Abstract
Purpose: :
Prostaglandin analogues may have an effect on corneal biomechanical parameters via alterations in matrix metalloproteinase activity. The purpose of this study was to assess the effect of two prostaglandin analogues on corneal hysteresis.
Methods: :
30 previously untreated subjects with glaucoma or ocular hypertension were randomly allocated to a prostaglandin analogue, either Travaprost or Bimatoprost, in one eye. Pressures were measured at baseline and subsequently using both Goldmann and Pascal Tonometers. Corneal Hysteresis was measured using an Ocular Response Analyser, and CCT was recorded at each visit.A multiple variable model was used to test for effects of the prostaglandins at follow-up, using initial Goldmann intraocular pressure (IOP) as well as change in Pascal IOP and CCT (central corneal thickness) as covariates.
Results: :
Using paired T tests, corneal hysteresis (CH) increased significantly in intervention eyes (8.06 to 9.04, p<0.0001) but not in control eyes (8.5 to 8.7, p<0.4). Mean Goldmann IOP decreased in intervention eyes from 24 to 17 mmHg (p<0.0001). The change in CH was not significant (p<0.78) when Pascal IOP and CCT were included as covariates in a multiple variable analysis model.There was no significant difference in CH (p=0.32), Pascal IOP (p=0.46), Goldmann IOP (p=0.30), or CCT (p=0.99) between the prostaglandin analogues.
Conclusions: :
Apparent changes in CH following introduction of prostaglandin analogues maybe confounded by concurrent changes in intraocular pressure and corneal thickness.
Clinical Trial: :
www.clinicaltrials.gov NCT00328835
Keywords: intraocular pressure • clinical (human) or epidemiologic studies: systems/equipment/techniques • cornea: clinical science