Genetic Testing of Inherited Retinal Disease in Australian Private Tertiary Ophthalmology Practice

Sena A Gocuk,1 Yuanzhang Jiao,2 Alexis Ceecee Britten-Jones,1,3,4 Nathan M Kerr,5 Lyndell Lim,3,5 Simon Skalicky,5 Richard Stawell,5 Lauren N Ayton,1,3,4 Heather G Mack3– 5 1Department of Optometry and Vision Sciences, University of Melbourne, Melbourne, Victoria, Australia; 2University Hospital Geelong, Geelong, Victoria, Australia; 3Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia; 4Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia; 5Eye Surgery Associates, East Melbourne, Victoria, AustraliaCorrespondence: Lauren N Ayton, Email layton@unimelb.edu.auBackground: To assess the prevalence of genetic testing for inherited retinal diseases (IRDs) in a tertiary practice setting.Methods: Single-centre retrospective analysis of patients with diagnosed or suspected IRD.Results: Four hundred and sixty-four patient records were analysed. Patients had received care for different IRDs grouped as follows: panretinal pigmentary retinopathies (283, 61%), macular dystrophies (136, 29.3%), stationary diseases (23, 5%), hereditary vitreoretinopathies (14, 3%), and other IRDs (8, 1.7%). The suspected pattern of inheritance of patients’ IRD was predominantly autosomal recessive (205, 44.2%). Genetic testing was performed with the corresponding results available for 44 patients (9.5%). Diagnostic yield was 65.9% for the results received. Genetic test results were available mostly for younger patients (13.1% for < 45 years vs 6.2% ≥ 45 years of age, p = 0.01) and those who received greater than 12 months of care (16% for ≥ 12 months vs 4% for < 12 months, p < 0.01). For patients without genetic testing results, reasons include awaiting a geneticist consultation (17.9%), awaiting test results (4.5%), or patient refusal (8.4%). Most clinical records (69.2%) did not document genetic testing status.Conclusion: Genetic testing is increasingly being utilised in the work-up for patients with IRD worldwide. This large Australian private practice IRD cohort shows a low uptake of testing (around 10%), reflecting historical management patterns and accessibility of genetic counselling and testing. The results show that younger patients and those with a longer duration of care were more likely to have received genetic testing. As the importance of IRD genetic testing continues to increase, we expect to see a change in patient management within the Australian private ophthalmology system and testing rates to increase. Further research is required to identify and address clinician and patient barriers to improving genetic testing rates for IRD.Keywords: inherited retinal disease, retinitis pigmentosa, macular dystrophy, genetic testing