1. age-related macular degeneration (AMD)
Macular degeneration is a common problem that is encountered in patients over 60 years of age. There may be a family history and broadly the disease is split into 2 main categories:
- Dry AMD – progressive loss of pigment cells under the retina leading to gradual blurring of central vision.
- Wet AMD – these patients may have had some dry features for some time but develop a rapid onset of blurring and distortion due to blood vessel leakage under the central retina.
Dry AMD is very hard to treat and there are no obvious cures available. In the last 10-20 years very much effort has been put into finding dietary supplements e.g. vitamins that can slow the progression of the disease and reduce the chance of developing wet changes. Dietary supplements on the form of vitamins may be recommended in certain cases. In years to come we may have drugs and retinal procedures to improve the outlook in dry AMD.
Wet AMD is an urgent situation where rapid diagnosis and treatment can arrest the disease process and also allow some recovery of vision. The treatment involves injections of drugs to halt the leaking process and allow the eye to naturally repair itself. To date there are 3 drugs available with slightly different pros and cons. These are Avastin, Lucentis and Eylea. Treatment requires long term monitoring and early reinjection of drugs if there is any sign of disease reactivation. Overall the treatment results are good with over 90% of eyes stable on treatment and a significant vision improvement in a third of patients after starting therapy.
Occasionally wet AMD may present with a sudden vision loss due to haemorrhage requiring vitrectomy surgery and drugs to break up a blood clot at the back of the eye. This can be a very difficult situation and requires careful judgment as to whether surgery should proceed to try to regain useful vision.
2. retinal tears, holes and detachments
Posterior Vitreous Detachment (PVD)
A condition where there is a sudden onset of floaters in the vision of one eye associated in some cases by marked flashes of light. The vitreous gel becomes more liquid with age and at some point may spontaneously separate from the nearby retina giving rise to these symptoms.
In the vast majority of cases the symptoms settle within a few weeks to leave a few tiny floaters but there are a number of risks:
Patients with a torn retina are at high risk of retinal detachment. If the holes can be treated in good time with laser the risk of detachment is significantly reduced.
A few patients remain very annoyed by floaters in their field of vision. I would always recommend waiting for a period of months but occasionally vitrectomy surgery can be used to remove the floating debris with a resulting improvement in vision.
Particularly in patients where there has been a retinal tear some scar tissue can develop on the surface of the retina. While there may be few symptoms initially (known as cellophane maculopathy) there is a risk of blurring and distortion of vision caused by the scar tissue (epi-retinal membrane). Vitrectomy surgery is sometimes necessary to remove this scar tissue and has a high success rate in appropriately chosen cases
In the unfortunate situation where retinal detachment occurs, often urgent surgery is needed to close any retinal tears and allow the retina to reattach to the underlying layers in the eye. Retinal detachment may be accompanied by a history of vitreous floaters, flashing lights and a steady loss of the field of vision over a few hours or days. When the central retina (the macula) detaches, the risk to vision is even greater and patients may have a worse outcome despite successful surgery.
Patients who are at higher risk of retinal detachment include:
- Highly myopic patients (short sighted)
- Patients who have had a retinal tear or detachment in their fellow eye sometime previously
- Recent eye surgery including YAG laser, cataract or lens implant surgery
- A family history of retinal detachment
Treatment of retinal detachment may be complex but modern techniques allow a greater chance than ever of maintaining or improving vision when compared to preceding generations. In general about 85% of retinal detachments will successfully settle after 1 operation and further surgery will treat 95% of the remaining cases.
Types of Surgery Used
- Laser treatment for retinal holes / tears
- Vitrectomy surgery
- Scleral buckling surgery
3. Macular surgery
This condition stems from abnormal adhesion between the vitreous gel and the central retina (macula). Contraction of the gel can cause formation of a macular hole resulting in symptoms of distortion and vision loss. Confirmation of the diagnosis is by slit lamp examination and OCT scan. Most cases of macular hole will result in poor central vision if not treated and many patients will have vitrectomy surgery to peel off the abnormal gel and seal the hole with a temporary gas bubble inside the eye.
Results of macular hole surgery are often very good with hole closure in over 90% of cases and many patients returning to good reading vision and the driving standard in the affected eye.
Epi-retinal membrane (macular pucker)
See above under vitreous detachment
This condition is quite rare but may be a mild form of retinal traction similar to macular hole patients.
Some cases may settle without treatment but vitrectomy is usually effective if required.
Surgery for macular problems
4. Diabetic eye disease
In diabetic eye disease vision is under threat from leaking blood vessels in the central retina (macular oedema) and from bleeding abnormal "new" vessels (proliferative diabetic retinopathy – PDR) that may grow from the retinal surface.
Macular oedema can be treated by laser and anti VEGF injections e.g. Lucentis but these may need to be repeated to maintain good vision. Tight control of blood pressure, lipid levels and blood sugar are also required to limit vision loss.
Proliferative diabetic retinopathy requires peripheral scatter laser treatment that is highly effective. A few patients may still go on to suffer vitreous haemorrhage or traction on the retina and they may require vitrectomy surgery to deal with these complications. Generally 90% of patients having vitrectomy for these problems will have a good outcome with improved stable vision in the long term.
Treatments for diabetic eye disease include: -
- Vitrectomy for proliferative Diabetic eye disease
- Laser treatments
- Anti VEGF injections
5. Vitrectomy Surgery
In vitrectomy surgery tiny instruments are inserted into the back of the eye to deal with a number of different vitreo-retinal problems.
Removal of the vitreous is performed to clear debris e.g. vitreous haemorrhage and to provide access to the retina for other procedures e.g. removal of membranes or laser treatment to the retina.
Indications for vitrectomy include: -
- Retinal Detachment Surgery
- Epi-retinal membrane removal
- Macular Hole Surgery
- Diabetic vitrectomy
- Removal of vitreous Debris e.g. haemorrhage or floaters
Anaesthesia for surgery
Vitrectomy procedures are often carried out in complete comfort under local anaesthetic. Some patients are very concerned about surgery and a general anaesthetic is available if required. I always operate with an experienced consultant anaesthetist and we can tailor the anaesthetic to allow you to have surgery in a relaxed setting.
Most vitrectomy procedures are carried out as day surgery – occasionally an overnight stay is needed and this will be arranged if required.