Little 1995.

Methods	Method of allocation: after participants eligibility was ascertained and participant consent was obtained, 1 eye was randomised to photocoagulation treatment; the right eye was assigned to treatment if participant's birth date was an odd month, the left if it was an even month Masking: participant: unclear; provider: unclear; outcome assessor: unclear Exclusions after randomisation: none reported Losses to follow‐up: a minimum 1‐year follow‐up was obtained (mean 3.2 years) Unusual study design: paired study
Participants	Country: US Number randomised: 27 participants (54 eyes) Age: mean 69.7 years Sex: 9 men/18 women Inclusion criteria: symmetrical drusen; minimum drusen size 100 μm; at least 20 drusen or 10 drusen + 2 drusen at least 500 μm in diameter; drusen within 500 μm from foveola; VA at least 20/60 Exclusion criteria: PED; atrophy; subretinal fluid, haemorrhage, exudate; any other eye disorder which could affect VA
Interventions	Treatment: 577‐ to 620‐nm wavelength laser with 100‐200 μm spot size, 0.05‐0.1 seconds' duration, 100‐200 power. Direct treatment of the drusen Control: observation Duration: 1‐ to 6‐year follow‐up
Outcomes	Snellen VA; colour vision (Farnsworth panel D‐15  colour‐test); central visual field with Humphrey 10‐2
Notes	No COI for any author
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	After participants eligibility was ascertained and participant consent was obtained, 1 eye was randomised to photocoagulation treatment; the right eye was assigned to treatment if person's birth date was an odd month, the left if it was an even month
Allocation concealment (selection bias)	High risk	See above, the enrolling researcher could have foreseen which eye would have been treated. Nonetheless, this can be irrelevant since both eyes of each participant were included, i.e. there was no risk of confounding
Blinding (performance bias and detection bias) Development of CNV/geographic atrophy	Low risk	Unmasked study, but CNV occurrence was sufficiently objective as a diagnosis to be considered unbiased
Blinding (performance bias and detection bias) Measurement of vision	High risk	Not reported. Participants could not be masked since no sham procedure was mentioned
Incomplete outcome data (attrition bias) All outcomes	Low risk	Unclear: only last visit data reported, thus being impossible to reconstruct the pattern of missing data; 4/27 participants were followed for ≥ 1 year but < 2 years. However, in the updated version of this review, we considered missing data as no risk of bias in bilateral studies because a participant with paired treatment and control eyes is missed
Selective reporting (reporting bias)	Low risk	Development of CNV and atrophy, as well as loss of ≥ 3 lines of VA were well defined and relevant outcomes
Other bias	Unclear risk	Unclear