Factors affecting patients' pain intensity during in office intravitreal injection procedure

To determine factors associated with patients' comfort during routine in-office intravitreal injection.

Sixty patients receiving intravitreal injections over 15 months for macular edema because of diabetes, age-related macular degeneration, or retinal vein occlusion who were randomized into 3 groups to receive 1 of 3 commonly used forms of anesthesia-TetraVisc, proparacaine HCl, or tetracaine HCl-before receiving intravitreal injection were studied. Fifteen minutes after injection, patients were asked to rate their pain from 0 (no pain/no distress) to 10 (agonizing pain/unbearable distress) using a Visual Analog Pain score survey. Self-reported pain scores were stratified by age, gender, diagnosis, injection number, substance injected, needle gauge, and visual acuity improvement.

Intravitreal injection was associated with low pain scores. Patients receiving tetracaine reported a statistically significant lower pain score (3.05 ± 2.01) than patients receiving proparacaine (3.17 ± 2.18) or TetraVisc (3.3 9± 2.26; P < 0.01). Other important factors influencing pain score significantly (P < 0.01) included improved vision from previous injection, female sex, and age >65 years. Pain scores decreased with each consecutive injection.

Pain associated with intravitreal injection is generally mild, and may be associated with epidemiologic and environmental factors.