Objective To compare visual field outcomes of ocular hypertensive and glaucoma patients treated with Medicine-1st against those treated with selective laser trabeculoplasty (SLT, Laser-1st). Design Secondary analysis of patients from Laser in Glaucoma and Ocular Hypertension (LiGHT), a multicentre randomised controlled trial. Participants and controls 344 patients (588 eyes) treated with Medicine-1st, 344 patients (590 eyes) treated with Laser-1st. Methods Visual fields (VFs) were measured using standard automated perimetry and arranged in series (median length and duration: 9 VFs over 48 months). Hierarchical linear models were used to estimate pointwise VF progression rates, which were then averaged to produce a global progression estimate for each eye. Proportions of points and patients in each treatment group with fast (< -1 dB/y) or moderate (< -0.5 dB/y) progression were compared using log-binomial regression. Main outcome measures Pointwise and global progression rates of total deviation (TD) and pattern deviation (PD). Results A greater proportion of eyes underwent moderate or fast TD progression in the Medicine-1st group compared with the Laser-1st group (26.2% vs. 16.9%; Risk Ratio, RR = 1.55 [1.23, 1.93], P < 0.001).A similar pattern was observed for pointwise rates (Medicine-1st 26.1% vs. Laser-1st 19.0%, RR = 1.37 [1.33, 1.42], P < 0.001). A greater proportion of pointwise PD rates were categorised as moderate or fast in the Medicine-1st group (Medicine-1st 11.5% vs. Laser-1st 8.3%, RR = 1.39 [1.32, 1.46], P < 0.001). There was no statistical difference in the proportion of eyes that underwent moderate or fast PD progression (Medicine-1st 9.9% vs. Laser-1st 7.1%, RR = 1.39 [0.95, 2.03], P = 0.0928). Conclusion A slightly larger proportion of ocular hypertensive and glaucoma patients treated with Medicine-1st underwent rapid VF progression compared with those treated with Laser-1st.