When to treat
When intravitreal injections are not enough on their own, or when the disease is already advanced, treatment moves on to laser or vitrectomy. These are complementary procedures, chosen according to the type of damage and the condition of the retina — both aim to save sight when the damage risks becoming permanent.
- Laser indication
- Proliferative form or resistant macular oedema — outpatient, can be repeated.
- Vitrectomy indication
- Persistent vitreous haemorrhage or tractional retinal detachment — in the operating theatre.
- Common goal
- To save sight when intravitreal injections alone are no longer enough to control the disease.
- Follow-up
- Always needed — diabetic retinopathy is a chronic condition that requires monitoring for life.
Laser treatments
Laser treatments for diabetic retinopathy are outpatient procedures that are quick and well tolerated. The technique chosen depends on the stage of the disease and whether macular oedema is present.
Panretinal photocoagulation (PRP) is the first-choice treatment for the proliferative form: it selectively destroys the ischaemic areas to stop neovascularisation. Focal or grid laser is instead used for diabetic macular oedema, especially when anti-VEGF injections are not sufficient or not available. The two techniques can be combined.
The procedure
The treatment is carried out by placing a contact lens on the eye that focuses the laser beam, after anaesthetic eye drops and a protective gel. Generally painless, it may cause mild discomfort (a pricking sensation) and glare from the flashes of light. Duration: 15-30 minutes per session; complete PRP often requires 2-3 sessions spread over a few weeks.
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Panretinal photocoagulation (PRP)
Proliferative retinopathyIt involves making hundreds of small laser burns on the peripheral retina, leaving the macula intact. The ischaemic areas stop producing the factors that stimulate neovascularisation: neovascularisation regresses, and vitreous haemorrhage and tractional detachment are prevented.
It is the standard treatment for the proliferative form and is usually combined with anti-VEGF injections. Frequent side effects include reduced peripheral vision and difficulty seeing at night. These are the price paid for saving central vision and preventing blindness.
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Focal and grid laser
Diabetic macular oedemaIt selectively treats the microaneurysms that leak fluid into the macula (focal laser), or creates a grid pattern of small burns around the area of oedema (grid laser). The aim is to reduce leakage and macular oedema.
Today it has largely been replaced by anti-VEGF injections, which are more effective and less destructive, but it remains indicated in selected cases: focal macular oedema with visible microaneurysms, patients who do not respond to anti-VEGF drugs, or when injections are not feasible.
Expected results
PRP causes neovascularisation to regress in most patients and greatly reduces the risk of blindness from the proliferative form (historic DRS study: 50% reduction in severe vision loss). Focal laser can improve macular oedema but is now a second-line option compared with anti-VEGF. Both treatments are complementary to injections, not alternatives — the combination of laser and anti-VEGF is often the standard of care. Follow-up after laser remains required: retinopathy continues to evolve and further treatment may be needed.
Vitrectomy and surgery
When injections and laser are not enough — usually because there is already a significant haemorrhage in the vitreous or a tractional retinal detachment — incisional surgery is performed: pars plana vitrectomy. It is a highly complex operation carried out in the operating theatre.
Vitrectomy involves removing the vitreous body (the gel that fills the eye) through three small incisions (25 or 27 gauge microsurgery), clearing any haemorrhage, cutting away the scar tissue that pulls on the retina and — when necessary — repositioning and securing the detached retina. At the end, the vitreous is replaced with saline, gas or silicone oil, depending on the case.
The operation takes 1-3 hours, under local anaesthesia with sedation or general anaesthesia. It is performed with a digital operating microscope and instruments calibrated to the micrometre. Modern minimally invasive techniques have made this surgery much safer and quicker to recover from than in the past.
When there is strong macular traction, during vitrectomy the internal limiting membrane (ILM) peel is often also performed: a very thin membrane is gently lifted off the retina with fine forceps to free the macula from residual mechanical forces.
When it is truly necessary
Vitrectomy is reserved for advanced cases or acute situations: vitreous haemorrhage that does not clear within a few weeks, tractional or rhegmatogenous retinal detachment, or macular oedema with significant vitreoretinal traction. It is not a first-line procedure — it is used when less invasive treatments are no longer sufficient or when the damage puts sight immediately at risk.
After surgery
Recovery after vitrectomy requires discipline and care: the success of the operation depends largely on how closely the patient follows the instructions. The following are examples only: always follow those given by the centre that operated on you.
What to do
- Use your eye drops (antibiotic, anti-inflammatory, dilating) following the schedule carefully given in your discharge letter.
- If gas or silicone oil has been injected, maintain the required position (usually face down or on your side) for the number of days stated.
- Protect the operated eye with sunglasses during the day and, if prescribed, with a rigid eye shield at night, for the period advised by the centre.
- Gently clean the eyelids with sterile gauze and saline solution, without pressing on the eyeball.
- Attend all post-operative check-ups scheduled by the centre: they are essential for spotting early complications.
What to avoid
- DO NOT strain your eye: ask the centre when to resume reading, screens and activities that require intense visual focus.
- No physical exertion and no lifting of heavy objects, including carrying children, for the period advised by the centre.
- DO NOT fly if there is gas in the eye (it can expand with cabin pressure): wait until it has fully absorbed, as advised by your ophthalmologist.
- No swimming pools, the sea, saunas or hot tubs for the period advised by the centre.
- Avoid dusty, smoky or windy environments in the first few weeks.
- DO NOT sleep on the operated side, for the period advised by the centre.
Important to remember
Both laser and vitrectomy require regular post-operative check-ups, but they do not replace control of diabetes: without good control of blood sugar, blood pressure and lipids retinopathy continues to progress. Contact your ophthalmologist straight away if you have sudden, severe pain, a sudden drop in vision, marked redness, flashes of light or an increase in floaters — these can be signs of complications (endophthalmitis, retinal detachment) that require urgent treatment.