Cataract Surgery and Macular Degeneration

The macula is the central area of the retina with highly-concentrated light-sensitive cells called cones. It gives us our central vision, necessary for reading or any close work.

Please see How the Eyes Work for more details.

Macular degeneration occurs in older people (typically aged 60 or older) and is often called Age-Related Macular Degeneration (ARMD or AMD). Since it involves deterioration of the retinal area responsible for our sharpest vision, it can interfere significantly in daily life as it progresses and becomes more severe.

The exact causes are not well understood and research is ongoing. It does seem to run in families and to occur more often in Caucasians, especially in Caucasian females. Various studies have connected it to smoking, obesity, high blood pressure, inactivity, light eye color, and over-exposure to sunlight. However, some study results contradict other study results.

Two AMD Stages

AMD starts out as Dry AMD and progresses to Wet AMD. This distinction has to do with the development of new blood vessels in the macula that should not be there.

Dry AMD involves an age-related thinning of the macular tissue and the appearance of pigmented spots called drusen. It causes some gradual loss of central vision and there is no FDA-approved treatment for it. Wet AMD occurs only in about ten percent of all AMD cases and causes more severe vision loss. Small blood vessels form underneath the retina but they are dysfunctional. They leak blood and fluid into the retinal tissue, which damages the light-sensitive cells and causes their death. This leaves blind spots in the field of vision. Scarring may also occur, which causes further vision loss.

Does Cataract Surgery Increase Risk of AMD?

Cataracts are a problem in the eye’s lens, while AMD involves the retina. At first glance they would seem to be quite unrelated. However, in 2003, the American Journal of Ophthalmology published an article about the data from three large studies on the association between AMD and cataract surgery. When those three sets of results were merged, it was found that the risk of AMD was 1.7 times higher after cataract surgery.

There is no consensus on why this should be. It could simply be that as we age, we are more likely to develop both AMD and cataracts. Or perhaps these two conditions share some risk factors that are not clear yet.

Another theory is that after cataractous lenses are removed, the retina is exposed to more blue light wavelengths. This theory gives rise to discussions as to whether blue-blocking IOLs will endanger older people by reducing their vision in dim light. IOLs that block blue light are Alcon’s ReSTOR IOL and aspheric AcrySofIQ IOL. Yellow-tinted sunglasses also block blue light and can be purchased everywhere.

Six years later, in February, 2009, a study was published that studied data from 4,577 participants aged 55 to 81, some of whom had had cataract surgery. These researchers compared that group with the other participants who had not had cataract surgery and found little evidence that cataract surgery increases incidence of AMD. They theorized that advances in IOL technology and in surgical techniques may explain why previous studies found more connection between AMD and cataract surgery.

Since studies contradict each other, more research is needed. If you would like to learn more about how these considerations apply to your own situation, please contact us for an experienced ophthalmologist near you.