Subject(s)
Cataract/epidemiology , Laser Therapy , Lens Capsule, Crystalline/pathology , Lenses, Intraocular , Postoperative Complications/epidemiology , Biocompatible Materials , Cataract/etiology , Humans , Lens Capsule, Crystalline/surgery , Lens Implantation, Intraocular , Phacoemulsification , Postoperative Complications/surgeryABSTRACT
AIM: To design, develop and test a system for analysis of photic phenomena. METHOD: Extensive background research, patient interviews and theoretical studies led to development of a set of photographic images resembling photic phenomena experienced by patients. These photographic images were processed and digitally altered to create scales of severity for each photic phenomenon in which patients indicated their severity of symptoms by choice of image. The system was tested for stability and validity. RESULTS: The system showed excellent repeatability and reliability. Face, content, criterion and construct validity were all found to be acceptable. CONCLUSION: The photographic images of photic phenomena analyser is an acceptable, validated measure for the assessment of photic phenomena, in both pseudophakic patients and those with cataract.
Subject(s)
Glare , Light , Severity of Illness Index , Surveys and Questionnaires , Vision Disorders/diagnosis , Choice Behavior , Humans , Photography , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
PURPOSE: To develop and test a questionnaire to assess quality of vision in pseudophakic patients. METHODS: The problems with existing health measurement scales and the need for a new questionnaire are first discussed. Development of the new questionnaire from concept to completion is presented and all stages discussed. The questionnaire is then tested for internal consistency, reliability and validity. RESULTS: The Cronbach Alpha for internal consistency was 0.92. British Standards Institution repeatability coefficient was satisfactory at 6.6. Discriminant construct validity testing by extreme groups demonstrated excellent discrimination between patients with functionally significant posterior capsule opacification (PCO) and no significant PCO (Mann-Whitney U test, p = 0.001). CONCLUSION: The questionnaire is validated as a robust, stable measure of pseudophakic visual symptoms with a high degree of clinical utility. It should be invaluable for the many studies that compare outcomes from different forms of modern cataract surgery with implantation of different intraocular lenses.
Subject(s)
Pseudophakia/psychology , Quality of Life , Vision, Ocular/physiology , Activities of Daily Living , Cataract Extraction , Health Status Indicators , Humans , Patient Satisfaction , Reproducibility of Results , Self-Assessment , Surveys and Questionnaires , Treatment Outcome , Visual AcuityABSTRACT
This paper demonstrates the wide variety of systems for the analysis of posterior capsular opacification (PCO). No single system has been proved to be a gold standard and it is difficult to comment on the advantages of one system over another with the limited current knowledge on the effects of PCO on vision. There are few studies that actually compare the different systems of analysis. Researchers must ensure that the systems they use for PCO analysis are objective and must give maximum consideration to ensuring potential systematic errors are reduced to a minimum. Further research is required into how the various types and locations of PCO affect vision and how well different systems of analysis perform.
