From the Guidelines
Atropine is the most potent anticholinergic eye drop, with a potency ranking that can be inferred from its efficacy in slowing myopia progression.
Potency Ranking
- Atropine: The most potent, with concentrations ranging from 0.01% to 0.5% 1.
- Cyclopentolate: Less potent than atropine, with a concentration of 1% 1.
- Tropicamide: The least potent, with a concentration of 1% showing no significant difference in myopia progression compared to controls 1.
- Pirenzepine: A selective muscarinic antagonist, with a concentration of 2% showing efficacy in slowing myopia progression, but further investigation was abandoned 1.
Concentration-Dependent Efficacy
The efficacy of atropine is concentration-dependent, with 0.05% atropine being the most effective concentration in slowing myopia progression 1. However, lower concentrations such as 0.01% atropine have been found to have similar efficacy with fewer side effects 1.
From the Research
Potency Ranking of Anticholinergic Eye Drops
- The potency ranking of anticholinergic eye drops can be inferred from various studies, including those that evaluated the anticholinergic burden of different medications 2, 3, 4.
- One study found that atropine eye drops 1% had the strongest efficacy on myopia control, but its use was limited by side effects, while lower concentrations (0.01-0.05%) had good efficacy with minimal side effects 5.
- Another study developed a uniform list of anticholinergic drugs, differentiating for anticholinergic potency, and found that 100 drugs had clinically relevant anticholinergic properties, with 47 being high-potency and 53 being low-potency 2.
- The Anticholinergic Drug Scale (ADS) categorizes anticholinergic medicines into levels 1 (low-potency) to 3 (high-potency), with Level 1 medicines contributing 72.7% of the total anticholinergic load, and Level 3 medicines contributing 26.5% 3.
- The atropinic burden of anticholinergic drugs can be calculated as the sum of the atropinic score of each drug, and tools such as the ADS and other scales can help decrease atropinic exposure in the elderly 4.
- Cyclopentolate-1% eye drops have been found to affect the central nervous system and may cause altered consciousness, drowsiness, and sleep, with evidence suggesting it has the potency to act as a short-acting CNS depressant 6.