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Introduction: Inherited retinal dystrophies (IRDs) represent a genetically diverse group of progressive, visually debilitating diseases. Adult and paediatric patients with vision loss due to IRD caused by biallelic mutations in the 65-kDa retinal pigment epithelium (RPE65) gene are often clinically diagnosed as retinitis pigmentosa (RP), and Leber congenital amaurosis (LCA). This study aimed to understand the epidemiological landscape of RPE65 gene-mediated IRD through a systematic review of the literature, as the current evidence base for its epidemiology is very limited., Methods: Medline, Embase, and other databases were searched for articles on the epidemiology of RPE65 gene-mediated IRDs from inception until June 2021. Studies were included if they were original research articles reporting the epidemiology of RP and LCA and/or proportion of RPE65 gene mutations in these clinically diagnosed or molecularly confirmed IRDs patients., Results: A total of 100 studies with relevant data were included in this systematic review. The range for prevalence of LCA and RP in the literature was 1.20-2.37 and 11.09-26.43 per 100,000, respectively. The proportion of RPE65 mutations in clinically diagnosed patients with LCA was found to be between ~ 2-16% within the US and major European countries (France, Germany, Italy, Spain, and the UK). This range was also comparable to our findings in the Asian region for RPE65-LCA (1.26-16.67%). Similarly, for these European countries, RPE65-RP was estimated between 0.23 and 1.94%, and RPE65-IRD range was 1.2-14%. Further, in the Americas region, mutations in RPE65 were reported to cause 1-3% of RP and 0.8-3.7% of IRD cases. Lastly, the RPE65-IRD range was 4.81-8% in the Middle East region., Conclusions: There are significant variations in reporting of RPE65 proportions within countries as well as regions. Generating robust epidemiological evidence on RPE65 gene-mediated IRDs would be fundamental to support rare disease awareness, timely therapeutic intervention, and public health decision-making., (© 2022. The Author(s).)

Introduction: RLBP1 RP is an autosomal recessive form of retinitis pigmentosa (RP), characterized by night blindness, prolonged dark adaptation, constricted visual fields and impaired macular function. This study aimed to better understand the patient experience of RLBP1 RP and evaluate the content validity of existing patient reported outcome (PRO) instruments in this condition., Methods: Semi-structured concept elicitation and cognitive debriefing interviews were conducted with RLBP1 RP patients in Canada and Sweden. Interviews started with open-ended concept elicitation questioning, and then patients were cognitively debriefed on The National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25), the Low Luminance Questionnaire (LLQ) and four light/dark adaptation items of the Visual Activities Questionnaire (VAQ). Qualitative interviews were also conducted with three expert clinicians. Anonymized, verbatim transcripts were analyzed using thematic analysis., Results: Twenty-one patients were interviewed (Canada n = 10; Sweden n = 11). Symptoms reported included night blindness (n = 21), difficulty adapting to changes in lighting (n = 21) and difficulties seeing in bright lighting (n = 18). Patients experienced substantial impacts on daily activities (n = 21) and physical functioning (n = 17). Patients had difficulty interpreting and selecting a response for some items in the NEI VFQ-25 and LLQ. Some items were not relevant to patients' disease experience. There were both gaps and overlaps in the conceptual coverage of the instruments., Conclusions: Visual impairment due to RLBP1 RP has a substantial impact on physical functioning and daily activities. To adequately assess all important symptoms and associated functional impacts in RLBP1 RP, it is recommended to either modify one or more existing instruments or to develop a new non-syndromic RP specific instrument.

Introduction: Few studies have examined outcomes and potential complications among glaucoma patients who are prescribed topical beta-blockers. This study examined resource usage (number of GP visits and hospitalizations) and diagnoses of respiratory or cardiovascular conditions among glaucoma patients prescribed beta-blockers compared to patients not prescribed beta-blockers., Methods: A retrospective cohort analysis was conducted using data from the UK Clinical Practice Research Datalink (CPRD) database over the period January 1, 2006 to March 31, 2014. Adult patients with at least one diagnosis of glaucoma were categorized into beta-blocker users and non-beta-blocker users. Beta-blocker users were further separated into patients that maintained beta-blocker therapy and patients that discontinued beta-blocker treatment in year 2 of the post-index period. The CPRD data was queried directly to obtain the number of GP visits, and hospitalizations were extracted by linking the CPRD and Hospital Episode Statistics (HES) patient-level data., Results: In the 12 months after being prescribed beta-blockers, patients that later discontinued beta-blocker treatment had a significantly higher average number of hospitalizations than patients that maintained beta-blocker therapy and the non-beta-blocker users (p < 0.05). In the year after beta-blocker initiation, there was a statistically significant within-group difference pre- and post-beta-blocker initiation for all groups, but the greatest number of GP visits occurred in the patients that subsequently discontinued beta-blocker treatment (mean 19.27). Patients that discontinued beta-blocker treatment were significantly more likely to have cardiovascular events than non-beta-blocker users in the post-index period (p < 0.05)., Conclusion: This study suggests that the introduction of beta-blockers in a certain group of patients who later discontinue their use is associated with increased use of medical resources (higher number of GP visits and hospitalizations) in glaucoma patients in the UK, which may be indicative of a potential relationship between use of topical beta-blockers in glaucoma therapy and adverse outcomes.