Healthcare operations · Public research overview
Treatment-interval decisions for geographic atrophy
Clinical background, treatment evidence, and the open question behind visit-by-visit scheduling.
Haibei (Laura) Zhao
Research with Arlen Dean · Olin Business School, Washington University in St. Louis
November 2026
01 · Clinical background
Dry and wet
AMD affects the macula. As the disease advances, an eye can develop geographic atrophy, neovascular AMD, or both.
· Late dry AMD
Retinal tissue is lost in patches. Lesions can enlarge toward the fovea and impair central vision.
Our research starts here: before the first CNV event in the treated eye.
· Wet AMD
Abnormal blood vessels can leak fluid or blood and damage the macula. Anti-VEGF treatment helps control leakage.
Clinical management changes if CNV is detected.
If develops in an eye with GA, the atrophy remains. A scheduling decision can affect when the event is detected.
02 · Treatment evidence
Current treatments
Two U.S.-approved complement inhibitors slow GA lesion growth and have a neovascular safety signal. Pegcetacoplan motivates our interval question.
Pegcetacoplan (Syfovre)
C3 inhibitor. OAKS and DERBY compared monthly and every-other-month dosing from baseline. The U.S. label specifies 25–60 days between doses.
Avacincaptad pegol (Izervay)
C5 inhibitor. GATHER2 found slower lesion growth in year 1. The U.S. label specifies approximately monthly dosing.
The bars summarize separate trial programs and different follow-up periods; they are not a head-to-head comparison. The EMA declined European authorization for Syfovre in 2024, citing uncertainty about functional benefit and safety concerns. EMA assessment ↗
03 · Decision setting
Why choose the next interval at each visit?
For an eye with GA, the selected interval sets the timing of the next examination and, if that examination is negative, the next dose.
GA functional protection
The value of another dose may depend on how much tissue remains at risk and where that tissue is located.
CNV risk and consequences
Treatment-related risk and the time until examination both matter when weighing a shorter against a longer interval.
Conceptual research schematic; it is not an individualized treatment recommendation.
04 · Research gap
The gap in GA interval scheduling
We study complement-inhibitor scheduling for GA before the first CNV event in the treated eye. Existing work informs different parts of this decision.
Scheduling in established nAMD
During anti-VEGF care, DeRoos et al. learn a patient’s maximum safe treatment interval from fluid recurrence by the next visit.
DeRoos et al. · MSTI ↗GA cost-effectiveness
Patel et al. compare fixed monthly and every-other-month regimens using GA-related utility and CNV treatment costs. Cummings Joyner et al. examine an extrafoveal subgroup.
Patel et al. ↗ · Cummings Joyner et al. ↗Spatial GA progression
Vogl et al. estimate local lesion growth and response to pegcetacoplan using spatial features, including distance to the fovea.
Vogl et al. ↗The open decision question
As retinal status and treatment history change, when should the next visit be sooner or later, given the trade-off between GA protection and first-event CNV risk?
05 · Research direction
Dynamic interval decisions for GA
Our goal is to connect the state of tissue that can still be protected with the value of returning sooner.
Choose at each visit
Use the current retinal status and treatment history to choose the next interval, then update the decision as new observations arrive.
Balance benefit and harm
Consider GA-related functional protection alongside treatment-associated CNV risk, its consequences, and the burden of additional visits.
Understand when choices change
Which states favor a shorter or longer return? How much decision loss might arise if treatment-induced CNV risk is ignored?
This public overview presents the clinical motivation and research questions.