Accuracy of Perceived Cause of Glaucoma: Impact on Treatment and Perception

Abstract

Purpose : The perceived cause of the disease is an important and modifiable factor linked with treatment outcomes but has yet to be fully assessed in primary open-angle glaucoma (POAG). This study aimed to assess the accuracy of patients’ perceived cause of POAG and its association with medication adherence and illness perceptions.

Methods : Patients with POAG completed the Brief Illness Perception Questionnaire, which contains 8 questions assessing illness perceptions. The 9^th question asks patients to rank the 3 most important causes of their disease. POAG risk factors published by the American Academy of Ophthalmology were used to code responses as accurate or inaccurate. Using three different methods (Ms), accuracy was assessed based on: all ranks (M1), the 1st rank (M2), and all ranks, which were then weighted (M3). Medication adherence was measured electronically. Mann-Whitney U test was used to detect differences in medication adherence and illness perception between accuracy groups.

Results : Of the 114 eligible patients, 97 (69.1 ± 8.2 years) identified a cause for their POAG. The proportion of patients who reported an accurate cause was 86.6% (M1), 78.4% (M2), and 79.4% (M3) (p<0.001 for all Ms). Patients who reported an accurate cause were younger (68.4 ± 8.2 versus 73.8 ± 6.1 years) only using M1 (p=0.01). Mean medication adherence was 86.0% ± 17.8 and was similar between accuracy groups (p>0.05 for all Ms). Using M2 and M3, patients who reported an accurate cause believed that their illness would last for a longer time compared to patients who reported an inaccurate cause (p=0.03). M3 showed that patients who reported an accurate cause for their POAG had a lower perceived understanding of their illness (p=0.048).

Conclusions : Older patients were less likely to report an accurate cause for their POAG, suggesting that interventions to improve health literacy and disease knowledge may be useful in this high-risk group. Patients who reported an accurate cause believed that their disease would last longer, consistent with the lifelong nature of POAG. However, these patients also had lower perceived POAG knowledge. It is possible that greater awareness of the complex nature of the causes of POAG resulted in less confidence in their knowledge level. This study highlights the close link between disease knowledge and illness perceptions.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.