Canadian Rhinology Working Group consensus statement: biologic therapies for chronic rhinosinusitis

BACKGROUND

Recent evidence suggests that biologic therapy with targeted activity within the Type 2 inflammatory pathway can improve the clinical signs and symptoms of chronic rhinosinusitis with nasal polyposis (CRSwNP). There remains a population in CRSwNP that despite medical therapy and endoscopic sinus surgery have persistent signs and symptoms of disease. Therefore, biologics, monoclonal antibody agents, could be beneficial therapeutic treatments for these patients. There have been eight randomized, double-blind, placebo-controlled trails performed for CRSwNP targeted components of the Type 2 inflammatory pathway, notably interleukin (IL)-4, IL-5 and IL-13, IL-5R, IL-33, and immunoglobulin (Ig)E. However, there are no formal recommendations for the optimal use of biologics in managing Chronic Rhinosinusitis (CRS) within the Canadian health care environment.

METHODS

A Delphi Method process was utilized involving three rounds of questionnaires in which the first two were completed individually online and the third was discussed on a virtual platform with all the panelists. 17 fellowship trained rhinologists across Canada evaluated the 28 original statements on a scale of 1-10 and provided comments. A rating within 1-3 indicated disagreement, 8-10 demonstrated agreement and 4-7 represented being neutral towards a statement. All ratings were quantitively reviewed by mean, median, mode, range and standard deviation. Consensus was defined by removing the highest and lowest of the scores and using the "3 point relaxed system".

RESULTS

After three rounds, a total of 11 statements achieved consensus. This white paper only contains the final agreed upon statements and clear rationale and support for the statements regarding the use of biologics in patients with CRS.

CONCLUSION

This white paper provides guidance to Canadian physicians on the use of biologic therapy for the management of patients with CRS, but the medical and surgical regimen should ultimately be individualized to the patient. As more biologics become available and additional trials are published we will provide updated versions of this white paper every few years.

Contour interaction in amblyopia: scale selection

It has been known for some time that visual acuity in amblyopia is higher for single letters than for letters in a row (termed crowding). Early work showed that this could not be accounted for on the basis of the destructive interaction of adjacent contours (termed contour interaction), which was shown to be, in resolution units, normal in amblyopia. We have re-examined this issue using a letter stimulus that is modulated about a mean light level. This allows an examination of the effects of contrast polarity and spatial filtering within the contour interaction paradigm. We show that the majority of strabismic amblyopes that we investigated exhibit an anomalous contour interaction that, in some cases, was dependent on the contrast polarity of the flanking stimuli. Furthermore, we show that while amblyopes do select the optimum scale of analysis for unflanked stimuli, they do not select the optimum scale of analysis for flanked stimuli. For reasons that may have to do with their poorer shape discrimination, they select a non-optimal scale to process flanked stimuli.

Contour interaction in fovea and periphery

It has been known for some time that both foveal and peripheral visual acuity are higher for single letters than for letters in a row. Early work showed that this was due to the destructive interaction of adjacent contours (termed contour interaction). It has been assumed to have a neural basis, and a number of competing explanations have been advanced that implicate either high-level or low-level stages of visual processing. Our previous results for foveal vision suggested a much simpler explanation, one determined primarily by the physics of the stimulus rather than the physiology of the visual system. We show that, under conditions of contour interaction or crowding, the most relevant physical spatial-frequency band of the letter is displaced to higher spatial frequencies and that foveal vision tracks this change in spatial scale. In the periphery, however, beyond 5 degrees, the physical explanation is not sufficient. Here we show that there are genuine physiological lateral spatial interactions, which are due to changes in the spatial scale of analysis.