Orbital decompression in Australia over 20 years: a retrospective population-based study.

OBJECTIVE: To examine the frequency and cost of orbital decompression in Australia over a 20-year period and estimate the incidence of thyroid eye disease (TED) using orbital decompression data. DESIGN: Retrospective population-based study. PARTICIPANTS: Individuals undergoing orbital decompression in Australia from July 2002 to June 2022, identified using the National Hospital Morbidity and Medicare databases. METHODS: Annual orbital decompression rates (Poisson regression) were calculated, overall and by sex. RESULTS: Of the 2661 orbital decompressions performed during the study period, most were for individuals aged 45-64 years (49.6%) and females (68.0%, female:male ratio 2.1:1). From 2002-2003 to 2021-2022, annual orbital decompression rates fluctuated but overall increased 1.6-fold (58.1%), from 3.7 to 5.8 surgeries per 1 000 000, respectively. Annual decompression rates stabilized during 2011-2022. During 2002-2022, annual decompression rates were greater in females than in males (mean, 7.9 vs 3.7 surgeries per 1 000 000). The estimated mean annual procedural cost associated with orbital decompression was AU$2.4 million. Over 20 years, the estimated annual incidence of TED was 7.2 per 100 000, greater in females than in males (9.8 vs 4.7 per 100 000). CONCLUSIONS: Orbital decompression rates increased in Australia over 20 years, stabilizing in the last decade. Decompression had a significant cost burden. These data provide a useful baseline for comparison in future studies. Decompression rates and TED incidence may vary further as novel immune-modulating therapies for Graves disease and TED, such as teprotumumab, become available in Australia.