Diseases

NHP Login

 
 

Malingering or Simulation (also known as functional visual loss) is defined as intentional counterfeiting a disease with instinct of benefit. It manifests as either simulating an eye disease (positive simulation), or denial of ophthalmic disease (negative simulation). In case of simulation suspect, clinician should exclude disease/disorder first before diagnosis of malingering. In case of exaggeration, patient misattributes symptoms to another irrelevant clinical entity. If patient really believes to be sick, then it is called conversion reaction or hysteria. In conversion, subject lives with symptoms and cannot control or even know that they are psychogenic in origin.

There is single instinct of benefit only (monetary or non-monetary) in all cases of real simulation/malingering or negative simulation.

Almost all ophthalmic sensory and motor functions including vision, visual field, colour vision and night blindness may be simulated. In cases of simulation examination, appropriate tests should be administered to satisfy subject and to defend it legally.

 

References

Chaudhuri Zia, Vanathi Murugesan. Postgraduate Ophthalmology Volume 2. Jaypee Brothers Medical Publishers (P) Ltd. 2012. P 1589-1593.

Schiefer Ulrich, Wilhelm Helmut, Hart William. Clinical Neuro-Ophthalmology, A Practical Guide. Springer-Verlag Berlin Heidelberg 2007. P 203-214.

Hirsch Alan R. Neurological Malingering. CRC Press, Taylor & Francis Group, LLC 2018.

Denniston Alastair K O, Murray Philip I. Oxford Handbook of Ophthalmology Third Edition. Oxford University Press 2014. P 730- 731.

Roy Frederick Hampton, Fraunfelder Frederick W, Fraunfelder Frederick T, Tindall Renee, Jensvold Bree. Roy and Fraunfelder’s Current Ocular Therapy Sixth Edition. Elsevier Inc. 2008. P 215- 216.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3808926/

http://www.ijo.in/article.asp?issn=0301-4738;year=1972;volume=20;issue=4;spage=173;epage=178;..

https://eyewiki.aao.org/Functional_Visual_Loss

https://bjo.bmj.com/content/bjophthalmol/73/8/651.full.pdf

The patient present with ophthalmic symptoms of positive or negative simulation.

Positive simulation

  • Visual field defect simulation as nonspecific contraction, tunnel or spiral view
  • Exaggeration of existing field defect
  • Simulation of wide blind spot
  • Simulation of hemianopic, quadrantic, or altitudinal field defects
  • Night blindness
  • Colour blindness
  • Uniocular or binocular diplopia
  • Nystagmus

Negative simulation

Subject tries to hide and deny conditions such as

  • Colour blindness
  • Amblyopia
  • Night blindness
  • Low level of stereopsis
  • Refractive surgery

 

Malingering or simulation manifests as either simulating an ophthalmic condition (positive simulation), or denial of ophthalmic disease (negative simulation).

Conscious behaviour and compensation are prominent features of malingering.

Some suggests that malingering is a manifestation of underlying psychopathology. Sometimes conversion disorder is included in this group because of this reason.

It depends upon the clinical history and examination. Almost all ophthalmic sensory and motor functions including visual acuity, colour vision, visual field and night vision may be subject of simulation. Appropriate tests are conducted to convince patient and to defend against litigation.

Tests which may be required includes

Tests for light sensation

  • Visually evoked potential (VEP)
  • Electroretinography (ERG)
  • Electronystagmography (ENG)

Tests for visual acuity

  • Pattern Visually evoked potential (VEP)
  • Optokinetic nystagmus

Tests for retinal pathology

  • Optical Coherence Tomography (OCT)
  • ERG
  • Fluorescein angiography (FA)
  • Indocyanine angiography (ICG)

 

Management includes

Malingerers need to be handled cautiously since they feel accused and react with hostility. Mild cases are treated with reassurances that the symptoms will resolve. Normal findings of the examination should be emphasised.

Stay calm and do not confront the patient concerning his inconsistencies on examination. The examination of a malingerer should be extended over a period of time. It is resumed on subsequent days and should include repetition of tests to uncover inconsistencies. It allow patients to recover and save face.

Patients with real ocular disease with associated secondary psychosomatic features are difficult to treat.

 

Prognosis

Stress a good prognosis to the patient because it provides a way out to the patient. Normalisation of visual function takes place in majority of patients.