Did you know

“   Bertrand Russel:

    The good life is inspired by love and guided by knowledge.  ”


  1.    Eye Dryness
  2.    Phantom pain and non-painful phantom sensations
  3.    Implications of monocular vision  (LOSS OF ONE EYE)
  4.    Safety and Eye Protection
  5.    Longevity of prosthetics


Many times we seem to have a problem and we think we know the cause and at the end of the day our opinion is wrong..

Some of the common issues we experienced in the past with patients  are described here with further added information and knowledge..


Eye dryness


Generic and environment  causes of eye dryness

Possible causes..

An expanded description of eye dryness causes and artificial eyes.

In the cases were we have atrophy of the eye globe or evisceration or enucleation a great part of the mechanism  that  increases tear flow on demand is not functioning anymore..


Therefore in many cases were there are hard conditions such as heat  for example the specific eye does not increase tear flow accordingly therefore  causing eye dryness.

It is wise in this case to use eyedrops such us natural tears for example, and of course  according to your ophthalmologist’s  description and recommendation.

Also added causes to the problem exist, such as smoking.

Either personally or inside a smoking environment.

Many times in that case further to eye dryness a general irritation in the specific areas take place

Air conditioned environment cause dehydration of the surrounding atmosphere that can increase the eye dryness problem.

Eye dryness related to the prosthetic device.

All types of lenses need cleaning and removal of the protein deposits ,  it is therefore obvious that a good and efficient cleaning of the prosthetic device  should take place according to the manufacturer's recommendation in order to decrease possible friction

Cause of Dry Eyes

Tears lubricate  the eye, washing out dust and debris and keeping the eye moist.

In dry eye syndrome, the eye doesn't produce enough tears, or the tears have a chemical composition that causes them to evaporate too quickly.

Dry eye syndrome has several causes. It occurs as a part of the natural aging process, as a side effect of many medications, such as antihistamines, antidepressants, certain blood pressure medicines, Parkinson's medications and birth control pills; or because you live in a dry, dusty or windy climate.

If your home or office has air conditioning or a dry heating system, that too can dry out your eyes. Another cause is insufficient blinking, such as when you're staring at a computer screen all day.

Dry eyes are also a symptom of systemic diseases such as lupus, rheumatoid arthritis..

Long-term contact lens  wear is another cause; in fact, dry eyes are the most common complaint among contact lens wearers.

Incomplete closure of the eyelids, eyelid disease and a deficiency of the tear-producing glands are also other causes.


Phantom pain and non-painful phantom sensations

Phantom pain and non-painful phantom sensations result from changes in the central nervous system due to denervation of a body part.Phantom eye pain is considerably less common than phantom limb pain. The prevalence of phantom pain after limb amputation ranged from 50% to 78%. The prevalence of phantom eye pain, in contrast, is about 30%.

Post-amputation changes in the cortical representation of body parts adjacent to the amputated limb are believed to contribute to the development of phantom pain and nonpainful phantom sensations. One reason for the smaller number of patients with phantom eye pain compared with those with phantom limb pain may be the smaller cortical somatosensory representation of the eye compared with the limbs.

In limb amputees, some[3] but not all studies have found a correlation between preoperative pain in the affected limb and postoperative phantom pain. There is a significant association between painful and nonpainful phantom experiences and preoperative pain in the symptomatic eye and headache.[4] Based on the present data it is difficult to determine if headaches or preoperative eye pain play a causal role in the development of phantom phenomena, or if headache, preoperative eye pain, and postoperative phantom eye experiences are only epiphenomena of an underlying factor. However, a study in humans demonstrated that experimental pain leads to a rapid reorganization of the somatosensory cortex.[5] This study suggests that preoperative and postoperative pain may be an important cofactor for somatosensory reorganization and the development of phantom experiences.


Visual hallucinations

Enucleation of an eye and, similarly, retinal damage, lead to a cascade of events in the cortical areas receiving visual input. Cortica (GABA: Gamma-aminobutyric acid) inhibition decreases and cortical glutamatergic excitation increases, followed by increased visual excitibility or even spontaneous activity in the visual cortex.[6] It is believed that spontaneous activity in the denervated visual cortex is the neural correlate of visual hallucinations.


