Man Eyes

Cataracts, Part I of II

Today I am talking about an eye related health issue that most people have probably heard about, but that many people might not fully understand.  When I ask patients about their family medical history during their eye exam, the most common eye condition that people report to me is cataracts.  Everyone knows about a grandparent, or an aunt or an older sibling with cataracts, and many people know that there is a surgery to correct this condition.  The good news for people is that cataracts are an extremely common and treatable ocular health issue, so let's take some time to describe exactly what people should know about cataracts.    

 So that's why I hate driving at night?!?

 In order to understand cataracts and their effect on a person's vision, we first need to do a little eye anatomy lesson.  When light hits your eye, it is first refracted by the cornea (the clear part on the front of your eye) as it is focused onto the retina.  as light passes through the pupil, it is then refracted through a structure called the crystalline lens which is located just behind the colored iris.  This lens is made up of transparent fibers suspended within a clear capsule.  This capsule is then held in place by muscle fibers located behind the iris.  During your eye exam, when examining the structure of the eye, these lens fibers can be visualized to detect any abnormalities.  For various reasons, this lens can become less transparent which will in turn cause light to be less efficiently refracted onto the retina.  This is the formation of a cataract.  The normally clear lens structure located behind the iris becomes more opaque causing reduced vision.  Patient's with cataracts will describe general reduction in vision that is often associated with an increase in glare with bright lights.  This is a classic symptom that lets me know to consider cataracts as part of the diagnosis.

Okay.....I know what they are now, but how did this happen to me??

Most people think that cataracts are only a problem for older people, but that is not really the entire story.  Cataracts can come in many shapes and sizes, and it is true that several types of cataracts are mainly related to aging eyes.  The crystalline lens of the eye helps absorb some of the ultraviolet light that enters the eye, and after decades of this damage, the lens begins to discolor and a cataract forms.  This is part of the reason why wearing good protective sunglasses is important.  By reducing the amount of UV light entering the eye, sunglass wear over time can help to reduce the risk of certain types of cataract formation.  In general, age-related cataracts are a very slow process that initially does not have any significant effect on a patient's vision.  It is not uncommon for me to tell a patient in their 40's or 50's that they are developing cataracts, but that there is no need to treat them at this time because there are no symptoms.  Most people will eventually show some signs of cataracts, but not everyone will necessarily need them treated.  Beyond standard age-related cataracts, there are many other factors that can cause a patient's crystalline lens to change appearance.

I am too young for cataracts right?  That is something my grandmother has!

In addition to the standard run of the mill age -related cataracts, there are many factors that can influence cataract formation at any age.  People can actually be born with cataracts, and if not treated promptly, a congenital cataract can be devastating to visual development out of the affected eye.  Certain medications can also cause cataracts, and one of the most common is corticosteroids.  This class of medication is very commonly used in order to reduce inflammation, but extensive use over time can lead to cataract formation.  Among other reasons, this is one of the major reasons why steroid medications are generally only used for short durations.  I have had patients who have had ocular surgery which then required steroid use, and then after all of that they developed cataracts from the steroid use which required an additional surgery!  If a patient needs to be on long term steroid therapy, we will periodically monitor for the formation of cataracts.  Seemingly unrelated systemic health conditions, especially diabetes, can also contribute to cataract formation.  It is therefore very important for any diabetic patients to have regularly scheduled eye exams in order to assess overall eye health with attention to potential cataract formation.  Like I mentioned previously, cataract progression is generally a very slow process, but some interesting cases of sudden cataract formation can be related to trauma.  In the case of blunt trauma to the eye, the resulting impact force can cause the fibers of the crystalline lens to be disrupted and lose their transparent structure.  These cases are generally pretty obvious because of the patient history, but they can present as interesting cataract variations.

Well, I have a cataract, so what do I do about it??

Once it is determined that a patient's vision reduction or other symptoms are caused by a cataract, it is then important to determine the proper treatment options.  It might be something as simple as a change of the patient's glasses or contact lens prescription, but in many cases cataract treatment requires surgery.  Cataract surgery is a very common and effective procedure that we will talk about........next month!

-Dr.  Z

17 May, 2019