1

CORRELATIONS BETWEEN VISUAL FIELD INDEX AND

QUALITY OF LIFE IN GLAUCOMA PATIENTS USING

THE NEI-VFQ-25 QUESTIONNAIRE

Fatrin Patrycia, Elsa Gustianty, Ine Renata Musa

Ophtalmology Department Faculty of Medicine Padjajaran University

Cicendo Eye Hospital National Eye Center Bandung

ABSTRACT

Introduction

Glaucoma management aims not only to maintain visual function, but also the patients’

quality of life (QOL). A reliable visual field assessment is needed to monitor progression

of glaucoma, as well as assessing visual disability. Visual Field Index (VFI) as the latest

global index offers a practical summary of visual field status and has the advantage of not

being affected by cataract and focuses on the central visual field.

Objective

To determine the correlation between visual field deterioration using VFI and the QOL of

glaucoma patients using National Eye Institute Visual Function Questionnaire-25 (NEI-

VFQ-25).

Method

We found 72 subjects who were diagnosed primary open or closed angle glaucoma on both

eyes and whose visual fields were unaffected by other condition besides glaucoma. All

subjects had reliable 24-2 or 30-2 visual field test within last 6 months and had been

interviewed with NEI-VFQ-25 Indonesian version. Correlations were calculated between

the better eye’s VFI and NEI-VFQ-25 subscales. A single linear regression analysis was

utilized between composite score and better eye’s VFI.

Results

Modest correlations were found between VFI and majority of NEI-VFQ subscales: general

vision, near acuity, distance acuity, social function, mental health, role difficulties, and

dependency. Weak correlations were found between VFI and ocular pain, and general

health. Strong correlations were found between VFI and composite scores (r=0.746).

Conclusions

A strong positive correlation was found between visual field defect as represented by VFI

and with QOL in glaucoma patients.

Keyword: visual field, glaucoma, visual field index, quality of life

INTRODUCTION

Glaucoma is a chronic and

progressive optic neuropathy.

Blindness due to glaucoma is ranked

third worldwide. The International

Agency for the Prevention of

Blindness (IAPB) states that in 2015

there were 253 million people with

2

visual impairment, with 36 million of

them are blind. From these numbers,

about 2.78% of visual impairment and

1.91% of blindness caused by

glaucoma. Blindness on both eyes is

estimated to occur in 5.9 million

people with open-angle glaucoma and

5.3 million people with closed-angle

glaucoma.1-5

Glaucoma patients need treatment

and clinical evaluation for life,

therefore the management of

glaucoma not only to maintain visual

function, but also the quality of life.

The use of vision-specific

questionnaire is more recommended

than generic questionnaire in

evaluating the correlation of quality of

life with visual field in glauoma.

Although glaucoma specific

questionnaires are available such as

Glaucoma Quality of Life-15 (GQL-

15), NEI-VFQ-25 has better

correlation and reliability than GQL-

15. The NEI-VFQ-25 questionnaire

has also been used in assessing the

quality of life of glaucoma patients in

multicentered studies with large

populations.6-9

Most study regarding the quality of

life of glaucoma patients and

decreased visual field use the global

index Mean Deviation (MD).

Although MD can reliably evaluate

field deterioration, it is not sensitive in

identifying focal depression and

affected by cataracts. Decreased

visual field due to cataracts or

glaucoma needs to be distinguished,

because both conditions are age-

related and often occur together. In

recent years, VFI was developed for

calculating the rate of glaucoma

progression. Bengtsson and Heijl

reported that VFI was more accurate

in detecting central visual field

abnormalities without being affected

by cataracts. Sawada et al compared

the correlation of VFI and MD with

the quality of life in glaucoma patients

in Japan using the NEI-VFQ-25

instrument. The result is VFI has

better correlation than MD.

Unfortunately studies of quality of life

for glaucoma patients using VFI

parameters are still minimal. Until

today, little information has been

obtained regarding the quality of life

of glaucoma patients in Indonesia, as

well as its relationship with the

decreased visual field. Therefore this

study aims to evaluate the correlation

between visual field deterioration

based on VFI, with the quality of life

in glaucoma patients.10-15

SUBJECTS AND METHODS

This study is an analytic cross-

sectional study conducted at the

Glaucoma Unit of the National Eye

Center Cicendo Eye Hospital

3

Bandung in March-May 2020. The

inclusion criteria were subjects aged

40-80 years, had been diagnosed

primary glaucoma (open angle or

closed angle) in both eyes, and have

reliable perimetry in the past 6

months, or can undergo Humphrey

SITA Standard 30-2 or 24-2 visual

field examination, at least in one eye.

