Tip of the Month
Publishing date: February 2014
Tip Editors: John Salmon and Gordana Sunaric Mégevand
Tip reviewer: Roger Hitchings
The Science behind the Tip
To determine change in visual function in patients with glaucoma, regular visual field testing is undertaken using automated static perimetry. When interpreting the visual field results the effect of refractive error (particularly uncorrected hyperopia) and cataract formation should be considered, as these factors can result in a change in threshold measurements (1,2).
A recent study has shown that the use of multifocal implants can cause a diffuse change in the visual field of approximately - 2dB, which is not found when standard implants are used. Patients with glaucoma who undergo phacoemulsification and multifocal IOL implantation should undergo perimetry soon after surgery in order to establish new base-line measurements (3).
Contributor: John Salmon, Oxford
1. Weinreb RN, Perlman JP. The effect of refractive correction on automated perimetric thresholds. Am J Ophthalmol 1986; 101 (6) 706-709.
2. Chen PP, Budenz DL. The effects of cataract extraction on the visual field of eyes with chronic open-angle glaucoma. Am J Ophthalmol 1998; 125 (3) 325-333.
3. Aychoua N, Junoy Montolio FG, Jasonius NM. JAMA ophthalmology 2013; 131: 481-485