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Visual disturbances in Alzheimer's disease
Eye Safev
Tips Louise Hunt, RN, MS, CRNO
Visual disturbances disease
in Alzheimer’s
lzheimer’s disease was first described in 1907 by a German neuropsychiatrist named Alois .Alzheimer. It is the fourth leading cause of death among elderly persons, and the duration and rates of progression vary. Visual complaints of reading problems and the inability to detect the exact location of an object in space are often among the initial complaints of a person with Alzheimer’s disease. Visual acuity examinations may be normal during the early stage of the disease. The family may notice that the person is clumsy when reaching for an object and bumps into the furniture when walking quickly through a room. The diagnosis at this time may still be uncertain. The greater the severity of Alzheimer’s disease, the greater the visual pathway disturbances.l The person may develop problems in recognizing objects and familiar faces, orienting themselves in their environment, determining visual direction, maintaining eye fixation, and performing hand-eye coordination.2 Alzheimer’s disease involves the visual association cortex that can cause abnormalities in the higher visual processing. One study examined 30 patients with Alzheimer’s disease and 30 controls to characterize the complex visual disturbances. The subjects had full neurologic and ophthalmologic evaluations and had best refracted Snellen visual acuities of 20/40 or better. They were given test items designed to screen seven areas of higher visual processing. The complex visual tests were: visual object recognition, face recognition, color recognition, complex form discrimination, figure-ground analysis, visual synthesis, and spatial localization. The results of the study revealed that all 30 patients with Alzheimer’s disease had
disturbances in figure-ground analysis when they were asked to identify three Luria hidden figures (house, hand, a hat) and three groups of overlapping figures from the Southern California FigureGround Test. They were also impaired in the visual evaluation of common objects, recognizing famous faces, spatial localization, and complex figures. They had good visual acuity and color recognition.2 Another study administered tests that taxed visual-spatial skills, form identification, color vision, and visual memory to 25 patients with Alzheimer’s disease and a control group of 53 subjects. The purpose of the study was to determine whether visual symptoms of patients with Alzheimer’s disease are derived from visual-spatial deficits. Fourteen of the 25 patients had sought ophthalmologic consultation for blurred vision. Questions posed to spouses or care givers revealed that the patients had difficultly reading, driving, dressing, manipulating objects, judging distances, or identifying or locating familiar objects or persons. The 14 patients who had prominent visual symptoms performed poorly on all the visualspatial tests compared with the 11 patients with Alzheimer’s disease without such symptoms. This study concluded that the visual symptoms in Alzheimer’s disease are related primarily to visual-spatial deficits.” Mendez et a1.2 had concluded that the visual complaints of patients with Alzheimer’s disease were most closely related to figure-ground tests. The discrepancy in the results of the two studies may be due to the degree of dementia of the disease in the patients, the manner in which the patients were selected, or in the differences between the particular tests used. The parieto-occipital regions of the brain
INSIGHT
The Journal
of the
American
Society
of Ophthalmic
Registered
Nurses,
Inc.
Volume
XXII,
No.