The exclusion criteria are patients

with best corrected visual acuity less

than 1/60, had a history of intraocular

surgery within 3 months, patients with

acute angle closure glaucoma, ocular

inflammation such as blepharitis,

conjunctivitis, keratitis, and uveitis,

corneal abnormalities that affect

visual axis such as keratopathy,

patients with ocular pathology of the

retina or optic nerve, and who have

known comorbid diseases that affect

quality of life such as mental

disorders, dementia, end-stage renal

failure, stroke and malignancy.

Patients who had speech impairment

or unable to speak Indonesian, and

were not cooperative during interview

were also excluded.

After obtaining approval from

institutional ethics board, due to

Corona Virus pandemic situation,

subjects were enlisted in two ways,

consecutive visit at Glaucoma clinic

and based on medical records. Data

search through medical records was

performed using the 10th Revision of

the International Statistical

Classification of Disease and Related

Health Problems (ICD-10) code with

diagnosis of primary open angle

glaucoma (code H40.1) and primary

angle closure glaucoma (code H40.2)

who have undergone Humphrey's

perimetry examination in November

2019 - May 2020. Patients who met

the inclusion criteria were contacted

via telephone, then given explanation

of the procedure and benefits of the

study.

Data collection includes the

patient's name, gender, age,

residential address, and contact

number. The socioeconomic status of

the patient including education level,

occupation, and income level was also

recorded. Data related to glaucoma

including diagnosis and type of

glaucoma, intraocular pressure,

history of anti-glaucoma medications

and eye surgery. Systemic disease and

treatment were also recorded. Visual

acuity, anterior segment examination

using slit lamp biomicroscopy,

intraocular pressure measurement

with Goldmann aplanation tonometer,

and evaluation of optic nerve with

Digital Wide Field lens or 78 D lens

were done. For subjects who could not

visit the glaucoma clinic, clinical

4

examination data were taken from the

latest visit.

Perimetry data used were

Humphrey Visual Field 24-2 or 30-2

SITA Standard strategy with

reliability index fixation losses <20%,

false-negative and false-positive

errors <15%. The VFI values in better

eye were obtained for correlation

analysis with the NEI-VFQ-25

questionnaire.

The interview method was chosen

with the aim that all patients had same

perception for each question. All

scores from each subscale of each

respondent will be added up and

averaged to become a composite score

according to the NEI-VFQ-25

manual.

Data normality were analyzed

using the Kolmogorov-Smirnov test.

The statistical correlation between

numerical data used the Spearman

correlation test. The correlation

strength (r) based on the Guillford

criteria are: 0.0 - <0.2 = very weak or

negligible; 0,2 - <0,4 = weak; 0.4 -

<0.7 = moderate; 0.7 - <0.9 = strong.

Linear regression analysis was used to

assess the correlation strength and

direction (positive or negative)

between the VFI score and the

composite score.

RESULTS

The total medical record search

results were 349 datas, but the data

that fit the inclusion criteria were 102

datas. From these data, 28 subjects

could not be contacted via telephone,

and 2 subjects were excluded because

uncooperative during interview. Total

of 72 subjects met the inclusion

criteria, of which 18 subjects were

obtained from Glaucoma unit follow

up visits, while 54 subjects were

obtained from medical records.

Table 1 shows similar percentage

between male subjects (48.6%) and

women (51.4%). The mean age of

participants was 63.28 years. Majority

of patients had moderate level of

education (54.2%), and unemployed

(66.7%). Patients with low incomes

were 33.3%, while those with high

and very high incomes were 25%.

5

Table 1. Demographic Social Characteristics of Research Subjects

Variabel Total (n= 72) Percentage (%)

Gender

Male 35 48.6

Female 37 51.4

Age(Years)

Mean±SD 63.28±9.085

Rentang (minimal-maksimal) 41.00-80.00

Education Level

Low 25 34.7

Moderate 39 54.2

High 8 11.1

Occupation

Unemployed 48 66.7

Employee 11 15.3

Entrepreneur 12 16.7

Other 1 1.4

Income Level

Low 24 33.3

Moderate 12 16.7

High 18 25

Very High 18 25 Notes:SD = Standard Deviation

Subjects were primary open angle

glaucoma patients (56.9%) and

primary angle closure glaucoma

patients (43.1%). Most subjects had

good vision, 54.2% included in the

category of no visual impairment and

23.6% mild visual impairment (table

2). The mean intraocular pressure

were under control (<21 mmHg). The

median value of VFI in better the eye

is 78.50%.

