Pre-AMD: Duty to warn?

In my last post a few weeks ago I used the term “pre-AMD.” I love this term. I have been using it since Vision Expo West, when I first heard it from Jeff Gerson, OD, during a lecture he gave.

The question Dr. Gerson proposed was: At what point do we start to counsel patients to protect themselves from age-related macular degeneration?

By the Age-Related Eye Disease Study classification, a few small drusen (less than 63 microns in diameter) or no drusen is considered category 1, or no AMD. Several small drusen or a few medium-sized drusen (greater than 63 microns to less than 125 microns in diameter) in one or both eyes is considered category 2, or early-stage AMD. According to AREDS guidelines, these patients should not be prescribed the AREDS or AREDS2 formula.

However, if drusen or retinal pigment epithelium changes are noted on photographs or optical coherence tomography, isn’t this evidence of photo-oxidative retinal damage? Much like those with pre-diabetes, shouldn’t preventive steps be discussed with the patient and undertaken?

In a Primary Care Optometry News article, Jerry Sherman, OD, presents the case of an active 66-year-old with 20/25+ vision in each eye. During the optometrist’s exam, early cataracts and scattered drusen in the posterior pole were documented. The doctor addressed the cataracts with the patient, but not the drusen.

The following year, the patient returned with best corrected visual acuity of 20/200 OD and 20/25 OS. The patient assumed she needed her cataract removed. Unfortunately, late-stage wet AMD was diagnosed, and the patient went on to sue the optometrist. While the article did not state the stage of AMD due to confidentiality and the fact that the case was ongoing, what if this patient was category 1 or perhaps category 2 at her initial exam? Wouldn’t this patient have fallen under the classification of pre-AMD?

As optometrists, I feel we are obligated to warn patients with pre-AMD of the risk of future vision loss and what preventive steps can be taken. I include in this group those at risk of developing AMD later in life. In practice I do this by:

Case history: I ask if family members have been diagnosed with AMD. I also ask if family members such as parents, grandparents, aunts or uncles have lost vision. Many times patients don’t realize why a loved one lost vision until, through questioning, they dig a bit and find the answer, and many times the cause is AMD. I also ask questions regarding blue light exposure by asking how many hours per day are spent outdoors and how many hours are spent viewing digital screens including computers, tablets and smartphones. I, like most of you, have seen an increase in patient-reported symptoms of digital eyestrain. Will we see an increase in AMD incidence in the future, or incidence at a younger age? Time will tell.
Meaningful use: Many of us are now using electronic health records and participating in the meaningful use program. Clinical quality measures include tobacco use and cessation intervention and adult weight screening. Smoking and high body mass index are known risk factors for AMD development and progression. These measures present a counseling opportunity.
Macular pigment optical density (MPOD) testing: MPOD can be considered a biomarker for AMD risk. If someone measures low, I institute macular carotenoid supplementation to build macular pigment to protect against future photo-oxidative damage of photoreceptors and the RPE. Building macular pigment in patients also enhances contrast acuity, thus sharpening vision.
Genetic testing: I use genetic testing for patients with AMD as well as for patients with a family history to determine their risk of disease progression. Depending on their CFH and ARMS2 risk allele analysis, I also counsel patients on whether they should use or avoid supplemental zinc.
Blue-filtering spectacle lenses: Outdoor and indoor varieties of these lenses have become a mainstay in my practice. The sun is the most intense source of blue light routinely encountered, which is why the sky is blue! I now discuss with patients the importance of sunglasses that protect the eye from blue light as well as UV. Indoors, our blue light exposure has increased dramatically over the past 10 years due to the proliferation of electronic screens including tablets and smart phones. Consensus is that children and adults are spending 7 or more hours per day looking at these screens.

I realize I have only touched on a few of the many aspects around this concept of duty to warn those with pre-AMD of precautions they can take to help prevent disease progression. I think the real key to not ending up in the situation Dr. Sherman presented is to document the education you provide for your patient in your medical record. Obviously, we have a lot more to talk about!

References:

Awh CC, et al. Ophthalmology. 2014;120(11):2317-2323. http://dx.doi.org/10.1016/j.ophtha.2013.07.039.

Bernstein PS, et al. Vision Res. 2010;50(7):716–728.

Centers for Medicare and Medicaid Services. Medicare EHR Incentive Program for Eligible Professionals. http://www.cms.gov/Regulations-and-Guidance/Legislation/EHRIncentivePrograms/index.html?redirect=/ehrincentiveprograms/

Clemons TE, et al. Ophthalmology. 2005;112(4):533-539.

Seddon JM, et al. Arch Ophthalmol. 2003;121(6):785-792.

Sherman J. Optometrists should prepare for potential rise in AMD lawsuits. Primary Care Optometry News. 2013:18(11): 14.

Yu Y, et al. IOVS. 2012;53(3).