Glare From Cataracts Can Be Disabling
When the natural lens within the eye becomes cloudy, the result is a cataract. Surprisingly, there are over six different types of cataractous changes that can cloud our natural lens, including nuclear sclerotic, cortical and posterior subcapsular (PSC) cataracts, to name a few. The subject of this discussion is the PSC. Although not the most common type of cataract, the PSC can be one of the most visually disabling.
The lens inside of our eye is positioned behind the colored iris and serves to focus light rays onto the back wall of the eye (the retina) to form the images that we see. The cornea, which is the clear dome-shaped covering in front of the iris, makes up the anterior surface of the eye. Although the cornea can become cloudy, its opacification is never referred to as a cataract. A PSC derives its name from a localized clouding of the back surface of the lens, just beneath the membrane or capsule that envelopes the natural lens. The cloudy region has a crystalline appearance under the microscope, resembling rock candy.
When light passes through this crystalline opacity it is scattered, and significantly reduces the person's vision. It is similar to looking through a frost covered car windshield. If the sun is not directly shining on it, you can see through it. However, with just the slightest amount of sunlight, your view is completely washed out, making driving impossible.
Individuals with PSCs usually have significant difficulty with reading, night driving and working under bright lights. The normal constriction of the pupil during reading tends to make this type of cataract symptomatic with near tasks. The headlights of oncoming cars can temporarily blind the affected individual, making night driving dangerous.
Interestingly, with reduced lighting conditions, patients with PSCs can have 20/20 or a completely normal visual acuity.
Young patients (less than 60 years of age) who develop cataracts tend to develop a PSC more commonly than other types of cataracts. The youngest patient I have treated with this type of lens opacity was only thirteen years old. Although the cause is commonly unknown, diabetes and chronic use of steroids can lead to this problem at a young age.
Surgical removal with an intraocular lens implant is the standard treatment for this type of cataract. Removal of cataracts in people less than age 60 tends to be easier than older individuals since, overall the lens is much softer and more easily extracted. These patients tend to do very well, with a full recovery of vision.
