Abstract
Purpose: :
Evaluation of reliability and item validity of a questionnaire for the quantification of subjective optical quality and subjective optical symptoms in patients after cataract surgery.
Methods: :
The questionnaire was completed on two consecutive days by 50 patients 1 month after uncomplicated phacoemulsification with intraocular lens implantation. The data of 50 ametropic subjects served as a control. A visual analog scale marked the values on a scale from 0 ("perfect") -100 ("extremely poor"). The self rated quality of vision (SQV) and the intensity of the symptoms "glare", "halos", "starbursts", "blurred vision", "ghosting" where requested for three different lighting conditions (photopic, high-mesopic and low-mesopic) and for both eyes separately. Bland Altman analysis and multiple regression analysis were used to analyze the repeatability of the individual items as well as the impact of individual symptoms on SQV.
Results: :
The coefficient of repeatability (COR) of the group of the ametropics for the SQV was 11 under pohotopic conditions (high-mesopic: 9.1; low-mesopic: 13.3). The average COR of the symptom scores was 12±10 (photopic); 14±6 (high-mesopic) and 15±5 (low-mesopic). On the contrary, the COR values for the SQV (12.6, 13 and 15.8) as well as the symptom scores (11.7±6, 11±8, 12.3±7) were lower in the cataract-group. The SQV of both groups could largely be explained by the queried symptoms (ametropics: adjusted R 2: 0.76, 0.84, 0.91; cataract group: 0.74, 0.84, 0.85)
Conclusions: :
The scores collected by the questionnaire could be obtained with a satisfactory repeatability. The Selection of the queried symptoms appears to be valid to describe the overall subjective quality of vision.
Clinical Trial: :
http://www.kgu.de/index.php?id=735, 40796
Keywords: quality of life • treatment outcomes of cataract surgery