title: The impact of intraocular pressure reduction on retinal ganglion cell function measured using pattern electroretinogram in eyes receiving latanoprost 0.005% versus placebo.
abstract: OBJECTIVE
  To evaluate the impact of intraocular (IOP) reduction on retinal ganglion cell (RGC) function measured using pattern electroretinogram optimized for glaucoma (PERGLA) in glaucoma suspect and glaucomatous eyes receiving latanoprost 0.005% versus placebo.
  
  
  METHODS
  This was a prospective, placebo-controlled, double masked, cross-over clinical trial. One randomly selected eye of each subject meeting eligibility criteria was enrolled. At each visit, subjects underwent five diurnal measurements between 8:00 am and 4:00 pm consisting of Goldmann IOP, and PERGLA measurements. A baseline examination was performed following a 4-week washout period, and repeat examination after randomly receiving latanoprost or placebo for 4-weeks. Subjects were then crossed over to receive the alternative therapy for 4 weeks following a second washout period, and underwent repeat examination. Linear mixed-effect models were used for the analysis.
  
  
  RESULTS
  Sixty-eight eyes (35 glaucoma, 33 glaucoma suspect) of 68 patients (mean age 67.4 ± 10.6 years) were enrolled. The mean IOP (mmHg) after latanoprost 0.005% therapy (14.9 ± 3.8) was significantly lower than baseline (18.8 ± 4.7, p<0.001) or placebo (18.0 ± 4.3), with a mean reduction of -20 ± 13%. Mean PERGLA amplitude (μV) and phase (π-radian) using latanoprost (0.49 ± 0.22 and 1.71 ± 0.22, respectively) were similar (p > 0.05) to baseline (0.49 ± 0.24 and 1.69 ± 0.19) and placebo (0.50 ± 0.24 and 1.72 ± 0.23). No significant (p > 0.05) diurnal variation in PERGLA amplitude was observed at baseline, or using latanoprost or placebo. Treatment with latanoprost, time of day, and IOP were not significantly (p > 0.05) associated with PERGLA amplitude or phase.
  
  
  CONCLUSIONS
  Twenty percent IOP reduction using latanoprost monotherapy is not associated with improvement in RGC function measured with PERGLA.
authors.affiliation: Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Palm Beach Gardens, FL 33418, USA.
authors.forename: Mitra
authors.initials: M
authors.lastname: Sehi
authors.forename: Dilraj S
authors.initials: DS
authors.lastname: Grewal
authors.forename: William J
authors.initials: WJ
authors.lastname: Feuer
authors.forename: David S
authors.initials: DS
authors.lastname: Greenfield
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004596:Electroretinography; D005260:Female; D005901:Glaucoma / Q000188:drug therapy* / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D000077338:Latanoprost; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000188:drug therapy / Q000503:physiopathology; D011446:Prospective Studies; D011461:Prostaglandins F, Synthetic / Q000627:therapeutic use*; D012165:Retinal Ganglion Cells / Q000502:physiology*
chemical_list: D000959:Antihypertensive Agents; D011461:Prostaglandins F, Synthetic; D000077338:Latanoprost
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