Web-based automated vision testing for cataract surgery outcome monitoring

Project Details

Cataract surgery is one of the most common surgical procedures carried out. Surgical outcomes vary and depend on various factors, including lens maturity, secondary pathology, as well as surgeon performance. In order to ensure high standards of quality, systematic monitoring of cataract surgical outcomes is required.

At the same time, eye clinics and hospitals do not commonly collect and evaluate surgical outcomes in a standardized way. Few governments request cataract surgical outcomes data for quality assurance purposes.

Reported reasons for the lack of a systematic monitoring of cataract surgical outcomes include additional time required and unwillingness of the surgeon to share potentially sensitive information. In order to overcome the barrier of subjective visual acuity assessment, CERA researchers recently developed a web based data collection system and technology to objectively measure visual acuity in real time (Patent # CN104000553B Double-masked electronic visual acuity testing).

he video link https://www.youtube.com/watch?v=UsQf90livYc&list=UUM1PyPNY3x_cz86VfNk28XA provides a demonstration of the system in use. Here, the testing distance, ideally between 3 and 5 meters, is automatically measured using the 4 LED lights mounted on the paddle used to occlude the non-tested eye. VA, calculated from the correctly-identified optotypes and the measured distance, is automatically saved directly to the web-based system without revealing the outcome to either the examiner or patient. All results are synchronized to a server using the patient's fingerprint as a unique identification code. In preliminary trials involving 95 participants, all subjects successfully completed testing and VA outcomes correlated strongly with results from a conventional visual acuity chart. In addition, better reproducibility was achieved with the new system as compared to conventional VA testing.

Following pilot interventions in China, CERA aims to make this technology available to government and non-government services across the region.

Areas of interest:
*Quality assurance of eye care services
*Validation studies and tool development for large scale cataract surgical outcomes monitoring in hospitals
*Technology development for objective visual acuity assessment
*Expand the automated visual acuity measurement method to other areas, such as screening and at home vision testing.


Dr Andreas Muller, Deputy Director of WHO Collaborating Centre

Dr Liying Li, Research Assistant

Ms Candy Han Yue, Program coordinator

Dr William Yan, PhD student

Research Group

Ophthalmic Epidemiology Group

Faculty Research Themes

Infection and Immunology

School Research Themes

Critical Care

Key Contact

For further information about this research, please contact the research group leader.

Department / Centre


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