Clinical and Experimental Optometry 88.2 March 2005 73 Recent developments in perimetry McKendrick OPTOMETRY C L I N I C A L A N D E X P E R I M E N T A L Clin Exp Optom 2005; 88: 2: 73–80 Automated perimetry is used extensively for the assessment of visual function for health and disease. The power and affordability of modern computer technol- ogy have enabled the development of many new visual field tests in recent years. New test stimulus types and new algo- rithms for determining threshold values have been proposed. The overriding aim of these purported advances is to develop tests that are accurate and repeatable, while still being clinically efficient, and that provide results that accurately reflect underlying degrees of neural damage. This review describes recent perimetric developments that are commercially avail- able, and introduces some tasks that have potential to become clinically valuable in the future. Some of the historical frame- work underpinning the development of Recent developments in perimetry: test stimuli and procedures INVITED REVIEW Allison M McKendrick MScOptom PhD School of Psychology, University of Western Australia Automated perimetry has evolved substantially in recent years, in part due to modern computer technology that enables more complex visual stimuli and test procedures to be realised than those incorporated in traditional white-on-white luminance increment perimetry. This paper reviews briefly a number of advances in automated perimetry. The review includes discussion of new test types: frequency doubling technology perimetry, short wavelength automated perimetry, flicker perimetry, high-pass resolu- tion perimetry and rarebit perimetry. Test algorithms applied to perimetry such as zippy estimation of sequential thresholds (ZEST), Swedish interactive thresholding algorithm (SITA), tendency-oriented perimetry (TOP) and multi-sampling supra-threshold perimetry are also discussed. Key words: automated perimetry, glaucoma, visual fields Submitted: 11 November 2004 Revised: 9 February 2005 Accepted for publication: 10 February 2005 these tests is discussed, in an attempt to provide the perspective from which these tests have been developed and from which future developments may arise. The scope of this review is subjective perimetry, that is, perimetry in which the patients are required to make an active response regarding whether or not they see the test stimulus. WHY SEARCH FOR IMPROVEMENTS TO TRADITIONAL AUTOMATED WHITE-ON-WHITE PERIMETRY? The ideal perimetric test should be accu- rate, repeatable, efficient and reflect the extent of underlying neural damage. The first automated perimeters tested sensitiv- ity to luminance increments presented on white backgrounds (white-on-white perimetry). White-on-white perimetry is still the most common form of perimetry in a clinical setting and is utilised in most large clinical trials that have a visual field assess- ment component. 1,2 Unfortunately, white- on-white perimetry has been shown to be far from the ideal perimetric test. White- on-white perimetry performed with popu- lar test strategies, such as staircases or the Swedish interactive thresholding algorithm (SITA), has poor test-retest variability, par- ticularly in areas of visual field loss. 3-5 High levels of variability hamper the ability to determine whether visual field damage is worsening. 6 Furthermore, histological stud- ies demonstrate that retinal ganglion cell loss can be very high (25 to 50 per cent) prior to even mild deficits being revealed on standard white-on-white perimetry, 7-10 indicating that deficits on white-on-white perimetry do not adequately represent the extent of neural damage.