Sir,

Charalampidou et al1 described visual perceptions occurring after intravitreal injections of various medications. Their study addresses an important subject that is of interest to both healthcare professionals and patients, especially in view of the increasing number of intravitreal injections being performed to treat an expanding array of ocular pathologies.

The authors cited previous studies describing the visual experiences of patients undergoing various ophthalmic surgeries such as cataract extraction,2 vitrectomy,3, 4 and glaucoma filtration surgery.5 A key difference is that all these studies reported the visual perceptions experienced intraoperatively—that is, during the surgery itself.2, 3, 4, 5 Thus, any unusual or additional visual experiences reported could quite justifiably be attributed to the surgical procedure itself. For the current study, the cause of the visual perceptions at the 2-week interview may not be so clear. Were these perceptions the direct result of the intravitreal injection, or possibly some other cause?

Regarding the findings on light perception, we would like to clarify how the question was phrased at the second interview; specifically, whether additional clarification was provided to the patients. This is especially important as the 2-week questionnaire was self administered unless the patients were unable to see clearly.1 The question in table 1 simply states ‘Did you see light?’1 As many patients who answered yes had good to moderate corrected distance visual acuity (logMAR<0.7), they would definitely be able to perceive light in their daily activities. Was it made clear to the patients that the question referred to abnormal light perception and, if so, how was this distinction made consistently and reliably? If the light was not flashing (36% of patients),1 did this refer to a constant source of light in addition to normal visual perception that they would experience? This is an important question to address so that we can present our patients and colleagues with accurate information, and to allow valid comparisons with follow-on studies.

Nevertheless, this study reports important information, which we hope will increase awareness and stimulate further discussion on patients’ experiences during intravitreal injections.