Prevalence and incidence of dry eye in the USA: a systematic review protocol

Low Expression of Vitamin D Receptor in Patients With Dry Eye Disease

PURPOSE

This study aimed to compare the expression of vitamin D receptor (VDR) on the ocular surface of patients with dry eye disease (DED) and controls without ophthalmological pathologies.

METHODS

Patients with DED without previous treatment were studied and compared with healthy subjects. Ocular Surface Disease Index assessement and ocular surface cytology were performed in all patients. The immunohistochemical expression of VDR was evaluated using fully automated immunohistochemistry. The evaluation involved multiplying the percentage of nuclear-labeled cells (0-100) by their intensity (0-3), resulting in a score ranging from 0 to 300 (VDR H-score). Squamous metaplasia was morphologically evaluated using liquid-phase cytology with Papanicolaou/periodic acid-Schiff staining using Nelson's grade (scale 0-3, higher grade to higher metaplastic change).

RESULTS

Eighteen patients with DED without previous treatment and 10 healthy subjects were studied. Squamous metaplasia was observed in 74% of patients with DED, in contrast to 0% in the control group. In patients with DED, there was a lower expression of VDR than in the control group (VDR H-score: 11.2 ± 13.9 vs. 80.9 ± 56; P = 0.0001). Furthermore, an inverse correlation was observed between Nelson grade and VDR H-score ( P = 0.0001, rs = -0.71). No correlation was observed between Ocular Surface Disease Index and VDR H-score.

CONCLUSIONS

This is the first study to evaluate the VDR in patients with DED. These patients presented with a lower expression of VDR than healthy subjects. No correlation was found with more severe symptoms. Patients with DED also had a higher frequency of squamous metaplasia.

Prevalence of dry eye and Meibomian gland dysfunction in Central and South America: a systematic review and meta-analysis

BACKGROUND

Dry eye is one of the most common ophthalmic conditions and can significantly impact quality of life. Meibomian gland dysfunction (MGD) is a major cause of evaporative dry eye. We sought to conduct a systematic review and meta-analysis to estimate the prevalence and incidence of dry eye and MGD in Central and South America and to identify factors associated with disease burden.

METHODS

Data sources Ovid MEDLINE and Embase.

STUDY SELECTION

A search conducted on August 16, 2021, identified studies published between January 1, 2010, and August 16, 2021, with no restrictions regarding participant age or language of publication. Case reports, case series, case-control studies, and interventional studies were excluded.

DATA EXTRACTION AND SYNTHESIS

The review was based on a protocol registered on PROSPERO (CRD42021256934). Risk of bias was assessed in duplicate using a risk of bias tool designed for the purposes of descriptive epidemiological studies. Data were extracted by one investigator and verified by another for accuracy. Prevalence of dry eye and MGD were grouped based on study participant characteristics.

MAIN OUTCOMES AND MEASURES

Prevalence and incidence of dry eye and MGD in Central and South America. Summary estimates from meta-analysis with 95% confidence intervals (CI).

RESULTS

Fourteen studies (11,594 total participants) were included. The population prevalence of dry eye was 13% (95% CI, 12%-14%) in Brazil and 41% (95% CI, 39%-44%) in Mexico based on one study each. Meta-analyses suggested that dry eye prevalence was 70% among indoor workers (95% CI, 56%-80%; I2, 82%; 3 studies), 71% among students (95% CI, 65%-77%; I2, 92%; 3 studies), and 83% in general ophthalmology clinics (95% CI, 77%-88%; I2, 88%; 2 studies). MGD prevalence ranged from 23% among indoor workers (95% CI, 16%-31%; 1 study) to 68% in general ophthalmology clinics (95% CI, 62%-72%; 1 study). No studies reported incidence of dry eye or MGD.

CONCLUSIONS

This systematic review and meta-analysis demonstrated considerable variation in the published prevalence of dry eye and MGD among the general population and subpopulations in Central and South America. Local and subpopulation estimates of dry eye disease burden may be valuable to assist needs assessments and implementation of measures to mitigate the condition.

Prevalence and Incidence of Dry Eye and Meibomian Gland Dysfunction in the United States: A Systematic Review and Meta-analysis

Importance

Dry eye is a common clinical manifestation, a leading cause of eye clinic visits, and a significant societal and personal economic burden in the United States. Meibomian gland dysfunction (MGD) is a major cause of evaporative dry eye.

Objective

To conduct a systematic review and meta-analysis to obtain updated estimates of the prevalence and incidence of dry eye and MGD in the United States.

Data Sources

Ovid MEDLINE and Embase.

Study Selection

A search conducted on August 16, 2021, identified studies published between January 1, 2010, and August 16, 2021, with no restrictions regarding participant age or language of publication. Case reports, case series, case-control studies, and interventional studies were excluded.

Data Extraction and Synthesis

The conduct of review followed a protocol registered on PROSPERO (CRD42021256934). PRISMA guidelines were followed for reporting. Joanna Briggs Institute and Newcastle Ottawa Scale tools were used to assess risk of bias. Data extraction was conducted by 1 reviewer and verified by another for accuracy. Prevalence of dry eye and MGD were combined in separate meta-analyses using random-effects models.

Main Outcomes and Measures

Prevalence and incidence of dry eye and MGD in the United States. Summary estimates from meta-analysis of dry eye and MGD prevalence with 95% CI and 95% prediction intervals (95% PI).

Results

Thirteen studies were included in the systematic review. Dry eye prevalence was reported by 10 studies, dry eye incidence by 2 studies, and MGD prevalence by 3 studies. Meta-analysis estimated a dry eye prevalence of 8.1% (95% CI, 4.9%-13.1%; 95% PI, 0%-98.9%; 3 studies; 9 808 758 participants) and MGD prevalence of 21.2% (95% CI, 7.2%-48.3%; 95% PI, 0%-100%; 3 studies; 19 648 participants). Dry eye incidence was 3.5% in a population 18 years and older and 7.8% in a population aged 68 years and older. No studies reported MGD incidence.

Conclusions and Relevance

This systematic review and meta-analysis demonstrated uncertainty about the prevalence and incidence of dry eye and MGD in the United States. Population-based epidemiological studies that use consistent and validated definitions of dry eye and MGD are needed for higher-certainty estimates of dry eye and MGD prevalence and incidence in the United States.