Methodological quality of the review: Low confidence

Authors:  Wang Y, Alnwisi S, Ke M.

Region: Nigeria, Sydney and Scotland

Sector: Glaucoma

Sub-sector: Quality of life

Equity focus: None specified

Review type: Other review

Quantitative synthesis method: Meta-analysis

Qualitative synthesis method: Not applicable

Background:

Intraocular pressure (IOP), visual acuity, optic disc, and computerized perimetry have traditionally been used as clinical indicators in the assessment and management of glaucoma. However, clinicians’ awareness of the importance of QoL in patients with glaucoma has gradually increased. Therefore, several studies have demonstrated a correlation between clinical indices for glaucoma (such as vision, the visual field, and visual function) and patients’ QoL. Of these clinical variables, visual acuity is the most important indicator of daily functioning. In addition, visual field has recently been strongly associated with QoL in glaucoma patients.

Objectives:

To compare the effects of mild, moderate, and severe visual field loss on QoL in patients with glaucoma.

Main findings:

In total, 401 patients with glaucoma and 205 patients without glaucoma participated in four studies. The GQL-15 summary scores are statistically different between patients with and without glaucoma (standard mean difference [SMD]=0.94, 95% confidence interval [CI]: 0.73–1.16, P<.01). GQL-15 summary scores for patients with mild, moderate, and severe visual field loss all differed significantly from those of patients without glaucoma; the SMDs for their summary scores were as follows: mild: 1.24, 95% CI: 0.26 to 2.22, P=.01; moderate: 2.05, 95% CI: 0.91 to 3.19, P<.001; and severe: 2.57, 95% CI: 1.44 to 3.71, P<.001. Two factor scores for central and near vision (SMD=-0.35, 95% CI:1.01 to 0.30, P=.29) and glare and dark adaptation (SMD=-0.36, 95% CI: -1.01 to 0.30, P=.28) did not differ significantly between patients with mild and moderate visual field loss. However, summary scores and two factor scores (peripheral vision and outdoor mobility) differed significantly between patients with mild and moderate glaucoma. In addition, summary scores and all four factor scores differed significantly between patients with mild and severe glaucoma. Moreover, summary scores and three factor scores (peripheral vision, glare and dark adaptation, and outdoor mobility) differed significantly between patients with moderate and severe glaucoma. However, scores for one factor (central and near vision) did not differ significantly between any of the patient groups (SDM=-0.53, 95% CI=-1.33 to 0.27, P=.19).

Methodology: 

The authors searched PubMed, EMABSE and CNKI databases for published studies. Searches were conducted using the key words “glaucoma”, “quality of life OR QoL”, and “Glaucoma Quality of life-15 OR GQL-15”. In addition, the authors searched google scholar for additional studies. Studies that met the following criteria were included in the analysis: patients with glaucoma and a control group without glaucoma as participants; measurement of QoL in glaucoma patients using the GQL-15; classification of glaucoma patients into three groups according to disease stage, determined via examination of the visual field using perimetry; and original articles in English and Chinese.

Patients’ QoL was measured using the GQL-15 questionnaire. The GQL-15 includes 15 items divided between four factors pertaining to visual disability: central and near vision, peripheral vision, dark adaptation and glare, and outdoor mobility. The maximum summary score is 75, and higher scores indicate poorer QoL.

The authors extracted data of included studies and from the GQL-15. Statistical analyses were performed for each comparison and outcome. Standardized mean differences were calculated for the GQL-15 scores, and 95% confidence intervals were calculated for all outcomes. Heterogeneity was assessed using a X² test with calculation of I². If heterogeneity presented, authors used random-effects model.

Applicability/external validity:

The authors did not discuss the generalizability of findings

Geographic focus

The authors did not discuss the applicability of finings to low- and middle- income settings.

Summary of quality assessment:

Overall, there is low confidence in the conclusions about the affects of this study. The authors did not conduct a thorough search of the literature to ensure that all relevant studies were included in the review. They did not use rigorous methods to screen studies for inclusion and extract data of included studies. In addition, they did not avoid language bias.