6

Table 2. Clinical Characteristics of Research Subjects

Variable n=72 subjects , n (%)

Primary Glaucoma Types

Open Angle 41(56.9)

Closed Angle 31(43.1)

Visual Acuity (Better eye)

Good (≥ 6/12) 39 (54.2)

Mild (6/18 - < 6/12) 17 (23.6)

Moderate (6/60 - < 6/18) 12 (16.7)

Severe (3/60 - < 6/60) 4 (5.5)

Blindness (NLP - < 3/60) 0

Intraocular Pressure

Right Eye

Mean±SD 18.13±7.394

Left Eye

Mean±SD 15.67±4.876

Visual Field Index (Better Eye)

Median 78.50%

Range (min-max) 2.00-97.00%

Mean Deviation (Better Eye)

>-6 dB 17 (23.6)

6-12 dB 22 (30.6)

< - 12 dB 33 (45.8) Notes:SD = Standard Deviation.. NLP: No Light Perception

The result of Spearman correlation

test between the VFI variables with

each subscale variable and the

composite score from the NEI-VFQ-

25 questionnaire had a value of r =

0.251 - 0.746 (p <0.05). The color

vision subscale was not analyzed

because the response of subjects who

responded to color vision was less

than 50% (24 patients). The

correlation between the two variables

was conducted using the Guilford

criteria. Weak correlation was found

between VFI and the general health

subscale and eye pain. Strong

correlation was found between VFI

and the peripheral vision subscale (r =

0.70) and the composite score (r =

0.746), while other subscales had

moderate correlation (table 3).

7

Table 3. Correlation Analysis of Visual Field Index (VFI) with Composite Score and

Quality of Life Subscale using the NEI-VFQ-25 Questionnaire

A positive correlation was found

between VFI score and NEI-VFQ-25

composite score, with a linear

regression equation y = 0.484x +

38.034. The single linear regression

line in Figure 1 shows that the higher

the Visual Field Index value, the

higher the quality of life score on the

NEI-VFQ-25 questionnaire.

Variabel r Nilai p

VFI with Composite Score 0.746 0.0001*

VFI with General Health 0.251 0.033*

VFI with General Vision 0.683 0.0001*

VFI with Eye pain 0.378 0.0001*

VFI with Near Vision 0.605 0.0001*

VFI with Distance vision 0.683 0.0001*

VFI with Social Function 0.638 0.0001*

VFI with Mental Health 0.666 0.0001*

VFI with Role limitation 0.581 0.0001*

VFI with Dependency 0.607 0.0001*

VFI with Driving 0.633 0.001*

VFI with Color Vision Tidak dianalisis

VFI with Peripheral Vision 0.700 0.0001* Note: the significance value is p <0.05. The sign * indicates statistical significance,

r: correlation coefficient using the Spearman correlation test.

0.0

20.0

40.0

60.0

80.0

100.0

120.0

0 20 40 60 80 100 120

Co

mp

osi

t sc

ore

Visual Field Index score

y= 0,484x + 38,034

Figure 1. Scatter plot correlation of quality of life scores with Visual Field Index

8

Figure 2 shows an overview of the

results of each subscale score and

composite score of the NEI-VFQ 25

questionnaire. A score of 0 on the

NEI-VFQ-25 questionnaire is the

worst value, while a score of 100

indicates no visual impairment. The

highest score in this study is the social

function subscale (median 87.50),

while the lowest score is the driving

subscale (median 45.83). The mean

composite score of the NEI-VFQ-25

questionnaire from all subjects in this

study was 67.49.

