The clock draw test is a rapid, inexpensive, and validated screening tool for visuospatial ability in patients suspected of having neurodegenerative disease (e.g., Alzheimer disease) as the cause of their visual complaints. The patients often have no insight into their deficits and may deny having any problem. In this setting the chief complaint might be “Brought in by spouse” or “Can’t read” despite many new glasses & 20/20 OU. Another common visual presentation of visual variant of Alzheimer disease (VVAD) is a homonymous hemianopsia or cortical blindness with reportedly negative neuroimaging (e.g., brain MRI). Careful review of these neuroimaging studies however might reveal subtle posterior cortical atrophy (PCA) in the occipital lobe and visual association cortex corresponding with the homonymous hemianopic field defect. Later the more typical loss of executive function and memory loss will develop but some patients present with visuospatial complaints in the visual variant of Alzheimer’s disease, or PCA. Formal neuropsychologic testing by neuropsychologist consultation might reveal deficits predominantly in visuospatial domains, but also deficits in more typical neurocognitive domains for Alzheimer disease, or may direct attention towards other neurodegenerative disorders.

Visual loss is associated with and may worsen dementia or delirium [115–117]. Dementia can present with visuospatial complaints. The symptoms typically center around visual processing, including getting lost in familiar areas, reading difficulty (despite normal distance and near visual acuity), difficulty with simultaneous (e.g., simultagnosia) or complex visual tasks (e.g., driving), or loss of calculation and visual multitasking abilities. Visuospatial abnormalities present in reading due to the complexity of processing multiple letters in a word, multiple words in a sentence, and multiple sentences in a paragraph. If asked specifically, the patient may agree that they can see the words, but by the time they get to the end of the sentence or paragraph they do not know what they have read, in part from the additional effort it takes just to track along a written phrase. To make matters more complex, pre-existing vision loss may worsen dementia symptoms (loss of visual cues analogous to “sundowning”) and sometimes as in our case vignette, the vision loss may be the presenting or only sign of Alzheimer dementia (i.e., visual variant Alzheimer dementia or PCA).

Reyes-Ortiz et al found that the mini-mental status exam (MMSE-blind) declined more among older Hispanics with near-vision impairment than among those with normal near vision [118]. Anstey et al. reported an association between memory loss over 2 years with vision impairment [119].

In this case, the patient was referred after the abnormal clock draw to cognitive neurology. Formal neuropsychological testing confirmed findings consistent with Alzheimer dementia and treatment was started in the hope of slowing the progression of the dementia. The patient was counseled on the diagnosis and eventually met with the Dean and elected to take retirement.

The patient was also advised to discontinue driving. The task of driving is very complex, and involves not only visual acuity but also visual processing, the cognitive ability to recognize ongoing and simultaneous tasks and challenges (e.g., oncoming traffic, children, animals, and changing visual spatial position of intersecting streets), and the rapidly employed motor response to those tasks. Visual loss can impair the older person’s ability to drive, and legal requirements vary from state to state [7, 20, 120–125]. Unfortunately, decreased Snellen visual acuity is not the only factor for successful driving and other visual factors might impact the ability to drive safely (e.g., dynamic vision, visual processing speed, visual search, light sensitivity, and near vision). Although most states require vision screening for driver’s license renewal, some do not and there is considerable variation in the frequency and level of testing. In cases of cognitive processing deficits, neurology and neuro-psychology consultation are helpful in explaining to the patient and family the need to stop driving.

In one study, elderly patients were five times more likely to have received advice about limiting their driving; four times more likely to report difficulty with challenging driving situations; and two times more likely to reduce their driving exposure. Cataract patients were also found to be 2.5 times more likely to have had an at-fault crash in the prior 5 years. The Useful Field of View test had been validated as a tool to evaluate a patient’s risk of motor vehicle accident while driving; impairment of useful field of view was associated with both self-reported and state-recorded car accidents. In another study, glaucoma was a significant risk factor for state-recorded crashes [123] as were other age-related visual problems [121].