Sensory Loss Series – Sight

Every day 100 people in the UK start to lose their sight. This may happen gradually over time or in an instant without warning.

As part of our series focusing on how medical negligence can lead to injuries to the senses we explore how sight/vision loss can occur as a result of substandard care.

Types of vision loss include:

  • Hemianopia (or Hemianopsia) – reduced or complete loss of vision in one half of the visual field in one or both eyes. This is common after stroke or brain injury.
  • Quadrantanopia – reduced vision or vision loss in one quarter of the visual field.
  • Areas of Visual Loss or Impairment (Scotoma) – a visual blind spot occurring in part of the visual field. This could be darkness, lightness, blurring, or distortion.
  • Diffuse Visual Field Defects – for example, generally blurred vision, tunnel vision, scattered areas of darkness, and other problems affecting sight.

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Vision loss or impairment can be life changing and force us to rethink how we live our lives.

Everyday tasks that we all take for granted may become serious challenges. How do you care for yourself and your family? Can you still do your job or enjoy your hobbies? How will you get from A to B? Facing these questions is daunting in any circumstances; perhaps more so where the damage could potentially have been prevented. However, when sight is impaired or lost as a result of medical negligence compensation can be sought.

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Injuries affecting Sight

Injuries affecting sight fall into three main categories:

  1. Damage to the eye itself
  2. Optical nerve damage
  3. Brain and sensory processing injuries

We have the ability to ‘see’ because visual stimuli received through the eyes are transmitted via the optic nerve for interpretation and translation into images by various areas of the brain.

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Damage to the eye itself will typically result from disease, degeneration, infection, inflammation or trauma. Common eye conditions that affect sight include macular degeneration, glaucoma, detached retina, diabetic retinopathy and cataracts.

Degeneration of and damage to the optic nerve may lead to dimmed or blurred vision, a reduced field of vision and or difficulty seeing contrast and fine detail. Vision loss through optic nerve damage is usually permanent, but if the underlying cause can be identified and successfully treated without delay then further vision loss may be prevented.

The processing of visual information is estimated to involve as much as 40% of the brain. Visual impairment arises where the brain cannot consistently interpret the information received. Brain damage whether caused by hypoxia (lack of oxygen to the brain), increased intracranial pressure, stroke, cancer, infection or other causes can affect the areas of the brain that interpret visual information and translate it into images. This can result in temporary or permanent visual impairment. In addition to potential reductions or disruptions to the visual field, those affected may have difficulties recognizing faces or pictures, distinguishing between foreground and background or perceiving depth and distances.

How can medical negligence result in vision loss?

1. Eye damage and diseases

Delays in the diagnosis and treatment of eye disease or a failure to treat eye damage promptly can damage to your sight. The following are just a few examples of conditions where this can occur.

(a) Macular degeneration

There are two forms of age-related macular degeneration (AMD) – wet macular degeneration and dry macular degeneration. There is no cure for either, but steps can be taken to prevent further deterioration in the eye sight of patients with wet AMD.

Wet AMD occurs when abnormal blood vessels form underneath the macula and cause damage to the cells in the macula. Once diagnosed the formation of further blood vessels can be prevented by taking medication and the new blood vessels can sometimes be targeted using laser eye surgery. Early diagnosis and treatment of wet AMD is therefore critical to reduce the likelihood of significant vision loss.

(b) Glaucoma

Glaucoma is characterised by a build-up of pressure in the eye itself. The eyeball contains fluid called aqueous humour which is produced continuously and drains through tubes. Glaucoma occurs when the fluid fails to drain properly leading to increased pressure within the eyeball. This intraocular pressure can damage the nerve fibres in the retina and the optic nerve. If caught early then glaucoma can be treated, but a delay in treatment may result in permanent damage and vision loss.

Glaucoma can also develop as a result of using steroid-based medications, particularly in and around the eye. Patients applying steroid medications to the eye, eyelids or face should have their intraocular pressure monitored regularly. Failure to monitor pressure appropriately may be negligent.

(c) Delayed diagnosis of detached retina

The nerve cells on the retina at the back of the eye detect light and send nerve impulses via the optic nerve to the brain. The retina can become detached as a result of trauma, but more commonly occurs when the retina thins and becomes more brittle with age causing it to be pulled away from the blood vessels that supply it with oxygen and nutrients. Without a blood supply the nerve cells on the retina die causing vision loss. The faster the retinal detachment is diagnosed and treated, the sooner the blood supply can be restored and the more likely it is that sight can be preserved. As such any delay in treatment may have a significant impact on the extent of any vision loss.

2. Infection and Inflammation

Misdiagnosis, inappropriate treatment or delays in the diagnosis of infection and inflammation may result in avoidable damage to your sight. Infections in the eye itself can cause inflammation and damage to the structures of the eye if left untreated. Infections such as cellulitis around the eye may also spread to the eye itself if not diagnosed, monitored and treated appropriately.

