Five-Year Clinical Trial on Atropine for the Treatment of Myopia 2: Myopia Control with Atropine 0.01% Eyedrops.
OBJECTIVE
To compare the safety and efficacy of different concentrations of atropine eyedrops in controlling myopia progression over 5 years.


METHODS
Randomized, double-masked clinical trial.


METHODS
A total of 400 children originally randomized to receive atropine 0.5%, 0.1%, or 0.01% once daily in both eyes in a 2:2:1 ratio.


METHODS
Children received atropine for 24 months (phase 1), after which medication was stopped for 12 months (phase 2). Children who had myopia progression (≥-0.50 diopters [D] in at least 1 eye) during phase 2 were restarted on atropine 0.01% for a further 24 months (phase 3).


METHODS
Change in spherical equivalent and axial length over 5 years.


RESULTS
There was a dose-related response in phase 1 with a greater effect in higher doses, but an inverse dose-related increase in myopia during phase 2 (washout), resulting in atropine 0.01% being most effective in reducing myopia progression at 3 years. Some 24%, 59%, and 68% of children originally in the atropine 0.01%, 0.1%, and 0.5% groups, respectively, who progressed in phase 2 were restarted on atropine 0.01%. Younger children and those with greater myopic progression in year 1 were more likely to require re-treatment. The lower myopia progression in the 0.01% group persisted during phase 3, with overall myopia progression and change in axial elongation at the end of 5 years being lowest in this group (-1.38±0.98 D; 0.75±0.48 mm) compared with the 0.1% (-1.83±1.16 D, P = 0.003; 0.85±0.53 mm, P = 0.144) and 0.5% (-1.98±1.10 D, P < 0.001; 0.87±0.49 mm, P = 0.075) groups. Atropine 0.01% also caused minimal pupil dilation (0.8 mm), minimal loss of accommodation (2-3 D), and no near visual loss compared with higher doses.


CONCLUSIONS
Over 5 years, atropine 0.01% eyedrops were more effective in slowing myopia progression with less visual side effects compared with higher doses of atropine.
Singapore National Eye Center, Singapore; Singapore Eye Research Institute, Singapore.
Audrey
A
Chia
Singapore Clinical Research Institute, Singapore; Duke NUS Graduate Medical School, Singapore.
Qing-Shu
QS
Lu
Singapore National Eye Center, Singapore; Singapore Eye Research Institute, Singapore; Duke NUS Graduate Medical School, Singapore; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore. Electronic address: donald.tan.t.h@snec.com.sg.
Donald
D
Tan
D000065:Accommodation, Ocular / Q000187:drug effects; D000287:Administration, Topical; D001285:Atropine / Q000627:therapeutic use*; D058452:Axial Length, Eye / Q000187:drug effects; D002648:Child; D018450:Disease Progression; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D018727:Muscarinic Antagonists / Q000627:therapeutic use*; D009216:Myopia / Q000175:diagnosis / Q000188:drug therapy*; D009883:Ophthalmic Solutions / Q000627:therapeutic use; D011680:Pupil / Q000187:drug effects
D018727:Muscarinic Antagonists; D009883:Ophthalmic Solutions; D001285:Atropine