Intravitreal Injection Site and Perceived Pain

In this pilot cross-over study, the investigators aim at exploring a factor not studied yet on the perception of pain during the injection procedure, and that is the distance of the entry site from the limbus.

Study population: Pseudophakic patients needing multiple intravitreal injections. In case of bilateral eligibility, one eye per patient will be included (randomly- based on a random chart).

Intervention: two injections per eye, will be included in the study. All steps of the technique will be similar between the two injections except for the entry site distance from the limbus, which will be 3.5 in one and 4.00 mm in the other. To prevent bias, the first injection entry distance will be randomly selected (based on a randomized chart).

The patient is blind to the entry distance, and a questionnaire with a visual analog pain scale will be given to the patient by a technician (to prevent any bias) to be filled after the injection. The analog pain scale is a scale of numbers from 0 to 10 representing the degree of patient's perceived pain. A score of 0 indicates no perception of pain; a score of 10 indicates a perception of the worst pain possible. The scale is also illustrated with face emojis corresponding to a written description of pain perception from no perception of pain, represented by a green, fully smiling face to perception of the worst pain possible, represented by a red, crying, fully frowning face.

Inclusion criteria

• Age 18 -100 years
• Diagnosis of diabetic macular edema, age related macular degeneration, or retinal vein occlusion
• Treated with bevacizumab, ranibizumab, aflibercept
• The need for at least two intravitreal injections
• Pseudophakia

Exclusion criteria

• Texas Department of Corrections medical records
• Under 18 years-of-age
• First intravitreal injection experience of patient