A total of 122 patients with RP were included in the analyses: of these, 55 (45.1%) were men and 67 (54.9%) were women. Most of the survey responses were collected via the web-based survey (n = 101); 21 patients provided information via telephone interviews. The demographics and clinical/disease characteristics of the survey participants are presented in Table 1. The mean age of the patients was 57.4 years (n = 120), with only one patient aged < 18 years; 50/122 (41.0%) patients were employed, and 4/122 (3.3%) were students; 120/122 (98.4%) patients had a physical disability certificate (provided by prefectural governors, designated city mayors, or core city mayors to persons with physical disabilities as specified in the Act on Welfare of Physically Disabled Persons in Japan), with 45/122 (36.9%) classified as grade 1 and 67/122 (54.9%) as grade 2. Overall, 64/122 (52.5%) patients reported visual acuity < 0.05 (3/60), corresponding to “blindness” on the WHO definition of distance vision impairment. The distribution of visual impairment classes ranged from “near-normal vision” [5/122 (4.1%)] to “total blindness” [17/122 (13.9%)], as described by the AMA Guides.

The economic impacts evaluated in patients with RP included both direct out-of-pocket costs (including vision aids, medications and supplements, formal care including healthcare services, and paid care) and indirect costs from opportunity loss (including salary gaps and the costs of mental health effects), as shown in Table 2. The annual cost per patient was estimated to be 218,520 yen (2176 USD), with a calculated estimated lifetime cost per patient of 18,523,909 yen [184,501 USD; total annual cost × average life expectancy in Japan (84.77 years)]. Out-of-pocket costs stratified by demographic characteristics are reported in Table S1 in the electronic Supplementary Material. The responses to questions regarding the impact of the coronavirus disease 2019 (COVID-19) pandemic indicated that COVID-19 had almost no impact on outcomes in the study.

Additional exploratory analyses on the economic impacts on patients with RP, including robustness testing to exclude patients with inconsistent responses to visual impairment questions (n = 4) and outliers, are presented in Table 3. Each of the calculated costs with robustness testing is presented in Table S2 in the electronic Supplementary Material. This subset analysis revealed an increased estimated annual cost per patient and lifetime cost per patient of 783,176 yen (7801 USD) and 66,389,827 yen (661,253 USD), respectively.

The use of healthcare services by patients with RP is presented in Table 4. Out of 122 patients, 64 (52.5%) patients reported consulting with ophthalmologists who specialized in RP, and 79 (64.8%) patients reported consulting with general ophthalmologists. The majority of patients (96.7%) reported consulting with ophthalmologists. The use of vision aids by patients with RP is presented in Table 5. Of 122 patients, 97 (79.5%) patients reported using white canes, and 96 (78.7%) patients reported using smartphone apps as vision aids. Most patients [111/122 (91.0%)] reported paying for vision aids in the past, and approximately half [66/122 (54.1%)] reported paying for vision aids within the last year.

The care received by patients with RP is presented in Table 6. In total, 64/122 (52.5%) patients reported receiving paid care and 87/122 (71.3%) reported receiving unpaid care. Patients with more severe visual acuity loss, reflected in visual impairment class (AMA), reported receiving significantly more hours of paid care compared with patients with less severe visual acuity loss (Fig. S1, electronic Supplementary Material). Patients with a visual impairment class (AMA) of “total blindness” or “near-blindness” received 322.9 and 274.2 h of paid care per year, respectively, whereas patients with severe low vision received 38.4 h of paid care (“total blindness,” p = 0.004, and “near-blindness,” p = 0.0002).

