Central retinal artery occlusion (CRAO) refers to a sudden blockage of the central retinal artery. It is an ophthalmic emergency that can result in profound visual impairment. The Central retinal artery (CRA) is a branch of the ophthalmic artery which is a branch of the internal carotid artery. The CRA is the main blood supply to the inner retinal layers whereas the outer retina is supplied by the choriocapillaris of the choroid which branches off the ciliary artery. CRAO has an incidence of 1 in 100,000 people and is responsible for 1 in 10,000 outpatient ophthalmology appointments. It most commonly affects patients over the age of 60 with men affected more than women. This article will provide a brief outline on the pathophysiology, diagnosis, investigations, and management of CRAO.

Episcleritis is a benign inflammatory condition affecting the episcleral layer, the outermost layer of the sclera of the eye. There are two main types of episcleritis, nodular and simple. Nodular episcleritis accounts for 30% of cases and presents with a discrete elevated area of inflamed tissue (nodule) in the episcleral layer surrounded by dilated blood vessels. Simple episcleritis also presents with a red eye and dilated blood vessels but not an elevated area of inflamed tissue. It is subdivided into two groups; diffuse simple episcleritis, where the inflammation is generalised, and sectoral simple episcleritis, where the inflammation is restricted to one region.

Leber Congenital Amaurosis (LCA) is a rare genetic eye disorder that is the most common cause of inherited sight loss in children. It is estimated to affect 1 in 40,000 newborns and leads to severe, irreversible loss of vision by affecting the retina. LCA was named in 1957 after it was first described by Theodor Karl Gustav von Leber in 1869. He was responsible for the first description of Leber’s hereditary optic neuropathy, a completely different condition that is easy to confuse LCA with. In current literature, LCA is thought to represent 5% of all retinal dystrophies and accounts for 20% of visual impairment amongst children in special schools.

A cataract is a clouding of the lens which can lead to gradual reduction in vision and disturb every day activities such as driving and reading (1). The main symptoms include clouding or blurring of vision, glare, reduced night vision that is noticed when driving, haloes around lights and fading of colours. There are various risk factors of which increasing age is the most significant one. Others include lifestyle factors such as diabetes, smoking and hypertension, previous ocular trauma or surgery and iatrogenic causes such as use of long-term corticosteroids (which can typically lead to a posterior subcapsular cataract).

Glaucoma is a common eye condition which involves optic nerve damage, resulting in progressive peripheral vision loss. It is most commonly caused by raised intraocular pressure (IOP), therefore most medical and surgical treatments aim to lower the IOP by either reducing production or increasing drainage of aqueous humour in the anterior chamber of the eye. It is important to note that glaucoma management is centred around prevention of further vision loss rather than restoration of vision that has already been lost, and thus early diagnosis and management are paramount.