Biology and Medicine

Abstrait

A muscarinic receptor antagonist and an alpha-adrenergic agonist are required in combination to ensure stable mydriasis after intravitreal injection in mice

Deb Kumar Mojumder

Tropicamide (muscarinic receptor antagonist) and phenylephrine (α-adrenergic receptor agonist) are used to dilate the pupils by topical application. These two eye drops are often used, alone or in combination, to dilate the pupil and perform acute light-evoked physiological experiments (electroretinography, for example) before and after intravitreal injections of pharmacological agents to test their effect on retinal activity. This study aimed to determine whether treatment with one or both of these drugs is most effective in maintaining mydriasis after intravitreal injections. Changes in pupillary dilation before and after intravitreal injection of balanced salt solution (0.5 μl) were recorded. Phenylephrine (α-adrenergic agonist) and tropicamide (muscarinic agonist) when combined, but not alone, produced complete and stable pupillary dilation after intravitreal injections. Reinstillation of topical mydriatics after intravitreal injections was necessary for maximal pupillary dilation. A combination of a muscarinic receptor antagonist and an alpha-adrenergic agonist is necessary for stable mydriasis after intravitreal injection