Vision loss can also result from medical negligence in cases where inflammation and swelling of the optic disk and optic nerve is not detected and resolved promptly. Similarly infection and inflammation in the surrounding tissue can put damaging pressure on the optic nerve.

Brain infections such as encephalitis and meningitis can cause damage to the neural pathways and affect the areas of the brain that we use to perceive and interpret visual images. Whilst sadly in some cases such damage is unavoidable, in others it can be prevented with appropriate and timely medical intervention.

3. Stroke

Vision problems after a stroke can stem from damage to the brain and /or the optic nerve. The impact will depend on the location and extent of the damage. For example, damage to the occipital lobe of the brain affects the processing of visual images, whilst the damage to the temporal and parietal lobes can affect spatial awareness, facial recognition and the ability to identify objects. Medical negligence may occur in the failure to recognise and treat conditions that increase the risk of stroke, such blood conditions that increase the likelihood of blood clots, or alternatively when there is a failure to promptly diagnose and treat the stroke(s) itself.

4. Diabetic retinopathy

Diabetic retinopathy occurs when high blood sugar levels damage the retina cells at the back of the eye. The retina requires a continuous blood supply to work effectively and increased blood sugar levels can cause the blood vessels to narrow or leak interrupting the blood supply and damaging the retina.

You may not be aware of the damage until your sight is affected so it is important to maintain good blood sugar control and undergo diabetic eye screening to detect early signs. If diagnosed in time then vision loss can be prevented through improved diabetes control, but a delay in diagnosis can result in irreversible loss of vision and may therefore result in a medical negligence claim.

5. Hypertension

High blood pressure can place a strain on the blood vessels in the eyes and cause the blood vessels to either narrow or bleed. It may also cause the optic nerve to swell, impairing the transmission of visual information to the brain and reducing the ability to see well. Left untreated this can result in permanent sight loss. Effective management of blood pressure is important to prevent damage to the eyes and the optic nerve. Medical professionals can monitor blood pressure and examine the retina to evaluate the condition of blood vessels in the eye. Failure to monitor, detect or treat increases in pressure appropriately may be negligent. The longer high blood pressure remains untreated, the higher the likelihood of permanent damage. Similarly increased pressure in the brain (intracranial hypertension) can also cause the optic nerve to swell resulting in visual impairment (for example, loss of peripheral vision) and may cause permanent damage if not treated swiftly.

6. Cancer and Tumours

Cancers and non-malignant tumours in the brain, eye or optic nerve can all result in vision loss if not diagnosed and treated swiftly and effectively. Without prompt treatment, tumours can grow and spread causing further damage. For example, a cancer of the retina such as retinoblastoma can have a 90% recovery rate if treated early, but may otherwise spread to the eye socket and to the brain leading to loss of the eye itself and permanent brain damage. If substandard care prevents the early detection or treatment of a tumour (whether cancerous or benign) resulting in further injury or sight loss then a medical negligence claim can be made.

7. Surgical damage

Procedures to the eye such as laser eye treatment or cataract surgery carry a risk of damaging the eye. Vision loss may also result from damage to the brain or optic nerve during facial, brain or ear, nose and throat surgery. Whilst in some cases vision loss may be a recognised complication of the procedure, it may also be caused by negligence such as inappropriate technique or surgical error.

8. Medication

Optic nerve damage can arise as a side effect or complication when using certain medications including steroids, non-steroidal anti-inflammatory drugs, chemotherapies, heart drugs such as digoxin, and PDE-5 inhibitors like Viagra. Whilst these drugs may be prescribed to treat serious conditions, it is necessary that those prescribing them are made aware of any visual symptoms that you develop. If they fail to act in response to those symptoms then it may represent substandard care and that negligence could lead to more extensive damage and vision loss.

How We Can Help

I and other specialist solicitors at Bolt Burdon Kemp have substantial experience pursuing claims on behalf of those who have suffered blindness or visual impairment as a result of medical negligence. We have successfully recovered compensation in cases where substandard medical treatment has resulted directly in visual loss and also where a delay in diagnosing an underlying condition has either increased the extent of the damage or impaired recovery.

Compensation may not be able to restore your vision, but it may be used to fund treatment, equipment or technology to maximise the benefit of any residual vision you have. In cases involving permanent loss of sight, specialized equipment and techniques alongside access to assistance when you need it, can enable you to regain your independence. For example, adaptations to the home such as level access, better lighting and use of contrast colours can utilise any residual sight and help reduce the risks of trips or falls. Similarly technology including low vision devices, talking equipment and voice-operated apps can assist with day to day activities whether it is making a cup of tea, identifying colours so you can pick out clothing or checking your email. Whatever the barriers and difficulties you may face, we will work with you to identify solutions that are likely to work best for you and your family and construct your claim on that basis.