Eyes on eye disease: Cataracts

Invariably when I ask my patients about their family history of eye disease they’ll tell me 1. my parents wear reading glasses, and 2. my grandma had..umm…that thingy removed from her eyes last year..err macular?

No. Cataracts. You mean cataracts. If anyone had their macula removed they’d be in big trouble. Also, wearing reading glasses doesn’t mean an eye disease. Sass aside, I like to think of cataracts being as common as wrinkles, and the tendency is indeed for the prevalence of cataracts to increase with the number of wrinkles though no studies have looked into the direct correlation between the two as far as I know. If you’re a normal human being and live for long enough, you can be sure to end up with some degree of cataract (and wrinkle).

So what are cataracts exactly? A cataract is any opacity of the anatomical lens inside the eye. The most common cause of cataract is being old but they can also come about for other reasons including trauma, certain systemic metabolic diseases, congenital causes, or idiopathic (also known as “no real good reason why”). Many patients with cataracts describe their vision as filmy or cloudy as well as the usual blurry, and it doesn’t improve with rubbing the eyes or blinking; they also find they can no longer get away with reading in dim lighting. Cataracts are also known to alter colour perception as a particular type of cataract termed nuclear sclerosis causes the lens to turn yellow or brown, which filters out certain wavelengths of colours. Another effect of cataracts is an increased sensitivity to glare. This may be particularly apparent when driving at night-time and having to deal with street lamps or oncoming car headlights.

 

http://webeye.ophth.uiowa.edu/eyeforum/atlas/pages/Clear-Lens-normal/index.htm
A clear, healthy lens can be seen in the slit of light through the black pupil
https://timroot.com/nuclear-sclerotic-cataract-video/
Nuclear cataracts form in the centre of the lens, shown as the yellow-brown colouring seen through this pupil
http://dro.hs.columbia.edu/corticalcat.htm
Cortical cataracts form in the outer layers of the lens, often seen as spoke-like opacities around the edges

The next question my patients usually ask after I’ve told them they have early cataracts beginning is “What do I do about them?”. The real answer is “whatever you like”. Here’s a list of considerations when it comes to deciding whether the cataracts need to be removed, and comprises the actual content of my discussion with my cataract patients. I wanted to create a flowchart for the visual learners but I don’t know how to do that in WordPress so you’ll just have to read words.

  • Can you see what you want to see despite the cataracts? If yes, don’t get surgery just yet. If no, and the vision cannot be improved with updating spectacles then consider having the cataracts removed.
  • Do you meet the VicRoads driving vision standards? In Melbourne this currently sits at an acuity of 6/12 with two eyes open. Your optometrist will be able to tell you whether you meet this standard (and whether with or without vision correction). If despite glasses you still cannot reach the 6/12 line because of your cataracts then for the sake of everyone else on the road get them cataracts attended to or stop driving!
  • Do your job or hobbies require accurate colour perception? I had an art teacher with the earliest sign of cataract and still had 6/6 vision but she felt the early nuclear sclerosis was interfering with her colour vision so she opted to have the cataracts removed immediately.
  • Are you particularly affected by glare when driving at night-time? A follow up question to this would be asking if the patient actually does much night-time driving, or would like to if they felt more confident with their vision. Needless to say, problematic issues with glare sensitivity guides the decision for cataract extraction sooner rather than later.

Except in the case of young children with congenital cataracts which need to be addressed immediately, most patients can choose to continue about their daily lives after having being diagnosed with a cataract. Leaving a cataract be does not cause any permanent damage to the vision or eyes. In some rare cases a very progressed cataract can cause complications but if you keep up with routine eye tests then you’re not likely to reach that point. Since cataracts cannot be seen by looking in a mirror (unless you’re like the unfortunate canine in the picture), regular optometry appointments are recommended at least every 1 or 2 years.http://www.dog-health-handbook.com/dog-eye-cataracts.html

Another question my patients like to ask is “Are there any risks with cataract surgery?” Of course there are risks, can you imagine slicing open someone’s eyeball and not having any risks? (Sorry, a bit of sass crept back in there). What I actually say to them is something more along the lines of “Yes, there are always risks involved with any type of surgery, but cataract extraction is one of the most commonly done surgical procedures worldwide and the success rate is very high.” The procedure is usually performed under local anaesthetic and sedation (not general anaesthetic because unconscious people tend to roll their eyeballs upwards into their head which makes it difficult to perform eye surgery). A small incision is made in the cornea and an instrument inserted to break up the cataract and allow it to be suctioned out in fragments. A clear plastic implant is then inserted in the place of the cataract. Often the plastic implant can be created to correct for the patients refractive error even in cases of astigmatism or presbyopia, which reduces dependence on glasses or contact lenses.

If you are concerned about cataracts in either yourself or your more wrinkly family members, a visit to your local optometrist will be able to tell you whether this is something that needs to be addressed at this point in time. In the meantime, here’s a picture of a rather pretty cerulean blue-dot cataract.

https://www.researchgate.net/figure/26696797_fig5_Cerulean-cataract-in-family-2-The-right-eye-of-the-girl-with-cerulean-cataract-is-shown

Questions and comments are welcome below!

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