Description of the disease
Complications of diabetes that affects the eye are called diabetic retinopathy. Within the context of diabetic retinopathy, macular edema caused by diabetes requires a separate treatment approach, which is also described below.
At the onset of the disease, the wall of the small vessels becomes abnormally permeable (capillary hyperpermeability) and small dilatations develops (microaneurysms) causing fluid leakage between the tissues (edema) and grease deposits (lipid exsudate). In addition, bleeding and blockages of these vessels also occur, which will cause blood insufficiency (ischemia) on some parts of the retina.
Over time, as the process progresses and the blood deficiency of the tissues reaches a certain critical level new blood vessels will be formed (neovascularisation), but these will be abnormal, misplaced and leaking vessels that can lead to additional and more serious complications.
Different lesions are distinguished within diabetic retinopathy, like the edema of the central part of the retina (diabetic macular edema), the growth of new vessels (proliferative diabetic retinopathy) and the complications caused by these formentioned changes (vitreous haemorrhage, tractional retinal detachement). These are important because of needing different therapeutic approach.
One of the most important element of the treatment plan is the management of the general condition (blood sugar, blood fats, blood pressure management, physical activity, healthy diet). The goal of the ophthalmic treatments are to intervene in this gradually deteriorating process and trying to stop this vicious circle, thus preventing a severe and irreversible visual impairment.
Symptoms of diabetic retinopathy
The symtomps are varied according to the stage of the disease from none to sudden vision loss. These are the most common ones:
- blurred or patchy vision
- gradually worsening vision
- sudden vision loss
- eye pain or redness may develop at later stages.
Treatment of diabetic macular edema (DME)
We have two options for treating cystoid macular edema in diabetic retinopathy: injection into the back of the eye (intravitreal injections) and retinal laser treatment (panretinal photocoagulation).
Intravitreal injections
One type of intravitreal injections are the anti-VEGF injections. There are several anti-VEGF drugs, but initially each of them needs to be administered monthly and then at every 2-3 months for an indefined period of time. In certain advantageous cases a few (at least 5) injections are sufficient to permanently eliminate the macular edema, but unfortunately most often the treatment lasts for years due to fluid reoccurence.
Another similar injection therapy are the steroid implants, which are injected into the vitreous within a small absorbable container. They dispense the drug gradually and evenly over several months, which is a clear advantage, but due to its complications (glaucoma or cataract formation), we only use the treatment as a fallback solution in selected cases. Injection treatments are quite effective during their potency period in a large number of patients, but there are cases which don’t respond to treatment.
On the other side must be noted that the injections can cause severe complications, such as purulent endophthalmitis (severe, infectious inflammation of the eye) that often leads to permanent vision impairment or blindness. However if hygiene rules are followed, its incidence remains quite low.
Laser treatment
A modern treatment option for diabetic macular edema is micropulse laser treatment, which can be performed most accurately with the Navilas device. This procedure is primarily effective in cases of moderate macular edema and can be used as a standalone primary therapy or as a supplement to injection treatments. In the latter case, the goal is to increase the effectiveness of the injections and reduce the burden on the patient associated with frequent injections.
Although classic laser procedures have been used for decades due to their lasting effects, they are rarely used today due to tissue damage and scarring in the central part of the retina. In contrast, the new micro-pulse technology does not damage the retina, so it can be used safely even in areas critical to vision. The Navilas laser stimulates the absorption of accumulated fluid in micropulse mode, while in another setting it can also treat leaking microaneurysms, preventing the abnormal blood vessels from leaking again.
The treatment usually takes only one session, is completely painless, and since it does not cause external wounds or tissue damage, there are no restrictions for the patient after the procedure. Although one treatment is usually sufficient for improvement, the gentle nature of micro-pulse technology means that the procedure can be safely repeated at any time if necessary.
Treatment of macular microaneurysms
Microaneurysms play an important role in the development of macular edema, from which increased and continuous fluid filtration occurs into the layers of the retina. Closure of microaneurysms can be achieved with laser treatment, but since it is a very small lesion, precision treatment is of paramount importance, otherwise we will sacrifice special areas unnecessarily.
It is also possible to treat microaneurysms with conventional devices, but requires a high degree of discipline on the part of the patient, as any small movements can cause permanent vision damage. However with the Navilas laser device this risk can be eliminated: thanks to the eye tracker program and the treatment plans which are made based on images taken just before the procedure the laser will target just the intended abnormal areas.
Treatment of proliferative diabetic retinopathy
In diabetic retinopathy, the severe ischemia of the retina (blood supply deficient) leads to abnormal blood growth, a process called proliferative retinopathy. These abnormal blood vessels often rupture causing vitreous hemorrhage and with further grow leads to tractional retinal detachment, which has an unfavorable visual outcomes even after major surgery.
The easiest way to stop the neovascularization is to perform a proper fundus laser treatment, called panretinal photocoagulation. By treating the most ischemic peripheral parts of the retina, the proportion of areas supplied with blood improves, thereby causing the regression of the abnormal blood vessels.
The entire treatment of the fundus usually can be done in 4-6 sessions, but with modern devices (like Navilas Laser System) I can do it in up to 1-2 sessions. The patient’s pain sensation is significantly lower compared to conventional devices, since it is sufficient the application of one-fifth of energy intensity to achieve the effect.