Treatment of retinal diseases using intraocular injection of medication
For several years ophthalmologist therapy has been used in clinical practice to treat retinal diseases by injecting medication directly into the eye. This new therapeutic approach has improved the prognosis of various retinal diseases by reducing the percentage of visual deterioration.
What is intravitreal drug injection?
The drugs currently used and approved for use are intraocular anti-VEGF drugs (inhibitors for the formation of new blood vessels) and cortisone. The first medications (anti VEGF) are used in the treatment of exudative age-related macular degeneration, diabetic macular oedema and macular oedema secondary to thrombosis of the retinal vessels.
The second drugs (cortisone) are approved and used for the treatment of macular oedema secondary to a thrombosis of the retinal vessels, and for inflammatory diseases of the eye (such as uveitis).
How does the intravitreal injection of medication work?
The injection is performed in a controlled environment (operating room) in sterile conditions and on an outpatient basis. This means that the patient can be released from the hospital after the treatment and should be accompanied by a friend or family member. The treatment is performed under topical anaesthesia or by instillation of anaesthetic eye drops. The post injection therapy is collyrium based.The first follow up check is performed in the clinic the next day. The next check-up will be approximately after 2-3 weeks.
What are the advantages and disadvantages of intravitreal injection of medication?
Treatment with intraocular injections has demonstrated good effectiveness in the treatment of various retinal diseases such as exudative macular degeneration, macular oedema secondary to diabetic retinopathy and vein thrombosis. The reported side effects of these treatments are rare and some of them include: increased intraocular pressure, headaches, vitritis (inflammation of the eye), vitreous detachment, retinal haemorrhage (bleeding at the back of the eye), visual disturbances, eye pain, vitreous floaters (spots in the vision), conjunctival haemorrhage (bleeding in the anterior portion of the eye), eye irritation, sensation of a foreign body in the eye, increased lacrimation, blepharitis (inflammation of the eyelids), dry eyes, ocular hyperemia (redness), eye pruritus, arthralgia (joint pain) and nose pharyngitis (inflammation of the nose and throat). In rare cases, more serious complications may occur such as endophthalmitis (an infection inside the eye), serious eye inflammation, damage to the retina and cataracts. Moreover, the most serious or fearsome systemic complication is thromboembolism.
Is the intravitreal injection painful?
The injection time is very fast, lasting about 1 minute, and the sensation felt by the patient is minimal.
Which patients can undergo the treatment?
There are no absolute contraindications to intravitreal injections for systemic retinal diseases. There are different risk factors especially for patients with heart disease and vascular disease or allergies to the drug content within these medicines.
The check-ups performed after the intravitreal injections are as important as the therapy itself. The check-ups must be performed regularly as instructed by the ophthalmologist to ensure proper therapeutic efficacy.
Standards of preparation
The surgery is performed in the supine position, in a sterile surgical environment (operating room), with the help of the surgeon operating the microscope. The surgical procedure consists of several phases:
- Disinfection of the skin around the eyes and the conjunctival sac
- Intravitreal injection at 3.5/4.0 mm from the limbus by a Transconjunctival approach
- Intraoperative control of IOP and possible paracentesis of the anterior chamber
After the procedure, the surgeon will provide patient instructions adjusted to each individual patient.