The goal of this observational study is to evaluate changes in retinal sensitivity over time in patients with geographic atrophy due to age related macular degeneration who are receiving pegcetacoplan as part of routine clinical care. The study aims to determine whether lesion tailored fundus-controlled perimetry can reliably measure functional changes near areas of atrophy and whether this testing can be implemented in everyday clinic care over 24 months. Participants will undergo repeated vision testing, standard eye imaging, and visual function questionnaires while continuing their prescribed treatment.

The study will prospectively recruit patients from the Retina Clinics at the John A. Moran Eye Center and its satellite clinics.

All team members will be trained and certified for their specific tasks to ensure that uniform procedures are followed in order to obtain comparable and reliable data.

The following study procedures will be performed after informed consent has been obtained (in chronologic order):

• Assessment of past and current ophthalmic history, and demographic details

• Best-corrected visual acuity (BCVA) for both eyes measured by Early Treatment Diabetic Retinopathy Study (ETDRS) or Snellen charts (performed at Visit [V]1, V2, V4 and V6)

• Fundus-controlled perimetry (FCP)

  • Training Test (performed at V1, V2, V3, V4, V5, V6)
  • Fixes macula pattern (performed at V1 and V6)
  • Patient-tailored pattern (performed at V2 [twice for test - re-test assessment], V3, V4, V5, V6)

• Vision Impairment in Low Luminance with 33 items (VILL-33), a 33-item questionnaire (performed at V2, V4, and V6)

• Fundus autofluorescence (FAF), near infrared (NIR) and simultaneous spectral domain optical coherence tomography (SD-OCT) imaging (performed at V1, V4 and V6)

• Color digital fundus photographs (optional at visits V1, V4, and V6)

• OCT-angiography (OCT-A) imaging (optional at visits V1, V4 and V6)

Data to be obtained and analyzed will include each participant's medical and ophthalmic history, current medications, smoking history, body mass index (BMI), and demographic information. Additional research data will include records of any adverse events, functional testing results such as best-corrected visual acuity (BCVA) and fundus-controlled perimetry (FCP), and digital imaging data including color fundus photographs, fundus autofluorescence (FAF) images, near-infrared reflectance (NIR) images, optical coherence tomography (OCT) images, and optical coherence tomography angiography (OCT-A) images.

Study data and documentation will be monitored throughout the study to ensure accuracy, completeness, and compliance with the approved protocol, Good Clinical Practice (GCP) standards, and institutional policies. Monitoring procedures will include periodic review of informed consent documentation and verification that data recorded in study forms and electronic databases are consistent with source documents.

Data management and analysis will be conducted by the Utah Retinal Reading Center (UREAD). UREAD will develop comprehensive study-specific documentation, including a Data Management Manual and a Grading Manual, which will outline standardized protocols for data processing, grading procedures, and quality assurance.

Prior to initiating formal data analysis, all image graders will undergo standardized training and certification using curated training datasets. Each imaging dataset will be independently evaluated by two certified readers to ensure objectivity. In cases of disagreement, a senior grader will perform an arbitration review to determine the final grading outcome.

At the screening visit (V1), structural inclusion and exclusion criteria will be assessed to determine patient eligibility. The Reading Center will provide three types of FCP testing patterns in Extensible Markup Language (XML) format: Training Pattern; Fixed Central Macula Pattern; and a Patient-Tailored Pattern.

All imaging and test data will be securely transferred from the study site to UREAD for centralized grading and analysis. Quality control procedures will be implemented throughout the study to ensure data integrity and consistency.

Inclusion Criteria:

• Age 65-90 years.

• Geographic Atrophy (GA) secondary to dry Age-related Macular Degeneration (AMD) in at least one eye with the following criteria:

  • GA lesion size between 1 and 15 mm² (≈ 0.4 to 6 disc areas)
  • GA borders must be at least 500 μm from the edge of the 30° × 25° optical coherence tomography (OCT) image frame
  • No confluent GA extending into peripapillary atrophy

• Receiving intravitreal pegcetacoplan per label (at least one injection before screening).

• Best-corrected visual acuity (BCVA) of 0.1 - 1.0 logMAR (≈ 20/20 to 20/200 Snellen)

• Able to undergo mesopic FCP and required imaging.

• Informed consent provided.

Exclusion Criteria:

• Currently or previously active exudative macular neovascularization in the study eye.
• High refractive errors (> ±5.00 Diopters [D] spherical equivalent) and significant astigmatism (> 2.50 D).
• Ocular comorbidities likely to confound sensitivity or imaging (e.g., diabetic retinopathy with macular edema, retinal vein occlusion (RVO), inherited retinal disease, uncontrolled glaucoma).
• Media opacity precluding reliable fundus-controlled perimetry (FCP) or imaging (e.g., dense cataract, corneal opacity, vitreous hemorrhage).
• Any systemic condition judged likely to compromise participation, follow-up, or data integrity.

Patients with Geographic Atrophy (GA) secondary to Age-related Macular Degeneration (AMD) in at least one eye will be included who already receive pegcetacoplan intravitreally according to the approved label as part of their routine clinical care. The study does not assign treatment prospectively; pegcetacoplan is prescribed and administered as part of routine clinical care at the discretion of the treating physician.

This is a collaborative project with Apellis Pharmaceuticals. The data sharing is regulated in the Research Collaboration Agreement.