Quality of fixation in eyes with neovascular age-related macular degeneration treated with ranibizumab

Eccentric Viewing Training for Age-Related Macular Disease: Results of a Randomized Controlled Trial (the EFFECT Study)

Purpose

Eccentric viewing training for macular disease has been performed for > 40 years, but no large studies including control groups have assessed the benefits of this training. The EFFECT (Eccentric Fixation From Enhanced Clinical Training) study is a large randomized controlled trial of 2 types of eccentric viewing training.

Design

Randomized controlled trial.

Participants

Two hundred adults with age-related macular disease.

Methods

Participants were randomized to either of the following: (1) a control group; (2) a group receiving supervised reading support; (3) a group receiving 3 sessions of training to optimize the use of their own preferred retinal locus; or (4) a group receiving 3 sessions of biofeedback training of a theoretically optimal trained retinal locus. All participants received standard low-vision rehabilitation.

Main Outcome Measures

The primary outcome was patient-reported visual task ability measured on the Activity Inventory instrument at goal level. Secondary outcomes included reading performance and fixation stability.

Results

There was no difference between groups on change in task ability (F(3,174) = 1.48, P = 0.22) or on any of the secondary outcome measures. Visual acuity and contrast sensitivity fell in all groups, suggesting that disease progression outweighed any benefit of training.

Conclusions

Eccentric viewing training did not systematically improve task ability, reading performance, or fixation stability in this study. Our results do not support the routine use of eccentric viewing training for people with progressing age-related macular disease, although this training may help people with end-stage disease. Rehabilitation of an inherently progressive condition is challenging.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Evaluation of Fixational Behavior throughout Life

Background: To quantify development of gaze stability throughout life during short and long fixational tasks using eye tracking technology. Methods: Two hundred and fifty-nine participants aged between 5 months and 77 years were recruited along the study. All participants underwent a complete ophthalmological assessment. Fixational behavior during long and short fixational tasks was analyzed using a DIVE (Device for an Integral Visual Examination), a digital test assisted with eye tracking technology. The participants were divided into ten groups according to their age. Group 1, 0–2 years; group 2, 2–5 years; group 3, 5–10 years; group 4, 10–20 years; group 5, 20–30 years; group 6, 30–40 years; group 7, 40–50 years; group 8, 50–60 years; group 9, 60–70 years; and group 10, over 70 years. Results: Gaze stability, assessed by logBCEA (log-transformed bivariate contour ellipse area), improved with age from 5 months to 30 years (1.27 vs. 0.57 deg² for long fixational task, 0.73 vs. −0.04 deg² for short fixational task), while fixations tend to be longer (1.95 vs. 2.80 msec for long fixational tasks and 0.80 vs. 1.71 msec for short fixational tasks). All fixational outcomes worsened progressively from the fifth decade of life. Log-transformed bivariate contour ellipse area (0.79, 0.83, 0.91, 1.42 deg² for long fixational task and 0.01, 0.18, 0.28, 0.44 deg² for short fixational task, for group 7, 8, 9, and 10 respectively). Stimuli features may influence oculomotor performance, with smaller stimuli providing prolonged fixations. Conclusions: Fixational behavior can be accurately assessed from 5 months of age using a DIVE. We report normative data of gaze stability and duration of fixations for every age group. Currently available technology may increase the accuracy of our visual assessments at any age.

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

PURPOSE

Diabetic maculopathy can be treated with intravitreal injection of vascular endothelial growth factor (VEGF) inhibitors. However, the therapy is not effective in all patients, and it would be desirable to have parameters for differentiating patients who will benefit from treatment from those who will not. Retinal fixation has been shown to be impaired in patients with low visual acuity (VA) secondary to macular disease, but the changes in fixational eye movements after anti-VEGF treatment for diabetic maculopathy have not been investigated.

METHODS

Retinal fixation was studied in 29 patients with diabetic macular oedema before three monthly anti-VEGF injections, and 1 and 4 months after the last injection. The change in VA was correlated with changes in area, frequency, amplitude and total number of fixational saccades.

RESULTS

During three monthly injections, best-corrected visual acuity (BCVA) increased from (mean ± SD) 74.0 ± 11.5 Early Treatment Diabetic Retinopathy Study (ETDRS) letters to 78.3 ± 9.8 ETDRS letters, (p = 0.003) and central retinal thickness (CRT) decreased from (mean ± SD) 441.7 ± 107.0 μm to 339.5 ± 74.2 μm, (p = <0.0001), which was followed by the opposite changes after treatment (BCVA reduced nonsignificantly to 77.5 ± 10.4 ETDRS letters (p = 0.06), and CRT increased to 393.0 ± 9.8 μm, p = <0.0001). Both improvement and worsening of BCVA correlated with the fixation area (r²  = 0.28, p = 0.003 and r²  = 0.14, p = 0.045, respectively), but only improvement of BCVA correlated with the frequency (r²  = 0.15, p = 0.037) and total number of saccades (r²  = 0.18, p = 0.02). BCVA showed no correlation with the amplitude and most frequently occurring saccade amplitude.

