Psychogenic Visual Loss in Children

blindness. This condition usually resolves within 24 h but occasionally lasts for weeks.

The diagnosis of alexia without agraphia should be considered in the child with an acute isolated inability to read, even in the absence of homonymous hemianopia.242 The most common etiology of this disorder of higher cortical function is an infarction in the territory of the left posterior cerebral artery (hemianopia).242 In children, alexia without agraphia has been reported in the setting of bilateral occipital infarction,292 ruptured AVM,304 and following biopsy of a thalamic tumor,378 or acute disseminated encephalomyelitis hemianopia.242.

Congenital prosopagnosia can also simulate psychogenic visual loss. This newly recognized disorder has a prevalence of 2.5% in the general population and is inherited with an autosomal dominant transmission. A point mutation in a single gene may be responsible for the condition.146 The cardinal symptom is an inability to recognize familiar faces. Prosopagnosic children often overlook familiar people and confuse strangers with familiar persons.147 People with congenital prosopagnosia have no mental images of faces, not even of their nearest relatives.145 Interestingly, they recognize emotions on faces as easily as other people do. Their difficulties with facial recognition produce a special problem in crowded places. The underlying brain defect has not been localized. Anatomic MRI scans show normal cerebral structures, except for a slight gray matter deficit in parts of the anterior temporal lobe. As detailed in Chap. 1, premature children with periventricular leukomalacia may also display striking prosopagnosia.93,180,267,344

Psychogenic Visual Loss in Children

Psychogenic, or “functional,” visual loss is surprisingly common in children. Eames95 found that 9% of 193 unselected school children exhibit tubular visual fields. Bahn21 stated that “functional nervous disorders … are more frequently manifested in the visual mechanism than in any other of the special senses.” Psychogenic or functional visual loss in children has a clinical profile that differs from nonorganic visual loss in adults. It should be suspected when a discrepancy exists between the purported visual deficit and the objective findings or when a review of records shows that the level of acuity has varied considerably from one examination to the next. Psychogenic visual loss in children remains a diagnosis of exclusion, and some children who exhibit signs of psychogenic visual loss are later found to have an underlying organic disease.324 For example, the diagnosis of X-linked adrenoleukodystrophy should always be considered in boys who present with psychogenic visual loss in the first decade of life, who may display bizarre behavior and poor vision before optic atrophy or other neurologic signs develop.

Although the natural history is one of the spontaneous resolutions, long-term follow-up is important to rule out coexistent organic disease and to adequately treat children in whom psychogenic symptoms persist.324

Children and adults are differentially sensitive to their vision, as they are to health in general. Some tolerate substantial alterations in function without noticing them. Others are so sensitive that any floater or discomfort is perceived as disabling. Children who tend to dwell on their health, or whose parents closely monitor their physical well-being, are more apt to become concerned about subtle visual variations. Children can be viewed as existing along a spectrum with regard to their threshold for feeling visually intact. At one extreme is the intelligent child who needs glasses and is unaware that he or she cannot see well. The child with psychogenic visual loss represents the opposite extreme.

Clinical Profile

Psychogenic visual loss is most commonly seen in prepubescent girls in the 9- to 11-year age range.255 Mantyjärvi255 estimated the incidence at 1.4/1,000 per year. Psychogenic visual loss is often said to preferentially affect children who are of above average intelligence and who are high achievers at school,323 but this information is largely anecdotal and has never been verified by careful studies. When true, it is unclear whether such children have unusually high self-expectations of themselves or whether psychogenic visual loss occurs when the child’s psyche eventually “yields” in some way to the high expectations imposed on them by others.

Systematic psychological evaluation data of children with psychogenic visual loss are generally lacking, and many published opinions represent impressions of ophthalmologists. Mantyjärvi255 referred to psychogenic visual loss as the “amblyopic schoolgirl syndrome,” which he attributed to the stress of puberty and prepuberty. Rabinowicz323 believed that psychogenic visual loss usually represents a cry for help and, particularly, for parental attention. Rada,324 a psychiatrist, observed that inadequately understood feelings of being threatened, usually because of strife within the family, tend to predominate in young children with psychogenic visual loss. He concluded that information obtained from psychological tests and parental interviews suggests a neurotic conflict between the wish to express feelings of hostility and the wish not to lose the love of their parents.324 Psychological testing of affected children usually shows a significantly high “neurosomatic” score.394 In another psychiatric study, adolescents who had previously presented with psychogenic disorders of vision were more likely to report having experienced school difficulties and the loss of a significant figure at the time of presentation, to rate their mothers as overly