We wish to thank the people involved for the following issue, for they have efficiently managed to explain it:


Phantom eye syndrome: types of visual hallucinations and related phenomena.

Eye Clinic, 2061, Rigshospitalet, University of Copenhagen, Copenhagen Ø, Denmark.

PURPOSE: To describe the prevalence of phantom eye syndrome in eye-amputated patients, to give a description of visual hallucinations, and to identify triggers, stoppers, and emotions related to visual hallucinations. METHODS: The hospital database was screened, using surgery codes for patients who had received ocular evisceration, enucleation, or secondary implantation of an orbital implant in the period 1993-2003. A total of 267 patients was found and invited to participate, 173 accepted. Patients who accepted participation had their records reviewed, and a structured interview about visual hallucinations and pain was performed by one trained questioner (M.L.R.R.). RESULTS: The prevalence of phantom eye syndrome was 51%. Elementary visual hallucinations were present in 36%, complex visual hallucinations in only 1%, and other visual hallucinations in 14%. The elementary visual hallucinations were most often white or colored light, as a continuous sharp light or as moving dots. The most frequent triggers were darkness, closing of the eyes, fatigue, and psychological stress; 54% of patients had the experience more than once a week. Ten patients were so visually disturbed that it interfered with their daily life. CONCLUSIONS: Phantom eye syndrome is common, and the authors recommend that surgeons inform their patients about the phenomenon.

Link to the article:

http://www.ncbi.nlm.nih.gov/pubmed/19966655

http://journals.lww.com/op-rs/Abstract/2009/09000/Phantom_Eye_Syndrome__Types_of_Visual.13.aspx

References

  1. 1.^ a b c Sörös, P.; O. Vo, I.-W. Husstedt, S. Evers and H. Gerding (May 2003). "Phantom eye syndrome: Its prevalence, phenomenology, and putative mechanisms". Neurology 60 (9): 1542–3. PMID 12743251. Retrieved 2008-09-23.
  2. 2.^ Ramachandran, Vilayanur S.; W Hirstein (September 1998). "The perception of phantom limbs. The D. O. Hebb lecture". Brain 121 (9): 1603–30. doi:10.1093/brain/121.9.1603. PMID 9762952. Retrieved 2008-09-23.
  3. 3.^ a b Nikolajsen, L.; T. S. Jensen (July 2001). "Phantom limb pain". British Journal of Anaesthesia 87 (1): 107–16. doi:10.1093/bja/87.1.107. PMID 11460799. Retrieved 2008-09-23.
  4. 4.^ Nicolodi, M.; R. Frezzotti, A. Diadori, A. Nuti and F. Sicuteri (June 1997). "Phantom eye: features and prevalence. The predisposing role of headache". Cephalalgia 17 (4): 501–4. doi:10.1046/j.1468-2982.1997.1704501.x. PMID 9209770. Retrieved 2008-09-23.
  5. 5.^ Sörös, Peter; Stefan Knechta, Carsten Bantelb, Tanya Imaia, Rainer Wüstenb, Christo Pantevc, Bernd Lütkenhönerc, Hartmut Bürkleb and Henning Henningsen (February 2001). "Functional reorganization of the human primary somatosensory cortex after acute pain demonstrated by magnetoencephalography". Neuroscience Letters 298 (3): 195–8. doi:10.1016/S0304-3940(00)01752-3. PMID 11165440. Retrieved 2008-09-23.
  6. 6.^ Eysel, Ulf T.; Georg Schweigart, Thomas Mittmann, Dirk Eyding, Ying Qu, Frans Vandesande, Guy Orban and Lutgarde Arckens (1999). "Reorganization in the visual cortex after retinal and cortical damage". Restorative Neurology and Neuroscience 15 (2-3): 153–64. PMID 12671230. Retrieved 2008-09-23.


