Short-term changes of visual hallucinations after intravitreal injection of ranibizumab in age related macular degeneration

Sir,

We thank Tan¹ for his interest and the response to our letter. Tan is correct in pointing out that the term Charles Bonnet Syndrome that we used early in our report² relates just to the complex or structured visual hallucinations that some of our patients had experienced. Visual hallucinations in our patients may be compounded by iatrogenic entoptic phenomena. We did investigate the possibility of increase of visual hallucinations after the intravitreal injection of rabimizumab in our patients and found that it was not a notable phenomenon in this small series; therefore we did not mention this in Table 1. We agree that it is difficult to draw any definite conclusions about the change of visual experiences that had already existed in the small number (15) of our patients, but our results are valid for the 85 patients that we described in group III. Visual hallucinations are an under-investigated area given the widespread use of intravitreal therapy world-wide. A recent study published in this journal showed that the visual perceptions experienced following 15% of intravitreal injection of therapeutic agents gave cause for concern to the patient and more than half of the patients believed that preoperative counselling would have averted the concern.³