Louise Hunt is a nurse specialist in clinical physiology at Presbyterian Hospital, Oklahoma City. She is a member of the Editorial Board of Insight and has been a member of ASORN since 7 982. Reprint requests: Louise Hunt, RN, MS, CRNO, Presbyterian Hospital, 700 N. E. 7 3th St., Oklahoma City, OK 73104. Insight 1997;22:
7 19-20
Copyright 0 1997 by the American Society of Ophthalmic Registered Nurses. 1060-135X/97
$5.00 + 0
72/g/81493
4, December
1997
119
Hunt processvisual-spatial information. The temporo-occipital regions mediate form identification, visual memory, and color. There is evidence that pathologic and metabolic abnormalities are found in the parieto-occipital regions of patients with Alzheimer’s diseasewho had prominent visual complaints.3 One patient was studied and closely followed after his initial complaint of problems with reading and driving for the 12 years until his death from Alzheimer’s disease.Postmortem examination showed that this diseasecan affect the posterior cerebralhemispheres of the brain and causea mental impairment presenting with and dominated by visual disturbances.There was cortical atrophy with neurofibrillary tangles highest in the occipitoparietal areasand lowest in the frontal lobes. This is the reverseof the profile seenmost often in patients with Alzheimer’s disease.Throughout the courseof his illness, the visual defects gradually worsened; personality, social manners, and outward manifestations of his feelings and emotions remained normal, but memory and languageskills eventually failed.4 It has been learned that visual problems are likely to be common in patients with Alzheimer’s and may be the first complaint. Despite good visual acuities and fields, the subjective visual complaint may be related to visual pathway deficits. Contrast sensitivity tests to assess visual-spatial skills may be more effective in ophthalmologic screening of these patients. The
patient closely followed for 12 years expressedthe need for ideal lighting conditions, the right illumination, and the importance of the direction of the light sourcewhen he had difficulties in visual identification and location. The assessment of visual contrast sensitivity at both high and low ambient illumination needs to be studied further in patients with the visual variant of Alzheimer’s disease. The onset of Alzheimer’s diseaseis usually subtle and insidious. Health care providers should become acquainted with the symptoms that may suggest Alzheimer’s disease.Dr. Paul T. Costa,Jr, PhD, Director of the Gerontology Research at the National Institute on Aging, stated that early recognition of Alzheimer’s diseaseor identification of other types of dementias can prevent costly and inappropriate treatment and give patients and family members time to addressthe complex financial, legal, and medical issues these conditions present. References Sadun AA, Borchert M, De Vita E, Hinton DR, Bassi CJ.Assessmentof visual impairment in patient’s with Alzheimer’s disease.Am J Ophthalmol 1987:104:113-20. Mendez MF, Mendez.MA, Martin R, Smyth KA, Whitehouse PJ.Complex visual disturbances in Alzheimer’s disease.Neurology 1990;40:439-43. Butler CM, Trobe JD, FosterNL, Berent S. Visualspatial deficits explain visual symptoms in Alzheimer’s disease.Am J Ophthalmol 1996;122:97-105. Levine DN, LeeJM, FisherCM. The visual variant of Alzheimer’s disease:a clinicopathologic case study. Neurology 1993;43:305-13.
Subscriptions must be in force to qualify. Bound volumes are not available in place of a regular Journal subscription. 120
Volume XXII, No. 4, December 1997
INSIGHT
I
The Journal of the American Society of Ophthalmic RegisteredNurses, Inc.
Tips Louise Hunt, RN, MS, CRNO
Visual disturbances disease
in Alzheimer’s
lzheimer’s disease was first described in 1907 by a German neuropsychiatrist named Alois .Alzheimer. It is the fourth leading cause of death among elderly persons, and the duration and rates of progression vary. Visual complaints of reading problems and the inability to detect the exact location of an object in space are often among the initial complaints of a person with Alzheimer’s disease. Visual acuity examinations may be normal during the early stage of the disease. The family may notice that the person is clumsy when reaching for an object and bumps into the furniture when walking quickly through a room. The diagnosis at this time may still be uncertain. The greater the severity of Alzheimer’s disease, the greater the visual pathway disturbances.l The person may develop problems in recognizing objects and familiar faces, orienting themselves in their environment, determining visual direction, maintaining eye fixation, and performing hand-eye coordination.2 Alzheimer’s disease involves the visual association cortex that can cause abnormalities in the higher visual processing. One study examined 30 patients with Alzheimer’s disease and 30 controls to characterize the complex visual disturbances. The subjects had full neurologic and ophthalmologic evaluations and had best refracted Snellen visual acuities of 20/40 or better. They were given test items designed to screen seven areas of higher visual processing. The complex visual tests were: visual object recognition, face recognition, color recognition, complex form discrimination, figure-ground analysis, visual synthesis, and spatial localization. The results of the study revealed that all 30 patients with Alzheimer’s disease had
disturbances in figure-ground analysis when they were asked to identify three Luria hidden figures (house, hand, a hat) and three groups of overlapping figures from the Southern California FigureGround Test. They were also impaired in the visual evaluation of common objects, recognizing famous faces, spatial localization, and complex figures. They had good visual acuity and color recognition.2 Another study administered tests that taxed visual-spatial skills, form identification, color vision, and visual memory to 25 patients with Alzheimer’s disease and a control group of 53 subjects. The purpose of the study was to determine whether visual symptoms of patients with Alzheimer’s disease are derived from visual-spatial deficits. Fourteen of the 25 patients had sought ophthalmologic consultation for blurred vision. Questions posed to spouses or care givers revealed that the patients had difficultly reading, driving, dressing, manipulating objects, judging distances, or identifying or locating familiar objects or persons. The 14 patients who had prominent visual symptoms performed poorly on all the visualspatial tests compared with the 11 patients with Alzheimer’s disease without such symptoms. This study concluded that the visual symptoms in Alzheimer’s disease are related primarily to visual-spatial deficits.” Mendez et a1.2 had concluded that the visual complaints of patients with Alzheimer’s disease were most closely related to figure-ground tests. The discrepancy in the results of the two studies may be due to the degree of dementia of the disease in the patients, the manner in which the patients were selected, or in the differences between the particular tests used. The parieto-occipital regions of the brain
INSIGHT
The Journal
of the
American
Society
of Ophthalmic
Registered
Nurses,
Inc.
