The direction of research into visual disability and quality of life in glaucoma

Methodological quality of the review: Low confidence

Author: Glen FC, Crabb DP, Garway-Heath DF

Geographical coverage: Not reported

Sector: Glaucoma

Sub-sector: Visual disability and quality of life

Equity focus: None specified

Review type: Qualitative evidence review

Quantitative synthesis method: Narrative/thematic synthesis

Qualitative synthesis method: Not applicable

Background: Glaucoma impacts an individual’s visual ability, thereby also affects ability in their daily routines. Although there is published work regarding the management and treatment of the disease, there is not much published on the quality of life (QoL) and visual disability for persons with glaucoma. Compared to other diseases, QoL studies for glaucoma are minimal. More studies conducted in this area could improve management and rehabilitation in glaucoma.

Objectives: The objective of this review is to explore the extent of the published work in QoL and visual studies focusing on glaucoma, and compare them with other chronic conditions in similar research studies.

Main findings: An initial literature search yielded 294 papers for glaucoma and QoL, which were then shortlisted to 51 suitable papers. These papers illustrated a slight increase (1.2%) in the number of studies focusing on QoL in glaucoma from 1990 to 2009. Previously, there were no published studies on QoL and visual disability in glaucoma patients, and this rise in the number of publications indicates that the importance of QoL in glaucoma is gradually being understood.

In recent years, the importance of QoL studies in glaucoma has been better recognised and therefore increased. However, authors note that compared to the overall work published in the field of glaucoma, QoL studies still make up a small fraction.

The authors emphasise that current QoL assessment strategies are quite limiting, even though they function as the best way to measure the patient’s perspective on their disease at present.

Authors note that although there has been a surge of studies on QoL in glaucoma, it still bears no comparison to the other published studies in glaucoma, let alone on QoL in other chronic diseases. Research in this area can help to better manage glaucoma and, as a result, turn the focus on individuals being impacted by visual loss in their day-to-day lives.

Methodology: A systematic literature search was carried out using MEDLINE, EMBASE and the Psychiatry and Global Health database using the Ovid search platform on March 16 2010. This search included indexed publications up to December 2009. Searches for seven chronic conditions (glaucoma, AMD, Type 2 diabetes, rheumatoid arthritis, hearing impairment, Parkinson’s disease and multiple sclerosis) using certain keywords as their titles were conducted. This search was done over a ten-year period (1999-2009) and then extended over a 20-year period (1989-2009) in order to observe the trend in glaucoma-related publications as an alternate measure for research activity trends.

The results were combined from each search with results from abstract search using QoL keywords or phrases: quality of life, functional consequences, performance, real world, functional ability, everyday, daily living, daily life, behaviour, activities of daily living, independent living. Results were limited to papers containing any one of the disease keywords and at least one of the QoL keywords. There were no language or country restrictions. The review articles, as well as the reference sections of key papers, were searched carefully for relevant papers that may have been overlooked and not indexed in the searched databases.

To avoid possible exclusion of relevant papers from the search due to the specific phrasing of the keywords, a manual search of abstracts was also carried out. In order for the paper to be included, it had to be a systematic research approach with a strong focus on the impact of the disease on the QoL of the patient. The abstracts and full texts for the papers in the 20-year glaucoma search were surveyed for information regarding the methods used to examine the QoL in each study.

Applicability/external validity: The authors discussed how more attention on QoL studies can essentially provide insight into the patients’ perspective of the disease’s impact on their day-to-day life. This can, in turn, help manage and rehabilitate those patients affected by glaucoma in a much more effective way.

Geographic focus: Geographical location of included studies was not reported.

Summary of quality assessment: Low confidence was attributed in the conclusions about the effects of this study as important limitations were identified. This review lacks a robust methodological approach to extracting and analyzing data. The reliability of the evidence is weak considering there were no independent reviewers from the start of the data screening. The study bases weight on certain keywords for an inclusion criterion, which is not necessarily a strong framework to conduct a thorough assessment of the available published data. This leads to questioning the reliability of the methods and conclusion of this review.