lucia
authors.initials: L
authors.lastname: Noronha
authors.forename: Paulo Augusto
authors.initials: PA
authors.lastname: Mello
authors.forename: Fabiano
authors.initials: F
authors.lastname: Montiani-Ferreira
authors.forename: Sebastião Cronemberger
authors.initials: SC
authors.lastname: Sobrinho