Abstract
Abstract: :
Purpose: To evaluate the physical properties of the eye patch and their influence on adherence as part of the study identifying risk factors for non–adherence to occlusion therapy for amblyopia. Methods: Four brands of patches were used: 3M, Beiersdorf, Pro–Ophta and Orthopad. The physical and mechanical properties of the patches were measured: water vapour resistance at 23°C and 33°C, resistance to water penetration, opacity, and maximum force grab method. In all children the brand of used patches was registered and by means of a questionnaire (filled in by the parents) comfort, size, adhesion and hygiene of the patch was assessed. For 30 months, since July 2001, adherence was measured in all newly diagnosed amblyopic children. Univariate analysis and logistic regression were performed to calculate the influence of the various patch parameters on the level of adherence. Results: 303 children were included; 171 used 3M, 85 Orthopad, 28 Pro–Ophta and 19 Elastopad. Physical properties of the patch included that one brand had moderate water permeability at 23°C (Orthopad) and two had good water permeability at 33°C (Pro–Ophta and Orthopad). All brands, except Orthopad were water resistant. One brand was able to eliminate more than 70% of the light transmitted (Beiersdorf), whereas other brands eliminated 20% (3M), 48% (Pro–Ophta) and 50% (Orthopad) of the light. To remove the patches from the skin an average force of 2.6 Newton (Pro–Ophta), 3.2N (3M), 5.9 N (Orthopad), and 8.8 N (Beiersdorf) was necessary. The brand of patch prescribed was not significantly related to the age of the children, cause of amblyopia, start acuity or the number of prescribed hours of occlusion. It was, however, significantly related to gender (p=0.016), in a sense that 3M patches were prescribed especially for boys. Adherence was not significantly related to the brand (p=0.381), neither to the use of different colors (p=0.263) nor the stickers (p=0.268). Conclusions: When prescribing a certain brand the wide variety in physical properties of the patch need to be considered. Further study into these properties is necessary; especially water permeability and opacity of the eye patch require improvement since children often wear them for a longer period of time.