Table 1. Primary outcomes in geographic atrophy randomised controlled trials.

Primary outcomea	Number of outcomes for GA RCTs	Examples of outcome description
Visual acuity	6	ETDRS change in BCVA at 12 months, change in BCVA at 24 months, increase in VA at week 4, loss of 3 or more lines of VA
Lesion area	6	Change in the total GA area from baseline to 24 months, rate of change in area of GA from baseline, rate of enlargement in area of GA in the study eye during the treatment period, annualised lesion growth rates
Autofluorescence	5	The mean reduction in the rate of growth of GA area, growth of GA lesions from baseline to month 6, change in area of atrophy from baseline to week 48
Biomarkers	4	Plasma xanthophyll concentration, fatty acids profile, reological markers
Adverse and safety outcomes	2	Number of eyes with serious ocular adverse events occurring over the first 12 months of the study, time between baseline treatment and need to escape to standard of care
Electroretinogram	1	Demonstration of the short-term multifocal electroretinogram effect
Fundus photography	1	Rate of change in area of GA at 2 years compared with baseline

Abbreviations: BCVA, best corrected visual acuity; ETDRS, The Early Treatment Diabetic Retinopathy Study Eye Charts; GA, geographic atrophy; RCT, randomised controlled trial; VA, visual acuity.

^aNumber of RCTs does not have to be the same as number of primary outcomes as each RCT may have multiple primary outcomes.