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dr. G.A. (Gera) de Haan

Universitair Docent

2019 - present: Compensatory Reading Training for People with Homonymous Visual Field Defects - A Randomized Controlled Trial

A common consequence of stroke in the posterior region of the brain is a visual field defect. People with blindness for half of their visual field due to brain damage (homonymous hemianopia) frequently experience difficulties with reading, such as decreased reading speed, making more errors, being less able to read for a prolonged time and a decreased understanding of the text.

This project aims to determine the effectiveness of two reading interventions: Vistra and text rotation. The goal of Vistra is to learn compensating eye movements during reading, to decrease the negative effects of the visual field defect. Text rotation aims to reduce the effects of the visual field defect by learning people to read in a different direction, such as vertically or diagonally. The optimal angle is determined with the help of visual field assessment and people learn to apply the technique themselves.

The design of the study allows for comparison of both interventions with a control group and with each other. Furthermore the study will provide insight in the reading behaviour of people with hemianopia. Follow-up measurements are used to determine whether the interventions may have lasting effects.

The project will eventually result in well-founded knowledge on the effectiveness of two reading trainings for people with hemianopia. The final goal is to ensure people with hemianopia to read with more ease, by making use of a training that suits them best.

The following persons and institutions are involved in this project: Sarah Tol, Msc (UG), dr. Gera de Haan, dr. Joost Heutink (UG/Royal Dutch Visio), Annette Bootsma, Birgit van Iddekinge, dr. Bart Melis-Dankers (Royal Dutch Visio), Evert Veldman, dr. Frank Hoeben en dr. Kerstin Spielmann (Bartiméus). Funding: ZonMw-InZicht 60-00635-98-222

2019 - present: Scanning behavior in hemianopia: The Next Step

Homonymous Hemianopia refers to a visual field defect in which the left or right half of the visual field is not perceived, contralateral to the brain damage and where the defect is similar for both eyes. People with hemianopia experience difficulties in daily life, mainly with regards to reading, searching and mobility. They benefit from training aimed to decrease the impact of the visual field deficit through optimizing visual scanning. Therefore, it is of utmost importance to inform patients about how their (lack of) scanning behavior relates to difficulties they experience in daily life and how they can improve it to overcome these difficulties.

Knowledge about which scanning behavior is optimal, however, is mostly based on experiences and assumptions of professionals, and not supported by scientific literature and empirical data. Innovative techniques such as mobile eye-tracking and Virtual Reality allow us to examine scanning behavior in a standardized manner. In the current project, existing prototypes using these techniques are being developed into measures that can be used in clinical practice.

The aim of this project is to use these innovative techniques to examine the relationship between scanning behavior and various behaviors (mobility, searching) in patients with hemianopia, people with simulated hemianopia and a control group with normal vision. Insight into efficient scanning behavior will contribute to an improvement of the clinical practice of people with hemianopia.

The project will take place from 2019 to 2023 at Royal Dutch Visio, center of expertise for blind and partially sighted people, in collaboration with the University of Groningen (UG) and the University Medical Center Groningen (UMCG). Josephien Jansen, PhD student at the UG will conduct the research. The project leaders are dr. G.A. de Haan, dr. J.H.C. Heutink (UG, Royal Dutch Visio) and prof. dr. F.W. Cornelissen (UMCG).

The project is financially supported by the Novum foundation and ZonMw. 

2016 - present: NAH-Progress: research on visual complaints in patients with multiple sclerosis, Parkinson’s disease and dementia

Care for patients with multiple sclerosis (MS), Parkinson’s disease and dementia is improving. However, visual complaints and disorders are often neglected, and visual rehabilitation is not always applied. Royal Dutch Visio (Haren) has the knowledge and expertise to make the step towards high-quality clinical care. Consequently, people with neurodegenerative disorders are able to get the complex and specialistic diagnosis and rehabilitation they need. NAH-Progress, a project financially supported by Stichting Novum and ZonMw Expertisefunctie Zintuiglijk Gehandicapten, aims at organizing high-quality chain-based care and scientifically support this need.

In 2016, Royal Dutch Visio, Punt voor Parkinson, MS Centrum Noord-Nederland and the UMCG memory clinic started collaborating. The collaboration concerns patient screening, referral routes and scientific research. Patients who are registered at these centers are screened for visual complaints and if necessary referred to Royal Dutch Visio. Data yielded during this process are collected and analyzed in order to better understand the visual problems patients with neurodegenerative disorders may experience and to support rehabilitation care.

The aim of NAH-Progress is to develop a national guideline for referral, diagnosis and rehabilitation of visual complaints and impairments in patients with MS, Parkinson’s disease and (early) dementia.

2014-2016: Effects of low vision on neuropsychological assessment.

PhD project Gera de Haan, sep 2009 – sep 2013: The effects of Scanning Compensatory Therapy for patients with homonymous visual field defects a randomised controlled trial

Last modified:25 June 2022 12.42 p.m.