Research Article The Effect of Cataract on Eye Movement Perimetry G. Thepass, 1,2,3 J. J. M. Pel, 1 K. A. Vermeer, 2 O. Creten, 3 S. R. Bryan, 2,4 H. G. Lemij, 2,3 and J. van der Steen 1,5 1 Vestibular and Ocular Motor Research Group, Department of Neuroscience, Erasmus MC, P.O. Box 2040, 3000 CA Rotterdam, Netherlands 2 Rotterdam Ophthalmic Institute, P.O. Box 70030, 3000 LM Rotterdam, Netherlands 3 Rotterdam Eye Hospital, P.O. Box 70030, 3000 LM Rotterdam, Netherlands 4 Department of Biostatistics, Erasmus MC, P.O. Box 2040, 3000 CA Rotterdam, Netherlands 5 Royal Dutch Visio, P.O. Box 1180, 1270 BD Huizen, Netherlands Correspondence should be addressed to G. epass; g.thepass@oogziekenhuis.nl Received 16 February 2015; Revised 28 April 2015; Accepted 1 May 2015 Academic Editor: Lisa Toto Copyright © 2015 G. epass et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Purpose. To determine how different grades of cataract affect sensitivity threshold and saccadic reaction time (SRT) in eye movement perimetry (EMP). Methods. In EMP, the visual field is tested by assessing the saccades that a subject makes towards peripheral stimuli using an eye tracker. Forty-eight cataract patients underwent pre- and postoperative EMP examination in both eyes. e subjects had to fix a central stimulus presented on the eye tracker monitor and to look at any detected peripheral stimulus upon its appearance. A multilevel mixed model was used to determine the factors that affected the sensitivity threshold and the SRT as a function of cataract grade. Results. We found no effect of cataract severity (LOCS III grades I through IV) on SRT and the sensitivity thresholds. In cataract of LOCS III grade V, however, we found an increase by 27% and 21% ( < 0.001), respectively, compared to the SRT and the sensitivity threshold in LOCS III grade I. Eyes that underwent cataract surgery showed no change in mean SRTs and sensitivity thresholds aſter surgery in LOCS III grade IV and lower. Conclusion. e present study shows that EMP can be readily used in patients with cataract with LOCS III grade IV and below. 1. Introduction Standard automated perimetry (SAP) has become the stan- dard of care in assessing visual fields. Both clinicians and patients agree that better and less demanding tests are desir- able [1]. We recently developed an eye movement perimetry (EMP) test that uses an eye tracking system [2]. EMP takes advantage of the natural reflex to direct our gaze with a saccadic eye movement towards a visual stimulus that appears in our peripheral visual field [3, 4]. Such saccadic responses are relatively uncontaminated by the subject’s uncertainty resulting from task instructions, as saccades are in practice performed with little awareness by the subject. Monitoring of this saccade with an eye tracker offers the objective registration of stimulus detection and the possibility to determine additional parameters. One such parameter is the saccadic reaction time (SRT) [5]. e SRT depends on many factors, such as stimulus intensity, diameter, and eccentricity [2, 6–8]. SRTs in visual field testing show little variability at various locations in a 30-degree visual field [2, 9]. In glaucoma, a disorder that progressively affects the retinal ganglion cells and their axons, an increasingly larger area of the visual field becomes irreversibly damaged [10]. is change in visual field integrity is most commonly tested with SAP, which tests retinal sensitivity thresholds in predefined locations. EMP provides a quantitative measure of visual field responsiveness and may therefore contribute to the early detection of glaucomatous damage in parts of the retina [11]. Relatively little is known about any confounding factors in EMP. A likely confounding factor is cataract, a condition that is highly prevalent in the elderly population in which also glaucoma is common [12, 13]. If cataract was indeed a significant confounder in EMP, it would limit the clinical use of EMP. All cataract subtypes affect contrast sensitivity Hindawi Publishing Corporation Journal of Ophthalmology Volume 2015, Article ID 425067, 9 pages http://dx.doi.org/10.1155/2015/425067