“Doctor, my child is 8 years old and always squints when he sees things. I suspect that he is short-sighted, and I want to give him an optometry.” “At his age, he needs to have his pupils dilated.”
“Doctor, I have been diabetic for 7 years, and my blood sugar is not well controlled. The endocrinologist suggested that I come to the ophthalmologist to check the fundus.” “In this case, you need to dilate your pupils so that you can see the peripheral retina clearly.”
“Doctor, I may have iridocyclitis again, please show me.” “You need hormone eye drops, mydriatic drugs, anti-inflammatory drugs…”
< p> When you go to the eye doctor, you may often hear from the doctor that you need to dilate your pupils. Why would you want to dilate?
Mydriasis is a routine ophthalmology examination and treatment that involves dilating the pupil with mydriatic or cycloplegic drugs. After dilating the pupil, the doctor can observe the peripheral part of the retina and get a comprehensive understanding of the fundus. Children and adolescents have a strong ability to adjust the ciliary muscle of the eye, and if the pupil is not dilated, the refraction result will be inaccurate. Mydriasis also prevents posterior pupillary adhesions, relieves pain and photophobia.
Common mydriatic drugs are divided into slow-diffusion and fast-diffusion. Slow powder starts to work within 30 to 40 minutes after instillation, the maximum effect is reached within 2 hours, and the effect lasts for about 2 weeks. The quick powder drops will work about half an hour after application, and it will recover after about 6 hours. Whether it is a slow powder or a fast powder, if the drug contains atropine, there may be adverse reactions such as flushing, fever, dry mouth, tachycardia, nausea, etc. Disorientation, incoherence, etc. Quick-dispersing medicines containing compound tropicamide are safer and cause fewer systemic adverse reactions, but the mydriatic effect is not as good as eye drops containing atropine.
Mydriatic and cycloplegic drugs temporarily dilate the pupil and do not harm the eyes. However, after dilation, there will be symptoms such as photophobia and blurred vision. Therefore, after dilation, you should avoid strong light stimulation, wear sunglasses and sun hats when you go out, and avoid reading books, computers and mobile phones at close range. Avoid driving and cycling, and pay attention to personal safety.
(Author: Zhao Hailiang, ophthalmologist, Beijing Longfu Hospital)