Abstract
Abstract: :
Purpose:to explore IOP–unrelated effect of brimonidine on visual function in human glaucoma Methods:prospective, randomized, investigator–masked, clinical trial. Eligibility:glaucomatous visual field defect(24/2 Humphrey FT),IOP<19mmHg with 2 drugs,open angle,glaucomatous optic neuropathy (HRT,Moorfields regression analysis),clear lens(LOCS2 score < C1, N0, P0),b.c.visual acuity < 0.2 LogMAR, refraction within – 5 / + 2 diopters,no AMD and diabetic retinopathy,negative history for neurological diseases. Flow–chart: a)18 months run–in with ongoing therapy, visual field examinations (24/2 Humphrey full threshold) IOP, visual acuity and optic disk evaluation every 3–4 months,total amount of 5–6 fields/eye. b) randomization to further treatment(brimonidine 0.2% b.i.d. or argon laser trabeculoplasty, 360°,one session,either one on top of the pre–existing therapy).In case of < 10% IOP drop,the eye was crossed over the other treatment. c) 18 months follow up (see "run–in"). Main outcome: change of the mean slope of field loss (dB / year, Progressor software) between the first and second phase of the study. Results:n = 52 eyes enrolled. 27 randomized to brimonidine and 25 to ALT. After crossing the failing eyes to the other treatment, 50 eyes qualified for follow up (29 brimonidine, 21 ALT). 41 eyes (22 brimonidine, 19 ALT) completed follow up.
The effect of brimonidine on mean slope was significant with a power = 90% and alpha probability = 5% . Field progression upon brimonidine was slower than upon ALT (power = 85% and alpha probability = 10%). No significant difference (p = 0.124) was observed in the baseline sensitivity of the points showing progression throughout the whole study (21.3 + 6 dB) with respect to those points who either stopped or reversed progression upon randomization to brimonidine or ALT (22.9 + 4 dB) Conclusions:0.2% brimonidine b.i.d., in spite of offering a poorer IOP control, was more effective than 360° laser trabeculoplasty in reducing field deterioration in progressing human glaucomatous eyes
Keywords: neuroprotection • visual fields • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials