It is tempting to call prostaglandin analogues (PGAs) ‘the new kids on the block’, however, that would be inaccurate, as they have been available since the mid-1990s. PGAs may well be the medication of ‘first-choice’, but not necessarily ‘first-line’ for initial treatment of POAG/COAG. In contrast to beta-blockers, which reduce the production of aqueous humour, PGAs lower IOP by increasing outflow and have generic names ending in ‘prost’ such as Latanoprost or Travoprost.
PGAs are generally as effective as beta-blockers, normally dosing only in the evening (although morning dosing is equally effective), and they are normally well tolerated with fewer systemic side-effects.
However, as with all drugs, there are potential side-effects and these are more localised to the eye: eye stinging, conjunctival hyperaemia (hence the preference for evening administration, the eye is red while asleep, whiter during the day), increased lash length, thickness and darkening of lashes (versions of these drugs are sold abroad purely for this side-effect), and irreversible iris colour darkening. In predisposed individuals with a history of anterior uveitis or certain corneal diseases or specific patients who are now aphakic or have had a post-cataract surgery lens implant, side effects can occur.