Retinal Tears & Detachment

Qn 1: What is the Retina?

The retina is a transparent, thin layer of light sensitive cells that line the inside back wall of the eye. The retina is very important for good vision.

Referring to the diagram of a camera, the retina is like the film of a camera. (Fig 5) If the film of the camera is damaged, there will not be good quality pictures. Similarly, if the retina is damaged, the images received by the brain will be blurred and the vision will not be clear. In the colour picture of the normal retina shown, the central part of the retina is called the macula. (Fig 6) The macula is the area of the retina most critical to fine, discriminatory central vision. The rest of the retina outside the macula is important for peripheral (side) vision.


Retinal Detachment/Figure 1

Qn 2: What causes retinal tears or retinal holes?

The vitreous is the gel-like structure that occupies the space between the lens and the retina. When the vitreous gel is healthy, it has a firm, uniform consistency and acts as a support to the retina, keeping it in place against the choroid and sclera. It undergoes gradual degeneration and liquefaction with age and in certain ocular conditions (such as high myopia, ocular trauma, intra-ocular inflammation or ocular surgery). Due to increasing liquefaction, it will eventually collapse upon itself and separate from its attachment to the retinal surface in most areas except at the vitreous base (anterior edge of the retina). (Fig 7)

Retinal Detachment/Figure 2


Retinal Detachment/Figure 3

In most individuals, the vitreous separates cleanly from the retinal surface without causing any damage to the retina. In some cases, some part(s) of the vitreous is abnormally adherent to the retina and in the process of detaching, causes a tear(s) to the retina. (Fig 8a, 8b) Liquefied vitreous entering the tear into the subretinal space then causes a retinal detachment. (Fig 9)

 

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Qn 3: Why is a retinal detachment dangerous?

A retinal detachment is dangerous because it can cause blindness. When liquefied vitreous enters through a retinal tear and separates the retina causing a retinal detachment, the photoreceptor cells of the retina that are crucial for vision lose their blood supply and begin to die off.

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Qn 4: I have been seeing ‘floaters’ and ‘flashing lights’. Is this a sign of a retinal tear?

‘Floaters’ are essentially shadows of opacities in the vitreous cavity cast onto and appreciated by the retina. As the vitreous liquefies and detaches from the retinal surface, there is a prominent opacity in the form of a ring or part of a ring that marks the vitreous attachment to the optic nerve. This manifests as a prominent floater at or around the point of fixation. Other causes of ‘floaters’ include blood or strands in the vitreous that casts a shadow on the retina. ‘Floaters’ have been described by patients in all shapes and sizes, ranging in appearance from ‘flying saucers’, ‘cobwebs’, ‘strings’, ‘showers of black dots’, ‘veils’ etc. ‘Floaters’ are usually more easily observed in areas of bright illumination, especially against a plain light coloured background.

‘Flashing lights’ are another common symptom of vitreoretinal disease. If a retinal tear has developed, there may be some bleeding due to torn blood vessels and the blood in the vitreous gel will cast shadows on the retina giving rise to the sensation of ‘floaters’. These floaters are usually like a ‘shower of black dots’. Hence, ophthalmologists will warn their patients that if they experience a sudden onset of ‘floaters’ and ‘flashing lights’, they should be screened by their ophthalmologists for a retinal tear.

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Qn 5: How are retinal tears treated?

Retinal tears, if detected early without any detachment occurring, can be treated in the following ways:

  1. Laser photocoagulation around the tears. The laser is a bright light source which treats around the tear creating a scar, preventing it from progressing to a retinal detachment. It is performed at a slit lamp machine fitted with the laser under topical anaesthesia (where ‘numbing drops’ are applied to the eye). This numbs the eye and a special lens is applied to the eyeball. The laser procedure usually takes about 15 – 20 minutes for small retinal tears.
    The actual lasering may be uncomfortable to the patient as bright flashes of light will occur and there may be ‘pinprick’ sensations as the laser is applied. Inform the surgeon when the procedure becomes too uncomfortable and the surgeon will stop and either adjust the laser power or allow the pain to subside.
  2. Cryopexy around the tears. Cryopexy is performed using a cryoprobe which freezes through the wall of the eyeball around the tear and creates a scar. It uses cold energy to freeze the surrounding retina around the tear and create inflammation which eventually results in a scar forming around the tear. It is performed as an outpatient procedure and usually topical anaesthesia is given.

The picture below is that of a surgeon performing laser treatment of a retinal tear. (Fig 11a, 11b, 12).


