Age Related Macular Degeneration (Dry AMD without Geographic Atrophy)

*Please note that this information is for illustrative purposes only, providing a general overview on the topics listed. For any specific questions or concerns regarding your condition, please contact our office so that you can consult with the appropriate person or department to address your needs.

DRY AGE RELATED MACULAR DEGENERATION
Overview

There are two types of Age Related Macular Degeneration (ARMD).  Dry ARMD accounts for 85 - 90% and Wet ARMD accounts for 10 - 15% of patients with macular degeneration.  There are approximately 4 - 5 million people in the United States affected by ARMD and that number is estimated to increase to 6 - 7 million by the year 2030.

Causes

The retina is a thin membrane that lines the inner wall of the eye (much like the thin membrane on the inner side of an egg shell).  The retina has two types of cells: the rods (nighttime, black & white vision) and cones (daytime & color vision) that receive and process images.

ARMD occurs in the center of the retina called the macula (image to follow).  The degeneration of the cells in the macula damages the photoreceptors (mostly cones that receive central visual images and send them to the brain via the optic nerve) and retinal pigment epithelial cells (a.k.a. RPE cells which are the cells under the retina that assist with the metabolism and support the health of the retinal cells adjacent to them).  The process begins with the abnormal storage of lipofuscin (waste products of the metabolism of the photoreceptors) within the RPE cells.  The storage of lipofuscin causes growth and swelling of the RPE cells which creates drusen (yellow deposits under the retina).

Stages

The size and number of these drusen, and the presence of geographic atrophy determines the stage of Dry ARMD.

Stage 1 Dry ARMD – Small sized drusen

Stage 2 Dry ARMD – Intermediate sized drusen

Stage 3 Dry ARMD – Many intermediate drusen or one or more large drusen, may be associated with a pigment epithelial detachment (PED), pigmentation of the RPE or intraretinal pigment migration.

When the RPE cells become damaged, and the cells begin to die off, a condition called Geographic Atrophy (GA) develops which leads to the most advanced stage of Dry ARMD (Stage 4).

Stage 4 Dry ARMD – Some or all of the findings in Stage 3 Dry ARMD with geographic atrophy (GA) of any size.

GA is essentially an area of loss of RPE cells that increases in size over time.  The death of the RPE cells causes a disruption in the normal metabolism of the retina and leads to the death of the overlying photoreceptors (that depend on the RPE cells to eliminate waste product).  When the overlying photoreceptors die this process creates a scotoma (blind spot) in the central vision.  As the area of GA enlarges the patients’ scotoma or blind spot will also enlarge.

Symptoms

Dry ARMD is often asymptomatic (showing no symptoms) in Stages 1 - 3.  When symptoms are present they include decreased color vision, diminished ability to read fine print, need for brighter light when reading or difficulty adapting to changes in light (difficulty seeing when entering a dark room).

Dry ARMD becomes more symptomatic in Stage 4 where patients will begin to notice a blind spot in their central or near central vision, experience difficulty recognizing  faces, decreased ability to read fine print, need for brighter light when reading, decreased color vision, difficulty with light adaption, occasionally a little distortion of straight lines and rarely visual hallucinations in advanced cases of geographic atrophy.

Risk Factors

Age – the prevalence is about 10% of patients age 60-69, 20% of patients age 70-79, 30% of patients age 80-89 and 40-50% of patients age 90 and older.

Race – ARMD more commonly affects patients with lighter complexion (Caucasians), but can be seen in patients regardless of their skin complexion.

Genetics – Patients with a family history of ARMD have a higher risk of developing the disease.

Smoking – Patients who smoke have a 2 - 3 times increased risk of developing ARMD.

Vascular Disease, Hypercholesterolemia & Hypertension – Patients with peripheral vascular disease, high cholesterol and hypertension who develop hardening of the arteries have a higher risk of developing ARMD.

Diagnostic Testing

Amsler Grid is a checkerboard like grid of vertical and horizontal lines that is used to detect progression of ARMD.  Patients who notice distortion of central or paracentral vertical or horizontal lines should report these changes to their eye doctor immediately.

Optical Coherence Tomography (OCT) is used to evaluate the macular anatomy and to look for drusen, pigment epithelial detachments, geographic atrophy and signs of conversion to Wet ARMD such as subretinal fluid, intraretinal edema and abnormal blood vessel growth.

Fundus Photography (FP) is used to document and assess the stage of ARMD and for comparison to evaluate progression at future exams.

Fluorescein Angiography (FA) is used to evaluate the macular and peripheral circulation.  Many patients with Stage 1-3 Dry ARMD will show evidence of staining of macular drusen and pigment epithelial detachments. Patients with Stage 4 Dry ARMD will show evidence of transmitted hyperfluorescence through areas of GA.

Indocyanine Green Angiography (ICG) is typically not used in patients with Dry ARMD.  ICG is used when a patient presents with a large submacular (subretinal) hemorrhage or pigment epithelial detachment (PED) and is suspected of having Wet ARMD.

Treatment

The treatment of Dry ARMD depends on the stage of the disease.  
Stage 1 – Daily multivitamin (i.e. Centrum Silver) with Lutein, sunglass use whenever outdoors , diet rich in dark green leafy vegetables (kale, spinach, collard greens, broccoli, etc.), dark meat fish (salmon, tuna, sardines, mackerel, etc.), and no smoking or tobacco use
Stage 2 – Same as stage 1
Stage 3 – Same as stage 1 & 2 with the addition of AREDS 2 formula vitamins
Stage 4 – Same as stage 3

AREDS 2 Vitamins contain Vitamin C (500 mg), Vitamin E (400 IU), Zinc (80 mg), Copper (2 mg), Lutein (10 mg), Zeaxanthin (2 mg)
AREDS 2 formula vitamins (in addition of a daily multivitamin like Centrum Silver with Lutein) has been shown to decrease the  risk of progression to Wet ARMD by 25%.

Research Trials

There is currently no FDA approved treatment that is effective at reducing the rate of progression of enlargement of geographic atrophy in Stage 4 Dry ARMD.

Retina Center of New Jersey, LLC is currently participating in the CHROMA clinical trial sponsored by Genentech using a drug called Lampalizumab that may slow the progression of geographic atrophy in these patients.

Lampalizumab is a drug that affects the alternative complement pathway (factor D inhibitor) that may slow the progression of cell death at the edges of geographic atrophy.

For additional information regarding the criteria for participating in this clinical trial, please click on the following link: https://clinicaltrials.gov/ct2/results?term=CHROMA&Search;=Search

Patients interested in participating in this clinical trial should contact our Research Department for more information:

Diane Deininger (Clinical Research Director), ddeininger@retinacenternj.com
Susan Anderson (Clinical Research Manager), sanderson@retinacenternj.com
Valerie Benavides (Clinical Research Coordinator), vbenavides@retinacenternj.com
Kathleen Rodriguez, Clinical Research Coordinator, krodriguez@retinacenternj.com
They can both be reached via phone at 973-707-5632

*Please note that this information is for illustrative purposes only, providing a general overview on the topics listed. For any specific questions or concerns regarding your condition, please contact our office so that you can consult with the appropriate person or department to address your needs.