title: Tear clearance and ocular symptoms in patients treated with preservative-free prostaglandins.
abstract: OBJECTIVE
  To assess the effects on dry eye symptoms and tear dynamics of switching from a prostaglandin with a preservative to a preservative-free prostaglandin.
  
  
  METHODS
  Fourteen patients (N=28 eyes) with open-angle glaucoma and dry eye symptons, treated with preserved latanoprost, travoprost or bimatoprost were included in this uncontrolled prospective study. Ocular symptoms were analysed using a validated ocular surface disease questionnaire and ocular signs were assessed with tear clearance, Schirmer and tear function index test (TFI=Schirmer/clearance). Patients were assigned to preservative-free tafluprost treatment, and measurements were repeated 4 weeks after change of medication. Wilcoxon test and Spearman correlation coefficient were used in the statistical analysis.
  
  
  RESULTS
  No statistically significant difference in intraocular pressure (IOP) was observed after switching to tafluprost. Mean IOP at baseline was 20.4 mmHg (SD2.2) and after 4 weeks 19.9 mmHg (SD2.6), (P>.05). The mean questionnaire score significantly decreased from 9.7 (SD3.7) at baseline to 5.4 (SD2.7) after one month (P<.001). No significant differences in tear clearance, Schirmer or TFI were found (P>.05). At baseline, tear clearance=0.13 (SD0.07), Schirmer=10.7 mm (SD6) and TFI=80 (48-156). After 4 weeks, tear clearance=0.1(SD0.07), Schirmer=9.5 mm (3.9) and TFI=104 (48-216). A significant association between questionnaire score and tear clearance after 4 weeks was observed (Spearman coefficient=0.62; P=.014).
  
  
  CONCLUSIONS
  Switching from preservative prostaglandin with a preservative to preservative-free tafluprost treatment improves dry eye symptoms and suggests an improvement in TFI.
authors.affiliation: Servicio de Oftalmología, Hospital Reina Sofía, Córdoba, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Giménez-Gómez
authors.forename: M R
authors.initials: MR
authors.lastname: García-Catalán
authors.forename: J M
authors.initials: JM
authors.lastname: Gallardo-Galera
mesh_terms: D000368:Aged; D015352:Dry Eye Syndromes / Q000150:complications / Q000188:drug therapy*; D005260:Female; D005902:Glaucoma, Open-Angle / Q000150:complications / Q000188:drug therapy; D006801:Humans; D008297:Male; D011310:Preservatives, Pharmaceutical; D011446:Prospective Studies; D011453:Prostaglandins / Q000627:therapeutic use*; D011460:Prostaglandins F / Q000627:therapeutic use*; D013666:Tears
chemical_list: D011310:Preservatives, Pharmaceutical; D011453:Prostaglandins; D011460:Prostaglandins F; C485333:tafluprost