Retinal Detachment/Figure 4

Retinal Detachment/Figure 5

The patient usually lies down on an examination couch or in the reclining chair of the examination room. This procedure may be uncomfortable for the patient as the cryoprobe becomes very cold and this may be felt through the eyelid skin. There may also be some pressure applied to the wall of the eyeball during this procedure. If the procedure becomes too uncomfortable, inform the surgeon and he will stop to relieve the discomfort and possibly add more anaesthesia. The picture on the left is that of a retinal surgeon performing cryopexy treatment of a retinal tear. (Fig 13) After the cryopexy procedure, the treated eye will become swollen, red and may have a slight mucous discharge up to 10 days. This is a normal reaction to the inflammation caused by the cryopexy procedure.

 

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Qn 6: How are retinal detachments treated?

Retinal Detachment/Figure 6

Retinal detachments are a serious threat to vision. (Fig 14) If the macula (the central part of the retina that is crucial for good vision) is involved by the retinal detachment, the chances of seeing well after successful surgery is significantly reduced.

It is always preferable to treat early when the retinal tear has just occurred without any detachment, or when there is a retinal detachment without macula involvement.

There are many possible ways of surgically treating retinal detachments. The actual choice of the surgical procedure will rely heavily on the surgeon’s personal preferences, his previous experience with the different procedures and the complexity of the retinal detachment.

 

The procedures that are used to surgically treat retinal detachments include the following:

  1. Lincoff’s balloon
  2. Pneumatic retinopexy
  3. Scleral buckling surgery
  4. Vitrectomy with adjunctive procedures such as the use of heavy liquids, long acting gases, silicone oil etc.

Qn 6a: What is the Lincoff balloon procedure?

The Lincoff balloon (Fig 15) is a device that allows the retinal detachment to be treated by a temporary balloon which is removed once the detachment is successfully treated. It works by using the balloon which inflates and compresses the retinal tear against the vitreous gel. This will close the break and the tear can later be treated with laser or cryopexy once the detachment has reattached.

 

Retinal Detachment/Figure 7
 

Qn 6b: What is pneumatic retinopexy?

Pneumatic retinopexy surgery for retinal detachments is the use of a gas bubble to seal the retinal break. (Fig 16) Once the retinal break is sealed, the detachment will reattach and laser or cryopexy can be applied to the retinal tear. This requires the patient to adopt a special head position or posture for as long as 2 weeks to ensure that the gas bubble is over the retinal break and to ensure that a adequate laser or cryopexy scar is formed around the retinal tear.

Retinal Detachment/Figure 8
 

Qn 6c: What is the scleral buckling procedure?

The scleral buckling procedure is a universally accepted procedure for the treatment of simple and complicated retinal detachments. It may be used as an adjunctive procedure in addition to a vitrectomy in complicated retinal detachment surgeries. The principle of using scleral buckles is rather simple: the scleral buckle creates an indentation of the eyeball and the retinal tear is brought closer to the eyewall (the sclera). This will close the retinal tear and the retinal detachment will reattach. The indentation created by the scleral buckle also relieves any existing vitreous gel traction on the retina. In Fig 19, the various types of scleral buckles used by retinal surgeons are shown.

Retinal Detachment/Figure 9

In the diagram shown, a scleral buckle is shown sutured to the wall of the eyeball creating the necessar y indent tion. (Fig 18) The type and size of the scleral buckle chosen will depend on the location and size of the retinal tear, with the decision made by the surgeon intraoperatively. In the early years, scleral buckles were made from varying materials such as rubber, plastic but most modern scleral buckles are now made from silicone rubber. (Fig 19)

Retinal Detachment/Figure 10

 

Qn 6d: What is a vitrectomy procedure?

A vitrectomy procedure is an elegant method of repairing retinal detachments. It utilises microsurgical instruments of small calibre which enter the eyeball through small openings. There is always an opening through which fluid is infused into the eye to maintain a constant pressure inside the eyeball. There are also another two openings through which instruments to illuminate the inside of the eye, to cut and remove the vitreous gel, microsurgical scissors, intraocular laser probes etc, can be introduced to repair the detachment. As the diagram illustrates, the vitrectomy procedure occurs in a controlled, closed environment within the eyeball. (Fig 20)

Retinal Detachment/Figure 11

In almost all vitrectomy procedures for retinal detachments, the retinal surgeon will choose to use a long acting substance to provide additional pressure onto the retinal tear. This may be a long acting gas such as sulfur hexafluoride or perfluoropropane, or a liquid such as silicone oil. The long acting gases may be left in the eye as the gases will be eventually reabsorbed. However, silicone oil is usually removed some time later during another surgical procedure. The decision to use long acting gases or silicone oil depends on the complexity of the retinal detachment.

 

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Qn 7: What is the probability of having more than one retinal detachment surgery to reattach the retina? Is there the chance of going completely blind?

Despite the many advances in vitreoretinal surgery, the patient should be made to understand that there is the probability of 10% of having more than one surgery to reattach the retina. There is also the risk of up to 5% that all may fail and the eye will become blind. For complex retinal detachments, the possibility of having multiple surgeries is quite high. The overall prognosis is different for each case and this should be discussed thoroughly with the vitreoretinal surgeon in charge.

