Prevalence of Dry Eye Disease among Elderly Korean PopulationPrevalence of Dry Eye Disease

among Elderly Korean Population

Sang Beom Han, MD,1 Joon Young Hyon, MD,1

Won Ryang Wee, MD,2,3 Jin Hak Lee, MD,1, 3

 Department of Ophthalmology, Seoul National University College of Medicine, Seoul National

University Bundang Hospital1, Seongnam, Korea

Department of Ophthalmology, Seoul National University College of Medicine2, Seoul, Korea

Seoul Artificial Eye Center, Seoul National University Hospital Clinical Research Institute3, Seoul, Korea

Financial Disclosure: None

BackgroundBackground

Prevalence of Dry Eye• Several population-based studies have reported prevalence of dry

eye from 4.3% to 52.1%.• Large disparity in reported prevalence of dry eye

• Lack of standardized diagnostic definition

• Difference in the study population.

Risk Factors of Dry Eye• A few risk factors including old age, female gender, and hazardous

environment have been assumed to be associated with dry eye. • Ethnic difference in the prevalence of dry eye between Caucasian

and Asian population has been suggested.Schein et al. Am J Ophthalmol 1997;124:723-8. Shimmura et al. Cornea 1999;18:408-11.

PurposePurpose

To assess the population-based prevalence of dry eye in elderly Korean population.

To investigate the associated risk factors and affected quality of life. Conducted from May 2008 to February 2009 in Yongin city, Korea.

Why Yongin?• Yongin was considered to be an ideal community for a population-based study in Korea since

it is one of the largest cities with rural/urban mixture in Korea.

4

SampleSample

Towns within Yongin were randomly selected to cover about

10,000 residents aged 65 years old or above.

10% of them were randomly drawn, and finally 1,060 elderly subjects were sampled.

657 agreed to participate in this study and completed a symptom questionnaire.

Two-Stage DesignTwo-Stage Design

Phase I population survey• Dry Eye Questionnaire (DEQ) • Schirmer test

DEQDuring recent 2 weeks1.Do your eyes feel dry? 2.Do you feel gritty or sandy sensation in your eyes?3.Do your eyes ever have a burning sensation?4.Do your eyes ever feel sticky?5.Do your eyes ever feel watery or tearing?6.Are your eyes ever red?

Allowed responses to the questions were ‘none”, ‘rarely’, ‘sometimes’, and ‘often or all the time’.

Dry eye was defined as having one or more symptoms often or all the time.

Phase II evaluationPhase II evaluation Tear film breakup time (BUT) test Fluorescein stain Examination of meibomian gland dysfunction

Positive signs were defined as • Tear film BUT ≤10 seconds• Schirmer test score ≤ 5 mm• Fluorescein score ≥ 1• or the presence of meibomian gland disease

Statistical AnalysisStatistical Analysis

In each subject, the worse eye was used for analyses.

Standardized prevalence rates were also estimated using the direct standardization method.• The prevalence rates were adjusted by age, gender, and urbanicity

to the total Korean population, as given in the 2005 national census.

Association between demographic variables (age, sex, and area) and dry eye symptoms or signs was evaluated using Pearson Chi-square tests.

ResultsResults

Total 657 subjects• Mean age was 72.0 ± 5.9 years (mean ± SD, range 65-95)• M : F ratio was 48.2%: 51.8% (317 : 340) • Schirmer test was completed in 648 subjects

139 subjects completed this Phase II evaluation.

Prevalence of Dry eye• The crude prevalence rate, define as presence of one or more of

the six dry eye symptoms, was 30.3%.• Sex, age, and area adjusted prevalence based on the Korea 2005

census population was 33.2% (95% CI 28.9 -37.4).

Prevalence rates According to the potential predictorsPrevalence rates According to the potential predictors

Variables

Positive dry eye symptoms

NoCrude rate

%Adjusted rate% (95% CI)

P valueOdds Ratio(95% CI)

Total rate 199 / 657 30.3 33.2 (28.9 -37.4)

Age groups65-6970-7475-7980-84≥85

84 / 27652 / 18836 / 11315 / 5212 / 28

30.427.731.928.842.9

34.3 (27.8-40.7)33.3 (25.5-41.0)35.1 (24.7-45.5)31.1 (16.3-45.9)35.7 (13.9-57.5)

0.575

SexMale

Female81/ 317

118 / 34025.634.7

29.8 (24.1-35.5)37.7 (31.6-43.8)

0.0111.55

(1.11 - 2.17)

AreaUrbanRural

125 / 346 74 / 311

36.123.8

36.5 (31.4-41.6)23.7 (19.0-28.5)

0.0011.81

(1.29 – 2.55)

Dry Eye SignsDry Eye Signs

Frequency of positive dry eye tests according to the presence or absence of dry eye symptoms.

Variables

No (%)

P valueOdds Ratio

(95% CI)Positive dry eye symptoms

Negative dry eye symptoms

Schirmer I test ≤ 5 mm 63 / 192 (32.9%) 113 / 456 (24.8%) 0.042* 1.48 (1.03 – 2.14)

BUT ≤10 seconds 63 / 74 (85.1%) 56 / 65 (86.1%) 1.000 0.92 (0.36 – 2.38)

Fluorescein score ≥ 1 29 / 74 (39.1%) 21 / 65 (32.3%) 0.47 1.35 (0.67 -2.71)

Presence of meibomian gland disease

40 / 74 (54.1%) 32 / 65 (49.2%) 0.61 1.21 (0.62 – 2.37)

*Only Schirmer test score was shown to have significant association with positive dry eye symptoms, although the test also showed high false-positive rate

Risk factorsRisk factors

Ethnicity• High prevalence of 33.2% in this study is similar to those among

Asians, but much higher than those among Caucasians.

Gender• Sex hormones may influence ocular surface condition through their

effects on lacrimal gland, meibomian glands, conjunctival goblet cell density, and ocular surface sensitivity.

Area• The exact cause is yet to be elucidated, although air pollution in the

urban region may, at least in part, contribute to the difference.

ConclusionConclusion

Dry eye is very common condition with an estimated national prevalence of 33.2% among elderly Koreans population.

Women and urban dwellers are more likely to suffer from dry eye symptoms.