DEVELOPING AND VALIDATION OF AN DEVELOPING AND VALIDATION OF AN ARABIC VERSION OF THE VISUAL ARABIC VERSION OF THE VISUAL

FUNCTIONING INDEX VF14 FOR CATARACT FUNCTIONING INDEX VF14 FOR CATARACT

PATIENTSPATIENTS

Abdulrahman Al-Muammar, MD, FRCSCAbdulrahman Al-Muammar, MD, FRCSC

King Abdul Aziz University HospitalKing Abdul Aziz University Hospital

College of MedicineCollege of Medicine

King Saud UniversityKing Saud University

Mr Ahmed MousaMr Ahmed Mousa

Dr Hatem KalantonDr Hatem Kalanton

Dr Ali AlghamdiDr Ali Alghamdi

RATIONALE

The rationale for developing this index was the need for a tool that can accurately measure the outcome of cataract surgeries whereas visual acuity was found to be an incomplete measure to do that

It has been first developed by Earl P. Steinberg in the early nineties

(Earl P. Steinberg et al (1994)

The index has been widely accepted and utilized in different purposes including

• measuring the impact of ocular diseases on vision• estimation of need for cataract surgery • evaluation and comparison of different surgical

techniques related to visual functioning• cataract outcome assessment

THE VF 14The index has been used to support research in:

GlaucomaRetinaCorneaMacular degenerationLow visionPrevention of blindness

In different languages

African regionFrench GermanChineseItalianSpanish

CATARACT AS A CAUSE OF LOW VISION AND BLINDNESS

45%

55%

Catarcat Other Causes

52.2 million inhabitants are blind from cataract in the middle east region. WHO report (2004)

Due to the large number of Arabic speaking Due to the large number of Arabic speaking countries who are around 300,000,000 countries who are around 300,000,000 inhabitants and dramatic increase in ocular inhabitants and dramatic increase in ocular science research in the Arabic region, there is science research in the Arabic region, there is a tremendous need to develop and validate a a tremendous need to develop and validate a reliable Arabic version of the VF 14reliable Arabic version of the VF 14

ESSENTIAL STEPS OF VALIDATION PROCESS

MethodsMethodsThe original VF 14 questionnaire was solely The original VF 14 questionnaire was solely translated into Arabic language by two different translated into Arabic language by two different ocular researchersocular researchers

The two version were matched and unifiedThe two version were matched and unified

The new Arabic questionnaire was translated back to The new Arabic questionnaire was translated back to English by a third researcher (ophthalmologist)English by a third researcher (ophthalmologist)

Native English speaker researcher was asked to Native English speaker researcher was asked to match the original and the re-translated versionsmatch the original and the re-translated versions

Minimal modifications took place by the research Minimal modifications took place by the research team to formulate a final version of the Arabic VF 14team to formulate a final version of the Arabic VF 14

MethodsMethods

Cataract medical forms were filled by an Cataract medical forms were filled by an ophthalmologistophthalmologist

• Snellen’s visual acuitySnellen’s visual acuity• Global measure of visionGlobal measure of vision• Cataract symptoms scoreCataract symptoms score

The Arabic VF 14 questionnaire was The Arabic VF 14 questionnaire was done by an ophthalmic techniciandone by an ophthalmic technician

Methods

Scoring of the VF 14 indexGlobal measure of visionCataract symptoms score

Testing validity using Pearson correlation test between the VF 14 and three international standardized tools:

Global measure of visionCataract symptoms scoreSnellen’s visual acuity LogMAR score

Testing reliability using Cronbach’s Alpha test

RESULTS

1380 patients representing four hospitals;

Two in Egypt

Two in Saudi Arabia

Mean (SD) age : 63.41 (11.19).

840 (60.9%) males

540 (39.1%) females

Arabic VF Score: mean (SD) = 62.18 (19.34)

61%

39%

Male Female

VALIDATION RESULTS

Correlation with:

Cataract Symptoms Score. p < 0.0001

Global measure of vision.• Trouble index. p < 0.0001• Dissatisfaction index. p < 0.0001

Visual Acuity (LogMAR): p < 0.0001

RELIABILTY RESULTS

Cronbach’s α test:

α = 0.763, 95% CI: [0.743 – 0.782].

P value < 0.0001

MEASUREMENTS OF VF 14 INDEX AT LEVELS OF VISUAL ACUITY

Normal

Low Vision

Severe L. V.

Blind

0

10

20

30

40

50

60

70

80

90

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

FV 1

4 In

dex

(Sco

re)

Visual Acuity Scale (Log MAR)

CONCLUSIONThe Arabic VF 14 is a reliable and valid tool for evaluation of both visual functioning and quality of visual life among cataract patients who are being prepared for cataract surgery

The VF 14 can be used in evaluating visual functioning as an outcome of surgical intervention either in cataract or in other ocular diseases

It can be also used in decision making process for surgical interventions and for prioritization of surgical waiting lists

Arabic VF 14 would facilitate comparing and contrast research results with similar results worldwide