Evaluating the Relationship Between Function and Structure Using Data From a GA Natural History Cohort

This is a monocentric, retrospective observational study designed to evaluate the relationship between visual function and retinal anatomical features in a population with geographic atrophy (GA) secondary to dry age-related macular degeneration.

The study will analyze a natural history cohort identified from previously collected clinical and imaging data obtained during routine care at IRCCS Ospedale San Raffaele. Eligible eyes meet predefined inclusion and exclusion criteria consistent with those used in recent clinical trials, including well-demarcated GA lesions, preserved baseline visual acuity, and the absence of choroidal neovascularization or prior intravitreal treatment.

The primary objective is to estimate the proportion of eyes experiencing a loss of at least 15 ETDRS letters from baseline and to characterize the trajectory of visual acuity decline over time. Secondary objectives include the identification of baseline anatomical features associated with the risk and timing of significant visual loss, such as GA lesion size, foveal involvement, fundus autofluorescence patterns, lesion focality, and outer retinal layer thickness measured on optical coherence tomography.

Exploratory analyses will investigate the relationship between visual function decline and ellipsoid zone integrity metrics, where available, and will apply multivariable and machine learning-based models to explore non-linear associations between anatomical and functional parameters.

As this is a retrospective study, no investigational medicinal products, devices, or study-specific interventions are involved. All analyses are performed on pseudonymized or anonymized data derived from existing medical records and imaging archives. No additional patient contact, visits, or procedures are required.

Inclusion criteria

• Male or female patients aged 50 years or older at baseline.
• Diagnosis of geographic atrophy secondary to dry age-related macular degeneration in the study eye.
• Well-demarcated geographic atrophy lesions confirmed by fundus autofluorescence imaging, with a total lesion area between 2.5 mm² and 17.5 mm².
• Presence of hyperautofluorescence in the junctional zone of the geographic atrophy lesion.
• Best-corrected visual acuity between 45 and 83 ETDRS letters at baseline.
• Availability of longitudinal clinical and imaging data with at least 6 months of follow-up.

Exclusion criteria

• Evidence or history of neovascular (wet) age-related macular degeneration in the study eye.
• Prior intravitreal therapy or systemic treatments specifically targeting age-related macular degeneration.
• Geographic atrophy lesions contiguous with peripapillary atrophy.
• Coexisting ocular diseases that could independently affect visual acuity or retinal structure.
• Incomplete or poor-quality clinical or imaging data precluding reliable assessment of study outcomes.