Intraocular Injections

Intraocular injections may be needed in patients who have macular oedema or abnormal new blood vessels due to moisture from age-related macular degeneration, diabetes, occlusion of the retinal vein or some other eye disease. During the intraocular injection procedure a medicinal product is introduced into that eye that has an effect against macular oedema and new blood vessels by decreasing the amount of certain substances in the eye that cause these changes.

Quite frequently it may be necessary to repeat intraocular injection as macular oedema and new blood vessels tend to recur after the effect of the drug disappears and vision impairment occurs. The presence of oedema can be monitored with optical coherence tomography (OCT) investigation. At this investigation the retina of the eye is photographed layer by layer, which enables the condition of the retina and presence of oedema to be assessed very precisely. OCT will take approximately 5 minutes to be performed and no special preparations from the side of the patients are necessary.

Depending upon the disease causing impairment of vision the following medicines may be used for intraocular injection: anti-VEGFs (medicines against the growth factor of the internal layer of the wall of blood vessels (endothelium)) or synthetic corticosteroids. On rare occasions both these medicines may be used in combination.

Anti-VEGF therapy has been effective in all performed studies. Several medicinal products with similar effect are available for this purpose.

Lucentis is a licensed ophthalmic medicine. The active ingredient in Lucentis, ranibitzumab, is a humanised (i.e. processed to resemble human) fragment of a recombinant monoclonal antibody (certain protein) against human vascular endothelial growth factor A (VEGF-a). The level of VEGF-a is high in the eyes of the patients with the abovementioned eye diseases. Blocking of this factor reduces the growth of new blood vessels and macular oedema.

Avastin, containing bevacizumab as an active ingredient, is also a monoclonal antibody (certain protein), which recognises the specific structure (antigen) in the cells of a body or blood, and binds to this antigen. Bevacizumab binds to vascular endothelial growth factor (VEGF). VEGF is a circulating protein that promotes the growth of blood vessels; by binding to VEGF Avastin blocks its effects and inhibits the growth of new blood vessels.
Avastin is currently not licensed in Estonia as an ophthalmic medicine. However, it has been successfully used for almost 7 years, and the results of treatment have been good in all studies. Avastin is used as an off-label medicine, which means that although the product is in use in medicine, it is not licensed as an ophthalmic drug. However, the efficacy and safety of the medicines has been proven. Avastin may be used if the patient has been informed before the injection procedure, and the patient has given his/her consent for its use.

Eylea is a licensed ophthalmic medicine that contains aflibercsept as an active ingredient. Aflibercept is a recombinant fusion protein that binds with vascular endothelial growth factor A (VEGF-a) and placental growth factor (PIGF). This inhibits the growth of new blood vessels and decreases macular oedema in the eye.
Synthetic corticosteroids used for intraocular injection include Ozurdex and Kenalog.

Kenalog contains triamcinolon as an active ingredient that is a synthetic corticosteroid with potent anti-inflammatory effect. Triamcinolon also has some anti-VEGF activity. Kenalog solutions with different concentration are used. Its use is mainly limited to significant macular oedema. Triamcinolon can cause an increase in intraocular pressure and the development of cataracts. Eye drops decreasing intraocular pressure are usually sufficient for normalising intraocular pressure after the use of triamcinolon. Kenalog is not licensed as an ophthalmic medicine, but it has been effective in all performed studies.

Ozurdex, containing dexamethasone as an active ingredient, is a synthetic corticosteroid with a potent anti-inflammatory effect and some anti-VEGF effect. Ozurdex is a licensed ophthalmic medicine, and it is used mainly in case of macular oedema caused by venous occlusion and intraocular inflammation. Recent studies have shown that it can also be used for the treatment of macular oedema caused by diabetes. Dexamethasone can also increase intraocular pressure and contribute to the development of cataracts, but these adverse effects are less pronounced than with Kenalogi.

The intraocular injection procedure will be performed by the ophthalmologist in sterile conditions in an operating room in an outpatient setting and hospital stay is not necessary. Eye drops that widen the pupil are instilled into the eye, their effect appears within 20-30 minutes. Intraocluar injection procedure is painless as local anaesthetic eye drops are used to anaesthetise the eye. The necessary amount of the medicine is introduced into the eye (cavity of the vitreous body) via a superfine needle. After the injection antibacterial eye drops are instilled into the eye. Your visual acuity may be impaired for up to 12 hours after the procedure.

Mild redness and irritation of the eye can occur after an intraocular injection. These symptoms usually disappear within a few days. Eye floaters (black spots or dots in vision) might occur quite frequently. These are caused by the dimness of the vitreous body and are harmless.

Other possible complications of intraocular injection include:

  • significant eye inflammation or endophthalmitis;
  • retinal tear and detachment;
  • haematoma of vitreous body;
  • mechanical injury of lens;
  • increase in intraocular pressure.

These complications may require treatment with additional procedures and surgeries. Please turn to ophthalmologist immediately if you develop eye pain or sudden impairment of vision after intraocular injection procedure.