Current Management of Inherited Retinal Degeneration Patients in Europe: Results of a 2-Year Follow-Up Multinational Survey by the European Vision Institute Clinical Research Network - EVICR.net.

Introduction: An increasing number of gene-specific therapies are being developed for inherited retinal degenerations (IRDs). Identification of well-characterized patients is an emerging need. We conducted the second multinational survey among the www.evicr.net and ERN-EYE members to understand the management and treatment of IRDs in Europe and compared it to the 2019 survey.

Methods: An electronic survey questionnaire was developed and sent to 124 clinical centers (25 countries) by June/July 2021. Statistical analysis was performed with Excel and R.

Results: The overall response rate was 44% but varied among countries. Only 9% of responding centers do not see IRD patients (2019 survey 14%), 42% follow at least 200 patients per year, 18% follow 500-999, and 2% more than 1,000. Databases exist in 86% of the centers (local 86%; national web based 12%). IRD patients are referred to www.evicr.net and ERN-EYE centers mainly by general ophthalmologists, patient self-referral, or medical retina specialists. Most IRD patients are first seen as adults. Signs and symptoms depend on age of onset: in infancy, nystagmus; at older age, night blindness and reduced visual field; reduced visual acuity is described at any age. Comprehensive ophthalmic examination always includes visual acuity and almost always visual field multimodal retinal imaging, electrophysiology, color vision testing, and refraction. Identification of genotypes is successful in 72% of centers in 40-80% of cases (2019 survey 69% of centers). The time for confirmation of the genetic diagnosis varies from 2-4 weeks to 24 months (2019 survey >4 weeks ≤10 years). Genetic testing is covered by public health service in 83%, private health insurance in 29%, research funds in 24%; 5% do not have access to genetic testing (2019 survey 15%). The most striking result is the high increase in the involvement of centers in natural history and gene therapy trials that more than doubled for the latter.

Discussion: This second multinational survey on management of IRDs in Europe highlights persistent important differences in the number of IRD patients managed per center, comparable diagnostic work-up, and increasing genotyping in diagnostic laboratories. The important increase in involvement of centers in natural history and gene therapy trials reflects the rapidly evolving field of gene therapy development. The survey provides important follow-up data for researchers, clinicians, caregivers, patient advocate groups, pharmaceutical companies, and investors.