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Qn 8: Will I be able to see clearly immediately after my retinal detachment operation? When should I change my spectacle prescription?

Almost all patients will not be able to see clearly immediately after the retinal detachment operation. This is due to the inflammation, redness and soreness immediately after the operation. If there is increasing pain, redness, discharge containing pus and a drop in vision, the patient must immediately inform the vitreoretinal surgeon as there may be a dangerous infection occurring.

The vision may take up to 6 months to recover to its maximum level. Most vitreoretinal surgeons would therefore recommend that patients recheck their spectacle prescription about 3 months after the surgery.

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Qn 9: I have had laser/cryopexy surgery for a retinal tear. Are there any special precautions that I must take?

Laser/cryopexy surgery for a retinal tear is a relatively straightforward procedure. There is no need to take any special precautions. The following is recommended:

  1. One should avoid physical activities such as boxing, kickboxing, bungee jumping etc, which have the risk of injury to the eyeball. Activities such as walking, gardening, going to an office job etc, are fine and will not have any effect on the laser surgery.
  2. There is no need for dietary restriction or any special head posture.
  3. Washing the face or shampooing the hair immediately after the laser surgery is fine.
  4. If there was bleeding into the vitreous due to the retinal tear, you may be advised to sleep with the head propped up to allow the blood to settle down and the vision to improve.
  5. Flying is not contraindicated.

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Qn 10: I have had a pneumatic retinopexy for a retinal detachment. Are there any special precautions that I must take?

There are special instructions for patients who just had a pneumatic retinopexy:

  1. It must be emphasised again that the success of the procedure wholly depends on the ability and total compliance of the patient to maintain the head posture for 24 hours a day for a total duration of at least 1 week. The vitreoretinal surgeon will indicate which particular head posture is desirable and the patient should take careful note of it. The head posture has to be maintained even when sleeping, walking, watching TV etc. There are special devices that help patients maintain their head posture – please check with your vitreoretinal surgeon as to their availability. (Fig 21)
  2. or short periods of time, especially if an uncomfortable head posture is necessary, the patient can straighten his head to eat or go to the bathroom or to receive eye drops.
  3. It is recommended that the patient should avoid all strenuous physical activity for at least 3 weeks. Any lifting of heavy objects is not advised (the recommended weight will vary according to the size and strength of the individual but any weight that requires significant effort is not recommended) Physical activity that involves movement of the head (includes jogging, aerobics, swimming, golf and sex) should be avoided. Reading, gardening, watching TV is fine as long as the head posture is maintained.
  4. The patient is advised to stop work during this period of 2 – 3 weeks. The ophthalmologist will write a medical report to support his disability claim. However, for some patients who have absolutely crucial work to do during this period, they may do so provided they maintain the head posture and avoid strenuous activity.
  5. There is no dietary restriction necessary.
  6. The patient can wash his face or shampoo his hair provided that no soap or shampoo enters the treated eye. It is therefore recommended that for the first week, the patient may wish to wash his face with a face towel or shower with swimming goggles on. Shampooing the hair can be done at a hair salon with strict instructions to the hairdresser not to let shampoo enter the eyes.
  7. Flying is presently contraindicated if the gas bubble is still in the eye. A study conducted by the authors as to the safety of flying with an intraocular gas bubble showed that it is not safe to fly if the intraocular gas bubble is still present.

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Qn 11: I have had a scleral buckle surgery for my retinal detachment. What special precautions must I take?

There are special precautions to take after a scleral buckle surgery. There are additional precautions to take especially if long acting gases are used.

