Binocular Fixation Reduces Fixational Eye Movements in the Worst Eye of Patients with Center-Involving Diabetic Macular Edema

Abstract

Purpose: Treatment of diabetic maculopathy with vascular endothelial growth factor inhibitors is in some patients ineffective, and, therefore, parameters predicting visual outcome after treatment should be identified. It has been shown that fixational saccades are increased in patients with reduced visual acuity secondary to diabetic maculopathy, but it is unknown to what extent these saccades in an eye affected by diabetic maculopathy are influenced by the other eye during binocular fixation. Methods: In 57 eyes from 29 diabetic patients with clinically significant macular edema, fixational eye movements were recorded using the iView X™ video-based eye tracker, and quantitative measures of fixation with the worst eye obtained during monocular and binocular fixation were compared. Results: Fixational saccades during monocular fixation had a significantly higher frequency (p = 0.005), a larger amplitude (p = 0.03), and involved a larger retinal area (p = 0.02) than during binocular fixation. There was a significant negative correlation (r² = 0.18, p = 0.02) between visual acuity and the area of fixation during monocular but not during binocular fixation (r² = 0.007, p = 0.68). Conclusion: Binocular fixation can reduce the area of fixation and the amplitude of fixational saccades in the worst eye of patients with diabetic maculopathy. Fixational saccades in diabetic maculopathy should be studied during monocular fixation.

The area of fixation covaries with short‐term changes in visual acuity after anti‐vascular endothelial growth factor treatment in patients with diabetic macular oedema

“…Subsequently, the data were processed as described by Jakobsen et al (2017). Subsequently, the data were processed as described by Jakobsen et al (2017).…”

“…Subsequently, the data were processed as described by Jakobsen et al (2017). In each patient, the fixation area was described by the bivariate contour ellipse area which represents 68% of the area that includes identified fixation points (Steinman 1965), the total number of saccades calculated from the area under the curve describing the number of saccades as a function of median saccade amplitude assessed in 0.2 degrees intervals, and the most frequently represented amplitude among these saccades (Jakobsen et al 2017;. In each patient, the fixation area was described by the bivariate contour ellipse area which represents 68% of the area that includes identified fixation points (Steinman 1965), the total number of saccades calculated from the area under the curve describing the number of saccades as a function of median saccade amplitude assessed in 0.2 degrees intervals, and the most frequently represented amplitude among these saccades (Jakobsen et al 2017;.…”

“…During the untreated period after the third injection, the functional and anatomical parameters worsened, which increased the focus on followup routines in the clinic to ensure that the patients were offered more frequent injections and other relevant treatment options such as laser photocoagulation (Lang et al 2017) during that period. The validity of these measurements was increased by only considering data from monocular fixation which ensured that the masking of unstable fixation by the better eye could be avoided (Jakobsen et al 2017). The validity of these measurements was increased by only considering data from monocular fixation which ensured that the masking of unstable fixation by the better eye could be avoided (Jakobsen et al 2017).…”

“…The equipment and the practical procedure are described in details in (Jakobsen et al 2017). The video-based eye tracking system iView X TM High Speed, version 2.7.09 (Senso Motoric Instruments, Berlin, Germany), was used for the examinations.…”

“…Each examination of fixational eye movements consisted of a calibration procedure where the patient fixated targets with a predefined location, followed by eight sessions (duplicate recordings during monocular and binocular fixation) with the recording of fixational eye movements, each lasting 40 seconds, during fixation of a target in the centre of the computer monitor (Jakobsen et al 2017). Data were obtained from the duplicate recordings which were therefore pooled for the analysis.…”