Volume
XXII,
No.
Louise Hunt is a nurse specialist in clinical physiology at Presbyterian Hospital, Oklahoma City. She is a member of the Editorial Board of Insight and has been a member of ASORN since 7 982. Reprint requests: Louise Hunt, RN, MS, CRNO, Presbyterian Hospital, 700 N. E. 7 3th St., Oklahoma City, OK 73104. Insight 1997;22:
7 19-20
Copyright 0 1997 by the American Society of Ophthalmic Registered Nurses. 1060-135X/97
$5.00 + 0
72/g/81493
4, December
1997
119
Hunt processvisual-spatial information. The temporo-occipital regions mediate form identification, visual memory, and color. There is evidence that pathologic and metabolic abnormalities are found in the parieto-occipital regions of patients with Alzheimer’s diseasewho had prominent visual complaints.3 One patient was studied and closely followed after his initial complaint of problems with reading and driving for the 12 years until his death from Alzheimer’s disease.Postmortem examination showed that this diseasecan affect the posterior cerebralhemispheres of the brain and causea mental impairment presenting with and dominated by visual disturbances.There was cortical atrophy with neurofibrillary tangles highest in the occipitoparietal areasand lowest in the frontal lobes. This is the reverseof the profile seenmost often in patients with Alzheimer’s disease.Throughout the courseof his illness, the visual defects gradually worsened; personality, social manners, and outward manifestations of his feelings and emotions remained normal, but memory and languageskills eventually failed.4 It has been learned that visual problems are likely to be common in patients with Alzheimer’s and may be the first complaint. Despite good visual acuities and fields, the subjective visual complaint may be related to visual pathway deficits. Contrast sensitivity tests to assess visual-spatial skills may be more effective in ophthalmologic screening of these patients. The
patient closely followed for 12 years expressedthe need for ideal lighting conditions, the right illumination, and the importance of the direction of the light sourcewhen he had difficulties in visual identification and location. The assessment of visual contrast sensitivity at both high and low ambient illumination needs to be studied further in patients with the visual variant of Alzheimer’s disease. The onset of Alzheimer’s diseaseis usually subtle and insidious. Health care providers should become acquainted with the symptoms that may suggest Alzheimer’s disease.Dr. Paul T. Costa,Jr, PhD, Director of the Gerontology Research at the National Institute on Aging, stated that early recognition of Alzheimer’s diseaseor identification of other types of dementias can prevent costly and inappropriate treatment and give patients and family members time to addressthe complex financial, legal, and medical issues these conditions present. References Sadun AA, Borchert M, De Vita E, Hinton DR, Bassi CJ.Assessmentof visual impairment in patient’s with Alzheimer’s disease.Am J Ophthalmol 1987:104:113-20. Mendez MF, Mendez.MA, Martin R, Smyth KA, Whitehouse PJ.Complex visual disturbances in Alzheimer’s disease.Neurology 1990;40:439-43. Butler CM, Trobe JD, FosterNL, Berent S. Visualspatial deficits explain visual symptoms in Alzheimer’s disease.Am J Ophthalmol 1996;122:97-105. Levine DN, LeeJM, FisherCM. The visual variant of Alzheimer’s disease:a clinicopathologic case study. Neurology 1993;43:305-13.
Subscriptions must be in force to qualify. Bound volumes are not available in place of a regular Journal subscription. 120
Volume XXII, No. 4, December 1997
INSIGHT
I
The Journal of the American Society of Ophthalmic RegisteredNurses, Inc.