Eyes deliver four-fifths of the information that our brain receives. However, when it comes to eye diseases, one might miss marking any symptoms, since they are not easily detected or may be painless. There are several common and rare eye conditions which affect vision. A healthy retina is essential for clear vision.  Retinal diseases are common as they can affect any part of the eye retina. As retinal diseases affect the vital eye tissue, it causes serious problems, affects vision, some even leading to blindness. 

Common types of Retinal problems

Some common types of retinal diseases include:

1) Floaters

Floaters are generally small, black shapes which appear as squiggles, spots or threads in vision. They appear to float along with the movement of the eyes. 

Symptoms:

Symptoms of floaters may include:

  • Small shapes in the vision that appear as dark specks, transparent strings of floating material.
  • Small shapes, threads or strings which drift out of the line of vision.
  • Floaters are noticeable when you look at a plain bright background.

Causes:

Floaters occur when the vitreous layer, which is normally clear, a gel-like substance located in the centre of the eye becomes more liquid and clumps cast a shadow on the retina. They can be:

Age-related: Some eye conditions like severe near-sightedness, Vitreous haemorrhage, Inflammation in the back of the eye, bleeding in the eye etc. cause floaters. 

2) Retinal Tear

A retinal tear is a condition that occurs when the vitreous layer shrinks and peels away from the thin layer of tissue with enough traction to cause a tear or damage in the retina. 

Symptoms:

  • Sudden onset of floaters in the eye.
  • Photopsia or flashes of light
  • In some patients, a retinal tear may not show any noticeable symptoms. 

Causes:

By birth, the vitreous is attached to the retina. However, the gel separates from the lining of the retina as a normal ageing process.  In the majority of the people, this process happens without any issue. However, people with “sticky” vitreous face retinal tear once the vitreous layer separates from the retina.

3) Retinal detachment

A condition where the retinal layer separates from the back of the eye, and this occurs when the fluid vitreous passes through a retinal tear. It distances the retina away from its normal position.

Symptoms: 

Although retinal detachment itself is painless, here are some warning symptoms which almost always appear before it occurs:

  • The sudden appearance of floaters in the vision field
  • Flashes of light in the affected eye 
  • Blurred vision
  • Reduced peripheral vision
  • A curtain-like shadow over the field of vision.

Causes:

  • Age-related changes in the eye
  • An eye injury
  • Short-sightedness/myopia
  • Lattice degeneration 
  • Previous eye surgery for cataracts
  • A family history of retinal detachment.

4) Diabetic retinopathy

A condition like Diabetic retinopathy is caused by high blood sugar levels that damage the blood vessels of the light-sensitive retina. 

Symptoms:

Diabetic retinopathy, in its early stages, is painless and hard to notice. It doesn’t show any noticeable symptoms until it’s further advanced. As diabetic retinopathy progresses, it shows the following signs: 

  • Gradually worsening of vision
  • Floaters
  • Sudden loss of vision
  • Impaired colour vision
  • Blurred vision or empty areas in your vision

Causes: 

In this condition, there is an abnormal growth of blood vessels from the retina that causes scarring and bleeding. The blood vessels deteriorate and leak fluid into and under the retina. This leads to retinal swelling, which eventually blurs or distorts the vision. 

5) Epiretinal membrane

Epiretinal membrane is a thin, delicate, transparent tissue-like scar or membrane that forms over the macula. The membrane pulls the retina and distorts the vision. 

Symptoms:

  • The epiretinal membrane does not cause total blindness, but it typically affects the central vision. However, the peripheral vision of the affected eye remains unaffected. 
  • Blurring of vision
  • A distorted central part of the vision. 

Causes:

Epiretinal membrane is caused by the formation of a thin and delicate sheet of fibrous tissue on the macula. This membrane acts as a film, obstructing the vision. It can contract like the scar tissue and can pull the retina, causing puckering of the macula. All this leads to distorted vision or swelling of the retina. 

6) Macular hole

It is a small gap or defect in the centre of the retina (macula). It may develop from abnormal traction between the vitreous and the retina, or due to an eye injury. A macular hole is very common in people aged 50 to 70. 

Symptoms:

  • Affected central vision
  • Difficulty in reading
  • Black or grey spots in the vision
  • Black areas in the vision
  • Blurring or distorted vision.
  • Straight lines of poles, text lines etc. appear bent or wavy.

Causes:

As a normal process of ageing, the vitreous gel present inside the eye shrinks naturally. During this process, it pulls away from the retina with no problems. Occasionally, the vitreous gel can stick on the retina, causing the macula to stretch and create a hole. 

7) Macular degeneration

In macular degeneration, the centre of the retina (macula) begins to deteriorate. 

Symptoms:

  • Blurred central vision 
  • Blindspot in the centre of the visual field 
  • Changed or reduced colour perception.

Causes:

The exact cause of macular degeneration is still unknown. Changes occur in the retina as we age. It is also suspected that genetic and environmental factors are involved in the development of this retinal disease.

8) Retinal Vein Occlusion

Also known as ‘eye stroke’, this is a condition in which one of the veins carrying blood from the retina to the heart gets blocked. 

Symptoms: 

  • Blurred vision
  • Empty blank spaces in the vision
  • Floaters
  • Eye pain 
  • Pressure in the eye

Causes:

A vein gets blocked generally as a result of a blood clot. This blockage obstructs the flow of blood.  Although the exact cause of this is still unknown, certain conditions like glaucoma, high cholesterol, diabetes, and high blood pressure make it more likely. 

S L Prabhavathi

S L Prabhavathi

MS, FVRS, Vitreo-Retina Surgeon at Neoretina
MBBS (2006-2011): Siddartha Medical College Vijayawada(AP)

MS (2013-2016): PGIMER, Chandigarh

FVRS(2016-2018) LVPEI, Bhubaneshwar

Special Interests: Retinopathy of Prematurity, Diabetic Retinopathy, Retinal Dystrophies, Pediatric Retina.
S L Prabhavathi