Clinicopathological Correlations of Visual Depth Perception in Patients with Cerebrovascular Disease

Abstract

Visual depth perception in 100 patients with cerebrovascular disease was evaluated using the Titumus stereotest. Twelve patients showed depth perception impairment. CT scans revealed that the lesion was located on the right hemisphere in 6 patients and on the left hemisphere in 3 patients, and that the remaining 3 patients had multiple infarctions. lnI SPECT was performed in 7 patients with moderate to severe depth perception impairment, of whom 6 patients showed a reduced blood flow in the posterior half of both the right and left cerebral hemispheres. Moderate to severe impairment of depth perception was more frequently observed in patients with a lesion in the right hemisphere or in the posterior half of either hemisphere.

Investigating the Link Between Subjective Depth Perception Deficits and Objective Stereoscopic Vision Deficits in Individuals With Acquired Brain Injury

“…Although three individuals in the RH-damage control group did not achieve the normal level on the TNO Stereo Test, none reported experiencing any depth perception deficits that affected their daily lives. This mismatch between the subjective perception of normal depth and objective stereoscopic vision test results in individuals with RH damage is consistent with numerous past findings (Benton and Hécaen, 1970; Carmon and Bechtoldt, 1969; Koh et al, 2008; Murphy et al, 2016; Tsuda et al, 1993).…”

“…Because difficulties with stereoscopic vision are closely linked to depth perception deficits (Brenner and van Damme, 1998; Howard and Rogers, 1995; Johnston et al, 1993; Schaadt et al, 2015), we used two stereoscopic vision tests that are related to binocular disparity. Previous lesion studies on depth perception deficits after ABI have primarily investigated this aspect of vision using stereoscopic vision tests (Berryhill et al, 2009; Koh et al, 2008; Murphy et al, 2016; Tsuda et al, 1993).…”

“…To determine whether our three patients’ stereoscopic vision performance was specific to them when compared to other individuals with ABI or healthy individuals, we compared the performance of our patients with that of two control groups consisting of five individuals each. Including the control group of individuals with ABI is especially important because even if individuals with ABI do not achieve the normal level on stereoscopic vision tests, few report experiencing any depth perception deficits that significantly affect their daily lives (Benton and Hécaen, 1970; Carmon and Bechtoldt, 1969; Koh et al, 2008; Murphy et al, 2016; Tsuda et al, 1993). Thus, the inclusion of this control group enables us to assess whether the results of stereoscopic vision tests are indeed related to subjective depth perception deficits.…”

“…Using random dot stereograms, researchers (Benton and Hécaen, 1970; Carmon and Bechtoldt, 1969) established that a notable proportion of individuals with a lesion in the right hemisphere (RH) of the brain exhibit impaired depth perception compared to those with a lesion in the left hemisphere. Subsequently, other researchers identified depth perception deficits in individuals with acquired brain injuries (ABIs) (Berryhill et al, 2009; Koh et al, 2008; Murphy et al, 2016; Tsuda et al, 1993).…”

“…These researchers used various tests such as the Topcon New Objective (TNO) Stereo Test (Abd-Manan, 2000; Berryhill et al, 2009), Titmus Fly Test (Koh et al, 2008; Tsuda et al, 1993), and modified random dot stereograms (Murphy et al, 2016) to assess stereoscopic vision and found that the depth perception deficits were associated with a lesion in the occipitoparietal area, with a predominance in the RH (Berryhill et al, 2009; Koh et al, 2008; Murphy et al, 2016; Tsuda et al, 1993). However, it is worth noting that individuals with these deficits rarely report subjective complaints of depth perception deficits that significantly affect their daily activities.…”