Implications of monocular vision  (LOSS OF ONE EYE)

Acquired monocular vision will affect vision and the individual in several ways. There are two main issues which are uniformly and predominantly addressed by the published literature and authorities. The two primary deficits are loss of stereoscopic binocular vision and reduction of peripheral field of vision. Most of the ramifications and symptoms of monocular vision are a result of these two deficiencies.

Further information link:  http://nora.cc/content/view/26/70/


Safety and Eye Protection



It is important to realize the need for safety concerns “they should wear protective eyewear” with lenses made out of polycarbonate material. Precautions must be addressed to protect the remaining good eye in individuals with monocular vision loss. Even if in the case were  individuals require no lens prescription for visual acuity, they should wear protective eyewear with lenses made out of polycarbonate material.

Polycarbonate is an industry standard for safety and eye protection.

Here are some possible good recommendations:


The individual will require multiple pair of safety type eyeglasses with polycarbonate lenses for the following reasons and purposes. There should be a minimum of two pair of each recommended as follows so if ever one is lost, broken or otherwise not available, then the individual will have a spare to wear so as not to go without the protection. Bifocal prescription may be necessary in addition to single vision lenses depending on the age, accommodation, and specific occupation and avocation needs of the monocular individual. Sunglasses for photophobia are recommended. Glasses for at night, especially night time driving with anti-reflective coating to enhance acuity, decrease reflection and decrease potential eye strain from glare are recommended. Special safety protection for sports are recommended if the individual engages in sports. Safety protection for the work place may be required in addition if the individual is engaged in any type of potentially hazardous  environments. For non-work environments, eyeglass frames would be recommended to be manufactured out of sturdy ophthalmic materials and although not required by law, possibly meeting ANSI safety standards.


Using Eye protection meaning glasses may  improve also other perspectives related to the issue.


A good example is that by wearing glasses, a possible luck of eye movement is hidden this way  and is not presented due to the glass frame which prevents extreme eye movements.


Another good reason is a mild limit of eye dryness due to the ability of the glasses to reflect harsh wind conditions etc..


Some of our patients have even mentioned that their protective glasses also act as a “warning” not to act further and touch or rub the eye without first washing their hands..



Longevity of prosthetics


When do we replace it?

Gradual physical changes in the eye socket tissues and natural deterioration of the plastic and pigments will necessitate a new prosthesis at intervals. It is often the obligation of the ophthalmologist or ocularist to inform you of this fact.

The acrylic prosthesis should be replaced as needed to maintain a healthy socket and satisfactory cosmetic appearance. The lifetime of a plastic eye will vary with each patient and the chemistry of the socket. Five years is the average useful life, however many patients are able to go for longer periods with no problem.

If the artificial eye is three or more years old, it should be evaluated for proper size, alignment and color. The surface should be examined for roughness and de-lamination. De-lamination commonly occurs at the edge, or around the iris.

It appears as a fine, dark line that progressively develops into complete separation as the plastic fatigues. This is often the cause of eyelid irritation and increased secretion from the socket.

De-lamination may also occur in the pigment layers and may appear as a "cataract" in the pupil, or as a silvery reflection in the region of the iris. Changes may also occur in the pigments themselves; the colors become either lighter or darker, or more commonly,  develop a bleached, yellowish tint with brown spots.

Because the deterioration of the prosthesis is gradual, you may not be aware of the possible serious consequences of these changes. If physical damage to the socket has occurred from irritation by a deteriorating prosthesis,  it may become impossible to provide the wearer with the good cosmetic effect he once enjoyed.  Even contracted socket syndrome has been noticed from old stock eyes. Therefore, having the prosthesis checked periodically and your socket examined to prevent unnecessary problems.  Most ocularists recommend that you have your prosthesis checked every six to twelve months.

Finally a very important factor that sometimes is not considered is the following:
Custom ocular Prosthetics have a permanent constant shape , were human beings change throughout the course of their lives and that creates changes to the human body including the socket and or the atrophy of the eye globe.

Therefore when these changes take place replacement is important.

That is why a three to five year barrier is considered and suggested.



© Sankey International 2016