Study	Reason for exclusion
Ahmadieh 1999	Bilateral surgery in 14 of 45 eyes. No data are available in the article as to what treatment the bilateral cataracts received and their particular outcomes. Written correspondence attempted.
Basti 1996	No randomisation. Cannot infer results for bilateral cataracts.
Basti 1999	Comparing intra‐ocular lens types. All participants had same surgery.
Bayramlar 2004	Not randomised. All were bilateral cataracts. All right eyes had heparin in irrigation fluid while left eyes did not.
Hoyt 1982	No randomisation. Obvious selection and outcome bias.
Kugelburg 2005	Cannot distinguish unilateral from bilateral cases. No visual acuity data.
Ram 2003	Randomisation either insufficient or unclear.
Saini 2003	Randomisation insufficient. The outcome data do not include information on vision improvement and we cannot tell whether the cataracts were bilateral.
Thouvenin 1995	Retrospective study (author correspondence).
Vasavada 1997	No randomisation. Cannot extract data on the two pairs of bilateral cataracts.
Vasavada 2000	Well designed study. Failed or reversed optic capture cases were added to the no capture group. They were not analysed on an intention‐to‐treat basis.
Vasavada 2003	Well‐designed study but the outcome data (duration of lens aspiration in seconds and volume of aspiration fluid used) are not included as a significant outcome.