What is a retinal tear?
The eye is like a camera with the lenses at the front and the photographic film (retina) at the back and between the two in the “body” of the camera is a clear jelly called vitreous. This jelly gradually degenerates with the passage of time into a more watery consistency and eventually the remaining jelly that is up against the retina pulls away from it and in most people collapses down into smaller lumps causing some floaters in the vision which usually improve as they float down to the bottom of the eye with gravity.
A small number of patients however have abnormal adhesion between the jelly and the retina in places and as the jelly pulls away it does not want to “let go” of the retina and pulls so hard it tears the retina. These patients usually notice a sudden shower of new floaters associated with flashing light sensations as the retina tears. Patients who are short sighted are more prone to this occurring as their jelly degenerates at a younger age that normal sighted people and they are also more likely to have abnormal adhesion between the retina and jelly. If a retinal tear is diagnosed quickly then treatment can be applied as an out-patients procedure to “spot weld” it in place with laser.
If left untreated the tear in the retina usually progresses into a retinal detachment as the watery component of the jelly in the main eye cavity can get underneath the retina through the tear and the retina starts to come away from the back wall of the eye. When the retina starts “detaching” from the back wall of the eye it comes away from its main blood supply and therefore stops functioning and the detached retina results in a blurred patch in the vision. The blurring usually therefore comes on after a sudden onset of flashes and floaters and develops over hours or days from the side or periphery of the vision and as the detachment spreads towards the centre of the retina so the blurred patch increases towards the central vision and if left untreated the whole retina can detach results in very poor vision.
It is best therefore to treat the retinal tear before the retina detaches with laser but if the retina starts to detach it is still important to treat as soon as possible as the prognosis for obtaining good vision following surgery if much better if caught at an early stage and in particular if surgery takes place before the central retina (macula) detaches (macular “on” retinal detachment).
What is the surgical treatment of retinal detachment?
Most retinal detachments occur when the jelly (vitreous) that occupies the main eye cavity starts to liquefy and pulls away from the back of the eye but does not want to “let go” of a particular area of the retina (photographic film lining the back wall of the eye). The retina tears in this location and the watery component of the jelly (the part that has liquefied) can pass thought the tear under the retina and the retina starts coming away (detaching) from the back wall of the eye. If left untreated the retina completely detaches and the vision is lost in that eye.
Treatment is therefore needed with a degree of urgency and it is always better if the retina can be reattached before the central part of the retina (macular) comes away. Most operations for retinal detachment require a procedure called a vitrectomy which removes the jelly that is pulling on the retina from the main eye cavity.
Once this pulling force has been removed the retina needs to be pushed up against the back wall of the eye into its correct location. This pushing force is usually with a gas bubble placed in the eye to push the retina back in place. Once the retina is in its normal position the tear (or tears) that resulted in the original problem need to be sealed to stop the retina from re-detaching. This is performed by applying laser around the tear(s) to “spot weld” them in place. The laser treatment does not however have an immediate effect as it works by creating inflammation in the retina but it is only when this inflammation changes into scar tissue that the full seal develops.
The retina therefore needs to be held in the correct position whilst this scarring is taking place and hence the need to “posture” following retinal detachment surgery. The posturing allows the gas bubble to float up against the tear and keep it pressed against the back wall of the eye whilst the scarring develops. The position of the posture depends on where the tear or tears are situated. The duration of the posturing also depends on the size and position of the tear(s) and the type of gas used. It is rare that posturing is needed for more than five days however.
Whilst the gas is inside the eye the vision will be very blurred and then it will gradually improve as the gas gets absorbed back into the blood stream. Different gases are used depending on the type of detachment and the gas can last anywhere between 1 week if air is used to 6 weeks with a long acting gas. It is advisable not to drive until the gas bubble has completely disappeared and you must certainly not fly. If you have a general anaesthetic for any other condition whilst there is still some gas in the eye then do please ensure that the anaesthetist knows about your gas bubble.
If the central retina (macular) has detached for any length of time prior to surgery the central vision may not return completely even with successful reattachment of the retina. This is why it is so important to treat the condition as quickly as possible. The retina can be successfully reattached nine times out of ten but sometimes more than one operation is needed.
If excess scar tissue forms inside the eye (not related to the laser) it can contract and pull the retina off once more. If this occurs more extensive surgery is required to remove the scar tissues and sometimes clear silicone oil has to be placed in the main eye cavity to keep the retina in position for several months before the oil is removed with another operation.
Sometimes holes develop in the retina due to gradual thinning of the retina rather than the jelly pulling on the retina. These are called atrophic holes and are less frequently seen but may be treated in a different way. These holes can be sealed from the outside rather than the inside and this usually involves placing some plastic called a scleral buckle on the outside of the eye overlying where the hole is situated. The buckle is stitched to the sclera (the white of the eye) and this creates an indentation pushing the sclera in towards the hole in the retina and this helps seal the tear. The buckle stays in position permanently but is covered by the conjunctiva which is the skin that covers the white of the eye and is therefore not visible. A scleral buckling procedure usually does not require gas inside the eye or any posturing.
Problems we can help with
I will explain with the aid of video clips the various eye problems I treat. This includes cataract surgery, refractive lens exchange in patients over 50 and medical and surgical treatments of all retinal and macular problems.
I provides advanced micro-incision cataract surgery and will advise on the appropriate intra-ocular lens for your particular needs. This includes toric lenses to correct astigmatism and extended range of vision multifocal lenses to reduce spectacle dependance.
Refractive Lens Exchange (RLE)
Patients with strong glasses or contact lenses who's natural lens has lost its ability to focus (usually over 50 years) may benefit from RLE to reduce dependance on glasses or contact lenses. Surgery is beneficial for some but not all patients.
Patients with wet (neovascular) age-related macular degeneration can benefit from prompt injection treatments with various anti-VEGF agents. The first injection can usually be performed on the day of consultation as as "see and treat service".
Retinal Vein Occlusion
Blockage to the veins of the retina can produce significant visual disturbance and may require injection treatments with anti-VEGF agents or steroids at Exeter Eye. More severe cases may require laser or surgery at the West of England Eye Unit under Mr Simcock's care..
Diabetic Eye Disease
Diabetes is becoming increasingly common and can cause significant visual loss. If detected at an early stage vision can be maintained using injection treatments with anti-VEGF agents or steroids. More serious cases may require laser or surgery at the West of England Eye Unit.
Mr Simcock has pioneered macular hole surgery in the UK and performs a technique which includes lens removal to prevent patients returning for cataract surgery. The technique also benefits from no or limited (2 day) face down posturing to allow hole closure in most macular holes.
Scar tissue on the surface of the macular (central retina) causes blurring and distortion of vision. Surgical removal of scar tissue with vitrectomy can be performed if sufficiently troubled. Most patients notice a significant improvement in vision and reduced distortion with this surgery..
Patients troubled by floaters in their vision not improving over a period of at least 6 months may benefit from vitrectomy surgery to remove the floaters. Patient selection is important and depends on age (usually over 50) and the state of the jelly (vitreous) in the main eye cavity.