Patient and economic burden of presbyopia: a systematic literature review

Authors: Berdahl J, Bala C, Dhariwal M, Lemp-Hull J, Thakker D, Jawla S.

Geographical coverage: Global

Sector: Burden of disease

Sub-sector: Epidemiology

Equity focus: None specified

Study population: Patients with presbyopia

Review type: Other review

Quantitative synthesis method: Narrative synthesis (although describes itself as systematic review).

Qualitative synthesis method: Not applicable

Background:

Presbyopia is an age-related impairment of near vision characterised by gradual decrease in accommodation of the eye. It stems from a gradual thickening and loss of viscoelasticity of the natural lens. Presbyopia is near universal in older patients presenting for cataract surgery. In cataract patients undergoing surgery, removal of the cataractous lens and implantation with an artificial intraocular lens (IOL) leads to total loss of accommodation, resulting in postoperative presbyopia. Implantation of standard monofocal IOLs (usually buried under covered benefit) corrects only distance vision without near and intermediate vision correction. Uncorrected post-operative presbyopia still remains a challenge for patients, ophthalmologists and optometrists.

Objectives: The objective of this systematic literature review (SLR) was to collate, report and critique published evidence related to epidemiology and patient and economic burden of presbyopia.

Main findings:

Authors included 55 studies in the review. 43 addressed epidemiology of presbyopia, 14 assessed patient burden and one looked at the economic burden of presbyopia. In the 43 studies reporting on epidemiology, 10 were conducted in India; five were from Nigeria; three were conducted in China, Tanzania and worldwide; two were from Kenya, Pakistan, Timor-Leste, the USA; and one each from Australia, Bangladesh, Brazil, Eritrea, Fiji, Malawi, Nicaragua, South Africa, Tanzania and Venezuela.

Authors note the prevalence of presbyopia varies substantially across regions and by age groups, with the highest prevalence of 90% reported in the Latin American region in adults aged 35 years and above.

Authors found that among the risk factors attributed to presbyopia identified in the literature, age plays a significant role. The odds of developing presbyopia increases by 16% per year from age 40 to 50 (odds ratio [OR]: 1.16; 95% CI 1.12-1.20), and by just 1% per year after age 50 (OR: 1.01; 95% CI 0.99-1.03).

Among the included studies for presbyopia, patient burden, outcomes related to quality of life (QoL), and disability in daily activities were reported in 10 studies. Three studies reported the impact of presbyopia on vision-related quality of life. All identified studies were cross-sectional in design. Findings from these studies indicated that uncorrected presbyopia patients had reduced vision-related quality impacting on day-to-day activities such as reading, writing, using mobile phones, and so on.

One study included in the review assessed the productivity loss due to presbyopia. Across a total of 244 million working-age presbyopic patients worldwide, aged <50 years (both uncorrected and under-corrected), presbyopia was estimated to result in annual productivity losses of US$ 11.0 billion (0.016% of the global GDP). If all those people aged <65 years were assumed to be productive, the potential annual productivity losses would increase to US$ 25.4 billion or 0.037% of the global GDP.

Based on the literature included in this review, authors conclude that uncorrected presbyopia affects patients’ vision-related quality of life due to difficulty in performing near-vision-related tasks. In addition, un-/under-corrected presbyopia could lead to productivity losses in working-age adults.

Authors note the need for further studies, particularly those conducted in African regions to use standardised diagnosis definition and methods. Further evidence is needed to better understand the onset of presbyopia and to inform vision care guidelines and policies. Authors also recommend future studies should consistently provide clear definitions of diagnosis used in studies to help readers in interpreting evidence.

Methodology:

RCTs and systematic literature reviews, including information on 1) patients with presbyopia alone or combined with other refractive errors; 2) prevalence and incidence rates of presbyopia; 3) direct and indirect costs of presbyopia correction or health care resource utilisation or productivity loss; and 4) impact on vision-related quality of life or disability and impacts on daily activities or utility associated with presbyopia or patient satisfaction.

The systematic literature searches were conducted in the EMBASE, Medline, and Cochrane Library medical literature databases from the time of database inception through 26 October 2018. The search was restricted to articles published in English language. Additionally, abstracts presented at key ophthalmology congresses for the past three years (2015 to 2018) were hand searched to retrieve either recent studies that had not yet been published in journals as full-text articles or supplement results of previously published studies.

Study selection was conducted by two reviewers independently and data extraction was conducted by a single reviewer and checked for accuracy by a second reviewer.

Findings are synthesised narratively.

Applicability/external validity:

Authors note that findings varied between regions and, furthermore, prevalence of presbyopia may not be generalisable due to missing data from key demographics such as Europe and large developing economies such as India and Russia.

Geographic focus:

Based on identified literature conducted in Africa, authors found presbyopia prevalence rates ranged from 25.1% in Kenya to 89.2% in Tanzania for adults ≥30 years.15,19-32 The substantially lower reported presbyopia prevalence rate of 25.1% in the study from Kenya could be attributed to diagnostic uncertainty. Furthermore, authors note the study in Tanzania was performed in a nationally representative sample of 400 people aged between 40 and 50 years. However, other details, including the definition for presbyopia diagnosis, were not provided; therefore, it is difficult to interpret and contrast substantial differences in estimated presbyopia prevalence rate between these two African countries and data should be interpreted with caution.

Summary of quality assessment:

This review appropriately reports the inclusion and exclusion of studies eligible for inclusion, uses a comprehensive search period and uses appropriate methods to screen studies for inclusion in the review and synthesise the findings of included studies. However, important limitations were identified. The review does not report the overall quality of included studies, which is an important limitation impacting on the reliability of the review’s overall findings. Furthermore, the search strategy was not comprehensive enough to ensure that all relevant studies were included in the review (restricted to those published in English, reference sections not reviewed, and academics not consulted). Therefore, a low confidence is attributed in the conclusions about the effects of this review.