A recent study has examined the relationship between reading speed and bilateral [i.e., both eyes] visual field loss from glaucoma and relates the findings to potential applications in e-reading technology, such as the iPad or Kindle.
The Association for Research in Vision & Ophthalmology
Difficulty with Out-loud and Silent Reading in Glaucoma has been published online ahead-of-print in Investigative Ophthalmology & Visual Science, the official journal of the Association for Research in Vision and Ophthalmology (ARVO).
ARVO is an international organization that encourages and assists research, training, publication, and dissemination of knowledge in vision and ophthalmology, including low vision.
The authors are Pradeep Y. Ramulu, Bonnielin K. Swenor, Joan L. Jefferys, David S. Friedman, and Gary S. Rubin, who represent the following institutions: Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland; National Institute for Health Research (NIHR) Moorfields Biomedical Research Centre, University College London (UCL) Institute of Ophthalmology, United Kingdom.
About the Study
The purpose of the study was to evaluate and measure the impact of glaucoma on out-loud and silent reading rates. As summarized by ARVO in a recent press release,
… adults with glaucoma read slower when reading silently for long periods of time and are more likely to have their reading speed decrease over time, possibly as a result of reading fatigue.
The study was conducted with two groups from the Wilmer Eye Institute: (1) patients with bilateral visual field loss from glaucoma, and (2) [a normally-sighted] control group.
Both groups were evaluated with the following methods: (1) speed-reading an International Reading Speed Text (IReST) passage out loud, (2) maximum out-loud MNRead chart reading speed, (3) a sustained silent reading test over a 30-minute period, and (4) a comprehension evaluation corresponding to the sustained silent reading material.
(Note: IReST speed reading tests and vision charts are highly standardized multilingual reading tests that have been developed for clinical practice and research. The MNRead acuity charts are continuous-text reading acuity charts that measure the reading acuity [i.e., smallest print size that can be read] and reading speed of persons with regular and low vision.)
The Study Results
- On the IReST evaluation, subjects with glaucoma read 147 vs. the normally sighted control group’s 163 words per minute (wpm).
- On the MNRead, subjects with glaucoma read 172 vs. the control group’s 186 wpm.
- On the sustained silent reading test, subjects with glaucoma read 179 vs. the control group’s 218 wpm — a 16 percent slower reading speed.
The authors concluded that sustained silent reading speed for persons with glaucoma and bilateral visual field loss is significantly less than the speed associated with out-loud reading. Persons with glaucoma also experience fatigue during silent reading, resulting in slower reading speeds over time.
Glaucoma is a group of eye diseases that damage the optic nerve and is one of the leading causes of vision loss and blindness.
Glaucoma results in peripheral (or side) vision loss initially, and the effect can be like looking through a tube or into a narrow tunnel. This “tunnel vision” effect makes it difficult to walk without bumping into objects that are off to the side, near the head, or at foot level. It is an especially dangerous eye condition because most people do not experience any symptoms or early warning signs at the onset of glaucoma.
Glaucoma can be treated, but it is not curable. The damage to the optic nerve from glaucoma cannot be reversed. However, lowering the pressure in the eye can prevent further damage to the optic nerve and further peripheral vision loss. Early detection, therefore, along with appropriate and ongoing treatment, is critical.
The Potential Role of E-Readers and Associated Technology
From an interview with study author Pradeep Ramulu, MD, PhD:
Technological solutions such as e-readers – and the many apps being created for them – could help. “Right now, so many products are available for presenting reading material in a variety of formats,” says author Pradeep Ramulu MD, PhD, of the Wilmer Eye Institute, Johns Hopkins University. “If the optimal format for reading in the context of glaucoma could be determined, it would be easy to create an application to present text in this manner as part of a commercial device such as an iPad or Kindle.”
“The ultimate goal is to be able to rehabilitate individuals with reading difficulties due to glaucoma,” says Ramulu. “Our group and others are exploring possible reasons behind these impairments, including disruption of the tear film and [abnormal] eye movements. Understanding why people with glaucoma read slower and show reading fatigue will pave the way for solving these reading difficulties.”
VisionAware will provide updates of this ongoing glaucoma and reading research as they become available.
For additional information and reading, see New Research on Glaucoma, Impaired Eye Movements, and Daily Living Activities and Digital Tablets Can Improve Speed and Ease of Reading for People with Moderate Vision Loss.