|
| Ocular structures and clinical facts | Pathological changes |
|
| Retina | Deposition of proteins tau, Aβ, and pTAu [35, 38, 39, 118]; accumulation of phosphorylated tau protein [138, 139] |
| Impairment of amyloid β precursor protein (APP) metabolism [140, 141, 142] |
| Reduction in retinal ganglion cells (RGCs) [85–87,143] |
| Reduction of retinal thickness [85, 93, 144] |
| Reduction to the retinal nerve fibre layer (RNFL) thickness [89, 145] |
| Retrograde degeneration from loss of cortical neurons [146, 147] |
| Inflammation [148, 149, 150] |
|
| Retinal and choroidal vasculature | Retinal and choroidal vascular β-amyloid deposits in transgenic mouse model of AD lead to retinal degeneration [107] |
| Reduction of vascularization [151] |
|
| Retinal vascular blood flow | Blood flow abnormalities may cause neurodegeneration [152] |
|
| Optic nerve | Axonal degeneration in the axonal segments [85, 140] |
| Loss of optic nerve thickness [153, 154] |
| Papillary paleness due to axonal loss and perfusion alterations [155] |
|
| Lens | Correlation between AD and supranuclear cataract [156, 157] |
| Presence of abnormal protein deposits [124, 157] |
|
| Tears | Changes in the chemical barrier composition of tears [136] |
| Cornea | Reduced corneal sensitivity [137] |
|
| Pupil | Pupillary responses possible biomarker [158, 159] |
| Choroid | Attenuation of choroidal thickness [160, 161] |
|
| Aqueous humour | Detection of Alzheimer connected, β-amyloid peptides, and chemokines in the aqueous humour [162, 163] |
|
| Visual field | Dysfunction in different tasks of basic vision and visual cognition [164] |
| Visual acuity | Decreased visual acuity [165] |
|
| Sensory perception | Clinically important symptoms of visuospatial disorientation [166, 167] |
| Visual processing | Deficits of visual motion perception [168] |
|
| Contrast sensitivity | Contrast sensitivity disturbances and motion perception [169, 170] |
| Colour vision | Incomplete achromatopsia [171] |
|
| Stereopsis | Reduced stereoscopic depth perception [172, 173] |
|
| Circadian rhythm | Alterations in the circadian rhythm and β-amyloid deposits inside and surrounding degenerating mRGCs [174–176] |
|
