Effects of dipivefrin and pilocarpine on pupil diameter, automated perimetry and LogMAR acuity

Background: A study was carried out to ascertain, in ophthalmologically nor mal subjects, the short-term effects of dipivefrin hydrochloride 0.1% on vi sual performance and make comparisons with pilocarpine. Methods: Twelve nor mal volunteers aged 20-26 years attended on three occasions. One eye, rando mly selected, received one drop of either pilocarpine 2%, dipivefrin or sal ine 0.9%. High- and low-contrast LogMAR acuity at 6 m and pupil diameter (m easured by infra-red pupillometry) were recorded at baseline (TO) and at in tervals up to 90 min following instillation of drops. Program 30-2 of the H umphrey Visual Field Analyzer (HFA) was run at TO and at 60 min after treat ment instillation (T60). Saline was always instilled at visit 1, to allow f or learning effects. On visits 2 and 3 either pilocarpine or dipivefrin was randomly instilled into the treated eye. Results: Pilocarpine significantl y worsened the field global indices mean deviation (P<0.001) and pattern st andard deviation (P<0.01) compared with TO. There was no significant change with dipivefrin. A significant (P=0.01) pupil dilation from 5.44 mm (SD 0. 79) at T0 to 6.19 mm (SD 1.09) at T90 occurred with dipivefrin. Pilocarpine caused significant miosis. No significant changes in LogMAR values were fo und with dipivefrin. Pilocarpine significantly (P<0.01) increased LogMAR va lues (i.e. reduced acuity) compared with dipivefrin. At T30 the mean increa se in LogMAR was 0.76 (SD 0.30) for high and 0.83 (SD 0.11) for low contras t. By T90 recovery of acuity was virtually complete. Conclusions: in normal s dipivefrin causes mydriasis but does not affect the central visual field global indices (as assessed by STATPAC), or high-and low-contrast LogMAR ac uity. Pilocarpine adversely affects the visual field and both measures of a cuity. Knowledge of these effects is of value in glaucoma therapy and when monitoring the progression of visual loss.