Diseases of the Anterior Chamber and Uvea

Uveitis is the inflammation of the uvea, the pigmented middle layer of the eye, which comprises the iris, ciliary body, and choroid. The condition is categorized based on the site of disease; anterior uveitis is the most common. Uveitis can be caused by an infection or systemic disease, but in some cases the cause is idiopathic. Patients present with blurred vision, eye redness, and pain (frequently in anterior uveitis) or reduced vision and floaters (in intermediate and posterior uveitis). Diagnosis is by dilated funduscopy and slit-lamp examination. Treatment for anterior uveitis is topical steroids, while uveitis in deeper locations requires an injection. Uveitis from infections and systemic disorders requires etiology-directed therapy.

Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Frequently, there is peripheral vision loss that eventually leads to loss of central vision. The 2 main types of glaucoma are open-angle and angle-closure. Overproduction or reduced excretion of the aqueous humor leads to open-angle glaucoma. Onset of symptoms is gradual. Angle-closure glaucoma results from blockage in the angle (of the iris and cornea), preventing drainage of the aqueous fluid. Diagnosis involves IOP determination (tonometry) and angle visualization with slit lamp (gonioscopy). Treatment includes topical medications that reduce IOP, and eye surgery.

The pupil is the space within the eye that permits light to project onto the retina. Anatomically located in front of the lens, the pupil's size is controlled by the surrounding iris. The pupil provides insight into the function of the central and autonomic nervous systems. The afferent pathway for visual function starts from the retina and moves through the optic tracts and lateral geniculate nuclei, terminating in the visual cortex. Light stimulus is conducted by the parasympathetic system to the midbrain, while psychosensory reaction is processed by the sympathetic system. Efferent pathways produce the appropriate response: miosis and mydriasis from the parasympathetic and sympathetic innervations, respectively. Pupillary disorders result from defects in areas of the visual afferent and efferent pathways. Presentation varies with pupillary size along with response to light and medication.

Corneal anomalies are conditions in which the function of the cornea is impaired due to various congenital or acquired pathologies. Corneal anomalies are classified based on anomalies of size, clarity, ectatic anomalies, corneal dystrophies, and acquired conditions. Pathological changes can result in opacity or clouding of the cornea and, hence, reduce visual acuity. Corneal anomalies are usually diagnosed based on clinical findings. Management includes correction of refractive errors and treatment of the underlying conditions.