New glaucoma research from Investigative Ophthalmology & Visual Science, the official journal of the Association for Research in Vision and Ophthalmology (ARVO), indicates that persons with glaucoma read less, have reduced reading skills, and have less engagement with tasks that require sustained reading.
The authors conclude that additional research is critically necessary to define the best reading methods in persons with glaucoma by (a) using effective lighting to optimize contrast and reduce glare, (b) correcting inefficient and ineffective eye movements, (c) using low vision optical devices to enlarge text, and (d) teaching strategies to reduce visual fatigue from reading.
The authors also note that “…only a small percentage of glaucoma patients are referred to rehabilitative services. One barrier to referrals may be the fact that physicians may not view glaucoma patients as requiring visual rehabilitation services, [since] they most often refer patients with central vision deficits.”
The Association for Research in Vision & Ophthalmology
Reading Ability and Reading Engagement in Older Adults with Glaucoma was published in the August 2014 edition of 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 Angeline M. Nguyen; Suzanne W. van Landingham; Robert W. Massof; Gary S. Rubin; and Pradeep Y. Ramulu, who represent the following institutions: Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland; and National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital and University College London (UCL) Institute of Ophthalmology, United Kingdom.
About the Research
Excerpted from Study: Glaucoma patients have lower reading ability, engagement at Healio:
As detailed in the study, 63 glaucoma patients and 59 control patients with a diagnosis of glaucoma suspect or ocular hypertension participated.
[Editor’s note: A person can be considered a “glaucoma suspect” on the basis of above-normal intraocular (i.e., within the eye) pressure, an unusual appearance of the optic disc or visual field, a family history of glaucoma, or narrow angles between the iris and cornea.]
The study subjects engaged in ten reading activities from the Activity Inventory, which was developed to assess patients with low vision.
[Editor’s note: The Activity Inventory is an adaptive visual function questionnaire organized into three activity objectives (daily living, social interaction, and recreation), 50 activity goals, and 457 activity tasks.]
The reading tasks included word puzzles, bills, financial statements, handheld menus, magazines, religious texts, books, newspaper articles, typed mail, and written notes or mail. Nguyen and colleagues then evaluated the participants with an oral questionnaire and analyzed their responses … to determine ability.
Results showed that glaucoma patients had a lower reading ability than control participants, which was associated with greater visual field loss and lower contrast sensitivity. Additionally, glaucoma patients reported a greater difficulty reading in all reading activities except puzzles.
As reported by the participants, the most difficult tasks included finances, books and puzzles, and the least difficult tasks included bills, notes, and mail.
“While reading is a common complaint amongst glaucoma patients, only a small percentage of glaucoma patients are referred to rehabilitative services,” the authors also noted. “One barrier to referrals may be the fact that physicians may not view glaucoma patients as requiring visual rehabilitation services, as they most often refer patients with central vision deficits.”
“An additional barrier to referral may be that glaucoma patients do not often express severe reading difficulty to the extent that reading would be impossible,” they continued. “Finally, rehabilitative services, including efforts to enable reading, are primarily tailored to serve patients with central vision loss – not those with visual field loss.”
What Is Glaucoma?
The term “glaucoma” describes a group of eye diseases that can lead to blindness by damaging the optic nerve. It is one of the leading causes of vision loss and blindness. The human eye continuously produces a fluid, called the aqueous, that must drain from the eye to maintain healthy eye pressure.
Types of Glaucoma
- In primary open-angle glaucoma (POAG), the most common type of glaucoma, the eye’s drainage canals become blocked, and the resultant fluid accumulation causes pressure to build within the eye. This pressure can cause damage to the optic nerve, which transmits information from the eye to the brain. Vision loss is usually gradual and often there are no early warning signs.
- In normal-tension glaucoma, also called low-tension or low-pressure glaucoma, persons with the disease experience optic nerve damage and subsequent vision loss, despite having normal intraocular [i.e., within the eye] pressure (IOP). This type of glaucoma is treated much like POAG, but eye pressure needs to be kept even lower to prevent progression of vision loss.
- Secondary glaucomas develop as secondary to, or as complications of, other conditions, including cataracts, diabetes, eye trauma, eye surgery, or tumors. In many of these glaucomas, damage to the fluid drainage canal must be addressed with medication or surgery.
Eye Pressure and Glaucoma
Most eye care professionals define the range of normal within-the-eye pressure as between 10 and 21 mm Hg [i.e., millimeters of mercury, which is a pressure measurement]. Most persons with glaucoma have an IOP measurement of greater than 21 mm Hg; persons with normal-tension glaucoma, however, have an IOP measurement within the normal range.
Visual Field Loss from Glaucoma
Glaucoma results in peripheral (or side) vision loss initially, and the effect as this field loss progresses 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:
A simulation of visual field loss from glaucoma
Source: National Eye Institute
Glaucoma is an especially dangerous eye condition because most people do not experience any symptoms or early warning signs at the onset. Glaucoma can be treated, but it is not curable. The damage to the optic nerve from glaucoma cannot be reversed.
More about the Research from Investigative Ophthalmology & Visual Science
From the article abstract:
Purpose: We evaluated the impact of glaucoma-related vision loss on reading ability and reading engagement in 10 reading activities.
Methods: A total of 63 glaucoma patients and 59 glaucoma suspect controls self-rated their level of reading difficulty for 10 reading items, and responses were analyzed using Rasch analysis to determine reading ability. Reading engagement was assessed by asking subjects to report the number of days per week they engaged in each reading activity. Reading restriction was determined as a decrement in engagement.
Results: Glaucoma subjects more often described greater reading difficulty than controls for all tasks except puzzles. The most difficult reading tasks involved puzzles, books, and finances, while the least difficult reading tasks involved notes, bills, and mail…. Less reading ability was found for glaucoma patients compared to controls. Among glaucoma patients, less reading ability was associated with more severe visual field (VF) loss and contrast sensitivity.
Conclusions: Glaucoma patients have less reading ability and engage less in a variety of different reading activities, particularly those requiring sustained reading. Future work should evaluate the mechanisms underlying reading disability in glaucoma to determine how patients can maintain reading ability and engagement.