Figure 2. Average scores of each subscale and composite scores of all patients

DISCUSSION

This study included 72 patients

with age range of 41 to 80 years. The

global glaucoma prevalence in the

population of 40-80 years is 3.54%.3

The prevalence of primary angle

closure glaucoma varies depending on

race and ethnicity. The risk of primary

glaucoma increases with age. In

primary open-angle glaucoma, people

over 70 years have a risk 3-8 times

higher than the age of 40 years.16

Age, gender, occupation,

environment, ethnicity, and culture

can influence the results of

quantitative assessments of quality of

life. The average composite score in

this study was 67.49. This value is

lower than similar quality of life

studies in patients with open-angle

primary glaucoma in Japan (mean

composite score 78.3).14 Most patients

in this study were not of productive

age (average age of 63.28 years), had

a history of moderate education level,

9

and had low income. Glaucoma

patients with a younger age and higher

education are reported to have a

higher quality of life score.17-19

The general health subscale in the

NEI-VFQ-25 questionnaire assesses

an individual's perception of his

general health as a supporting part of

vision-related quality of life. In this

study the general health subscale is

decreased (score 50). Sawada defines

the NEI-VFQ-25 score subscale as

low if a score below 59.17 Open angle

primary glaucoma patients have lower

general health scores than those

without glaucoma using the generic

health questionnaire SF-36.7 Further

studies by Sawada and Madonna

using NEI-VFQ-25 questionnaire

found a significant but weak

correlation between general health

and VFI (r = 0.197 and r = 0.201).14, 20

Similar results were also found in this

study (r = 0.251). Most of the patients

(45.8%) in this study had severe

glaucoma (MD > 12 dB). McKean-

Cowdin stated that the decline in

quality of life in terms of general

health can occur even in patients with

mild visual field loss (6 dB <MD <2

dB).

There is a different individual

perceptions between people with

glaucoma and non-glaucoma

regarding vision-related quality of

life. This individual perception is

generally assessed through the eye

health subscale score. This study

shows a moderate correlation (r =

0.683) between the decrease in visual

field with the eye health subscale. The

median eye health score for all

subjects in this study was 60. This

score was slightly lower than the

study by Sawada (score 66.6) and

Riva (score 65.8).14, 22 Loss of visual

field, decreased visual acuity, and

complex treatment history in

glaucoma correlated with the patients’

perception of their eye health.

A weak correlation (r = 0.378) for

the eye pain subscale is explainable

because patients with eye pain such as

acute glaucoma have been excluded.

Chun et al found that gender may

affect on eye pain complaints. Women

generally had lower eye pain scores

than male patients.23 In this study the

mean eye pain score in male patients

was 78.6 while in women was 72.3.

The median eye pain subscale score

in this study was 75. Although there

was a decrease in score, 67% of

patients in this study responded to

pain that was mild and did not

interfere with daily activities. In

glaucoma with severe visual field

loss, lower eye pain scores are also

associated with poorer vision in the

eyes.23 Controlled intraocular

pressure showed that complaints of

eye pain from most patients did not

originate from raised intraocular

pressure, but may come from ocular

10

surface conditions. Ocular surface

disease has a prevalence of 15% in

individuals over the age of 65 years

and increased to 59% in patients with

glaucoma.24

Psychosocial conditions assessed

in NEI-VFQ-25 questionnaire include

the mental health subscale, social

functioning, role limitations, and

dependency. These four subscales

have a moderate correlation. Social

function is the subscale with the most

minimal reduction (median score of

87.5). There may be ethnic and

cultural influences related to such

outcomes. Correlation results between

decreased visual field with the

incidence of depression in people with

glaucoma also still vary.25,26 The

effect of direct visual field decrease

on limitations in driving, fear of

falling, and poor balance mentioned

contribute to the relationship between

glaucoma and depression.7 Prevalence

of anxiety and depression in patients

with primary open-angle glaucoma

was evaluated in a case-control study

using the Hospital Anxiety and

Depression Scale (HADS). The

prevalence of patients with anxiety

(13.0%) and depression (10.9%) is

significantly higher than in the control

group (7% and 5.2%).27 The study

also states that glaucoma patients with

a younger age tend to have more

anxiety than with older ones.

However, many factors needed to be

explored further in assessing the

correlation between objective

measurements with mental health

conditions. The mental health

subscale can be more influenced by

the patient's individual perception of

his vision than by objective clinical

measurements. In addition, the

condition of depression itself can

cause worse response to the

questionnaire questions.

This study shows a moderate

correlation (r = 0.633) between the

value of VFI and driving. The

Salisbury Eye Evaluation study found

a strong correlation between the

visual field with nighttime driving,

even after adjusting for contrast

sensitivity factors.28 The Los Angeles

Latino Eye Study reports that

moderate to severe bilateral visual

field loss has a significant effect on

driving, whereas severe unilateral

vision has minimal effect on driving

ability.29 Several studies have shown

that glaucoma patients tend to change

their driving habits as a result of the

visual perception. Habits changes

include stop driving at night, reducing

the frequency and duration of driving,

and stop driving in unfamiliar places.

Compared with individuals without

glaucoma, the decision to stop driving

is significantly more common in

patients diagnosed with bilateral

glaucoma than unilateral. Patients

with bilateral glaucoma were three

11

times more likely to stop driving than

those without glaucoma.30 In this

study where all subjects had bilateral

glaucoma, 42% of subjects had

stopped driving after being diagnosed

with glaucoma.

