Related Experiment Video
Updated: Apr 15, 2026

Optimizing Photoneuromodulation Techniques to Evaluate the Role of Green Light-Emitting Diodes in Pain Management
Published on: March 28, 2025
Clinical study of pain sensation during phacoemulsification with and without cryoanalgesia
Roberto Pinto Coelho1, Ricardo Helio Biaggi1, Rodrigo Jorge1
1From the Department of Ophthalmology, Otorrinolaringology and Head and Neck Surgery, Medical School of Ribeirão Preto, University of São Paulo-Ribeirão Preto, São Paulo, Brazil.
Purpose:
To compare the analgesic efficacy of 2 types of anesthetic techniques-topical and topical associated with cryoanalgesia-during cataract surgery.
Setting:
Department of Ophthalmology, University of São Paulo, Ribeirão Preto, Brazil.
Design:
Prospective randomized study.
Methods:
Patients with symmetrical bilateral cataract had phacoemulsification with the use of an intraocular irrigation solution at room temperature in 1 eye and a cold (4°C) solution in the contralateral eye (Group 2). The pain related to the procedure was assessed using a visual analog scale ranging from 0 to 100, with 0 representing no pain and 100 the worst pain. In addition, endothelial cell loss, the change in corneal thickness, and visual acuity were evaluated 30 days ± 2 (SD) after each surgery. The surgery duration, total irrigation volume, phacoemulsification time, and ultrasound power used were analyzed.
Results:
The study enrolled 25 patients (50 eyes). There was no statistically significant difference in the mean pain score between Group 1 (26.0 ± 3.7) and Group 2 (21.3 ± 3.6) (P = .2016, paired t test). No significant difference was found in the mean corneal endothelial cell loss (Group 1: 10.0% ± 0.4%; Group 2: 9.9% ± 0.3%; P = .7576), corneal thickness increase (Group 1: 1.5 ± 1.0 μm; Group 2: 1.4 ± 0.9 μm; P = .9340), or visual acuity gain (Group 1: 0.54 ± 0.06 logMAR; Group 2: 0.55 ± 0.09 logMAR; P = .8208).
Conclusion:
There is no difference in the intensity of pain during phacoemulsification with the use of topical anesthesia or topical anesthesia associated with cryoanalgesia.
Financial Disclosure:
No author has a financial or proprietary interest in any material or method mentioned.
More Related Videos
06:04Objective Nociceptive Assessment in Ventilated ICU Patients: A Feasibility Study Using Pupillometry and the Nociceptive Flexion Reflex
Published on: July 4, 2018
09:38Determining Pain Detection and Tolerance Thresholds Using an Integrated, Multi-Modal Pain Task Battery
Published on: April 14, 2016