CBS & Age-related macular degeneration (ARMD)

One of the most consistent findings of CBS in relation to eye disease is that age-related macular degeneration (ARMD) poses a significant risk. This link is not unexpected given that macular degeneration is one of the leading causes of blindness in the Western world. Current estimates suggest somewhere between 20 - 40% of people living with macular degeneration will develop CBS and the figure is believed to jump to 60% in advanced cases.

Despite this strong correlation, precious few macular degeneration books (for the public) provide any coverage of CBS. Further, the syndrome is mentioned in only ~25% of contemporary ophthalmology text books. This suggests that crucial information is not reaching the general layperson but perhaps more concerningly, future health professionals. This unfortunate state of affairs serves only to reproduce the maxim 'out of sight, out of mind.'

 

Dry and wet forms of macular degeneration

CBS risk applies to both the 'dry' and 'wet' forms of ARMD although as the wet form can affect vision far more dramatically, it represents a more acute risk.

The 'dry' form of macular degeneration is the most common type of ARMD. It is a more slow moving form such that deterioration of the macular tends to be gradual. Often CBS symptoms appear weeks, months and even years after the initial ARMD diagnosis.

The 'wet' form refers to where the blood vessels feeding the retina (a) start to abnormally sprout and branch out and can intrude into retinal layers and/or (b) burst and bleed into the eye. The leakage of blood into the retina needs to receive urgent attention as vision loss in this situation tends to be rapid. In this wet form of ARMD, CBS symptoms can appear much sooner.

There are two major treatments for the wet form of ARMD which aim to inhibit the growth of new blood vessels. One is called Avastin and the other Lucentis.

It needs to be noted that Avastin - also known as Bevacizumab - has been occasionally reported to trigger CBS. There are several clinical papers that discuss this and can be supplied upon request.  

 

Recommendations

  • Routine screening for, and forewarning of, CBS during the initial consultations with the eye specialist could prevent much needless suffering and anxiety.
  • For those who may be already experiencing CBS symptoms, the valuable reassurance that can be provided by the eye specialist (ie. that they're not losing their mind) can allay fears and doubts. 
  • For those yet to experience any signs of CBS, the doctor's forewarning can be readily drawn upon if something visually unusual occurs down the track.
  • That eye specialists planning to treat the 'wet' form of ARMD with Avastin notify patients of the possible risks associated with the use of this procedure in order that an informed decision can be made.
  • GPs and other health care professionals being alert to the above also. This can provide an additional layer of (clinical) support.
  • Stress and anxiety can emerge from living with ARMD. Stress has also been found to be a risk factor for inducing or exacerbating CBS symptoms. Therefore, attempts to keep stress levels to a minimum is advised.

 

For more detailed information on macular degeneration visit:  http://www.mdfoundation.com.au