Progression, reliability, predicting parameters and sample size calculations for quantitative fundus autofluorescence...

Area of Science:

• Ophthalmology
• Medical Imaging
• Genetics

Background:

• ABCA4-related retinopathy is a genetic disorder affecting vision.
• Quantitative autofluorescence (qAF) measures disease progression.
• The potential of qAF as a clinical trial endpoint requires investigation.

Purpose of the Study:

• To investigate the progression of quantitative autofluorescence (qAF) measures in ABCA4-related retinopathy.
• To assess the suitability of qAF as a clinical trial endpoint for this condition.

Main Methods:

• A longitudinal study involving 64 patients with ABCA4-related retinopathy and 110 healthy controls.
• Serial retinal imaging using optical coherence tomography (OCT) and qAF imaging.
• Analysis of qAF retest variability, changes over time, and association with genotype and phenotype.

Main Results:

• Patients with ABCA4-related retinopathy exhibited significantly elevated qAF levels compared to controls.
• qAF values increased in younger patients and those with milder disease/mutations, while decreasing in advanced stages.
• Test-retest reliability showed a 95% coefficient of repeatability of 20.37.

Conclusions:

• Standardized qAF imaging is reliable and suitable for quantifying disease progression in ABCA4-related retinopathy.
• qAF may serve as a potential clinical surrogate marker.
• Optimized trial designs incorporating baseline characteristics and genotype can reduce cohort size and visits.