CONCLUSION

Fixational eye movements may be used to monitor short-term effects of anti-VEGF treatment on diabetic macular oedema. Future studies should aim at investigating a possible predictive value of fixational eye movements for visual function in the long term.

Repeatability of swept-source optical coherence tomography retinal and choroidal thickness measurements in neovascular age-related macular degeneration

BACKGROUND

The aim was to determine the intrasession repeatability of swept-source optical coherence tomography (SS-OCT)-derived retinal and choroidal thickness measurements in eyes with neovascular age-related macular degeneration (nAMD).

METHODS

A prospective study consisting of patients with active nAMD enrolled in the Distance of Choroid Study at Moorfields Eye Hospital, London. Patients underwent three 12×9 mm macular raster scans using the deep range imaging (DRI) OCT-1 SS-OCT (Topcon) device in a single imaging session. Retinal and choroidal thicknesses were calculated for the ETDRS macular subfields. Repeatability was calculated according to methods described by Bland and Altman.

RESULTS

39 eyes of 39 patients with nAMD were included with a mean (±SD) age of 73.9 (±7.2) years. The mean (±SD) retinal thickness of the central macular subfield was 225.7 μm (±12.4 μm). The repeatability this subfield, expressed as a percentage of the mean central macular subfield thickness, was 23.2%. The percentage repeatability of the other macular subfields ranged from 13.2% to 28.7%. The intrasession coefficient of repeatability of choroidal thickness of the central macular subfield was 57.2 μm with a mean choroidal thickness (±SD) of 181 μm (±15.8 μm).

CONCLUSIONS

This study suggests that a change >23.2% of retinal thickness and 57.2 μm choroidal thickness in the central macular subfield is required to distinguish true clinical change from measurement variability when using the DRI OCT-1 device to manage patients with nAMD.

Decreased fixation stability of the preferred retinal location in juvenile macular degeneration

Macular degeneration is the main cause for diminished visual acuity in the elderly. The juvenile form of macular degeneration has equally detrimental consequences on foveal vision. To compensate for loss of foveal vision most patients with macular degeneration adopt an eccentric preferred retinal location that takes over tasks normally performed by the healthy fovea. It is unclear however, whether the preferred retinal locus also develops properties typical for foveal vision. Here, we investigated whether the fixation characteristics of the preferred retinal locus resemble those of the healthy fovea. For this purpose, we used the fixation-offset paradigm and tracked eye-position using a high spatial and temporal resolution infrared eye-tracker. The fixation-offset paradigm measures release from fixation under different fixation conditions and has been shown useful to distinguish between foveal and non-foveal fixation. We measured eye-movements in nine healthy age-matched controls and five patients with juvenile macular degeneration. In addition, we performed a simulation with the same task in a group of five healthy controls. Our results show that the preferred retinal locus does not adopt a foveal type of fixation but instead drifts further away from its original fixation and has overall increased fixation instability. Furthermore, the fixation instability is most pronounced in low frequency eye-movements representing a slow drift from fixation. We argue that the increased fixation instability cannot be attributed to fixation under an unnatural angle. Instead, diminished visual acuity in the periphery causes reduced oculomotor control and results in increased fixation instability.

Improved fixation quality provided by a Bessel beacon in an adaptive optics system

PURPOSE

We investigate whether a structured probe beam that creates the beacon for use in a retinal imaging adaptive optics system can provide useful side effects. In particular we investigate whether a Bessel beam that is seen by the subject as a set of concentric rings has a dampening effect on fixation variations of the subject under observation. This calming effect would allow longer periods of observation, particularly for patients with abnormal fixation.

METHOD

An experimental adaptive optics system developed for retinal imaging is used to monitor the fluctuations in aberrations for artificial and human subjects. The probe beam is alternated between a traditional beacon and one provided by a Bessel beam created by SLM.

RESULTS

Time-frequency analysis is used to indicate the differences in power and time variation during fixation depending on whether the Bessel beam or the traditional beacon is employed. Comparison is made with the response for an artificial eye to discount systemic variations.

CONCLUSION

Significant evidence is accrued to indicate the reduced fluctuations in fixation when the Bessel beam is employed to create the beacon.