  1. If long acting gases were used during the surgery for additional pressure (tamponade) upon the retina, the patient must strictly maintain a special head posture to keep the gas bubble at the desired position. Like the pneumatic retinopexy procedure, the patient will have to keep this head posture for at least 2 weeks. However, if the scleral buckle is adequate and correctly placed, the patient may not need to maintain the head posture for more than a few days – the vitreoretinal surgeon will decide for each individual case. As mentioned in the section on pneumatic retinopexy, there are several devices in the market for maintaining head posture in patients with long acting gases as tamponade (pressure) for retinal detachments. (please refer to Fig 21)
  2. The eyelids and the eyeball will be swollen and quite sore after the surgery. The discomfort from the operated eye should gradually subside over the first few days. There may normally be some discharge which contains mucous and blood from the eye for the first 3 – 4 days. If the discharge looks like pus or there is increasing pain or redness, it may be a sign of infection and the vitreoretinal surgeon should be notified immediately. It is advisable to wear an eye shield for the first week, after which only the eye shield should be worn at night.
  3. The patient should be on official medical leave for at least 3 weeks. However, if there are some pressing matters to attend to, the patient may go to work after the first week. If there is any discomfort felt during work, the patient should stop immediately and rest.
  4. Vigorous activity must be avoided for the first month after surgery. Any lifting of heavy objects should be avoided during the first 2 weeks (‘heavy’ depends on the size and strength of the individual but straining should be avoided). Activities such as jogging, aerobics, golf, swimming, sex etc, should be avoided. Activities with the possibility of injury such as boxing, kickboxing and bungee jumping are absolutely contraindicated.Gardening, watching TV, reading and other sedentary activities are permissible (if a long acting gas is used, the head posture must still be maintained during sleep and other sedentary activities).
  5. Washing the face and shampooing the hair is permissible provided that none of the soap or shampoo enter the eye. As the eye is swollen or sore during the first 2 weeks after surgery, any additional irritation may slow the recovery considerably. Most patients choose to use a face cloth to wash the face for the first 2 weeks or to wear swimming goggles if they use a shower. Shampooing the hair usually requires a visit to the hairdresser with special care taken not to allow shampoo into the affected eye.
  6. No dietary restrictions are necessary.
  7. Flying is presently contraindicated if a gas bubble is in the eye. A study conducted by the authors of this book as to the feasibility and dangers of flying with an intraocular gas bubble showed that it is unsafe to fly when the intraocular gas bubble is still present
Retinal Detachment/Figure 12
 

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Qn 12: What are the uses of the eyedrops given to me after my retinal detachment surgery?

In most circumstances, after a scleral buckling surgery or vitrectomy surgery for a retinal detachment, most vitreoretinal surgeons would give the following drops:

  1. Antibiotic eye-drops

    This is usually to prevent any infection that may occur while the eye is healing. The antibiotic chosen varies according to the surgeon’s preference but most surgeons choose an eye-drop that will be effective against the widest range of bacterial organisms (the broad spectrum antibiotics) or against the presumed most deadly and common type of bacterial organisms (in this case, aminoglycoside antibiotics that are effective against the Gram negative bacteria).

    Sometimes, patients may be sensitive to some antibiotics and may develop an allergic reaction to the antibiotic or its preservative. If the patient finds that after applying the eyedrops, the eye becomes red, itchy and swollen, please see your surgeon immediately.

  2. Steroid eye-drops

    Steroid eye-drops are used to control the normal inflammation that occurs after surgery. During the healing process, the eye will have some degree of inflammation which is uncomfortable and may cause the healing to be prolonged.

    Steroid eye-drops have side effects which have to be monitored:

    1. Rise in intraocular pressure causing steroid induced glaucoma.
    2. Cataract formation.
    3. Increase the susceptibility of the eye to certain infections.

    If the eye becomes red and painful, the patient should inform the surgeon immediately as it might be an infection.

  3. Dilating eye-drops

    Dilating eye-drops are used to ensure that the pupil remains dilated for retinal examination, to prevent the pupil from being ‘stuck down’ due to excessive inflammation and to relieve patient discomfort due to ciliary muscle spasm.

    Most surgeons would give dilating eye-drops for the first two weeks after surgery, with some tailing it down drastically after the first two weeks or stopping it totally.

    The side effects of dilating eye-drops are the following:

    1. It will cause blurring of vision, especially for near vision.
    2. It may cause an allergic reaction.
    3. It may cause increased sensitivity to light.

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Qn 13: Are people with high myopia prone to retinal detachments?

Severe shortsightedness (high myopia) is one of the common causes of legal blindness in young adults less than 40 years of age. Myopia (shortsightedness) is the condition where the focal point of the eye lies in front of the retina. Commonly, this is due to the axial length of the eyeball being too long for the refractive elements of the eye.High myopia is often defined as the refractive error being more than or equal to 600 degrees of shortsightedness (6 dioptres).

Patients with myopia often have peripheral retinal thinning and degeneration. They also have a higher incidence of peripheral retinal lattice degeneration.

In such patients, they definitely have a higher incidence of retinal tears and retinal detachment compared to the non-myopic population. People who have more than 600 degrees of shortsightedness have a 3 – 4 times greater chance of getting a retinal detachment than someone who is not short sighted. Patients who have high myopia and complain of ‘floaters’ and ‘flashing lights’ should consult their vitreoretinal surgeon urgently to exclude a retinal tear.

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Qn 14: I would like to go for laser treatment (PRK/LASIK/LASEK) to correct my severe shortsightedness. Is there a risk of a retinal detachment occurring after the laser?

Laser treatment for correction of shortsightedness has not been proven to predispose to retinal detachments.

It must be remembered that laser treatment for shortsightedness does not change the axial length of the eye or correct the natural tendency of highly myopic retina to developing retinal tears and retinal detachments.

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