Glaucoma may be divided into two groups: primary or secondary. Most types of glaucoma are primary and have no obvious cause. However, there is an important sub-group of glaucoma types called secondary glaucomas, where there is an identifiable cause for high eye pressure. Secondary types of glaucoma include traumatic, exfoliation, pigmentary, inflammatory, neovascular, and steroid-induced glaucoma.
Steroids were first used in the US in 1912. Steroid-induced glaucoma has been recognised for over 60 years after a report in 1950 of a rise in eye pressure after systemic adrenocorticotrophic hormone (ACTH).
Steroids are commonly used to treat a wide variety of medical conditions, including inflammatory, allergic, and immunologic diseases. This includes everything from nasal allergies to eczema, asthma, and rheumatoid arthritis. Preparations now include over-the-counter nasal sprays and skin creams. Prescription steroids include pills, inhalers, shampoo, joint injections, and ear drops.
Steroids cause changes in the aqueous fluid outflow system (trabecular meshwork, Shelmms’s canal, and the aqueous veins) resulting in increased eye pressure. This steroid response can occur in a few weeks, or in as little as a few days in highly sensitive people. If unrecognised, the steroid response can develop into steroid-induced glaucoma and cause permanent optic nerve damage. There are many risk factors for developing steroid-induced glaucoma. It occurs, for example, in up to 8% of the general population in the United States but is much more common in patients with glaucoma and their blood relatives. In fact, 90% of patients with open-angle glaucoma develop a steroid response.
Other risk factors include advanced glaucoma, family history of glaucoma (especially in a first degree relative), African descent, previous steroid response, use of stronger steroids, diabetes, high myopia, connective disease (e.g. rheumatoid arthritis), and inflammatory glaucoma.
If possible, people in high-risk groups should limit their exposure to steroids unless absolutely necessary. Fortunately, there are non-steroidal options for many conditions. High-risk patients considering steroid use should consult their prescribing physician and eye specialist.