Related Experiment Video
Updated: Mar 10, 2026
A Model of Glaucoma Induced by Circumlimbal Suture in Rats and Mice
Published on: October 5, 2018
Proparacaine-Induced Mydriasis During Strabismus Surgery
Brijesh Takkar1, Pradeep Sharma1, Nripen Gaur1
1a Dr. R. P. Centre for Ophthalmic Sciences , All India Institute of Medical Sciences , New Delhi , India.
Insights
Proparacaine hydrochloride (PH) causes pupil dilation and horizontal skewing in children undergoing strabismus surgery. Surgeons should account for this mydriatic effect during eye alignment assessment post-operation.
Area of Science:
- Ophthalmology
- Pediatric Surgery
- Anesthesiology
Background:
- Strabismus surgery in children often requires general anesthesia.
- Pupil dilation is crucial for surgical assessment but can be affected by anesthetic agents.
- Proparacaine hydrochloride (PH) is a topical anesthetic commonly used in ophthalmology.
Purpose of the Study:
- To evaluate the mydriatic effect of proparacaine hydrochloride (PH) in pediatric patients undergoing strabismus surgery.
- To assess the impact of PH on pupil diameter (PD) and pupil מרכז (PC) during strabismus surgery under general anesthesia (GA).
Main Methods:
- Pilot, prospective, non-randomized, self-controlled interventional study.
- Nine pediatric patients with esotropia or exotropia undergoing horizontal muscle surgery under GA.
- PH was instilled in one or both eyes; PD and PC changes were measured.
Main Results:
- Proparacaine hydrochloride (PH) demonstrated a significant mydriatic effect, increasing pupil diameter (PD) and pupil מרכז (PC) in study eyes.
- Dilated pupils showed horizontal skewing towards the operated muscle.
- Control eyes showed no changes in PD or PC.
Conclusions:
- Proparacaine hydrochloride (PH) possesses an intrinsic mydriatic effect, penetrating the sclera.
- The mydriatic effect can cause skewed pupil dilation, influencing intraoperative assessment.
- Surgeons must consider PH's effect on pupil alignment during strabismus surgery.
Aim:
To evaluate the mydriatic effect of proparacaine hydrochloride (PH) in children undergoing strabismus surgery under general anesthesia (GA).
Methods:
This was a pilot, prospective, non-randomized, self-controlled interventional study. Nine children with esotropia or exotropia undergoing horizontal muscle squint surgery under GA at a tertiary eye care center were included. The six Group 1 patients underwent both eye surgeries, while the three Group 2 patients underwent single eye surgery. PH was instilled in one eye of Group 1 patients and both eyes of Group 2 patients. Change in pupil diameter (PD) was analyzed as the main outcome measure.
Results:
Mean age of the patients was 4.67 ± 2.64 years. In the study eyes, mean average baseline PD was 1.59 ± 0.40 mm (range: 1.06-2.37), while postoperative average PD was 3.99 ± 1.34 mm (range: 1.79-6.02). The mean baseline PC had increased from 5.51 ± 1.09 mm to 12.6 ± 3.58 mm at the end of the surgery. PD and PC increased in all of the study eyes while no change in PD or PC was seen in the control eyes of either of the groups. The dilated pupil was skewed horizontally towards the muscle being operated upon in all of the study eyes.
Conclusions:
PH has a mydriatic effect of its own. It penetrates through the bare sclera and leads on to skewed dilation of the pupil. Surgeons should consider this effect while judging pupil alignment at the end of the surgery.
Related Concept Videos
01:11Direct-Acting Cholinergic Agonists: Therapeutic Uses
01:19Depolarizing Blockers: Pharmocokinetics
01:28Angle Closure Glaucoma: Treatment
01:31Skeletal Muscle Relaxants: Therapeutic Uses
01:28Depolarizing Blockers: Mechanism of Action
Succinylcholine is the most commonly used depolarizing blocker. Chemically, it constitutes two molecules of acetylcholine joined together by an acetate methyl group. They act on the receptors in the same way as acetylcholine. Because...
00:59Direct-Acting Cholinergic Agonists: Pharmacological Actions