Medical Retina

Diabetic retinopathy is a diabetes-related complication that can cause damage to the blood vessels in the retina at the back of the eye due to high blood sugar levels.

When the blood vessels in the retina are damaged, they may leak fluid or blood, leading to swelling and distorted vision. In addition, new abnormal blood vessels may also grow on the surface of the retina, which can further impair and impact sight.

There are three primary types of diabetic retinopathy:

• Non-proliferative retinopathy: In its early stage, this type involves the leakage of fluid or bleeding from retinal blood vessels.
• Macular oedema: This condition is characterised by swelling of the macula due to fluid leakage from retinal blood vessels, which can harm central vision.
• Proliferative retinopathy: In its advanced stage, this type involves the replacement of retinal blood vessels with fragile, easily bleeding new vessels, potentially leading to sudden vision loss.

Depending on its progression, severity and the type of diabetic retinopathy available treatment options encompass strategies such as controlling blood sugar levels, blood pressure, and cholesterol levels, to reduce the risk of damage to the retina. Regular eye exams are essential for early detection, management, monitoring and treatment. If progressed medical interventions such as intravitreal injections, laser therapy, and surgical procedures are also available to manage this condition.

When working with an ophthalmologist that specialises in the management of diabetic retinopathy, individuals with diabetes can reduce risk and maintain good eye health.

A retinal tear is a condition where the retina, the light-sensitive layer at the back of the eye, develops a small break or tear. This can lead to more serious issues, such as retinal detachment, if not treated promptly.

Some of the common causes of retinal tears are below:

• Vitreous Detachment: The gel-like substance in the eye can pull on the retina, causing a tear.
• Trauma: Injury to the eye can lead to a tear
• Extreme Myopia: People with severe near-sightedness are at higher risk

Some of the common symptoms and things to look out for if you suspect a retinal tear are:

• Flashes of light in your vision
• Floaters that look like small dark spots or lines in your vision
• A dark shadow or curtain effect over a portion of the visual field

Treatment options for retinal tears

At Wollongong Eye Specialists we can expertly assess, treat and manage patients with retinal tears. Depending on your individual eye health and the severity of the tear, your eye doctor will advise the best course of action in consultation with you. Treatment may involve any of the below options and will be a daytime procedure meaning you can rest and recover in the comfort of your own home.

• Laser Photocoagulation: A laser is used to create small burns around the tear, forming scar tissue that helps seal the retina to the underlying tissue.
• Cryotherapy: A freezing probe is applied to the eye to create scar tissue around the tear, similar to laser treatment.
• Pneumatic Retinopexy: In cases where the tear has led to detachment, this procedure involves injecting a gas bubble into the eye to help reattach the retina.
• Scleral Buckling: A surgical procedure that involves placing a silicone band around the eye to gently push the wall of the eye against the retina, facilitating reattachment.
• Vitrectomy: In more complex cases, this surgical procedure removes the vitreous gel to relieve traction on the retina, often combined with other methods to repair the tear.

After treatment, regular follow up appointments and management will be essential to monitor your tear and ensure your retina stays attached and your eyes healthy.

Flashes and floaters are quite common and often harmless, though sometimes they can be a sign of a problem with the retina at the back of the eye and are related to changes in the vitreous gel inside the eye or issues with the retina, so investigation is recommended.

Floaters are caused by small clumps of gel or cells inside the vitreous that cast shadows on the retina as they float around. Appearing as small, shadowy shapes that appear to drift or move across the visual field when you try and look at them, they are most noticeable in bright light. They can appear as spots, stars squiggly lines, or cobweb-like shapes.

Flashes are brief bursts or flickers of light in the visual field. These are commonly seen in low light or darkness and often described as seeing “lightning streaks” or “sparkles” and typically occur when the vitreous gel pulls on the retina, stimulating the light receptors in the retina, which the brain interprets as light.

Causes can include:

• Posterior vitreous detachment (PVD)
• Retinal tear or detachment
• Inflammation inside the eye (e.g., uveitis)
• Trauma or injury
• Aging (as the vitreous gel naturally shrinks and pulls away from the retina)

While flashes and floaters can be a normal part of aging, they can also signal more serious conditions like a retinal tear or detachment, which require urgent medical attention.

Intravitreal injections deliver the right amount of medication directly into the eye. It is used to treat several conditions, the most common of which is Age-Related Macular Degeneration (ARMD), Diabetic Macular Oedema and Retinal Vein Occlusions.

