Secondary glaucoma is a collection of progressive optic nerve disorders associated with a rise in intraocular pressure (IOP) which results in the loss of vision. In clinical settings, it is defined as the occurrence of IOP above 21 mmHg requiring the prescription of IOP-managing drugs. It can be broadly divided into two subtypes: secondary open-angle glaucoma and secondary angle-closure glaucoma, depending on the closure of the angle between the cornea and the iris. Principal causes of secondary glaucoma include optic nerve trauma or damage, eye disease, surgery, neovascularization, tumours and use of steroid and sulfa drugs. Risk factors for secondary glaucoma include uveitis, cataract surgery and also intraocular tumours. Common treatments are designed according to the type (open-angle or angle-closure) and the underlying causative condition, in addition to the consequent rise in IOP. These include drug therapy, the use of miotics, surgery or laser therapy. Pathophysiology
Secondary glaucoma has different forms based on the varying underlying ocular conditions. These conditions result in an increase in IOP that manifests as secondary glaucoma. Paediatric congenital cataract associated glaucoma
Based on the onset of secondary glaucoma in paediatric patients, it can be classified into early-stage and late-stage glaucoma cases. Early-stage secondary glaucoma, observed as angle-closure glaucoma, results from the blockage and inflammation of the peripheral anterior synechiae structure. However, early-stage secondary glaucoma rarely occurs with the readily available prescription of anti-inflammatory medications. On the other hand, late-stage glaucoma is commonly associated with open-angle glaucoma but the mechanisms are currently unconfirmed.
Drainage tube implants are also implicated in treatment of uveitic and inflammatory glaucoma.Minimally invasive glaucoma surgery is performed in order to overcome the risks and adverse effects associated with conventional surgical procedures. However, there are limited studies testing the efficacy of utilising this type of surgery for the treatment of uveitic glaucoma.In addition to the direct reduction of IOP, surgical procedures are used to remove blood, viscoelastic fluid and debris in glaucoma caused by cataract extraction and ocular trauma. They may also be utilized to remove depot steroids in corticosteroid glaucoma and ghost cells from the vitreous humour in ghost-cell glaucoma through a procedure known as vitrectomy. == References ==