Does the I-CARE e-learning programme improve primary care physicians' competence in LGBTI health? Protocol for a two-arm, parallel-group, superiority randomised controlled trial in French-speaking Swi

The introduction of adaptive optics (AO) technology in ophthalmology has revolutionized in vivo imaging of the human retina. Adaptive optics in combination with scanning light ophthalmoscopy (AOSLO) can achieve cellular resolution of the photoreceptor mosaic by compensating for the aberrations of the eye in real time while detecting non-confocal and confocal light reflected from the photoreceptors, thereby enabling visualization of the inner segment and waveguiding outer segment, respectively. In addition to providing a high-resolution view of cone mosaic structure, AOSLO technology enhanced with microperimetry allows investigators to probe cone function at a cellular scale. With AO microperimetry, diffraction-limited stimuli can be repeatedly delivered to specified retinal locations, and sensitivity can be measured for small spots confined to individual or small groups of cones. Previously, basic science psychophysical studies using the AO microperimetry platform have explored mechanisms of vision. These studies investigated the role of optical aberrations and fixational eye movements on spatial summation in the human fovea, fundamental properties of the waveguiding retina, and color vision in the trichromatic retina. AO microperimetry has also been applied to study retinal diseases including choroideremia, retinitis pigmentosa, and macular telangiectasia type 2. In choroideremia, AO microperimetry showed that visual sensitivity drops sharply in choroideremia at the atrophic border in close correlation with observed abnormalities in photoreceptor mosaic structure. On the other hand, AO microperimetry in associated retinitis pigmentosa showed a structure–function dissociation with lower sensitivity despite retained cone structure. In macular telangiectasia type 2, AO microperimetry revealed retained sensitivity at retinal locations with a gap in the inner segment layer but an intact external limiting membrane as imaged by OCT. The retained sensitivity was found despite a lack of visible cones in the AO image. Common to all these studies is that the AO microperimetry technique provided knowledge about structure–function relationships at high spatial resolution in the pathological conditions examined.