Keratoconus and the Impact of Treatment on Patients' Quality of Life: A Qualitative Study

Abstract

Introduction: Keratoconus has a significant impact on patients' quality of life (QoL), from diagnosis to the advanced stages of the disease. The aim of this research was to identify domains of QoL affected by this disease and its treatment.

Methods: Phone interviews were conducted using a semi-structured interview guide, with patients with keratoconus stratified according to their current treatment. A board of keratoconus experts helped identify the guide's main themes.

Results: Thirty-five patients (rigid contact lenses, n = 9; cross-linking, n = 9; corneal ring implants, n = 8; and corneal transplantation, n = 9) were interviewed by qualitative researchers. Phone interviews revealed several QoL domains affected by the disease and its treatments: "psychological", "social life", "professional life", "financial costs" and "student life". All domains were impacted, independently of the treatment history. Few differences were found between treatment regimens and keratoconus stages. Qualitative analysis enabled the development of a conceptual framework based on Wilson and Cleary's model for patient outcomes common to all patients. This conceptual model describes the relationship between patients' characteristics, their symptoms, their environment, their functional visual impairment and the impact on their QoL.

Conclusions: These qualitative findings supported the generation of a questionnaire to evaluate the impact of keratoconus and its treatment on patients' QoL. Cognitive debriefings confirmed its content validity. The questionnaire is applicable for all stages of keratoconus and treatments and may help tracking change over time in regular clinical settings. Psychometric validation is yet to be performed before its use in research and clinical practices.

Keywords: Contact lens; Corneal ring implantation; Corneal transplantation; Cross-linking; Keratoconus; Patient-reported outcomes; Quality of life; Questionnaire.

Fig. 1

Conceptual model of keratoconus and its treatment impact on patients’ lives. The conceptual model was developed and interpreted by the analyst using Wilson and Cleary’s model. The thickness of the arrows symbolizes the intensity of the relationship between the themes as reported by the analyst. As our aim was to develop a quality-of-life questionnaire, we did not explore in depth the detailed evaluation and interpretation between the detailed concepts but only between the general concepts

Fig. 2

Cumulative percentage of new concepts during interviews with RGPCL, CXL, ICRS and corneal transplantation patients. RGPCL patients: 61% of the concepts were found in the first interview (n = 9), and 96% of the concepts were obtained in the sixth interview. Total number of concepts, 29. CXL patients: 65% of the concepts were found in the first interview (n = 9), and 87% of the concepts were obtained in the third interview. Total number of concepts, 30. ICRS patients: 71% of the concepts were found in the first interview (n = 8), and 90% of the concepts were obtained in the fourth interview. Total number of concepts, 38. Corneal transplantation patients: 52% of the concepts were found in the first interview with corneal transplantation patients (n = 9), and 92% of the concepts were obtained in the fourth interview. Total number of concepts, 41. RGPCL stands for rigid gas permeable contact lens; CXL for corneal cross-linking; ICSR for intracorneal stromal rings; P for patient; and BL for baseline