Download Discipline of Optometry and Vision Science

Discipline of Optometry and Vision Science
PhD 2012
Title: Development of the corneal and the ocular surface (OSD) disease-specific item
banks to measure quality of life parameters
Brief outline of the project:
The cornea is the clear layer at the front of the eye and is critically important in
creation of an optical image in the eye. There are many diseases that affect the
cornea, leading to decreased vision and quality of life. The measurement of healthrelated quality of life (QOL) from the patient’s perspective is increasingly being
accepted as a valuable tool in clinical research. In addition to understanding the
burden of the disease, QOL assessment is instrumental for understanding treatment
efficacies. Therefore, QOL assessment in patients with corneal diseases is
paramount, in which a profound decrease in QOL has been observed.
Similarly, ocular surface diseases (OSDs) such as dry eyes are one of the
commonest reasons for patients’ visits to eye clinics. OSDs are often manifested with
symptoms (e.g. discomfort, pain, visual disturbances) which may lead to severe
compromise in visual function and subsequently poor quality of life (QOL). However,
measurement of QOL in patients with OSDs is currently limited by shortcomings of
available questionnaires.
Until now, there is no corneal disease-specific questionnaire available. Several
studies have used generic or other disease-specific questionnaires to assess the
impact of corneal diseases on patients. However, evidence suggests that these
questionnaires were not sensitive enough to capture the actual impact of the QOL in
patients with corneal diseases. Moreover, these existing questionnaires do not offer a
comprehensive and precise assessment of QOL. In case of OSDs, nineteen dry eyespecific questionnaires have been developed until now. However there are none
available for other wide spectrum of OSDs. On the other hand, the available
questionnaires are limited to measuring symptoms but not the holistic impact of the
disease on patient’s QOL.
An innovative approach called item banking with computer adaptive testing (CAT)
offers a scientifically improved approach to measuring the patient’s point of view
compared to old-fashioned questionnaires. Therefore, the overarching aim of the
study is to develop a corneal-disease and OSD-specific item banks to enable
comprehensive, efficient and precise measurement of QOL in patients with OSDs.
This study will require a full time student for a period of three years.
The first phase of the study is to identify content (items) for the OSD-specific item
bank. This involves qualitative approaches (literature review and focus groups with
patients and experts). The student will conduct a thorough literature review to identify
existing content. The student will recruit patients with OSDs from clinical settings and
participate in conducting and recording focus groups. Focus group output will be
transcribed and analysed to identify new content. All content will then be aggregated
and refined into pilot questionnaires (separate for each disease groups).
The second phase of the study is to calibrate items using a modern psychometric
assessment method called Rasch analysis. This includes administration of the pilot
questionnaires and quantitative analysis of the pilot data. The student will recruit
patients from clinical settings and administer pilot questionnaires, collate data and
analyse them. The calibrated items will be used to develop a CAT system to
implement the item banks.
The third phase includes validation of the item banks implemented via the CAT
system. This includes administration of the item banks using the CAT system to
corneal and OSD patients and people without any eye disease. The student will
recruit participants from the clinical settings and the community and administer the
item banks via a CAT system, collate data and carry out analysis for the validation of
the CAT system.
Key references:
1. Dougherty BE, Nichols JJ, Nichols KK. Rasch Analysis of the Ocular Surface
Disease Index (OSDI). Invest Ophthalmol Vis Sci 2011;52:8630-8635.
2. Kymes SM, Walline JJ, Zadnik K, Sterling J, Gordon MO. Changes in the
quality-of-life of people with keratoconus. Am J Ophthalmol 2008;145:611617.
3. Pesudovs K. Item banking: a generational change in patient-reported
outcome measurement. Optom Vis Sci 2010;87:285-293.
4. Wainer H. Computerized adaptive testing. A primer. 2nd ed. Mahway, NJ:
Lawerance Erlbaum; 2000.
5. Krueger R.A. Focus groups : a practical guide for applied research. 2nd ed.
Thousand Oaks,Calif: Sage Publications, c1994.
6. Bond TG, Fox CM. Applying the Rasch Model: Fundamental Measurement in
the Human Science. Second ed. London: Lawerance Erlbaum Associates;
2007.
7. Linacre JM. WINSTEPS Rasch measurement (Computer Program). 7.70.0
Chicago Winsteps; 2010.
Suitable applicants
This project may suit students from a diverse range of backgrounds. Optometrists,
medical graduates, sociologists, psychologists, nurses, medical scientists and other
health professionals are all encourages to apply.
Supervisors’ contact details:
Prof Konrad Pesudovs, Discipline of Optometry and Vision Science, Flinders Medical
Centre; Phone: 08 8204 5732; Email: [email protected]
Dr Jyoti Khadka, Discipline of Optometry and Vision Science, Flinders Medical
Centre; Phone: 08 8204 5730; Email: [email protected]
Entry requirements/scholarships
Details about the entry requirements, application form and scholarships can be found
in the following link
http://www.flinders.edu.au/medicine/sites/research-higher-degrees/programsavailable/doctor-of-philosophy.cfm