Disorders & diseases: N-Z

Nystagmus

Involuntary movement of the eye. This can be due to eye muscle problems at an early age. Treatment may include surgery.

Posterior vitreous detachment

This is a condition in which the vitreous humor (the gel in the eye ball) separates from the retina. Over time the vitreous changes, shrinking and developing pockets of liquification, which can eventually peel away from the retina. It can be sudden, but may also occur slowly over months. Consequently, symptoms include flashes of light and an increase of floaters in the vision. Any signs of a retinal detachment are serious and must be treated urgently.

Presbyopia

This occurs in all adults, usually aged 45 or older. It’s the natural aging process of the lens inside the eye, which results in near vision becoming blurry, while the long vision is unaffected. Click here to read more.

Pterygium

A wing-like growth across the eye, this is more common in hotter climates where outdoor sports, particularly surfing and swimming are popular. Caused by exposure to wind, sun and sand, symptoms include redness and inflammations. Treatment may be simply to use  lubricant drops for comfort, but a pterygium that is growing towards the centre of the cornea requires surgery. Because of a higher likelihood of recurrence, surgery usually involves a conjunctival graft to act as a a barrier to re-growth after excision of the pterygium. Even with this precaution, there may still be some chance of recurrence.

Ptosis

See ‘Droopy Eyelid’.

Retinal detachment

A disorder in which the retina becomes separated from the underlying layer of supportive tissue. The retina can’t function when these layers are detached, so it must be re-attached as soon as possible, to avoid permanent loss of vision. Click here to read more.

Retinal tear

See retinal detachment.

Retinal artery occlusion

The closure of the central retinal artery which blocks the blood flow to the retina, this can result in complete loss of vision in one eye. The most common symptom is an acute loss of vision in one eye. People who suffer from high blood pressure, diabetes or heart disease are more likely to suffer from an RAO. It is important to seek treatment immediately.

Retinal macroaneurysm

Related to high blood pressure, a retinal macroaneurysm can cause significant vision loss. Formed in a small retinal artery, the macroaneurysm balloons out, which can cause bleeding or leaking of fluid. Vitrectomy surgery will often be performed. If leaking fluid becomes a problem, retinal laser surgery will be performed.

Retinal vein occlusion

Blockages of the veins to the retina that can lead to tiny spot bleeding of the retina and leaking fluid from the capillaries. Most common in patients 50 plus who suffer from diabetes or high blood pressure and smokers. Treatment can range from laser photocoagulation to injections to vitrectomy surgery.

Retinoschisis

An eye disease that is characterised by the splitting of the neurosensory layers of the retina. Mostly asymptomatic, occasionally this results in the loss of vision. An ophthalmologist will most likely only monitor the progression is this disease – if secondary problems occur as a result, such as a detached retina, laser retinal surgery may be required.

Short sightedness

A condition of the eye where the incoming light doesn’t directly focus on the retina, but in front of it. The result is that distant objects appear out of focus, whereas close objects are in focus. Also referred to as myopia. Click here to read more.

Strabismus

A condition where the eyes are not properly aligned. More commonly known as a ‘squint’, it is caused by a lack of coordination between the muscles around the eye.

Subconjunctival hemorrhage

This is a condition in which there’s bleeding underneath the conjunctiva. The conjunctiva contains nerves and many small blood vessels which are fragile and can break. While it looks alarming, it is relatively painless and harmless.

Tumours

Tumors on the eye are usually the result of cancer, most commonly on the eyelid. Removal of the tumor by an oculoplastic surgeon will most likely be necessary.

Uveitis

An inflammation of the middle layer of the eye (the ‘uvea’), this require urgent attention. If treated promptly, the outlook is generally good, however serious complications may result in vision loss if left untreated. Treatment includes topical eye drops and injections.

Vitelliform macular dystrophy

A genetic disorder of the eye affecting the macula which causes progressive vision loss. Symptoms include loss or central vision and blurry or distorted  vision.

Vitreomacular traction syndrome

This is the result of an abnormal relationship between the vitreous (gel inside the eye) and the macula.This makes the vitreous pull forwards on the macula, stretching it. The effect on vision is distortion and blurring of central vision. This occasionally can go away over time, however if it persists a vitrectomy might be recommended.

Vitreous hemorrhage

A common cause of acute vision loss, a vitreous hemorrhage is bleeding inside the eye.  Symptoms include the sudden loss of vision, eye pain or blurring. Those at risk include diabetics and people who have had eye trauma or an injury. Treatment depends on the seriousness of the hemorrhage, and may require retinal laser treatment.