Which quadrant is less painful for intravitreal injection? A prospective study.

Area of Science:

• Ophthalmology
• Retinal Diseases
• Pharmacology

Background:

• Intravitreal injections are common treatments for various retinal conditions.
• Bevacizumab (IVB) is frequently used off-label for conditions like diabetic macular edema.
• Patient comfort and pain management are important considerations during intravitreal procedures.

Purpose of the Study:

• To investigate the correlation between the injection site of intravitreal bevacizumab (IVB) and the severity of pain experienced by patients.
• To identify other factors influencing pain perception, such as patient demographics and prior treatment history.

Main Methods:

• A prospective, randomized, four-armed clinical trial involving 1004 patients undergoing IVB injections.
• Patients were assigned to four injection quadrants: superotemporal (ST), superonasal (SN), inferotemporal (IT), and inferonasal (IN).
• Pain was assessed using the Visual Analog Scale (VAS); best-corrected visual acuity (BCVA) and central macular thickness (CMT) were secondary outcomes.

Main Results:

• The overall mean pain score was 2.86 ± 2.2.
• Pain severity significantly correlated with injection site (p < 0.001), with the ST quadrant being most painful and SN least painful.
• Females reported higher pain scores, and a negative correlation was found between pain and the number of previous injections (p = 0.03).

Conclusions:

• The superotemporal quadrant is the most painful site for IVB injections, while the superonasal quadrant is the least painful.
• Injection site, patient sex, and the number of prior injections are significant factors affecting pain severity.
• No significant complications were observed, indicating the safety of IVB injections across different sites.