To investigate the underlying causes and clinical characteristics of patients referred with intraocular pressure (IOP) elevation.

We retrospectively reviewed the medical records of patients who were referred with IOP elevation from July 2016 to July 2017. Patients with baseline IOP ≥ 22 mmHg and those who were treated and followed up for 6 months were included. The prevalence rates of the underlying diseases that caused IOP elevation were evaluated and the clinical characteristics were compared between patients with primary and secondary glaucoma.

A total of 127 patients were included (mean age, 59.3 ± 16.8 years; baseline IOP, 31.7 ± 10.5 mmHg). Among the study participants, 22.0%, 31.5%, and 46.5% had been diagnosed with ocular hypertension, primary glaucoma, and secondary glaucoma, respectively. Among the causes of IOP elevation, open-angle glaucoma (20.5%) had the highest prevalence rate among those with primary glaucoma and inflammation-related glaucoma (12.6%) was the most prevalent cause among those with secondary glaucoma. In a comparison between patients with primary and secondary glaucoma, the percentage of IOP reduction was not significantly different at 6 months after treatment (52.1% vs. 53.9%, p = 0.603). However, the rate of patients treated with drugs other than IOP lowering agents or who underwent surgery was significantly higher in the secondary glaucoma group compared with the primary glaucoma group (all p < 0.05). At 6-month follow-up, the secondary glaucoma group showed significantly higher improvement rates of visual acuity ( p = 0.004), but had a larger proportion of patients with a visual acuity of less than or equal to finger count ( p = 0.027).

Treatment and visual outcome can vary depending on the underlying cause of IOP elevation. Therefore, a thorough examination for determining the cause of IOP elevation is recommended at the initial stage.