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EYE EYE CARE AND
EYE CARE ANDCARE AND
QUALITY OF LIFE QUALITY OF LIFE
QUALITY OF LIFE

factor are one of the most common procedures performed in the retina
clinic. These injections result in maintenance of vision for millions of
patients who would otherwise become legally blind.
The understanding that the complement pathway plays a role in
the development of age-related macular degeneration has also led to
revolutionary changes in the care of patients. In 2023, two medica-
tions were FDA approved for the treatment of dry AMD. Patients
with “dry” or atrophic AMD may or may not develop neovasculariza-
tion (Figure 3). However, they have progressive loss of the outer retina
and RPE cells. This produces dense scotomas or blind spots. Today,
patients with the atrophic form receive intravitreal injections to help
preserve the retina and preserve visual function, such as reading, driv-
ing and recognizing faces. Inhibitors of complement C3 and C5 have Figure 2. Neovascular AMD demonstrating choroidal
proven to slow the growth rate of these atrophic lesions. neovascularization with subretinal and intraretinal
The future is becoming even brighter for patients with age-related hemorrhage. (Brown, Jeremiah. All About Macular
macular degeneration. Current therapies enable a longer duration of Degeneration, AMD Association Meeting Houston, Texas,
June 10, 2023.)
effect, reducing the number of injections required to maintain vision.
Gene therapy is a promising strategy to enable the retina to produce a
Revolutionary Changes in Treatment protein inhibitor of vascular endothelial growth factor. This strategy
may allow patients to go a year or more between injections compared
of Age-Related Macular Degeneration to the five to six weeks required for many patients currently. Gene
therapy may also prove to be an effective strategy for patients with the
atrophic form of AMD, once again, reducing the number of injections
required to maintain vision. Other strategies in clinical trials today
By Jeremiah Brown, Jr., MS, MD
strive to reduce inflammation in the retina via other pathways with the
goal of greater efficacy, and hopefully fewer injections.
evolutionary events are happening in the treatment of age-re- Approximately one in seven patients with macular degeneration Age-related macular degeneration is a fascinating, scientifically
lated macular degeneration (AMD). Despite being the leading develops the exudative form of AMD. In these patients, neovascular challenging and impactful disease. This area of research is one of my
Rcause of blindness in patients over age 60, significant advances tissue grows from the choroid into the retina, causing exudation, intra- passions, and it is so rewarding to see the effects of years of research
have occurred, leading to many additional years of useful functional retinal edema and subretinal fluid (Figure 2). The neovascular tissue reaching the clinic and preserving patients’ vision.
vision for our patients. and surrounding edema produce blurred vision, distorted vision and Figure 3. Atrophic dry AMD. This image demonstrates
Age-related macular degeneration is a multifactorial degenerative ultimately, blind spots. Unfortunately, this exudation usually develops atrophy involving the foveal center. Numerous yellow
disease of the retina. Approximately 70 percent of the risk of devel- in the macula, resulting in loss of the most precious area of detailed drusen are also noted. Courtesy of Dr. Jeremiah Brown.
oping macular degeneration is genetic. Environmental factors such as central vision in our patients. Massive hemorrhages can also occur, subretinal
smoking, diet and UV light exposure also play a role. Lastly, the inci- resulting in abrupt severe vision loss. drusenoid
dence of macular degeneration increases with age. In the early stages For many years, it was suspected that macular degeneration had deposits
of this condition, small extracellular deposits called drusen build up a genetic component. However, this was difficult to prove as most
at the level of the retinal pigmented epithelial cells (RPE) and Bruch’s patients’ parents were no longer living and their children were too young
membrane beneath the neurosensory retina. As time progresses, these to demonstrate phenotypic features of AMD. In the late 1990s, dramatic
deposits, along with chronic inflammation and oxidative stress, cause discoveries of activated complement fragments within drusen deposits
degeneration of the overlying photoreceptors, the light sensing cells in helped to refine the search for genetic causes. In 2006, several groups
the retina and RPE (Figure 1). This slow gradual degeneration caus- simultaneously identified complement factor H as the locus conveying
es distortion and gaps in an affected patient’s vision. Eventually blind the most risk for developing age-related macular degeneration. Since
spots may develop and visual acuity can be reduced to as low as count- that time, numerous other genes in the complement pathway have been
ing fingers, meaning that patients are unable to read any letters on the implicated, and have been proven to add additional risk or convey bene- Figure 1. Signs of intermediate Dr. Jeremiah Brown is a graduate of Harvard University. A U.S.
vision chart and can only count fingers held in front of them. fit to the development of age-related macular degeneration. AMD with drusen and subretinal Army veteran, Dr. Brown served as director of ophthalmology
Nutritional supplements were demonstrated in two large clinical Another revolutionary finding was understanding that vascular deposits. Fleckenstein M, Keenan research at the U.S. Army’s Laser Research Laboratory at Brooks
trials to have a beneficial effect in reducing the rate of progression to endothelial growth factor played a role in the development of choroidal TDL, Guymer RH, Chakravarthy Air Force Base, a division of the Walter Reed Army Institute of
advanced stages of macular degeneration. These supplements contain neovascularization. Dramatic clinical trials in the early 2000s demon- U, Schmitz-Valckenberg S, Research. He has co-authored more than 25 peer-reviewed articles in
vitamin C, vitamin E, zeaxanthin and zinc with supplemental copper. strated that with an antibody-derived inhibitor of vascular endothelial Klaver CC, Wong WT, Chew ophthalmology research as well as textbook chapters. He is a frequent
Epidemiologic surveys have also confirmed that a diet with green leafy growth factor, the abnormal vessels could be regressed and visual acuity EY. Age-related macular lecturer to ophthalmology residents as well as practicing ophthalmologists.
degeneration. Nat Rev Dis
vegetables such as spinach and kale, as well as oily fish such as salmon could be improved. Prior to this discovery, there had been no therapy Primers. 2021 May 6;7(1):31. Dr. Brown practices vitreoretinal diseases in San Antonio and Schertz,
and tuna, at least one to two times per week, also have a beneficial that could actually improve vision for patients with neovascular AMD. doi: 10.1038/s41572-021- and is a member of Retina Consultants of Texas and the Bexar County
effect in slowing progression. Today, intravitreal injections of inhibitors of vascular endothelial growth 00265-2. PMID: 33958600 Medical Society.

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