Injections are given through the white of the eye and are relatively painless. Adequate local anaesthetic is given prior to the injection and much care is taken to ensure that it is as comfortable as possible for you.

After the injection, the eye may appear bloodshot and feel gritty, but this will generally resolve within several days.

Most patients that receive injections will need to have them repeated on a schedule that your eye doctor will design and determine based on your individual eye health.

Intravitreal Injections are a day procedure and recovery is rapid and within one day. It is advised to refrain from driving for one day and to limit exercise and washing the eyes for 24 – 48 hours.

Retinal Vein Occlusion (RVO) is an eye condition that occurs when one of the veins carrying blood away from the retina (the light-sensitive tissue at the back of the eye) becomes blocked or obstructed. This can result in reduced blood flow, leading to swelling, haemorrhages, and sometimes vision loss.

There are two main types of RVO:

1. Branch Retinal Vein Occlusion (BRVO):
   • This occurs when one of the smaller, branch veins in the retina is blocked.
   • Typically, BRVO affects part of the retina, and vision loss is often limited to a portion of the visual field.
   • Risk factors include high blood pressure, high cholesterol, and glaucoma.
2. Central Retinal Vein Occlusion (CRVO):
   • This occurs when the central vein that drains blood from the entire retina becomes blocked.
   • CRVO often results in more severe vision loss than BRVO because the entire retina is affected.
   • It is associated with conditions like diabetes, hypertension, and glaucoma.

Symptoms of RVO

• Sudden, painless loss of vision or blurring, usually in one eye.
• Distorted or blurry central vision, which may gradually worsen.
• Dark spots or floaters in the field of vision due to haemorrhages.

Causes and Risk Factors

RVO is primarily caused by the narrowing or hardening of blood vessels which can lead to blood clots. Common risk factors include:

• High blood pressure (hypertension)
• Diabetes
• Glaucoma
• Smoking
• Age (more common in people over 50)
• High cholesterol levels

Diagnosis

Diagnosis is typically made through an eye exam and tests that help provide an understanding of blood flow in the retina.

Treatment options include:

• Injections to reduce swelling and prevent further damage
• Laser therapy to treat abnormal blood vessels or reduce fluid buildup
• Management of underlying conditions like diabetes or hypertension

Age-related Macular Degeneration (AMD) affects the macula, the central part of the retina responsible for sharp, detailed vision.

It is a leading cause of vision loss in people over the age of 50 and primarily impacts central vision, making tasks like reading, driving, and recognising faces difficult.

There are broadly two types of AMD:

1. Dry AMD (Atrophic)

• More common
• Occurs when the macula thins over time due to aging and the buildup of yellow deposits called drusen.
• Vision loss is gradual, and while it typically progresses slowly, it can still lead to significant central vision impairment over time.

2. Wet AMD (Neovascular or Exudative)

• Less common but more severe
• Occurs when abnormal blood vessels grow beneath the retina and leak blood or fluid, causing rapid damage to the macula.
• Vision loss from wet AMD can occur suddenly and worsen quickly, leading to significant loss of central vision if not treated.

Symptoms of AMD include:

• Blurry or distorted central vision.
• Straight lines appear wavy or distorted (particularly in wet AMD).
• Difficulty seeing fine details
• Dark or empty areas in the centre of the visual field.

Causes and Risk Factors of AMD include:

• Age
• Hereditary factors – family history increases risk
• Smoking is one of the strongest modifiable risk factors
• High blood pressure and cardiovascular disease
• Obesity can increase the likelihood of AMD progression.
• Diet – a poor diet low in leafy greens and antioxidants may increase risk
• Prolonged sun exposure to UV rays without protection can increase risk

Treatments and management strategies:

Early detection, monitoring and long-term care is important and regular eye exams, particularly for those at risk, are essential for early detection, management and slowing progression. 

While AMD cannot be cured, early detection and treatment, especially for Wet AMD, can significantly slow the progression of vision loss and improve the quality of life for affected individuals.

• Dry AMD: There is no cure, but nutritional supplements (vitamins and antioxidants) can slow its progression.
• Wet AMD: Treatments include anti-VEGF (vascular endothelial growth factor) injections, laser therapy, and photodynamic therapy (involving medication that is then activated by a specific light wavelength) to slow or stop abnormal blood vessel growth.