Glaucoma: Classification and Methods of Treatment, with Special Reference to Congenital and Secondary Glaucoma

Glaucoma is a group of progressive optic neuropathies characterized by retinal ganglion-cell loss, structural damage to the optic nerve head and corresponding visual-field defects. Raised intraocular pressure (IOP) is the most important modifiable risk factor, but glaucoma may occur even when measured IOP is within the statistically normal range. Because established glaucomatous damage is generally irreversible, early diagnosis and sustained treatment are essential.This review describes the basic anatomy and physiology of aqueous humour, mechanisms and classification of glaucoma, clinical presentation, diagnostic evaluation and current treatment approaches. Particular attention is given to primary congenital glaucoma and secondary glaucoma. Congenital glaucoma is usually caused by developmental abnormalities of the anterior chamber angle and may lead to corneal enlargement, buphthalmos and optic-nerve damage. Secondary glaucoma results from an identifiable ocular or systemic condition, medication exposure, trauma or previous surgery.Management is individualized and may include topical or systemic medication, laser procedures and incisional surgery. In childhood glaucoma, surgery is often the main treatment, while medication is used as an adjunct or temporary measure. In secondary glaucoma, treatment must address both IOP and the underlying cause.The central message is that glaucoma is not a single disease and cannot be managed by pressure measurement alone. Accurate classification, optic-nerve and visual-field assessment, appropriate pressure targets and lifelong follow-up are fundamental to preserving vision.