Ocular sarcoidosis prevalence and clinical features in the Northern Ireland population.

Background/objectives: To record the prevalence of ocular sarcoidosis (OS) cases present in Northern Ireland as diagnosed using the International Workshop on Ocular Sarcoidosis (IWOS) classification, 2019. There are currently no data regarding OS in this population.

Subjects/methods: Retrospective case review of OS cases as identified by IWOS criteria 2019. Mid-year population estimates were used to calculate disease prevalence. Additional data collected included uveitis features, ocular complications and the presence of ocular only or multi-system disease.

Results: A total of 86 patients were identified meeting the criteria for a diagnosis of OS, and the prevalence of OS in Northern Ireland was estimated to be 4.5 cases per 100,000. The most common type of uveitis was panuveitis in 36% of cases, and the most common ocular complication was ocular hypertension in 36% of cases and detectable glaucomatous changes in 10%. Overall, 80% of cases presenting with ocular only sarcoidosis subsequently developed second organ involvement at a rate of 14%/person-years. The most common extra-ocular site of sarcoidosis was pulmonary.

Conclusions: The Northern Ireland population has a relatively high prevalence of OS compared with other European countries. OS presenting with only ocular involvement progressed to second organ involvement in 80% of patients at a rate of 14%/person-years. Raised intra-ocular pressure with or without glaucomatous damage was a frequent finding. Thoracic CT imaging should be requested if clinical suspicion of OS exists and the presence of lymphopenia has utility in diagnosis with concurrent use of systemic ACE inhibitors.