The subjects' responses to the color

vision subscale differed from the

results of the other subscales The

NEI-VFQ-25 questionnaire contains

questions in the form of the patient's

ability to choose and match clothing.

Only 33% of patients still interested in

matching clothes, so the results of this

score could not describe the

assessment of all subjects for color

vision.

This study shows a strong

correlation (r = 0.70) between VFI

and peripheral field of view.

Mobilization is one of the daily

activities that is disrupted because of

visual field abnormalities in

glaucoma.

Positive and strong correlation was

shown between better eye VFI with a

composite score of quality of life

using the NEI-VFQ-25 questionnaire

(r = 0.746). Worsening of visual field,

as seen from the lower VFI score,

causing lower quality of life score on

the NEI-VFQ-25 questionnaire. This

indicates that VFI can potentially be

used as an indirect measure in

monitoring visual disability in the

management of glaucoma patients.

This finding also shows that clinicians

should not only pay attention to

poorer eye, but also to better eyes to

prevent glaucoma worsening and

result in decreased quality of life.

There are several limitations in this

study, including the potential for

reporting bias due to interviewer

differences. However both

interviewers have minimized this by

conducting the interview method as

much as possible in accordance with

the sentences listed in the

interviewer's NEI-VFQ-25

questionnaire format. Another

limitation of this study is not

analyzing the influence of

socioeconomic factors and

psychological conditions. Objective

measurements of the contrast

sensitivity, glare and stereoacuity was

also not done. Individual subjectivity

factors may make the results of the

questionnaire do not truly reflect the

actual disturbance experienced by

patients in their daily activities. The

use of performance-based tests may

provide a more objective

representation of decreased visual

field experienced by people with

glaucoma in their daily activities.

CONCLUSION

Positive and strong correlation was

found between visual field index

scores with the quality of life in

glaucoma patients using the NEI-

VFQ-25 questionnaire.

12

REFERENCES

1. Saunders, L. J., Medeiros, F. A

dkk. What rates of glaucoma

progression are clinically

significant? Expert Review of

Ophthalmology. 2016;11(3):

227–234

2. Ichhpujani P. Kumar S. What’s

New in Pathogenesis of

Glaucoma. In: Glaucoma. First

Edition. Singapore:

Springer;2019: p.1-2

3. Tham, Y.C., Li, X dkk. Global

Prevalence of Glaucoma and

Projections of Glaucoma Burden

through 2040. Ophthalmology.

2014; 121(11): 2081–90.

4. Balantrapu T. Latest Global

Blindness & Visual Impairment

prevalence figures published in

Lancet [document on the

Internet]. IAPB; 2017 [cited

2020 January]. Diunduh dari:

http:/

https://www.iapb.org/news/latest

global-blindness-vi-prevalence-

figures published-lancet/

5. Pascolini, D., & Mariotti, S. P.

Global estimates of visual

impairment: 2010. British

Journal of Ophthalmology.2011;

96(5): 614–618.

6. European Glaucoma Society.

Terminology and guidelines for

glaucoma. 4thed. Savona, Italy:

DOGMA; 2014.

7. Quaranta, L., Riva, I. dkk.

Quality of Life in Glaucoma: A

Review of the Literature.

Advances in Therapy. 2016;

33(6);959–81.

8. Mangione CM, Lee PP, Gutierrez

PR, et al; National Eye Institute

Visual Function Questionnaire

Field Test Investigators.

Development of the 25-item

National Eye Institute visual

function questionnaire. Arch

Ophthalmol 2001;119(7):1050–8

9. Kumar, S., Thakur S, Ichhpujani

P. The impact of primary open-

angle glaucoma: Comparison of

vision-specific (National Eye

Institute Visual Function

Questionnaire-25) and disease-

specific (Glaucoma Quality of

Life-15 and Viswanathan 10)

patient-reported outcome (PRO)

instruments. Indian J

Ophthalmol. 2019; 67(1): 83–88.

10. Heijl A; Vincent M P; Bengtsson

B. Effective Perimetry. Fourth

Edition. Dublin, CA : Carl Zeiss

Meditec Inc.; 2012:pp.1-22, 45-

72

11. Shaarawy TM, Sherwood MB,

dkk. Glaucoma Medical

Diagnosis and Therapy. Second

Edition. Philadelphia: Elsevier;

2015: pp.128-9, 272-3, 510-9

12. Bengtsson, B., & Heijl, A. A

Visual Field Index for

Calculation of Glaucoma Rate of

Progression. American Journal of

Ophthalmology.2008;145(2):

343–353.

