Study	Reason for exclusion
Allan 2007	Non‐randomised comparative studies comparing EK versus PK
Bahar 2008	Non‐randomised comparative studies comparing EK versus PK
Bohringer 2006	Retrospective questionnaire
Chen 2008	Retrospective case series
Das 2006	Retrospective case series
Dobbins 2000	Retrospective case series
Droutsas 2010	Non‐randomised prospective clinical trial
Erdumus 2009	Retrospective case series
Foster 2011	Retrospective study
Graupner 2000	Prospective case series
Ham 2009	Prospective case series
Heidemann 2008	Non‐randomised comparative studies comparing EK versus PK
Hjortdal 2009	Non‐randomised comparative studies comparing EK versus PK
Langenbucher 2000	Retrospective case series
Langenbucher 2002	Prospective case series
Langenbucher 2003	Retrospective case series
Lee JS 2009	Retrospective case series
Nguyen 2002	Prospective case series
Nguyen 2004	Prospective case series
Nguyen 2009	Retrospective case series
Pineros 1996b	Retrospective case series
Polack 1988	Retrospective case series
Price FW August 1991	Retrospective case series
Price FW March 1991	Retrospective consecutive case series
Price MO 2011	Retrospective, interventional case series
Price MO December 2009	Prospective, multicenter, consecutive case series
Price MO March 2009	Retrospective case series
Price MO March 2010	Non‐randomised comparative studies comparing EK versus PK
Price MO May 2010	Retrospective, interventional case series
Reinhard 2002	Retrospective case series
Seitz 1999	Prospective RCT of manual versus laser trephination in PKP
Seitz 2002	Prospective RCT of laser versus mechanical trephination in PKP
Seitz 2003	Prospective non‐randomised comparative case series of two suture techniques
Seitz January 2001	Prospective RCT of manual versus laser trephination in PKP
Seitz November 2001	Prospective RCT of manual versus laser trephination in PKP
Terry 2005	Prospective case series
Terry 2006	Retrospective review of consecutive case series
Terry 2009	Prospective case series
Thompson 2003	Retrospective non‐comparative case series