Financial aid received by patients with RP is presented in Table 7. Overall, 102/122 (83.6%) patients reported receiving a disability pension, whereas 16/122 (13.1%) patients reported receiving no financial aid. The mean total amount of financial support received was 97,830 yen (974 USD) per patient per month. There was a loss of work productivity of 26.2%, which was attributable to presenteeism. The impact on daily activities, other than work, was 31.6% (Table S3, electronic Supplementary Material). The overall employment rate of patients was 41.0% (50/122). Employed patients or working patients (n = 50) included those who were self-employed or employed by companies or corporations. Among patients who were employed by companies or corporations (n = 39, mean age 49.3 years), 56.4% (22/39) of the patients stated that they were in regular employment. The average annual income of working patients was 5,217,078 yen (51,963 USD) (n = 37, mean age 51.7 years). The overall employment rate, the regular employment rate, and the average annual income of working patients in this study [41.0%, 56.4%, and 5,217,078 yen (51,963 USD), respectively] were lower than those in the age-group-matched general Japanese population [82.2%, 68.8%, and 5,916,800 yen (58,932 USD), respectively] [19, 20].

In the robustness analysis, after removing outliers and data from patients with inconsistent responses to visual impairment questions, the average annual income of working patients was reduced to 2,938,625 yen (29,269 USD) (n = 35, mean age 52.1 years). Within the population of employed patients, there was a bias towards professional/technical work [26/50 (52.0%)] and clerical work [14/50 (28.0%)]; there were no sales personnel or manufacturing process workers among the study patients. Furthermore, of the patients employed in professional/technical work, 12/26 (46.2%) were employed in professions such as acupuncture, massage, and moxibustion. Overall, 86/119 (72.3%) patients had either given up on, or were unsuccessful at, securing a job they wanted because of visual impairment, and 15/82 (18.3%) patients who had interviewed for such positions reported having been rejected because of visual impairment. In terms of schooling, the mean number of days of missed classes in the past year was 3.5, of which 57.1% (2.0 days) were due to visual impairment. Students with RP reported that visual impairment had a large influence on both study (62.5%) and other daily activities (82.5%).

The VFQ-25, HUI3, and EQ-5D-5L outcomes are presented in Table 8. The overall mean scores of the VFQ-25 and the HUI3 were 42.0 and 0.393, respectively. The overall mean index score of the EQ-5D-5L was 0.833, and the overall mean visual analog scale score was 75.7. In total, 107/122 (87.7%) patients reported experiencing depression and 119/122 (97.5%) patients reported experiencing anxiety. Furthermore, 11/122 (9.0%) patients reported taking medication for either depression or anxiety.

Overall, 48/122 (39.3%) patients reported taking medications, including Adaptinol [a dark-adaptation-improving agent, 32/122 (26.2%)], isopropyl unoprostone [an ion channel opener, 15/122 (12.3%)], kallidinogenase [a circulatory-disorder-improving agent, 8/122 (6.6%)], and mecobalamin [a therapeutic agent for peripheral neuropathy, 8/122 (6.6%)]. In addition, 32/122 (26.2%) patients reported taking supplements, including lutein [23/122 (18.9%)], vitamin A [8/122 (6.6%)], and vitamin C [6/122 (4.9%)]. Nearly half [25/52 [48.1%)] of the patients in this study reported missing work or school every time they visited a medical institution; 78/119 (65.5%) patients reported requiring an accompanying person and 16/52 (30.8%) patients reported that their caregivers also missed work or school every time they attended a medical appointment.

The VFQ-25 and HUI3 data according to the degree of visual impairment are presented in Tables S4 and S5 in the electronic Supplementary Material, respectively. As measured by the VFQ-25, only 8/122 (6.6%) patients were currently driving, of whom 6/8 (75.0%) had either stopped driving at night or were finding it difficult to do so. Poor vision was reported as the main reason for the discontinuation of driving by 64/65 (98.5%) patients. The correlation between vision impairment measures and QOL measures is shown in Fig. 1. Both VFQ-25 scores and HUI3 scores correlated with physical disability grade, distance vision impairment (WHO), and visual impairment class (AMA) (polyserial correlation coefficients 0.628, −0.599, −0.641, and 0.622, −0.578, −0.536, respectively).

Vision impairment and quality of life scores are correlated in patients with retinitis pigmentosa. AMA American Medical Association, EQ-5D-5L the 5-level EQ-5D version, HUI3 Health Utilities Index Mark 3, SD standard deviation, VFQ-25 Visual Function Questionnaire-25, WHO World Health Organization