13. Peters, D., Heijl, A., Brenner, L.,

& Bengtsson, B. Visual

impairment and vision-related

quality of life in the Early

Manifest Glaucoma Trial after 20

years of follow-up. Acta

Ophthalmologica.2015;93(8);

745–752

13

14. Sawada, H., Fukuchi, T., & Abe,

H. Evaluation of the relationship

between quality of vision and the

visual function index in Japanese

glaucoma patients. Graefe’s

Archive for Clinical and

Experimental

Ophthalmology.2011; 249(11):

1721–1727

15. Rosalina D, Harijo W. Visual

Field Abnormality and Quality of

Life of Patient with Primary

Open Angle Glaucoma. Jurnal

Oftalmologi Indonesia. 2011;

7(5): 175−180

16. American Academy of

Ophthalmology. Section 10:

Glaucoma: Introduction to

Glaucoma: Terminology,

Epidemiology, and Heredity. In :

Basic and Clinical Science

Course. San Fransisco: American

Academy of Ophtalmology;

2019.

17. Medeiros, F. A., Gracitelli, C. P.

B., et al. Longitudinal Changes in

Quality of Life and Rates of

Progressive Visual Field Loss in

Glaucoma Patients.

Ophthalmology,2015;122(2):293

–301.

18. Sawada H, Fukuchi, T., &

Haruki, A. Evaluation of the

relationship between quality of

vision and visual function in

Japanese glaucoma patients.

Clinical Ophthalmology, Clinical

Ophthalmology 2011:5:259–67

19. Kuo, Y.S., Liu, C. J, et al. Impact

of socioeconomic status on

vision-related

quality of life in primary open-

angle glaucoma.

Eye.2017;31(10):1480–7.2010

[diunduh 17 Januari 2020].

Tersedia dari:

https://onlinelibrary.wiley.com/d

oi/abs/10.1111/j.1755-

3768.2010.4356.

20. Madonna R.J., D. Rutner, L.

Nehmad. Investigating the

Association between Visual

Field Index Scores and NEI

VFQ-25 Scores in Glaucoma

Patients. Investigative

Ophthalmology & Visual

Science [abstract]. 2019;50:3771

[diunduh 17 Januari 2020].

Tersedia dari:

https://iovs.arvojournals.org/arti

cle.aspx?articleid=2366157

21. McKean-Cowdin, R., Varma, R.,

et al. Severity of Visual Field

Loss and

Health-related Quality of Life.

American Journal of

Ophthalmology, 2007;143(6):

1013–23

22. Riva, I., Legramandi, L., dkk.

Vision-related quality of life and

symptom

perception change over time in

newly-diagnosed primary open

angle glaucoma patients.

Scientific Reports. 2019;9(1)

23. Chun, Y. S., Sung, K. R., Park, C.

K., et al. Factors influencing

visionrelated

quality of life according to

glaucoma severity. Acta

Ophthalmologica.

2019;97(2):216-24.

24. Leung EW, Medeiros FA,

Weinreb RN. Prevalence of

ocular surface disease in

glaucoma patients. J Glaucoma.

14

2008;17:350–5.

25. Skalicky, S. E., Martin, K. R,

dkk. Cataract and quality of life

in patients

with glaucoma. Clinical &

Experimental Ophthalmology.

2014;43(4), 335–41.

26. Jampel HD, Frick KD, Janz NK,

et al. Depression and mood

indicators in newly diagnosed

glaucoma patients. Am J

Ophthalmol 2007;144(2):238-

44.

27. Mabuchi F, Yoshimura K,

Kashiwagi K, et al. High

prevalence of anxiety and

depression in patients with

primary open-angle glaucoma. J

Glaucoma.2008;17:552–7.

28. Freeman EE, Munoz B, West SK,

Jampel HD, Friedman DS.

Glaucoma and quality of life: the

Salisbury eye evaluation.

Ophthalmology. 2008;115:233–

8.

29. McKean-Cowdin R, Wang Y

dkk. Impact of Visual Field Loss

on Health-Related Quality of

Life in Glaucoma. The Los

Angeles Latino Eye Study.

Ophthalmology.2008; 115:941-8

30. Freeman EE, Munoz B, Turano

KA, West SK. Measures of

visual function and their

association with driving

modification in older adults.

Invest Ophthalmol Vis Sci.

2006;47:514–20.